Split the s_texture.c file into two new files:
authorBrian Paul <brian.paul@tungstengraphics.com>
Thu, 15 Sep 2005 00:57:00 +0000 (00:57 +0000)
committerBrian Paul <brian.paul@tungstengraphics.com>
Thu, 15 Sep 2005 00:57:00 +0000 (00:57 +0000)
  s_texcombine.c - for texture combining/application
  s_texfilter.c - for texture sampling/filtering

src/mesa/sources
src/mesa/swrast/descrip.mms
src/mesa/swrast/s_texcombine.c [new file with mode: 0644]
src/mesa/swrast/s_texcombine.h [new file with mode: 0644]
src/mesa/swrast/s_texfilter.c [new file with mode: 0644]
src/mesa/swrast/s_texfilter.h [new file with mode: 0644]
src/mesa/swrast/s_texture.c [deleted file]
src/mesa/swrast/s_texture.h [deleted file]

index 0756dd36f7bbc1c11313694689fa9f5622a1842e..5087ff2c41e648444322753b471f6f9bdf506866 100644 (file)
@@ -103,7 +103,8 @@ SWRAST_SOURCES = \
        swrast/s_span.c \
        swrast/s_stencil.c \
        swrast/s_tcc.c \
-       swrast/s_texture.c \
+       swrast/s_texcombine.c \
+       swrast/s_texfilter.c \
        swrast/s_texstore.c \
        swrast/s_triangle.c \
        swrast/s_zoom.c
index 7b356277099d52d978da6ff9e65b40a828ee2990..9a89f86a69b42813302f48a9d17e4677004e51ac 100644 (file)
@@ -22,8 +22,8 @@ SOURCES = s_aaline.c s_aatriangle.c s_accum.c s_alpha.c \
        s_bitmap.c s_blend.c s_buffers.c s_context.c s_copypix.c s_depth.c \
         s_drawpix.c s_feedback.c s_fog.c s_imaging.c s_lines.c s_logic.c \
        s_masking.c s_nvfragprog.c s_pixeltex.c s_points.c s_readpix.c \
-       s_span.c s_stencil.c s_texstore.c s_texture.c s_triangle.c s_zoom.c \
-       s_atifragshader.c
+       s_span.c s_stencil.c s_texstore.c s_texcombine.c s_texfilter.c \
+       s_triangle.c s_zoom.c s_atifragshader.c
  
 OBJECTS = s_aaline.obj,s_aatriangle.obj,s_accum.obj,s_alpha.obj,\
        s_bitmap.obj,s_blend.obj,\
@@ -31,7 +31,7 @@ OBJECTS = s_aaline.obj,s_aatriangle.obj,s_accum.obj,s_alpha.obj,\
        s_copypix.obj,s_depth.obj,s_drawpix.obj,s_feedback.obj,s_fog.obj,\
        s_imaging.obj,s_lines.obj,s_logic.obj,s_masking.obj,s_nvfragprog.obj,\
        s_pixeltex.obj,s_points.obj,s_readpix.obj,s_span.obj,s_stencil.obj,\
-       s_texstore.obj,s_texture.obj,s_triangle.obj,s_zoom.obj
+       s_texstore.obj,s_texcombine.obj,s_texfilter.obj,s_triangle.obj,s_zoom.obj
  
 ##### RULES #####
 
@@ -71,6 +71,7 @@ s_readpix.obj : s_readpix.c
 s_span.obj : s_span.c
 s_stencil.obj : s_stencil.c
 s_texstore.obj : s_texstore.c
-s_texture.obj : s_texture.c
+s_texcombine.obj : s_texcombine.c
+s_texfilter.obj : s_texfilter.c
 s_triangle.obj : s_triangle.c
 s_zoom.obj : s_zoom.c
diff --git a/src/mesa/swrast/s_texcombine.c b/src/mesa/swrast/s_texcombine.c
new file mode 100644 (file)
index 0000000..65eccad
--- /dev/null
@@ -0,0 +1,1162 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  6.5
+ *
+ * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+#include "glheader.h"
+#include "context.h"
+#include "colormac.h"
+#include "imports.h"
+#include "macros.h"
+#include "pixel.h"
+
+#include "s_context.h"
+#include "s_texcombine.h"
+
+
+#define PROD(A,B)   ( (GLuint)(A) * ((GLuint)(B)+1) )
+#define S_PROD(A,B) ( (GLint)(A) * ((GLint)(B)+1) )
+
+
+/**
+ * Do texture application for GL_ARB/EXT_texture_env_combine.
+ * This function also supports GL_{EXT,ARB}_texture_env_dot3 and
+ * GL_ATI_texture_env_combine3.  Since "classic" texture environments are
+ * implemented using GL_ARB_texture_env_combine-like state, this same function
+ * is used for classic texture environment application as well.
+ *
+ * \param ctx          rendering context
+ * \param textureUnit  the texture unit to apply
+ * \param n            number of fragments to process (span width)
+ * \param primary_rgba incoming fragment color array
+ * \param texelBuffer  pointer to texel colors for all texture units
+ * 
+ * \param rgba         incoming colors, which get modified here
+ */
+static void
+texture_combine( const GLcontext *ctx, GLuint unit, GLuint n,
+                 CONST GLchan (*primary_rgba)[4],
+                 CONST GLchan *texelBuffer,
+                 GLchan (*rgba)[4] )
+{
+   const struct gl_texture_unit *textureUnit = &(ctx->Texture.Unit[unit]);
+   const GLchan (*argRGB [3])[4];
+   const GLchan (*argA [3])[4];
+   const GLuint RGBshift = textureUnit->_CurrentCombine->ScaleShiftRGB;
+   const GLuint Ashift   = textureUnit->_CurrentCombine->ScaleShiftA;
+#if CHAN_TYPE == GL_FLOAT
+   const GLchan RGBmult = (GLfloat) (1 << RGBshift);
+   const GLchan Amult = (GLfloat) (1 << Ashift);
+   static const GLchan one[4] = { 1.0, 1.0, 1.0, 1.0 };
+   static const GLchan zero[4] = { 0.0, 0.0, 0.0, 0.0 };
+#else
+   const GLint half = (CHAN_MAX + 1) / 2;
+   static const GLchan one[4] = { CHAN_MAX, CHAN_MAX, CHAN_MAX, CHAN_MAX };
+   static const GLchan zero[4] = { 0, 0, 0, 0 };
+#endif
+   const GLuint numColorArgs = textureUnit->_CurrentCombine->_NumArgsRGB;
+   const GLuint numAlphaArgs = textureUnit->_CurrentCombine->_NumArgsA;
+   GLchan ccolor[3][MAX_WIDTH][4];
+   GLuint i, j;
+
+   ASSERT(ctx->Extensions.EXT_texture_env_combine ||
+          ctx->Extensions.ARB_texture_env_combine);
+   ASSERT(SWRAST_CONTEXT(ctx)->_AnyTextureCombine);
+
+   /*
+   printf("modeRGB 0x%x  modeA 0x%x  srcRGB1 0x%x  srcA1 0x%x  srcRGB2 0x%x  srcA2 0x%x\n",
+          textureUnit->_CurrentCombine->ModeRGB,
+          textureUnit->_CurrentCombine->ModeA,
+          textureUnit->_CurrentCombine->SourceRGB[0],
+          textureUnit->_CurrentCombine->SourceA[0],
+          textureUnit->_CurrentCombine->SourceRGB[1],
+          textureUnit->_CurrentCombine->SourceA[1]);
+   */
+
+   /*
+    * Do operand setup for up to 3 operands.  Loop over the terms.
+    */
+   for (j = 0; j < numColorArgs; j++) {
+      const GLenum srcRGB = textureUnit->_CurrentCombine->SourceRGB[j];
+
+
+      switch (srcRGB) {
+         case GL_TEXTURE:
+            argRGB[j] = (const GLchan (*)[4])
+               (texelBuffer + unit * (n * 4 * sizeof(GLchan)));
+            break;
+         case GL_PRIMARY_COLOR:
+            argRGB[j] = primary_rgba;
+            break;
+         case GL_PREVIOUS:
+            argRGB[j] = (const GLchan (*)[4]) rgba;
+            break;
+         case GL_CONSTANT:
+            {
+               GLchan (*c)[4] = ccolor[j];
+               GLchan red, green, blue, alpha;
+               UNCLAMPED_FLOAT_TO_CHAN(red,   textureUnit->EnvColor[0]);
+               UNCLAMPED_FLOAT_TO_CHAN(green, textureUnit->EnvColor[1]);
+               UNCLAMPED_FLOAT_TO_CHAN(blue,  textureUnit->EnvColor[2]);
+               UNCLAMPED_FLOAT_TO_CHAN(alpha, textureUnit->EnvColor[3]);
+               for (i = 0; i < n; i++) {
+                  c[i][RCOMP] = red;
+                  c[i][GCOMP] = green;
+                  c[i][BCOMP] = blue;
+                  c[i][ACOMP] = alpha;
+               }
+               argRGB[j] = (const GLchan (*)[4]) ccolor[j];
+            }
+            break;
+        /* GL_ATI_texture_env_combine3 allows GL_ZERO & GL_ONE as sources.
+         */
+        case GL_ZERO:
+            argRGB[j] = & zero;
+            break;
+        case GL_ONE:
+            argRGB[j] = & one;
+            break;
+         default:
+            /* ARB_texture_env_crossbar source */
+            {
+               const GLuint srcUnit = srcRGB - GL_TEXTURE0;
+               ASSERT(srcUnit < ctx->Const.MaxTextureUnits);
+               if (!ctx->Texture.Unit[srcUnit]._ReallyEnabled)
+                  return;
+               argRGB[j] = (const GLchan (*)[4])
+                  (texelBuffer + srcUnit * (n * 4 * sizeof(GLchan)));
+            }
+      }
+
+      if (textureUnit->_CurrentCombine->OperandRGB[j] != GL_SRC_COLOR) {
+         const GLchan (*src)[4] = argRGB[j];
+         GLchan (*dst)[4] = ccolor[j];
+
+         /* point to new arg[j] storage */
+         argRGB[j] = (const GLchan (*)[4]) ccolor[j];
+
+         if (textureUnit->_CurrentCombine->OperandRGB[j] == GL_ONE_MINUS_SRC_COLOR) {
+            for (i = 0; i < n; i++) {
+               dst[i][RCOMP] = CHAN_MAX - src[i][RCOMP];
+               dst[i][GCOMP] = CHAN_MAX - src[i][GCOMP];
+               dst[i][BCOMP] = CHAN_MAX - src[i][BCOMP];
+            }
+         }
+         else if (textureUnit->_CurrentCombine->OperandRGB[j] == GL_SRC_ALPHA) {
+            for (i = 0; i < n; i++) {
+               dst[i][RCOMP] = src[i][ACOMP];
+               dst[i][GCOMP] = src[i][ACOMP];
+               dst[i][BCOMP] = src[i][ACOMP];
+            }
+         }
+         else {
+            ASSERT(textureUnit->_CurrentCombine->OperandRGB[j] ==GL_ONE_MINUS_SRC_ALPHA);
+            for (i = 0; i < n; i++) {
+               dst[i][RCOMP] = CHAN_MAX - src[i][ACOMP];
+               dst[i][GCOMP] = CHAN_MAX - src[i][ACOMP];
+               dst[i][BCOMP] = CHAN_MAX - src[i][ACOMP];
+            }
+         }
+      }
+   }
+
+   /*
+    * Set up the argA[i] pointers
+    */
+   for (j = 0; j < numAlphaArgs; j++) {
+      const GLenum srcA = textureUnit->_CurrentCombine->SourceA[j];
+
+      switch (srcA) {
+         case GL_TEXTURE:
+            argA[j] = (const GLchan (*)[4])
+               (texelBuffer + unit * (n * 4 * sizeof(GLchan)));
+            break;
+         case GL_PRIMARY_COLOR:
+            argA[j] = primary_rgba;
+            break;
+         case GL_PREVIOUS:
+            argA[j] = (const GLchan (*)[4]) rgba;
+            break;
+         case GL_CONSTANT:
+            {
+               GLchan alpha, (*c)[4] = ccolor[j];
+               UNCLAMPED_FLOAT_TO_CHAN(alpha, textureUnit->EnvColor[3]);
+               for (i = 0; i < n; i++)
+                  c[i][ACOMP] = alpha;
+               argA[j] = (const GLchan (*)[4]) ccolor[j];
+            }
+            break;
+        /* GL_ATI_texture_env_combine3 allows GL_ZERO & GL_ONE as sources.
+         */
+        case GL_ZERO:
+            argA[j] = & zero;
+            break;
+        case GL_ONE:
+            argA[j] = & one;
+            break;
+         default:
+            /* ARB_texture_env_crossbar source */
+            {
+               const GLuint srcUnit = srcA - GL_TEXTURE0;
+               ASSERT(srcUnit < ctx->Const.MaxTextureUnits);
+               if (!ctx->Texture.Unit[srcUnit]._ReallyEnabled)
+                  return;
+               argA[j] = (const GLchan (*)[4])
+                  (texelBuffer + srcUnit * (n * 4 * sizeof(GLchan)));
+            }
+      }
+
+      if (textureUnit->_CurrentCombine->OperandA[j] == GL_ONE_MINUS_SRC_ALPHA) {
+         const GLchan (*src)[4] = argA[j];
+         GLchan (*dst)[4] = ccolor[j];
+         argA[j] = (const GLchan (*)[4]) ccolor[j];
+         for (i = 0; i < n; i++) {
+            dst[i][ACOMP] = CHAN_MAX - src[i][ACOMP];
+         }
+      }
+   }
+
+   /*
+    * Do the texture combine.
+    */
+   switch (textureUnit->_CurrentCombine->ModeRGB) {
+      case GL_REPLACE:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            if (RGBshift) {
+               for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+                  rgba[i][RCOMP] = arg0[i][RCOMP] * RGBmult;
+                  rgba[i][GCOMP] = arg0[i][GCOMP] * RGBmult;
+                  rgba[i][BCOMP] = arg0[i][BCOMP] * RGBmult;
+#else
+                  GLuint r = (GLuint) arg0[i][RCOMP] << RGBshift;
+                  GLuint g = (GLuint) arg0[i][GCOMP] << RGBshift;
+                  GLuint b = (GLuint) arg0[i][BCOMP] << RGBshift;
+                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
+                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
+                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
+#endif
+               }
+            }
+            else {
+               for (i = 0; i < n; i++) {
+                  rgba[i][RCOMP] = arg0[i][RCOMP];
+                  rgba[i][GCOMP] = arg0[i][GCOMP];
+                  rgba[i][BCOMP] = arg0[i][BCOMP];
+               }
+            }
+         }
+         break;
+      case GL_MODULATE:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - RGBshift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = arg0[i][RCOMP] * arg1[i][RCOMP] * RGBmult;
+               rgba[i][GCOMP] = arg0[i][GCOMP] * arg1[i][GCOMP] * RGBmult;
+               rgba[i][BCOMP] = arg0[i][BCOMP] * arg1[i][BCOMP] * RGBmult;
+#else
+               GLuint r = PROD(arg0[i][RCOMP], arg1[i][RCOMP]) >> shift;
+               GLuint g = PROD(arg0[i][GCOMP], arg1[i][GCOMP]) >> shift;
+               GLuint b = PROD(arg0[i][BCOMP], arg1[i][BCOMP]) >> shift;
+               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_ADD:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = (arg0[i][RCOMP] + arg1[i][RCOMP]) * RGBmult;
+               rgba[i][GCOMP] = (arg0[i][GCOMP] + arg1[i][GCOMP]) * RGBmult;
+               rgba[i][BCOMP] = (arg0[i][BCOMP] + arg1[i][BCOMP]) * RGBmult;
+#else
+               GLint r = ((GLint) arg0[i][RCOMP] + (GLint) arg1[i][RCOMP]) << RGBshift;
+               GLint g = ((GLint) arg0[i][GCOMP] + (GLint) arg1[i][GCOMP]) << RGBshift;
+               GLint b = ((GLint) arg0[i][BCOMP] + (GLint) arg1[i][BCOMP]) << RGBshift;
+               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_ADD_SIGNED:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = (arg0[i][RCOMP] + arg1[i][RCOMP] - 0.5) * RGBmult;
+               rgba[i][GCOMP] = (arg0[i][GCOMP] + arg1[i][GCOMP] - 0.5) * RGBmult;
+               rgba[i][BCOMP] = (arg0[i][BCOMP] + arg1[i][BCOMP] - 0.5) * RGBmult;
+#else
+               GLint r = (GLint) arg0[i][RCOMP] + (GLint) arg1[i][RCOMP] -half;
+               GLint g = (GLint) arg0[i][GCOMP] + (GLint) arg1[i][GCOMP] -half;
+               GLint b = (GLint) arg0[i][BCOMP] + (GLint) arg1[i][BCOMP] -half;
+               r = (r < 0) ? 0 : r << RGBshift;
+               g = (g < 0) ? 0 : g << RGBshift;
+               b = (b < 0) ? 0 : b << RGBshift;
+               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_INTERPOLATE:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - RGBshift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = (arg0[i][RCOMP] * arg2[i][RCOMP] +
+                      arg1[i][RCOMP] * (CHAN_MAXF - arg2[i][RCOMP])) * RGBmult;
+               rgba[i][GCOMP] = (arg0[i][GCOMP] * arg2[i][GCOMP] +
+                      arg1[i][GCOMP] * (CHAN_MAXF - arg2[i][GCOMP])) * RGBmult;
+               rgba[i][BCOMP] = (arg0[i][BCOMP] * arg2[i][BCOMP] +
+                      arg1[i][BCOMP] * (CHAN_MAXF - arg2[i][BCOMP])) * RGBmult;
+#else
+               GLuint r = (PROD(arg0[i][RCOMP], arg2[i][RCOMP])
+                           + PROD(arg1[i][RCOMP], CHAN_MAX - arg2[i][RCOMP]))
+                              >> shift;
+               GLuint g = (PROD(arg0[i][GCOMP], arg2[i][GCOMP])
+                           + PROD(arg1[i][GCOMP], CHAN_MAX - arg2[i][GCOMP]))
+                              >> shift;
+               GLuint b = (PROD(arg0[i][BCOMP], arg2[i][BCOMP])
+                           + PROD(arg1[i][BCOMP], CHAN_MAX - arg2[i][BCOMP]))
+                              >> shift;
+               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_SUBTRACT:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = (arg0[i][RCOMP] - arg1[i][RCOMP]) * RGBmult;
+               rgba[i][GCOMP] = (arg0[i][GCOMP] - arg1[i][GCOMP]) * RGBmult;
+               rgba[i][BCOMP] = (arg0[i][BCOMP] - arg1[i][BCOMP]) * RGBmult;
+#else
+               GLint r = ((GLint) arg0[i][RCOMP] - (GLint) arg1[i][RCOMP]) << RGBshift;
+               GLint g = ((GLint) arg0[i][GCOMP] - (GLint) arg1[i][GCOMP]) << RGBshift;
+               GLint b = ((GLint) arg0[i][BCOMP] - (GLint) arg1[i][BCOMP]) << RGBshift;
+               rgba[i][RCOMP] = (GLchan) CLAMP(r, 0, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) CLAMP(g, 0, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) CLAMP(b, 0, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_DOT3_RGB_EXT:
+      case GL_DOT3_RGBA_EXT:
+         {
+            /* Do not scale the result by 1 2 or 4 */
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               GLchan dot = ((arg0[i][RCOMP]-0.5F) * (arg1[i][RCOMP]-0.5F) +
+                             (arg0[i][GCOMP]-0.5F) * (arg1[i][GCOMP]-0.5F) +
+                             (arg0[i][BCOMP]-0.5F) * (arg1[i][BCOMP]-0.5F))
+                            * 4.0F;
+               dot = CLAMP(dot, 0.0F, CHAN_MAXF);
+#else
+               GLint dot = (S_PROD((GLint)arg0[i][RCOMP] - half,
+                                  (GLint)arg1[i][RCOMP] - half) +
+                           S_PROD((GLint)arg0[i][GCOMP] - half,
+                                  (GLint)arg1[i][GCOMP] - half) +
+                           S_PROD((GLint)arg0[i][BCOMP] - half,
+                                  (GLint)arg1[i][BCOMP] - half)) >> 6;
+               dot = CLAMP(dot, 0, CHAN_MAX);
+#endif
+               rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = (GLchan) dot;
+            }
+         }
+         break;
+      case GL_DOT3_RGB:
+      case GL_DOT3_RGBA:
+         {
+            /* DO scale the result by 1 2 or 4 */
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               GLchan dot = ((arg0[i][RCOMP]-0.5F) * (arg1[i][RCOMP]-0.5F) +
+                             (arg0[i][GCOMP]-0.5F) * (arg1[i][GCOMP]-0.5F) +
+                             (arg0[i][BCOMP]-0.5F) * (arg1[i][BCOMP]-0.5F))
+                            * 4.0F * RGBmult;
+               dot = CLAMP(dot, 0.0, CHAN_MAXF);
+#else
+               GLint dot = (S_PROD((GLint)arg0[i][RCOMP] - half,
+                                  (GLint)arg1[i][RCOMP] - half) +
+                           S_PROD((GLint)arg0[i][GCOMP] - half,
+                                  (GLint)arg1[i][GCOMP] - half) +
+                           S_PROD((GLint)arg0[i][BCOMP] - half,
+                                  (GLint)arg1[i][BCOMP] - half)) >> 6;
+               dot <<= RGBshift;
+               dot = CLAMP(dot, 0, CHAN_MAX);
+#endif
+               rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = (GLchan) dot;
+            }
+         }
+         break;
+      case GL_MODULATE_ADD_ATI:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - RGBshift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = ((arg0[i][RCOMP] * arg2[i][RCOMP]) + arg1[i][RCOMP]) * RGBmult;
+               rgba[i][GCOMP] = ((arg0[i][GCOMP] * arg2[i][GCOMP]) + arg1[i][GCOMP]) * RGBmult;
+               rgba[i][BCOMP] = ((arg0[i][BCOMP] * arg2[i][BCOMP]) + arg1[i][BCOMP]) * RGBmult;
+#else
+               GLuint r = (PROD(arg0[i][RCOMP], arg2[i][RCOMP])
+                           + ((GLuint) arg1[i][RCOMP] << CHAN_BITS)) >> shift;
+               GLuint g = (PROD(arg0[i][GCOMP], arg2[i][GCOMP])
+                           + ((GLuint) arg1[i][GCOMP] << CHAN_BITS)) >> shift;
+               GLuint b = (PROD(arg0[i][BCOMP], arg2[i][BCOMP])
+                           + ((GLuint) arg1[i][BCOMP] << CHAN_BITS)) >> shift;
+               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
+#endif
+            }
+        }
+         break;
+      case GL_MODULATE_SIGNED_ADD_ATI:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - RGBshift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = ((arg0[i][RCOMP] * arg2[i][RCOMP]) + arg1[i][RCOMP] - 0.5) * RGBmult;
+               rgba[i][GCOMP] = ((arg0[i][GCOMP] * arg2[i][GCOMP]) + arg1[i][GCOMP] - 0.5) * RGBmult;
+               rgba[i][BCOMP] = ((arg0[i][BCOMP] * arg2[i][BCOMP]) + arg1[i][BCOMP] - 0.5) * RGBmult;
+#else
+               GLint r = (S_PROD(arg0[i][RCOMP], arg2[i][RCOMP])
+                         + (((GLint) arg1[i][RCOMP] - half) << CHAN_BITS))
+                   >> shift;
+               GLint g = (S_PROD(arg0[i][GCOMP], arg2[i][GCOMP])
+                         + (((GLint) arg1[i][GCOMP] - half) << CHAN_BITS))
+                   >> shift;
+               GLint b = (S_PROD(arg0[i][BCOMP], arg2[i][BCOMP])
+                         + (((GLint) arg1[i][BCOMP] - half) << CHAN_BITS))
+                   >> shift;
+               rgba[i][RCOMP] = (GLchan) CLAMP(r, 0, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) CLAMP(g, 0, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) CLAMP(b, 0, CHAN_MAX);
+#endif
+            }
+        }
+         break;
+      case GL_MODULATE_SUBTRACT_ATI:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - RGBshift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = ((arg0[i][RCOMP] * arg2[i][RCOMP]) - arg1[i][RCOMP]) * RGBmult;
+               rgba[i][GCOMP] = ((arg0[i][GCOMP] * arg2[i][GCOMP]) - arg1[i][GCOMP]) * RGBmult;
+               rgba[i][BCOMP] = ((arg0[i][BCOMP] * arg2[i][BCOMP]) - arg1[i][BCOMP]) * RGBmult;
+#else
+               GLint r = (S_PROD(arg0[i][RCOMP], arg2[i][RCOMP])
+                         - ((GLint) arg1[i][RCOMP] << CHAN_BITS))
+                   >> shift;
+               GLint g = (S_PROD(arg0[i][GCOMP], arg2[i][GCOMP])
+                         - ((GLint) arg1[i][GCOMP] << CHAN_BITS))
+                   >> shift;
+               GLint b = (S_PROD(arg0[i][BCOMP], arg2[i][BCOMP])
+                         - ((GLint) arg1[i][BCOMP] << CHAN_BITS))
+                   >> shift;
+               rgba[i][RCOMP] = (GLchan) CLAMP(r, 0, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) CLAMP(g, 0, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) CLAMP(b, 0, CHAN_MAX);
+#endif
+            }
+        }
+         break;
+      default:
+         _mesa_problem(ctx, "invalid combine mode");
+   }
+
+   switch (textureUnit->_CurrentCombine->ModeA) {
+      case GL_REPLACE:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            if (Ashift) {
+               for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+                  GLchan a = arg0[i][ACOMP] * Amult;
+#else
+                  GLuint a = (GLuint) arg0[i][ACOMP] << Ashift;
+#endif
+                  rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
+               }
+            }
+            else {
+               for (i = 0; i < n; i++) {
+                  rgba[i][ACOMP] = arg0[i][ACOMP];
+               }
+            }
+         }
+         break;
+      case GL_MODULATE:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - Ashift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = arg0[i][ACOMP] * arg1[i][ACOMP] * Amult;
+#else
+               GLuint a = (PROD(arg0[i][ACOMP], arg1[i][ACOMP]) >> shift);
+               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_ADD:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan  (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = (arg0[i][ACOMP] + arg1[i][ACOMP]) * Amult;
+#else
+               GLint a = ((GLint) arg0[i][ACOMP] + arg1[i][ACOMP]) << Ashift;
+               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_ADD_SIGNED:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = (arg0[i][ACOMP] + arg1[i][ACOMP] - 0.5F) * Amult;
+#else
+               GLint a = (GLint) arg0[i][ACOMP] + (GLint) arg1[i][ACOMP] -half;
+               a = (a < 0) ? 0 : a << Ashift;
+               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_INTERPOLATE:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - Ashift;
+#endif
+            for (i=0; i<n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = (arg0[i][ACOMP] * arg2[i][ACOMP] +
+                                 arg1[i][ACOMP] * (CHAN_MAXF - arg2[i][ACOMP]))
+                                * Amult;
+#else
+               GLuint a = (PROD(arg0[i][ACOMP], arg2[i][ACOMP])
+                           + PROD(arg1[i][ACOMP], CHAN_MAX - arg2[i][ACOMP]))
+                              >> shift;
+               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_SUBTRACT:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = (arg0[i][ACOMP] - arg1[i][ACOMP]) * Amult;
+#else
+               GLint a = ((GLint) arg0[i][ACOMP] - (GLint) arg1[i][ACOMP]) << Ashift;
+               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_MODULATE_ADD_ATI:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - Ashift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = ((arg0[i][ACOMP] * arg2[i][ACOMP]) + arg1[i][ACOMP]) * Amult;
+#else
+               GLint a = (PROD(arg0[i][ACOMP], arg2[i][ACOMP])
+                          + ((GLuint) arg1[i][ACOMP] << CHAN_BITS))
+                   >> shift;
+               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_MODULATE_SIGNED_ADD_ATI:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - Ashift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = ((arg0[i][ACOMP] * arg2[i][ACOMP]) + arg1[i][ACOMP] - 0.5F) * Amult;
+#else
+               GLint a = (S_PROD(arg0[i][ACOMP], arg2[i][ACOMP])
+                         + (((GLint) arg1[i][ACOMP] - half) << CHAN_BITS))
+                   >> shift;
+               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_MODULATE_SUBTRACT_ATI:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - Ashift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = ((arg0[i][ACOMP] * arg2[i][ACOMP]) - arg1[i][ACOMP]) * Amult;
+#else
+               GLint a = (S_PROD(arg0[i][ACOMP], arg2[i][ACOMP]) 
+                         - ((GLint) arg1[i][ACOMP] << CHAN_BITS))
+                   >> shift;
+               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      default:
+         _mesa_problem(ctx, "invalid combine mode");
+   }
+
+   /* Fix the alpha component for GL_DOT3_RGBA_EXT/ARB combining.
+    * This is kind of a kludge.  It would have been better if the spec
+    * were written such that the GL_COMBINE_ALPHA value could be set to
+    * GL_DOT3.
+    */
+   if (textureUnit->_CurrentCombine->ModeRGB == GL_DOT3_RGBA_EXT ||
+       textureUnit->_CurrentCombine->ModeRGB == GL_DOT3_RGBA) {
+      for (i = 0; i < n; i++) {
+        rgba[i][ACOMP] = rgba[i][RCOMP];
+      }
+   }
+}
+#undef PROD
+
+
+/**
+ * Apply a conventional OpenGL texture env mode (REPLACE, ADD, BLEND,
+ * MODULATE, or DECAL) to an array of fragments.
+ * Input:  textureUnit - pointer to texture unit to apply
+ *         format - base internal texture format
+ *         n - number of fragments
+ *         primary_rgba - primary colors (may alias rgba for single texture)
+ *         texels - array of texel colors
+ * InOut:  rgba - incoming fragment colors modified by texel colors
+ *                according to the texture environment mode.
+ */
+static void
+texture_apply( const GLcontext *ctx,
+               const struct gl_texture_unit *texUnit,
+               GLuint n,
+               CONST GLchan primary_rgba[][4], CONST GLchan texel[][4],
+               GLchan rgba[][4] )
+{
+   GLint baseLevel;
+   GLuint i;
+   GLint Rc, Gc, Bc, Ac;
+   GLenum format;
+   (void) primary_rgba;
+
+   ASSERT(texUnit);
+   ASSERT(texUnit->_Current);
+
+   baseLevel = texUnit->_Current->BaseLevel;
+   ASSERT(texUnit->_Current->Image[0][baseLevel]);
+
+   format = texUnit->_Current->Image[0][baseLevel]->Format;
+
+   if (format == GL_COLOR_INDEX || format == GL_YCBCR_MESA) {
+      format = GL_RGBA;  /* a bit of a hack */
+   }
+   else if (format == GL_DEPTH_COMPONENT) {
+      format = texUnit->_Current->DepthMode;
+   }
+
+   switch (texUnit->EnvMode) {
+      case GL_REPLACE:
+        switch (format) {
+           case GL_ALPHA:
+              for (i=0;i<n;i++) {
+                 /* Cv = Cf */
+                  /* Av = At */
+                  rgba[i][ACOMP] = texel[i][ACOMP];
+              }
+              break;
+           case GL_LUMINANCE:
+              for (i=0;i<n;i++) {
+                 /* Cv = Lt */
+                  GLchan Lt = texel[i][RCOMP];
+                  rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = Lt;
+                  /* Av = Af */
+              }
+              break;
+           case GL_LUMINANCE_ALPHA:
+              for (i=0;i<n;i++) {
+                  GLchan Lt = texel[i][RCOMP];
+                 /* Cv = Lt */
+                 rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = Lt;
+                 /* Av = At */
+                 rgba[i][ACOMP] = texel[i][ACOMP];
+              }
+              break;
+           case GL_INTENSITY:
+              for (i=0;i<n;i++) {
+                 /* Cv = It */
+                  GLchan It = texel[i][RCOMP];
+                  rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = It;
+                  /* Av = It */
+                  rgba[i][ACOMP] = It;
+              }
+              break;
+           case GL_RGB:
+              for (i=0;i<n;i++) {
+                 /* Cv = Ct */
+                 rgba[i][RCOMP] = texel[i][RCOMP];
+                 rgba[i][GCOMP] = texel[i][GCOMP];
+                 rgba[i][BCOMP] = texel[i][BCOMP];
+                 /* Av = Af */
+              }
+              break;
+           case GL_RGBA:
+              for (i=0;i<n;i++) {
+                 /* Cv = Ct */
+                 rgba[i][RCOMP] = texel[i][RCOMP];
+                 rgba[i][GCOMP] = texel[i][GCOMP];
+                 rgba[i][BCOMP] = texel[i][BCOMP];
+                 /* Av = At */
+                 rgba[i][ACOMP] = texel[i][ACOMP];
+              }
+              break;
+            default:
+               _mesa_problem(ctx, "Bad format (GL_REPLACE) in texture_apply");
+               return;
+        }
+        break;
+
+      case GL_MODULATE:
+         switch (format) {
+           case GL_ALPHA:
+              for (i=0;i<n;i++) {
+                 /* Cv = Cf */
+                 /* Av = AfAt */
+                 rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], texel[i][ACOMP] );
+              }
+              break;
+           case GL_LUMINANCE:
+              for (i=0;i<n;i++) {
+                 /* Cv = LtCf */
+                  GLchan Lt = texel[i][RCOMP];
+                 rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], Lt );
+                 rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], Lt );
+                 rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], Lt );
+                 /* Av = Af */
+              }
+              break;
+           case GL_LUMINANCE_ALPHA:
+              for (i=0;i<n;i++) {
+                 /* Cv = CfLt */
+                  GLchan Lt = texel[i][RCOMP];
+                 rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], Lt );
+                 rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], Lt );
+                 rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], Lt );
+                 /* Av = AfAt */
+                 rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], texel[i][ACOMP] );
+              }
+              break;
+           case GL_INTENSITY:
+              for (i=0;i<n;i++) {
+                 /* Cv = CfIt */
+                  GLchan It = texel[i][RCOMP];
+                 rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], It );
+                 rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], It );
+                 rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], It );
+                 /* Av = AfIt */
+                 rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], It );
+              }
+              break;
+           case GL_RGB:
+              for (i=0;i<n;i++) {
+                 /* Cv = CfCt */
+                 rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], texel[i][RCOMP] );
+                 rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], texel[i][GCOMP] );
+                 rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], texel[i][BCOMP] );
+                 /* Av = Af */
+              }
+              break;
+           case GL_RGBA:
+              for (i=0;i<n;i++) {
+                 /* Cv = CfCt */
+                 rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], texel[i][RCOMP] );
+                 rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], texel[i][GCOMP] );
+                 rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], texel[i][BCOMP] );
+                 /* Av = AfAt */
+                 rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], texel[i][ACOMP] );
+              }
+              break;
+            default:
+               _mesa_problem(ctx, "Bad format (GL_MODULATE) in texture_apply");
+               return;
+        }
+        break;
+
+      case GL_DECAL:
+         switch (format) {
+            case GL_ALPHA:
+            case GL_LUMINANCE:
+            case GL_LUMINANCE_ALPHA:
+            case GL_INTENSITY:
+               /* undefined */
+               break;
+           case GL_RGB:
+              for (i=0;i<n;i++) {
+                 /* Cv = Ct */
+                 rgba[i][RCOMP] = texel[i][RCOMP];
+                 rgba[i][GCOMP] = texel[i][GCOMP];
+                 rgba[i][BCOMP] = texel[i][BCOMP];
+                 /* Av = Af */
+              }
+              break;
+           case GL_RGBA:
+              for (i=0;i<n;i++) {
+                 /* Cv = Cf(1-At) + CtAt */
+                 GLint t = texel[i][ACOMP], s = CHAN_MAX - t;
+                 rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(texel[i][RCOMP],t);
+                 rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(texel[i][GCOMP],t);
+                 rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(texel[i][BCOMP],t);
+                 /* Av = Af */
+              }
+              break;
+            default:
+               _mesa_problem(ctx, "Bad format (GL_DECAL) in texture_apply");
+               return;
+        }
+        break;
+
+      case GL_BLEND:
+         Rc = (GLint) (texUnit->EnvColor[0] * CHAN_MAXF);
+         Gc = (GLint) (texUnit->EnvColor[1] * CHAN_MAXF);
+         Bc = (GLint) (texUnit->EnvColor[2] * CHAN_MAXF);
+         Ac = (GLint) (texUnit->EnvColor[3] * CHAN_MAXF);
+        switch (format) {
+           case GL_ALPHA:
+              for (i=0;i<n;i++) {
+                 /* Cv = Cf */
+                 /* Av = AfAt */
+                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
+              }
+              break;
+            case GL_LUMINANCE:
+              for (i=0;i<n;i++) {
+                 /* Cv = Cf(1-Lt) + CcLt */
+                 GLchan Lt = texel[i][RCOMP], s = CHAN_MAX - Lt;
+                 rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(Rc, Lt);
+                 rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(Gc, Lt);
+                 rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(Bc, Lt);
+                 /* Av = Af */
+              }
+              break;
+           case GL_LUMINANCE_ALPHA:
+              for (i=0;i<n;i++) {
+                 /* Cv = Cf(1-Lt) + CcLt */
+                 GLchan Lt = texel[i][RCOMP], s = CHAN_MAX - Lt;
+                 rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(Rc, Lt);
+                 rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(Gc, Lt);
+                 rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(Bc, Lt);
+                 /* Av = AfAt */
+                 rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP],texel[i][ACOMP]);
+              }
+              break;
+            case GL_INTENSITY:
+              for (i=0;i<n;i++) {
+                 /* Cv = Cf(1-It) + CcIt */
+                 GLchan It = texel[i][RCOMP], s = CHAN_MAX - It;
+                 rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(Rc, It);
+                 rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(Gc, It);
+                 rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(Bc, It);
+                  /* Av = Af(1-It) + Ac*It */
+                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], s) + CHAN_PRODUCT(Ac, It);
+               }
+               break;
+           case GL_RGB:
+              for (i=0;i<n;i++) {
+                 /* Cv = Cf(1-Ct) + CcCt */
+                 rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], (CHAN_MAX-texel[i][RCOMP])) + CHAN_PRODUCT(Rc,texel[i][RCOMP]);
+                 rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], (CHAN_MAX-texel[i][GCOMP])) + CHAN_PRODUCT(Gc,texel[i][GCOMP]);
+                 rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], (CHAN_MAX-texel[i][BCOMP])) + CHAN_PRODUCT(Bc,texel[i][BCOMP]);
+                 /* Av = Af */
+              }
+              break;
+           case GL_RGBA:
+              for (i=0;i<n;i++) {
+                 /* Cv = Cf(1-Ct) + CcCt */
+                 rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], (CHAN_MAX-texel[i][RCOMP])) + CHAN_PRODUCT(Rc,texel[i][RCOMP]);
+                 rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], (CHAN_MAX-texel[i][GCOMP])) + CHAN_PRODUCT(Gc,texel[i][GCOMP]);
+                 rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], (CHAN_MAX-texel[i][BCOMP])) + CHAN_PRODUCT(Bc,texel[i][BCOMP]);
+                 /* Av = AfAt */
+                 rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP],texel[i][ACOMP]);
+              }
+              break;
+            default:
+               _mesa_problem(ctx, "Bad format (GL_BLEND) in texture_apply");
+               return;
+        }
+        break;
+
+     /* XXX don't clamp results if GLchan is float??? */
+
+      case GL_ADD:  /* GL_EXT_texture_add_env */
+         switch (format) {
+            case GL_ALPHA:
+               for (i=0;i<n;i++) {
+                  /* Rv = Rf */
+                  /* Gv = Gf */
+                  /* Bv = Bf */
+                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
+               }
+               break;
+            case GL_LUMINANCE:
+               for (i=0;i<n;i++) {
+                  GLuint Lt = texel[i][RCOMP];
+                  GLuint r = rgba[i][RCOMP] + Lt;
+                  GLuint g = rgba[i][GCOMP] + Lt;
+                  GLuint b = rgba[i][BCOMP] + Lt;
+                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
+                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
+                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
+                  /* Av = Af */
+               }
+               break;
+            case GL_LUMINANCE_ALPHA:
+               for (i=0;i<n;i++) {
+                  GLuint Lt = texel[i][RCOMP];
+                  GLuint r = rgba[i][RCOMP] + Lt;
+                  GLuint g = rgba[i][GCOMP] + Lt;
+                  GLuint b = rgba[i][BCOMP] + Lt;
+                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
+                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
+                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
+                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
+               }
+               break;
+            case GL_INTENSITY:
+               for (i=0;i<n;i++) {
+                  GLchan It = texel[i][RCOMP];
+                  GLuint r = rgba[i][RCOMP] + It;
+                  GLuint g = rgba[i][GCOMP] + It;
+                  GLuint b = rgba[i][BCOMP] + It;
+                  GLuint a = rgba[i][ACOMP] + It;
+                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
+                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
+                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
+                  rgba[i][ACOMP] = MIN2(a, CHAN_MAX);
+               }
+               break;
+           case GL_RGB:
+              for (i=0;i<n;i++) {
+                  GLuint r = rgba[i][RCOMP] + texel[i][RCOMP];
+                  GLuint g = rgba[i][GCOMP] + texel[i][GCOMP];
+                  GLuint b = rgba[i][BCOMP] + texel[i][BCOMP];
+                 rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
+                 rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
+                 rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
+                 /* Av = Af */
+              }
+              break;
+           case GL_RGBA:
+              for (i=0;i<n;i++) {
+                  GLuint r = rgba[i][RCOMP] + texel[i][RCOMP];
+                  GLuint g = rgba[i][GCOMP] + texel[i][GCOMP];
+                  GLuint b = rgba[i][BCOMP] + texel[i][BCOMP];
+                 rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
+                 rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
+                 rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
+                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
+               }
+               break;
+            default:
+               _mesa_problem(ctx, "Bad format (GL_ADD) in texture_apply");
+               return;
+        }
+        break;
+
+      default:
+         _mesa_problem(ctx, "Bad env mode in texture_apply");
+         return;
+   }
+}
+
+
+
+/**
+ * Apply texture mapping to a span of fragments.
+ */
+void
+_swrast_texture_span( GLcontext *ctx, struct sw_span *span )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   GLchan primary_rgba[MAX_WIDTH][4];
+   GLuint unit;
+
+   ASSERT(span->end < MAX_WIDTH);
+   ASSERT(span->arrayMask & SPAN_TEXTURE);
+
+   /*
+    * Save copy of the incoming fragment colors (the GL_PRIMARY_COLOR)
+    */
+   if (swrast->_AnyTextureCombine)
+      MEMCPY(primary_rgba, span->array->rgba, 4 * span->end * sizeof(GLchan));
+
+   /*
+    * Must do all texture sampling before combining in order to
+    * accomodate GL_ARB_texture_env_crossbar.
+    */
+   for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
+      if (ctx->Texture.Unit[unit]._ReallyEnabled) {
+         const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
+         const struct gl_texture_object *curObj = texUnit->_Current;
+         GLfloat *lambda = span->array->lambda[unit];
+         GLchan (*texels)[4] = (GLchan (*)[4])
+            (swrast->TexelBuffer + unit * (span->end * 4 * sizeof(GLchan)));
+
+         /* adjust texture lod (lambda) */
+         if (span->arrayMask & SPAN_LAMBDA) {
+            if (texUnit->LodBias + curObj->LodBias != 0.0F) {
+               /* apply LOD bias, but don't clamp yet */
+               const GLfloat bias = CLAMP(texUnit->LodBias + curObj->LodBias,
+                                          -ctx->Const.MaxTextureLodBias,
+                                          ctx->Const.MaxTextureLodBias);
+               GLuint i;
+               for (i = 0; i < span->end; i++) {
+                  lambda[i] += bias;
+               }
+            }
+
+            if (curObj->MinLod != -1000.0 || curObj->MaxLod != 1000.0) {
+               /* apply LOD clamping to lambda */
+               const GLfloat min = curObj->MinLod;
+               const GLfloat max = curObj->MaxLod;
+               GLuint i;
+               for (i = 0; i < span->end; i++) {
+                  GLfloat l = lambda[i];
+                  lambda[i] = CLAMP(l, min, max);
+               }
+            }
+         }
+
+         /* Sample the texture (span->end fragments) */
+         swrast->TextureSample[unit]( ctx, unit, texUnit->_Current, span->end,
+                         (const GLfloat (*)[4]) span->array->texcoords[unit],
+                         lambda, texels );
+
+         /* GL_SGI_texture_color_table */
+         if (texUnit->ColorTableEnabled) {
+            _mesa_lookup_rgba_chan(&texUnit->ColorTable, span->end, texels);
+         }
+      }
+   }
+
+   /*
+    * OK, now apply the texture (aka texture combine/blend).
+    * We modify the span->color.rgba values.
+    */
+   for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
+      if (ctx->Texture.Unit[unit]._ReallyEnabled) {
+         const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
+         if (texUnit->_CurrentCombine != &texUnit->_EnvMode ) {
+            texture_combine( ctx, unit, span->end,
+                             (CONST GLchan (*)[4]) primary_rgba,
+                             swrast->TexelBuffer,
+                             span->array->rgba );
+         }
+         else {
+            /* conventional texture blend */
+            const GLchan (*texels)[4] = (const GLchan (*)[4])
+               (swrast->TexelBuffer + unit *
+                (span->end * 4 * sizeof(GLchan)));
+            texture_apply( ctx, texUnit, span->end,
+                           (CONST GLchan (*)[4]) primary_rgba, texels,
+                           span->array->rgba );
+         }
+      }
+   }
+}
diff --git a/src/mesa/swrast/s_texcombine.h b/src/mesa/swrast/s_texcombine.h
new file mode 100644 (file)
index 0000000..eca967c
--- /dev/null
@@ -0,0 +1,36 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  6.5
+ *
+ * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+#ifndef S_TEXCOMBINE_H
+#define S_TEXCOMBINE_H
+
+
+#include "mtypes.h"
+#include "swrast.h"
+
+extern void
+_swrast_texture_span( GLcontext *ctx, struct sw_span *span );
+
+#endif
diff --git a/src/mesa/swrast/s_texfilter.c b/src/mesa/swrast/s_texfilter.c
new file mode 100644 (file)
index 0000000..7435690
--- /dev/null
@@ -0,0 +1,2782 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  6.5
+ *
+ * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+#include "glheader.h"
+#include "context.h"
+#include "colormac.h"
+#include "imports.h"
+#include "texformat.h"
+
+#include "s_context.h"
+#include "s_texfilter.h"
+
+
+/**
+ * Constants for integer linear interpolation.
+ */
+#define ILERP_SCALE 65536.0F
+#define ILERP_SHIFT 16
+
+
+/**
+ * Linear interpolation macros
+ */
+#define LERP(T, A, B)  ( (A) + (T) * ((B) - (A)) )
+#define ILERP(IT, A, B)  ( (A) + (((IT) * ((B) - (A))) >> ILERP_SHIFT) )
+
+
+/**
+ * Do 2D/biliner interpolation of float values.
+ * v00, v10, v01 and v11 are typically four texture samples in a square/box.
+ * a and b are the horizontal and vertical interpolants.
+ * It's important that this function is inlined when compiled with
+ * optimization!  If we find that's not true on some systems, convert
+ * to a macro.
+ */
+static INLINE GLfloat
+lerp_2d(GLfloat a, GLfloat b,
+        GLfloat v00, GLfloat v10, GLfloat v01, GLfloat v11)
+{
+   const GLfloat temp0 = LERP(a, v00, v10);
+   const GLfloat temp1 = LERP(a, v01, v11);
+   return LERP(b, temp0, temp1);
+}
+
+
+/**
+ * Do 2D/biliner interpolation of integer values.
+ * \sa lerp_2d
+ */
+static INLINE GLint
+ilerp_2d(GLint ia, GLint ib,
+         GLint v00, GLint v10, GLint v01, GLint v11)
+{
+   /* fixed point interpolants in [0, ILERP_SCALE] */
+   const GLint temp0 = ILERP(ia, v00, v10);
+   const GLint temp1 = ILERP(ia, v01, v11);
+   return ILERP(ib, temp0, temp1);
+}
+
+
+/**
+ * Do 3D/trilinear interpolation of float values.
+ * \sa lerp_2d
+ */
+static INLINE GLfloat
+lerp_3d(GLfloat a, GLfloat b, GLfloat c,
+        GLfloat v000, GLfloat v100, GLfloat v010, GLfloat v110,
+        GLfloat v001, GLfloat v101, GLfloat v011, GLfloat v111)
+{
+   const GLfloat temp00 = LERP(a, v000, v100);
+   const GLfloat temp10 = LERP(a, v010, v110);
+   const GLfloat temp01 = LERP(a, v001, v101);
+   const GLfloat temp11 = LERP(a, v011, v111);
+   const GLfloat temp0 = LERP(b, temp00, temp10);
+   const GLfloat temp1 = LERP(b, temp01, temp11);
+   return LERP(c, temp0, temp1);
+}
+
+
+/**
+ * Do 3D/trilinear interpolation of integer values.
+ * \sa lerp_2d
+ */
+static INLINE GLint
+ilerp_3d(GLint ia, GLint ib, GLint ic,
+         GLint v000, GLint v100, GLint v010, GLint v110,
+         GLint v001, GLint v101, GLint v011, GLint v111)
+{
+   /* fixed point interpolants in [0, ILERP_SCALE] */
+   const GLint temp00 = ILERP(ia, v000, v100);
+   const GLint temp10 = ILERP(ia, v010, v110);
+   const GLint temp01 = ILERP(ia, v001, v101);
+   const GLint temp11 = ILERP(ia, v011, v111);
+   const GLint temp0 = ILERP(ib, temp00, temp10);
+   const GLint temp1 = ILERP(ib, temp01, temp11);
+   return ILERP(ic, temp0, temp1);
+}
+
+
+/**
+ * Do linear interpolation of colors.
+ */
+static INLINE void
+lerp_rgba(GLchan result[4], GLfloat t, const GLchan a[4], const GLchan b[4])
+{
+#if CHAN_TYPE == GL_FLOAT
+   result[0] = LERP(t, a[0], b[0]);
+   result[1] = LERP(t, a[1], b[1]);
+   result[2] = LERP(t, a[2], b[2]);
+   result[3] = LERP(t, a[3], b[3]);
+#elif CHAN_TYPE == GL_UNSIGNED_SHORT
+   result[0] = (GLchan) (LERP(t, a[0], b[0]) + 0.5);
+   result[1] = (GLchan) (LERP(t, a[1], b[1]) + 0.5);
+   result[2] = (GLchan) (LERP(t, a[2], b[2]) + 0.5);
+   result[3] = (GLchan) (LERP(t, a[3], b[3]) + 0.5);
+#else
+   /* fixed point interpolants in [0, ILERP_SCALE] */
+   const GLint it = IROUND_POS(t * ILERP_SCALE);
+   ASSERT(CHAN_TYPE == GL_UNSIGNED_BYTE);
+   result[0] = ILERP(it, a[0], b[0]);
+   result[1] = ILERP(it, a[1], b[1]);
+   result[2] = ILERP(it, a[2], b[2]);
+   result[3] = ILERP(it, a[3], b[3]);
+#endif
+}
+
+
+/**
+ * Do bilinear interpolation of colors.
+ */
+static INLINE void
+lerp_rgba_2d(GLchan result[4], GLfloat a, GLfloat b,
+             const GLchan t00[4], const GLchan t10[4],
+             const GLchan t01[4], const GLchan t11[4])
+{
+#if CHAN_TYPE == GL_FLOAT
+   result[0] = lerp_2d(a, b, t00[0], t10[0], t01[0], t11[0]);
+   result[1] = lerp_2d(a, b, t00[1], t10[1], t01[1], t11[1]);
+   result[2] = lerp_2d(a, b, t00[2], t10[2], t01[2], t11[2]);
+   result[3] = lerp_2d(a, b, t00[3], t10[3], t01[3], t11[3]);
+#elif CHAN_TYPE == GL_UNSIGNED_SHORT
+   result[0] = (GLchan) (lerp_2d(a, b, t00[0], t10[0], t01[0], t11[0]) + 0.5);
+   result[1] = (GLchan) (lerp_2d(a, b, t00[1], t10[1], t01[1], t11[1]) + 0.5);
+   result[2] = (GLchan) (lerp_2d(a, b, t00[2], t10[2], t01[2], t11[2]) + 0.5);
+   result[3] = (GLchan) (lerp_2d(a, b, t00[3], t10[3], t01[3], t11[3]) + 0.5);
+#else
+   const GLint ia = IROUND_POS(a * ILERP_SCALE);
+   const GLint ib = IROUND_POS(b * ILERP_SCALE);
+   ASSERT(CHAN_TYPE == GL_UNSIGNED_BYTE);
+   result[0] = ilerp_2d(ia, ib, t00[0], t10[0], t01[0], t11[0]);
+   result[1] = ilerp_2d(ia, ib, t00[1], t10[1], t01[1], t11[1]);
+   result[2] = ilerp_2d(ia, ib, t00[2], t10[2], t01[2], t11[2]);
+   result[3] = ilerp_2d(ia, ib, t00[3], t10[3], t01[3], t11[3]);
+#endif
+}
+
+
+/**
+ * Compute the remainder of a divided by b, but be careful with
+ * negative values so that GL_REPEAT mode works right.
+ */
+static INLINE GLint
+repeat_remainder(GLint a, GLint b)
+{
+   if (a >= 0)
+      return a % b;
+   else
+      return (a + 1) % b + b - 1;
+}
+
+
+/**
+ * Used to compute texel locations for linear sampling.
+ * Input:
+ *    wrapMode = GL_REPEAT, GL_CLAMP, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_BORDER
+ *    S = texcoord in [0,1]
+ *    SIZE = width (or height or depth) of texture
+ * Output:
+ *    U = texcoord in [0, width]
+ *    I0, I1 = two nearest texel indexes
+ */
+#define COMPUTE_LINEAR_TEXEL_LOCATIONS(wrapMode, S, U, SIZE, I0, I1)   \
+{                                                                      \
+   switch (wrapMode) {                                                 \
+   case GL_REPEAT:                                                     \
+      U = S * SIZE - 0.5F;                                             \
+      if (tObj->_IsPowerOfTwo) {                                       \
+         I0 = IFLOOR(U) & (SIZE - 1);                                  \
+         I1 = (I0 + 1) & (SIZE - 1);                                   \
+      }                                                                        \
+      else {                                                           \
+         I0 = repeat_remainder(IFLOOR(U), SIZE);                       \
+         I1 = repeat_remainder(I0 + 1, SIZE);                          \
+      }                                                                        \
+      break;                                                           \
+   case GL_CLAMP_TO_EDGE:                                              \
+      if (S <= 0.0F)                                                   \
+         U = 0.0F;                                                     \
+      else if (S >= 1.0F)                                              \
+         U = (GLfloat) SIZE;                                           \
+      else                                                             \
+         U = S * SIZE;                                                 \
+      U -= 0.5F;                                                       \
+      I0 = IFLOOR(U);                                                  \
+      I1 = I0 + 1;                                                     \
+      if (I0 < 0)                                                      \
+         I0 = 0;                                                       \
+      if (I1 >= (GLint) SIZE)                                          \
+         I1 = SIZE - 1;                                                        \
+      break;                                                           \
+   case GL_CLAMP_TO_BORDER:                                            \
+      {                                                                        \
+         const GLfloat min = -1.0F / (2.0F * SIZE);                    \
+         const GLfloat max = 1.0F - min;                               \
+         if (S <= min)                                                 \
+            U = min * SIZE;                                            \
+         else if (S >= max)                                            \
+            U = max * SIZE;                                            \
+         else                                                          \
+            U = S * SIZE;                                              \
+         U -= 0.5F;                                                    \
+         I0 = IFLOOR(U);                                               \
+         I1 = I0 + 1;                                                  \
+      }                                                                        \
+      break;                                                           \
+   case GL_MIRRORED_REPEAT:                                            \
+      {                                                                        \
+         const GLint flr = IFLOOR(S);                                  \
+         if (flr & 1)                                                  \
+            U = 1.0F - (S - (GLfloat) flr);    /* flr is odd */        \
+         else                                                          \
+            U = S - (GLfloat) flr;             /* flr is even */       \
+         U = (U * SIZE) - 0.5F;                                                \
+         I0 = IFLOOR(U);                                               \
+         I1 = I0 + 1;                                                  \
+         if (I0 < 0)                                                   \
+            I0 = 0;                                                    \
+         if (I1 >= (GLint) SIZE)                                       \
+            I1 = SIZE - 1;                                             \
+      }                                                                        \
+      break;                                                           \
+   case GL_MIRROR_CLAMP_EXT:                                           \
+      U = (GLfloat) fabs(S);                                           \
+      if (U >= 1.0F)                                                   \
+         U = (GLfloat) SIZE;                                           \
+      else                                                             \
+         U *= SIZE;                                                    \
+      U -= 0.5F;                                                       \
+      I0 = IFLOOR(U);                                                  \
+      I1 = I0 + 1;                                                     \
+      break;                                                           \
+   case GL_MIRROR_CLAMP_TO_EDGE_EXT:                                   \
+      U = (GLfloat) fabs(S);                                           \
+      if (U >= 1.0F)                                                   \
+         U = (GLfloat) SIZE;                                           \
+      else                                                             \
+         U *= SIZE;                                                    \
+      U -= 0.5F;                                                       \
+      I0 = IFLOOR(U);                                                  \
+      I1 = I0 + 1;                                                     \
+      if (I0 < 0)                                                      \
+         I0 = 0;                                                       \
+      if (I1 >= (GLint) SIZE)                                          \
+         I1 = SIZE - 1;                                                        \
+      break;                                                           \
+   case GL_MIRROR_CLAMP_TO_BORDER_EXT:                                 \
+      {                                                                        \
+         const GLfloat min = -1.0F / (2.0F * SIZE);                    \
+         const GLfloat max = 1.0F - min;                               \
+         U = (GLfloat) fabs(S);                                                \
+         if (U <= min)                                                 \
+            U = min * SIZE;                                            \
+         else if (U >= max)                                            \
+            U = max * SIZE;                                            \
+         else                                                          \
+            U *= SIZE;                                                 \
+         U -= 0.5F;                                                    \
+         I0 = IFLOOR(U);                                               \
+         I1 = I0 + 1;                                                  \
+      }                                                                        \
+      break;                                                           \
+   case GL_CLAMP:                                                      \
+      if (S <= 0.0F)                                                   \
+         U = 0.0F;                                                     \
+      else if (S >= 1.0F)                                              \
+         U = (GLfloat) SIZE;                                           \
+      else                                                             \
+         U = S * SIZE;                                                 \
+      U -= 0.5F;                                                       \
+      I0 = IFLOOR(U);                                                  \
+      I1 = I0 + 1;                                                     \
+      break;                                                           \
+   default:                                                            \
+      _mesa_problem(ctx, "Bad wrap mode");                             \
+   }                                                                   \
+}
+
+
+/**
+ * Used to compute texel location for nearest sampling.
+ */
+#define COMPUTE_NEAREST_TEXEL_LOCATION(wrapMode, S, SIZE, I)           \
+{                                                                      \
+   switch (wrapMode) {                                                 \
+   case GL_REPEAT:                                                     \
+      /* s limited to [0,1) */                                         \
+      /* i limited to [0,size-1] */                                    \
+      I = IFLOOR(S * SIZE);                                            \
+      if (tObj->_IsPowerOfTwo)                                         \
+         I &= (SIZE - 1);                                              \
+      else                                                             \
+         I = repeat_remainder(I, SIZE);                                        \
+      break;                                                           \
+   case GL_CLAMP_TO_EDGE:                                              \
+      {                                                                        \
+         /* s limited to [min,max] */                                  \
+         /* i limited to [0, size-1] */                                        \
+         const GLfloat min = 1.0F / (2.0F * SIZE);                     \
+         const GLfloat max = 1.0F - min;                               \
+         if (S < min)                                                  \
+            I = 0;                                                     \
+         else if (S > max)                                             \
+            I = SIZE - 1;                                              \
+         else                                                          \
+            I = IFLOOR(S * SIZE);                                      \
+      }                                                                        \
+      break;                                                           \
+   case GL_CLAMP_TO_BORDER:                                            \
+      {                                                                        \
+         /* s limited to [min,max] */                                  \
+         /* i limited to [-1, size] */                                 \
+         const GLfloat min = -1.0F / (2.0F * SIZE);                    \
+         const GLfloat max = 1.0F - min;                               \
+         if (S <= min)                                                 \
+            I = -1;                                                    \
+         else if (S >= max)                                            \
+            I = SIZE;                                                  \
+         else                                                          \
+            I = IFLOOR(S * SIZE);                                      \
+      }                                                                        \
+      break;                                                           \
+   case GL_MIRRORED_REPEAT:                                            \
+      {                                                                        \
+         const GLfloat min = 1.0F / (2.0F * SIZE);                     \
+         const GLfloat max = 1.0F - min;                               \
+         const GLint flr = IFLOOR(S);                                  \
+         GLfloat u;                                                    \
+         if (flr & 1)                                                  \
+            u = 1.0F - (S - (GLfloat) flr);    /* flr is odd */        \
+         else                                                          \
+            u = S - (GLfloat) flr;             /* flr is even */       \
+         if (u < min)                                                  \
+            I = 0;                                                     \
+         else if (u > max)                                             \
+            I = SIZE - 1;                                              \
+         else                                                          \
+            I = IFLOOR(u * SIZE);                                      \
+      }                                                                        \
+      break;                                                           \
+   case GL_MIRROR_CLAMP_EXT:                                           \
+      {                                                                        \
+         /* s limited to [0,1] */                                      \
+         /* i limited to [0,size-1] */                                 \
+         const GLfloat u = (GLfloat) fabs(S);                          \
+         if (u <= 0.0F)                                                        \
+            I = 0;                                                     \
+         else if (u >= 1.0F)                                           \
+            I = SIZE - 1;                                              \
+         else                                                          \
+            I = IFLOOR(u * SIZE);                                      \
+      }                                                                        \
+      break;                                                           \
+   case GL_MIRROR_CLAMP_TO_EDGE_EXT:                                   \
+      {                                                                        \
+         /* s limited to [min,max] */                                  \
+         /* i limited to [0, size-1] */                                        \
+         const GLfloat min = 1.0F / (2.0F * SIZE);                     \
+         const GLfloat max = 1.0F - min;                               \
+         const GLfloat u = (GLfloat) fabs(S);                          \
+         if (u < min)                                                  \
+            I = 0;                                                     \
+         else if (u > max)                                             \
+            I = SIZE - 1;                                              \
+         else                                                          \
+            I = IFLOOR(u * SIZE);                                      \
+      }                                                                        \
+      break;                                                           \
+   case GL_MIRROR_CLAMP_TO_BORDER_EXT:                                 \
+      {                                                                        \
+         /* s limited to [min,max] */                                  \
+         /* i limited to [0, size-1] */                                        \
+         const GLfloat min = -1.0F / (2.0F * SIZE);                    \
+         const GLfloat max = 1.0F - min;                               \
+         const GLfloat u = (GLfloat) fabs(S);                          \
+         if (u < min)                                                  \
+            I = -1;                                                    \
+         else if (u > max)                                             \
+            I = SIZE;                                                  \
+         else                                                          \
+            I = IFLOOR(u * SIZE);                                      \
+      }                                                                        \
+      break;                                                           \
+   case GL_CLAMP:                                                      \
+      /* s limited to [0,1] */                                         \
+      /* i limited to [0,size-1] */                                    \
+      if (S <= 0.0F)                                                   \
+         I = 0;                                                                \
+      else if (S >= 1.0F)                                              \
+         I = SIZE - 1;                                                 \
+      else                                                             \
+         I = IFLOOR(S * SIZE);                                         \
+      break;                                                           \
+   default:                                                            \
+      _mesa_problem(ctx, "Bad wrap mode");                             \
+   }                                                                   \
+}
+
+
+/* Power of two image sizes only */
+#define COMPUTE_LINEAR_REPEAT_TEXEL_LOCATION(S, U, SIZE, I0, I1)       \
+{                                                                      \
+   U = S * SIZE - 0.5F;                                                        \
+   I0 = IFLOOR(U) & (SIZE - 1);                                                \
+   I1 = (I0 + 1) & (SIZE - 1);                                         \
+}
+
+
+/*
+ * Compute linear mipmap levels for given lambda.
+ */
+#define COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda, level)       \
+{                                                              \
+   if (lambda < 0.0F)                                          \
+      level = tObj->BaseLevel;                                 \
+   else if (lambda > tObj->_MaxLambda)                         \
+      level = (GLint) (tObj->BaseLevel + tObj->_MaxLambda);    \
+   else                                                                \
+      level = (GLint) (tObj->BaseLevel + lambda);              \
+}
+
+
+/*
+ * Compute nearest mipmap level for given lambda.
+ */
+#define COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda, level)      \
+{                                                              \
+   GLfloat l;                                                  \
+   if (lambda <= 0.5F)                                         \
+      l = 0.0F;                                                        \
+   else if (lambda > tObj->_MaxLambda + 0.4999F)               \
+      l = tObj->_MaxLambda + 0.4999F;                          \
+   else                                                                \
+      l = lambda;                                              \
+   level = (GLint) (tObj->BaseLevel + l + 0.5F);               \
+   if (level > tObj->_MaxLevel)                                        \
+      level = tObj->_MaxLevel;                                 \
+}
+
+
+
+/*
+ * Note, the FRAC macro has to work perfectly.  Otherwise you'll sometimes
+ * see 1-pixel bands of improperly weighted linear-filtered textures.
+ * The tests/texwrap.c demo is a good test.
+ * Also note, FRAC(x) doesn't truly return the fractional part of x for x < 0.
+ * Instead, if x < 0 then FRAC(x) = 1 - true_frac(x).
+ */
+#define FRAC(f)  ((f) - IFLOOR(f))
+
+
+
+/*
+ * Bitflags for texture border color sampling.
+ */
+#define I0BIT   1
+#define I1BIT   2
+#define J0BIT   4
+#define J1BIT   8
+#define K0BIT  16
+#define K1BIT  32
+
+
+
+/*
+ * The lambda[] array values are always monotonic.  Either the whole span
+ * will be minified, magnified, or split between the two.  This function
+ * determines the subranges in [0, n-1] that are to be minified or magnified.
+ */
+static INLINE void
+compute_min_mag_ranges( GLfloat minMagThresh, GLuint n, const GLfloat lambda[],
+                        GLuint *minStart, GLuint *minEnd,
+                        GLuint *magStart, GLuint *magEnd )
+{
+   ASSERT(lambda != NULL);
+#if 0
+   /* Verify that lambda[] is monotonous.
+    * We can't really use this because the inaccuracy in the LOG2 function
+    * causes this test to fail, yet the resulting texturing is correct.
+    */
+   if (n > 1) {
+      GLuint i;
+      printf("lambda delta = %g\n", lambda[0] - lambda[n-1]);
+      if (lambda[0] >= lambda[n-1]) { /* decreasing */
+         for (i = 0; i < n - 1; i++) {
+            ASSERT((GLint) (lambda[i] * 10) >= (GLint) (lambda[i+1] * 10));
+         }
+      }
+      else { /* increasing */
+         for (i = 0; i < n - 1; i++) {
+            ASSERT((GLint) (lambda[i] * 10) <= (GLint) (lambda[i+1] * 10));
+         }
+      }
+   }
+#endif /* DEBUG */
+
+   /* since lambda is monotonous-array use this check first */
+   if (lambda[0] <= minMagThresh && lambda[n-1] <= minMagThresh) {
+      /* magnification for whole span */
+      *magStart = 0;
+      *magEnd = n;
+      *minStart = *minEnd = 0;
+   }
+   else if (lambda[0] > minMagThresh && lambda[n-1] > minMagThresh) {
+      /* minification for whole span */
+      *minStart = 0;
+      *minEnd = n;
+      *magStart = *magEnd = 0;
+   }
+   else {
+      /* a mix of minification and magnification */
+      GLuint i;
+      if (lambda[0] > minMagThresh) {
+         /* start with minification */
+         for (i = 1; i < n; i++) {
+            if (lambda[i] <= minMagThresh)
+               break;
+         }
+         *minStart = 0;
+         *minEnd = i;
+         *magStart = i;
+         *magEnd = n;
+      }
+      else {
+         /* start with magnification */
+         for (i = 1; i < n; i++) {
+            if (lambda[i] > minMagThresh)
+               break;
+         }
+         *magStart = 0;
+         *magEnd = i;
+         *minStart = i;
+         *minEnd = n;
+      }
+   }
+
+#if 0
+   /* Verify the min/mag Start/End values
+    * We don't use this either (see above)
+    */
+   {
+      GLint i;
+      for (i = 0; i < n; i++) {
+         if (lambda[i] > minMagThresh) {
+            /* minification */
+            ASSERT(i >= *minStart);
+            ASSERT(i < *minEnd);
+         }
+         else {
+            /* magnification */
+            ASSERT(i >= *magStart);
+            ASSERT(i < *magEnd);
+         }
+      }
+   }
+#endif
+}
+
+
+/**********************************************************************/
+/*                    1-D Texture Sampling Functions                  */
+/**********************************************************************/
+
+/*
+ * Return the texture sample for coordinate (s) using GL_NEAREST filter.
+ */
+static void
+sample_1d_nearest(GLcontext *ctx,
+                  const struct gl_texture_object *tObj,
+                  const struct gl_texture_image *img,
+                  const GLfloat texcoord[4], GLchan rgba[4])
+{
+   const GLint width = img->Width2;  /* without border, power of two */
+   GLint i;
+   (void) ctx;
+
+   COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapS, texcoord[0], width, i);
+
+   /* skip over the border, if any */
+   i += img->Border;
+
+   if (i < 0 || i >= (GLint) img->Width) {
+      /* Need this test for GL_CLAMP_TO_BORDER mode */
+      COPY_CHAN4(rgba, tObj->_BorderChan);
+   }
+   else {
+      img->FetchTexelc(img, i, 0, 0, rgba);
+   }
+}
+
+
+
+/*
+ * Return the texture sample for coordinate (s) using GL_LINEAR filter.
+ */
+static void
+sample_1d_linear(GLcontext *ctx,
+                 const struct gl_texture_object *tObj,
+                 const struct gl_texture_image *img,
+                 const GLfloat texcoord[4], GLchan rgba[4])
+{
+   const GLint width = img->Width2;
+   GLint i0, i1;
+   GLfloat u;
+   GLuint useBorderColor;
+   (void) ctx;
+
+   COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapS, texcoord[0], u, width, i0, i1);
+
+   useBorderColor = 0;
+   if (img->Border) {
+      i0 += img->Border;
+      i1 += img->Border;
+   }
+   else {
+      if (i0 < 0 || i0 >= width)   useBorderColor |= I0BIT;
+      if (i1 < 0 || i1 >= width)   useBorderColor |= I1BIT;
+   }
+
+   {
+      const GLfloat a = FRAC(u);
+      GLchan t0[4], t1[4];  /* texels */
+
+      /* fetch texel colors */
+      if (useBorderColor & I0BIT) {
+         COPY_CHAN4(t0, tObj->_BorderChan);
+      }
+      else {
+         img->FetchTexelc(img, i0, 0, 0, t0);
+      }
+      if (useBorderColor & I1BIT) {
+         COPY_CHAN4(t1, tObj->_BorderChan);
+      }
+      else {
+         img->FetchTexelc(img, i1, 0, 0, t1);
+      }
+
+      lerp_rgba(rgba, a, t0, t1);
+   }
+}
+
+
+static void
+sample_1d_nearest_mipmap_nearest(GLcontext *ctx,
+                                 const struct gl_texture_object *tObj,
+                                 GLuint n, const GLfloat texcoord[][4],
+                                 const GLfloat lambda[], GLchan rgba[][4])
+{
+   GLuint i;
+   ASSERT(lambda != NULL);
+   for (i = 0; i < n; i++) {
+      GLint level;
+      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
+      sample_1d_nearest(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]);
+   }
+}
+
+
+static void
+sample_1d_linear_mipmap_nearest(GLcontext *ctx,
+                                const struct gl_texture_object *tObj,
+                                GLuint n, const GLfloat texcoord[][4],
+                                const GLfloat lambda[], GLchan rgba[][4])
+{
+   GLuint i;
+   ASSERT(lambda != NULL);
+   for (i = 0; i < n; i++) {
+      GLint level;
+      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
+      sample_1d_linear(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]);
+   }
+}
+
+
+static void
+sample_1d_nearest_mipmap_linear(GLcontext *ctx,
+                                const struct gl_texture_object *tObj,
+                                GLuint n, const GLfloat texcoord[][4],
+                                const GLfloat lambda[], GLchan rgba[][4])
+{
+   GLuint i;
+   ASSERT(lambda != NULL);
+   for (i = 0; i < n; i++) {
+      GLint level;
+      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
+      if (level >= tObj->_MaxLevel) {
+         sample_1d_nearest(ctx, tObj, tObj->Image[0][tObj->_MaxLevel],
+                           texcoord[i], rgba[i]);
+      }
+      else {
+         GLchan t0[4], t1[4];
+         const GLfloat f = FRAC(lambda[i]);
+         sample_1d_nearest(ctx, tObj, tObj->Image[0][level  ], texcoord[i], t0);
+         sample_1d_nearest(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1);
+         lerp_rgba(rgba[i], f, t0, t1);
+      }
+   }
+}
+
+
+
+static void
+sample_1d_linear_mipmap_linear(GLcontext *ctx,
+                               const struct gl_texture_object *tObj,
+                               GLuint n, const GLfloat texcoord[][4],
+                               const GLfloat lambda[], GLchan rgba[][4])
+{
+   GLuint i;
+   ASSERT(lambda != NULL);
+   for (i = 0; i < n; i++) {
+      GLint level;
+      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
+      if (level >= tObj->_MaxLevel) {
+         sample_1d_linear(ctx, tObj, tObj->Image[0][tObj->_MaxLevel],
+                          texcoord[i], rgba[i]);
+      }
+      else {
+         GLchan t0[4], t1[4];
+         const GLfloat f = FRAC(lambda[i]);
+         sample_1d_linear(ctx, tObj, tObj->Image[0][level  ], texcoord[i], t0);
+         sample_1d_linear(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1);
+         lerp_rgba(rgba[i], f, t0, t1);
+      }
+   }
+}
+
+
+
+static void
+sample_nearest_1d( GLcontext *ctx, GLuint texUnit,
+                   const struct gl_texture_object *tObj, GLuint n,
+                   const GLfloat texcoords[][4], const GLfloat lambda[],
+                   GLchan rgba[][4] )
+{
+   GLuint i;
+   struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel];
+   (void) texUnit;
+   (void) lambda;
+   for (i=0;i<n;i++) {
+      sample_1d_nearest(ctx, tObj, image, texcoords[i], rgba[i]);
+   }
+}
+
+
+
+static void
+sample_linear_1d( GLcontext *ctx, GLuint texUnit,
+                  const struct gl_texture_object *tObj, GLuint n,
+                  const GLfloat texcoords[][4], const GLfloat lambda[],
+                  GLchan rgba[][4] )
+{
+   GLuint i;
+   struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel];
+   (void) texUnit;
+   (void) lambda;
+   for (i=0;i<n;i++) {
+      sample_1d_linear(ctx, tObj, image, texcoords[i], rgba[i]);
+   }
+}
+
+
+/*
+ * Given an (s) texture coordinate and lambda (level of detail) value,
+ * return a texture sample.
+ *
+ */
+static void
+sample_lambda_1d( GLcontext *ctx, GLuint texUnit,
+                  const struct gl_texture_object *tObj, GLuint n,
+                  const GLfloat texcoords[][4],
+                  const GLfloat lambda[], GLchan rgba[][4] )
+{
+   GLuint minStart, minEnd;  /* texels with minification */
+   GLuint magStart, magEnd;  /* texels with magnification */
+   GLuint i;
+
+   ASSERT(lambda != NULL);
+   compute_min_mag_ranges(SWRAST_CONTEXT(ctx)->_MinMagThresh[texUnit],
+                          n, lambda, &minStart, &minEnd, &magStart, &magEnd);
+
+   if (minStart < minEnd) {
+      /* do the minified texels */
+      const GLuint m = minEnd - minStart;
+      switch (tObj->MinFilter) {
+      case GL_NEAREST:
+         for (i = minStart; i < minEnd; i++)
+            sample_1d_nearest(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
+                              texcoords[i], rgba[i]);
+         break;
+      case GL_LINEAR:
+         for (i = minStart; i < minEnd; i++)
+            sample_1d_linear(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
+                             texcoords[i], rgba[i]);
+         break;
+      case GL_NEAREST_MIPMAP_NEAREST:
+         sample_1d_nearest_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
+                                          lambda + minStart, rgba + minStart);
+         break;
+      case GL_LINEAR_MIPMAP_NEAREST:
+         sample_1d_linear_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
+                                         lambda + minStart, rgba + minStart);
+         break;
+      case GL_NEAREST_MIPMAP_LINEAR:
+         sample_1d_nearest_mipmap_linear(ctx, tObj, m, texcoords + minStart,
+                                         lambda + minStart, rgba + minStart);
+         break;
+      case GL_LINEAR_MIPMAP_LINEAR:
+         sample_1d_linear_mipmap_linear(ctx, tObj, m, texcoords + minStart,
+                                        lambda + minStart, rgba + minStart);
+         break;
+      default:
+         _mesa_problem(ctx, "Bad min filter in sample_1d_texture");
+         return;
+      }
+   }
+
+   if (magStart < magEnd) {
+      /* do the magnified texels */
+      switch (tObj->MagFilter) {
+      case GL_NEAREST:
+         for (i = magStart; i < magEnd; i++)
+            sample_1d_nearest(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
+                              texcoords[i], rgba[i]);
+         break;
+      case GL_LINEAR:
+         for (i = magStart; i < magEnd; i++)
+            sample_1d_linear(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
+                             texcoords[i], rgba[i]);
+         break;
+      default:
+         _mesa_problem(ctx, "Bad mag filter in sample_1d_texture");
+         return;
+      }
+   }
+}
+
+
+/**********************************************************************/
+/*                    2-D Texture Sampling Functions                  */
+/**********************************************************************/
+
+
+/*
+ * Return the texture sample for coordinate (s,t) using GL_NEAREST filter.
+ */
+static INLINE void
+sample_2d_nearest(GLcontext *ctx,
+                  const struct gl_texture_object *tObj,
+                  const struct gl_texture_image *img,
+                  const GLfloat texcoord[4],
+                  GLchan rgba[])
+{
+   const GLint width = img->Width2;    /* without border, power of two */
+   const GLint height = img->Height2;  /* without border, power of two */
+   GLint i, j;
+   (void) ctx;
+
+   COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapS, texcoord[0], width,  i);
+   COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapT, texcoord[1], height, j);
+
+   /* skip over the border, if any */
+   i += img->Border;
+   j += img->Border;
+
+   if (i < 0 || i >= (GLint) img->Width || j < 0 || j >= (GLint) img->Height) {
+      /* Need this test for GL_CLAMP_TO_BORDER mode */
+      COPY_CHAN4(rgba, tObj->_BorderChan);
+   }
+   else {
+      img->FetchTexelc(img, i, j, 0, rgba);
+   }
+}
+
+
+
+/**
+ * Return the texture sample for coordinate (s,t) using GL_LINEAR filter.
+ * New sampling code contributed by Lynn Quam <quam@ai.sri.com>.
+ */
+static INLINE void
+sample_2d_linear(GLcontext *ctx,
+                 const struct gl_texture_object *tObj,
+                 const struct gl_texture_image *img,
+                 const GLfloat texcoord[4],
+                 GLchan rgba[])
+{
+   const GLint width = img->Width2;
+   const GLint height = img->Height2;
+   GLint i0, j0, i1, j1;
+   GLuint useBorderColor;
+   GLfloat u, v;
+   (void) ctx;
+
+   COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapS, texcoord[0], u, width,  i0, i1);
+   COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapT, texcoord[1], v, height, j0, j1);
+
+   useBorderColor = 0;
+   if (img->Border) {
+      i0 += img->Border;
+      i1 += img->Border;
+      j0 += img->Border;
+      j1 += img->Border;
+   }
+   else {
+      if (i0 < 0 || i0 >= width)   useBorderColor |= I0BIT;
+      if (i1 < 0 || i1 >= width)   useBorderColor |= I1BIT;
+      if (j0 < 0 || j0 >= height)  useBorderColor |= J0BIT;
+      if (j1 < 0 || j1 >= height)  useBorderColor |= J1BIT;
+   }
+
+   {
+      const GLfloat a = FRAC(u);
+      const GLfloat b = FRAC(v);
+      GLchan t00[4], t10[4], t01[4], t11[4]; /* sampled texel colors */
+
+      /* fetch four texel colors */
+      if (useBorderColor & (I0BIT | J0BIT)) {
+         COPY_CHAN4(t00, tObj->_BorderChan);
+      }
+      else {
+         img->FetchTexelc(img, i0, j0, 0, t00);
+      }
+      if (useBorderColor & (I1BIT | J0BIT)) {
+         COPY_CHAN4(t10, tObj->_BorderChan);
+      }
+      else {
+         img->FetchTexelc(img, i1, j0, 0, t10);
+      }
+      if (useBorderColor & (I0BIT | J1BIT)) {
+         COPY_CHAN4(t01, tObj->_BorderChan);
+      }
+      else {
+         img->FetchTexelc(img, i0, j1, 0, t01);
+      }
+      if (useBorderColor & (I1BIT | J1BIT)) {
+         COPY_CHAN4(t11, tObj->_BorderChan);
+      }
+      else {
+         img->FetchTexelc(img, i1, j1, 0, t11);
+      }
+
+      lerp_rgba_2d(rgba, a, b, t00, t10, t01, t11);
+   }
+}
+
+
+/*
+ * As above, but we know WRAP_S == REPEAT and WRAP_T == REPEAT.
+ * We don't have to worry about the texture border.
+ */
+static INLINE void
+sample_2d_linear_repeat(GLcontext *ctx,
+                        const struct gl_texture_object *tObj,
+                        const struct gl_texture_image *img,
+                        const GLfloat texcoord[4],
+                        GLchan rgba[])
+{
+   const GLint width = img->Width2;
+   const GLint height = img->Height2;
+   GLint i0, j0, i1, j1;
+   GLfloat u, v;
+   (void) ctx;
+   (void) tObj;
+   
+   ASSERT(tObj->WrapS == GL_REPEAT);
+   ASSERT(tObj->WrapT == GL_REPEAT);
+   ASSERT(img->Border == 0);
+   ASSERT(img->Format != GL_COLOR_INDEX);
+   ASSERT(img->_IsPowerOfTwo);
+
+   COMPUTE_LINEAR_REPEAT_TEXEL_LOCATION(texcoord[0], u, width,  i0, i1);
+   COMPUTE_LINEAR_REPEAT_TEXEL_LOCATION(texcoord[1], v, height, j0, j1);
+
+   {
+      const GLfloat a = FRAC(u);
+      const GLfloat b = FRAC(v);
+      GLchan t00[4], t10[4], t01[4], t11[4]; /* sampled texel colors */
+
+      img->FetchTexelc(img, i0, j0, 0, t00);
+      img->FetchTexelc(img, i1, j0, 0, t10);
+      img->FetchTexelc(img, i0, j1, 0, t01);
+      img->FetchTexelc(img, i1, j1, 0, t11);
+
+      lerp_rgba_2d(rgba, a, b, t00, t10, t01, t11);
+   }
+}
+
+
+
+static void
+sample_2d_nearest_mipmap_nearest(GLcontext *ctx,
+                                 const struct gl_texture_object *tObj,
+                                 GLuint n, const GLfloat texcoord[][4],
+                                 const GLfloat lambda[], GLchan rgba[][4])
+{
+   GLuint i;
+   for (i = 0; i < n; i++) {
+      GLint level;
+      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
+      sample_2d_nearest(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]);
+   }
+}
+
+
+
+static void
+sample_2d_linear_mipmap_nearest(GLcontext *ctx,
+                                const struct gl_texture_object *tObj,
+                                GLuint n, const GLfloat texcoord[][4],
+                                const GLfloat lambda[], GLchan rgba[][4])
+{
+   GLuint i;
+   ASSERT(lambda != NULL);
+   for (i = 0; i < n; i++) {
+      GLint level;
+      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
+      sample_2d_linear(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]);
+   }
+}
+
+
+
+static void
+sample_2d_nearest_mipmap_linear(GLcontext *ctx,
+                                const struct gl_texture_object *tObj,
+                                GLuint n, const GLfloat texcoord[][4],
+                                const GLfloat lambda[], GLchan rgba[][4])
+{
+   GLuint i;
+   ASSERT(lambda != NULL);
+   for (i = 0; i < n; i++) {
+      GLint level;
+      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
+      if (level >= tObj->_MaxLevel) {
+         sample_2d_nearest(ctx, tObj, tObj->Image[0][tObj->_MaxLevel],
+                           texcoord[i], rgba[i]);
+      }
+      else {
+         GLchan t0[4], t1[4];  /* texels */
+         const GLfloat f = FRAC(lambda[i]);
+         sample_2d_nearest(ctx, tObj, tObj->Image[0][level  ], texcoord[i], t0);
+         sample_2d_nearest(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1);
+         lerp_rgba(rgba[i], f, t0, t1);
+      }
+   }
+}
+
+
+
+/* Trilinear filtering */
+static void
+sample_2d_linear_mipmap_linear( GLcontext *ctx,
+                                const struct gl_texture_object *tObj,
+                                GLuint n, const GLfloat texcoord[][4],
+                                const GLfloat lambda[], GLchan rgba[][4] )
+{
+   GLuint i;
+   ASSERT(lambda != NULL);
+   for (i = 0; i < n; i++) {
+      GLint level;
+      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
+      if (level >= tObj->_MaxLevel) {
+         sample_2d_linear(ctx, tObj, tObj->Image[0][tObj->_MaxLevel],
+                          texcoord[i], rgba[i]);
+      }
+      else {
+         GLchan t0[4], t1[4];  /* texels */
+         const GLfloat f = FRAC(lambda[i]);
+         sample_2d_linear(ctx, tObj, tObj->Image[0][level  ], texcoord[i], t0);
+         sample_2d_linear(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1);
+         lerp_rgba(rgba[i], f, t0, t1);
+      }
+   }
+}
+
+
+static void
+sample_2d_linear_mipmap_linear_repeat( GLcontext *ctx,
+                                       const struct gl_texture_object *tObj,
+                                       GLuint n, const GLfloat texcoord[][4],
+                                       const GLfloat lambda[], GLchan rgba[][4] )
+{
+   GLuint i;
+   ASSERT(lambda != NULL);
+   ASSERT(tObj->WrapS == GL_REPEAT);
+   ASSERT(tObj->WrapT == GL_REPEAT);
+   ASSERT(tObj->_IsPowerOfTwo);
+   for (i = 0; i < n; i++) {
+      GLint level;
+      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
+      if (level >= tObj->_MaxLevel) {
+         sample_2d_linear_repeat(ctx, tObj, tObj->Image[0][tObj->_MaxLevel],
+                                 texcoord[i], rgba[i]);
+      }
+      else {
+         GLchan t0[4], t1[4];  /* texels */
+         const GLfloat f = FRAC(lambda[i]);
+         sample_2d_linear_repeat(ctx, tObj, tObj->Image[0][level  ], texcoord[i], t0);
+         sample_2d_linear_repeat(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1);
+         lerp_rgba(rgba[i], f, t0, t1);
+      }
+   }
+}
+
+
+static void
+sample_nearest_2d( GLcontext *ctx, GLuint texUnit,
+                   const struct gl_texture_object *tObj, GLuint n,
+                   const GLfloat texcoords[][4],
+                   const GLfloat lambda[], GLchan rgba[][4] )
+{
+   GLuint i;
+   struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel];
+   (void) texUnit;
+   (void) lambda;
+   for (i=0;i<n;i++) {
+      sample_2d_nearest(ctx, tObj, image, texcoords[i], rgba[i]);
+   }
+}
+
+
+
+static void
+sample_linear_2d( GLcontext *ctx, GLuint texUnit,
+                  const struct gl_texture_object *tObj, GLuint n,
+                  const GLfloat texcoords[][4],
+                  const GLfloat lambda[], GLchan rgba[][4] )
+{
+   GLuint i;
+   struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel];
+   (void) texUnit;
+   (void) lambda;
+   if (tObj->WrapS == GL_REPEAT && tObj->WrapT == GL_REPEAT) {
+      for (i=0;i<n;i++) {
+         sample_2d_linear_repeat(ctx, tObj, image, texcoords[i], rgba[i]);
+      }
+   }
+   else {
+      for (i=0;i<n;i++) {
+         sample_2d_linear(ctx, tObj, image, texcoords[i], rgba[i]);
+      }
+   }
+}
+
+
+/*
+ * Optimized 2-D texture sampling:
+ *    S and T wrap mode == GL_REPEAT
+ *    GL_NEAREST min/mag filter
+ *    No border, 
+ *    RowStride == Width,
+ *    Format = GL_RGB
+ */
+static void
+opt_sample_rgb_2d( GLcontext *ctx, GLuint texUnit,
+                   const struct gl_texture_object *tObj,
+                   GLuint n, const GLfloat texcoords[][4],
+                   const GLfloat lambda[], GLchan rgba[][4] )
+{
+   const struct gl_texture_image *img = tObj->Image[0][tObj->BaseLevel];
+   const GLfloat width = (GLfloat) img->Width;
+   const GLfloat height = (GLfloat) img->Height;
+   const GLint colMask = img->Width - 1;
+   const GLint rowMask = img->Height - 1;
+   const GLint shift = img->WidthLog2;
+   GLuint k;
+   (void) ctx;
+   (void) texUnit;
+   (void) lambda;
+   ASSERT(tObj->WrapS==GL_REPEAT);
+   ASSERT(tObj->WrapT==GL_REPEAT);
+   ASSERT(img->Border==0);
+   ASSERT(img->Format==GL_RGB);
+   ASSERT(img->_IsPowerOfTwo);
+
+   for (k=0; k<n; k++) {
+      GLint i = IFLOOR(texcoords[k][0] * width) & colMask;
+      GLint j = IFLOOR(texcoords[k][1] * height) & rowMask;
+      GLint pos = (j << shift) | i;
+      GLchan *texel = ((GLchan *) img->Data) + 3*pos;
+      rgba[k][RCOMP] = texel[0];
+      rgba[k][GCOMP] = texel[1];
+      rgba[k][BCOMP] = texel[2];
+   }
+}
+
+
+/*
+ * Optimized 2-D texture sampling:
+ *    S and T wrap mode == GL_REPEAT
+ *    GL_NEAREST min/mag filter
+ *    No border
+ *    RowStride == Width,
+ *    Format = GL_RGBA
+ */
+static void
+opt_sample_rgba_2d( GLcontext *ctx, GLuint texUnit,
+                    const struct gl_texture_object *tObj,
+                    GLuint n, const GLfloat texcoords[][4],
+                    const GLfloat lambda[], GLchan rgba[][4] )
+{
+   const struct gl_texture_image *img = tObj->Image[0][tObj->BaseLevel];
+   const GLfloat width = (GLfloat) img->Width;
+   const GLfloat height = (GLfloat) img->Height;
+   const GLint colMask = img->Width - 1;
+   const GLint rowMask = img->Height - 1;
+   const GLint shift = img->WidthLog2;
+   GLuint i;
+   (void) ctx;
+   (void) texUnit;
+   (void) lambda;
+   ASSERT(tObj->WrapS==GL_REPEAT);
+   ASSERT(tObj->WrapT==GL_REPEAT);
+   ASSERT(img->Border==0);
+   ASSERT(img->Format==GL_RGBA);
+   ASSERT(img->_IsPowerOfTwo);
+
+   for (i = 0; i < n; i++) {
+      const GLint col = IFLOOR(texcoords[i][0] * width) & colMask;
+      const GLint row = IFLOOR(texcoords[i][1] * height) & rowMask;
+      const GLint pos = (row << shift) | col;
+      const GLchan *texel = ((GLchan *) img->Data) + (pos << 2);    /* pos*4 */
+      COPY_CHAN4(rgba[i], texel);
+   }
+}
+
+
+/*
+ * Given an array of texture coordinate and lambda (level of detail)
+ * values, return an array of texture sample.
+ */
+static void
+sample_lambda_2d( GLcontext *ctx, GLuint texUnit,
+                  const struct gl_texture_object *tObj,
+                  GLuint n, const GLfloat texcoords[][4],
+                  const GLfloat lambda[], GLchan rgba[][4] )
+{
+   const struct gl_texture_image *tImg = tObj->Image[0][tObj->BaseLevel];
+   GLuint minStart, minEnd;  /* texels with minification */
+   GLuint magStart, magEnd;  /* texels with magnification */
+
+   const GLboolean repeatNoBorderPOT = (tObj->WrapS == GL_REPEAT)
+      && (tObj->WrapT == GL_REPEAT)
+      && (tImg->Border == 0 && (tImg->Width == tImg->RowStride))
+      && (tImg->Format != GL_COLOR_INDEX)
+      && tImg->_IsPowerOfTwo;
+
+   ASSERT(lambda != NULL);
+   compute_min_mag_ranges(SWRAST_CONTEXT(ctx)->_MinMagThresh[texUnit],
+                          n, lambda, &minStart, &minEnd, &magStart, &magEnd);
+
+   if (minStart < minEnd) {
+      /* do the minified texels */
+      const GLuint m = minEnd - minStart;
+      switch (tObj->MinFilter) {
+      case GL_NEAREST:
+         if (repeatNoBorderPOT) {
+            switch (tImg->TexFormat->MesaFormat) {
+            case MESA_FORMAT_RGB:
+            case MESA_FORMAT_RGB888:
+            /*case MESA_FORMAT_BGR888:*/
+               opt_sample_rgb_2d(ctx, texUnit, tObj, m, texcoords + minStart,
+                                 NULL, rgba + minStart);
+               break;
+            case MESA_FORMAT_RGBA:
+            case MESA_FORMAT_RGBA8888:
+            case MESA_FORMAT_ARGB8888:
+            /*case MESA_FORMAT_ABGR8888:*/
+            /*case MESA_FORMAT_BGRA8888:*/
+              opt_sample_rgba_2d(ctx, texUnit, tObj, m, texcoords + minStart,
+                                  NULL, rgba + minStart);
+               break;
+            default:
+               sample_nearest_2d(ctx, texUnit, tObj, m, texcoords + minStart,
+                                 NULL, rgba + minStart );
+            }
+         }
+         else {
+            sample_nearest_2d(ctx, texUnit, tObj, m, texcoords + minStart,
+                              NULL, rgba + minStart);
+         }
+         break;
+      case GL_LINEAR:
+        sample_linear_2d(ctx, texUnit, tObj, m, texcoords + minStart,
+                         NULL, rgba + minStart);
+         break;
+      case GL_NEAREST_MIPMAP_NEAREST:
+         sample_2d_nearest_mipmap_nearest(ctx, tObj, m,
+                                          texcoords + minStart,
+                                          lambda + minStart, rgba + minStart);
+         break;
+      case GL_LINEAR_MIPMAP_NEAREST:
+         sample_2d_linear_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
+                                         lambda + minStart, rgba + minStart);
+         break;
+      case GL_NEAREST_MIPMAP_LINEAR:
+         sample_2d_nearest_mipmap_linear(ctx, tObj, m, texcoords + minStart,
+                                         lambda + minStart, rgba + minStart);
+         break;
+      case GL_LINEAR_MIPMAP_LINEAR:
+         if (repeatNoBorderPOT)
+            sample_2d_linear_mipmap_linear_repeat(ctx, tObj, m,
+                  texcoords + minStart, lambda + minStart, rgba + minStart);
+         else
+            sample_2d_linear_mipmap_linear(ctx, tObj, m, texcoords + minStart,
+                                        lambda + minStart, rgba + minStart);
+         break;
+      default:
+         _mesa_problem(ctx, "Bad min filter in sample_2d_texture");
+         return;
+      }
+   }
+
+   if (magStart < magEnd) {
+      /* do the magnified texels */
+      const GLuint m = magEnd - magStart;
+
+      switch (tObj->MagFilter) {
+      case GL_NEAREST:
+         if (repeatNoBorderPOT) {
+            switch (tImg->TexFormat->MesaFormat) {
+            case MESA_FORMAT_RGB:
+            case MESA_FORMAT_RGB888:
+            /*case MESA_FORMAT_BGR888:*/
+               opt_sample_rgb_2d(ctx, texUnit, tObj, m, texcoords + magStart,
+                                 NULL, rgba + magStart);
+               break;
+            case MESA_FORMAT_RGBA:
+            case MESA_FORMAT_RGBA8888:
+            case MESA_FORMAT_ARGB8888:
+            /*case MESA_FORMAT_ABGR8888:*/
+            /*case MESA_FORMAT_BGRA8888:*/
+              opt_sample_rgba_2d(ctx, texUnit, tObj, m, texcoords + magStart,
+                                  NULL, rgba + magStart);
+               break;
+            default:
+               sample_nearest_2d(ctx, texUnit, tObj, m, texcoords + magStart,
+                                 NULL, rgba + magStart );
+            }
+         }
+         else {
+            sample_nearest_2d(ctx, texUnit, tObj, m, texcoords + magStart,
+                              NULL, rgba + magStart);
+         }
+         break;
+      case GL_LINEAR:
+        sample_linear_2d(ctx, texUnit, tObj, m, texcoords + magStart,
+                         NULL, rgba + magStart);
+         break;
+      default:
+         _mesa_problem(ctx, "Bad mag filter in sample_lambda_2d");
+      }
+   }
+}
+
+
+
+/**********************************************************************/
+/*                    3-D Texture Sampling Functions                  */
+/**********************************************************************/
+
+/*
+ * Return the texture sample for coordinate (s,t,r) using GL_NEAREST filter.
+ */
+static void
+sample_3d_nearest(GLcontext *ctx,
+                  const struct gl_texture_object *tObj,
+                  const struct gl_texture_image *img,
+                  const GLfloat texcoord[4],
+                  GLchan rgba[4])
+{
+   const GLint width = img->Width2;     /* without border, power of two */
+   const GLint height = img->Height2;   /* without border, power of two */
+   const GLint depth = img->Depth2;     /* without border, power of two */
+   GLint i, j, k;
+   (void) ctx;
+
+   COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapS, texcoord[0], width,  i);
+   COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapT, texcoord[1], height, j);
+   COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapR, texcoord[2], depth,  k);
+
+   if (i < 0 || i >= (GLint) img->Width ||
+       j < 0 || j >= (GLint) img->Height ||
+       k < 0 || k >= (GLint) img->Depth) {
+      /* Need this test for GL_CLAMP_TO_BORDER mode */
+      COPY_CHAN4(rgba, tObj->_BorderChan);
+   }
+   else {
+      img->FetchTexelc(img, i, j, k, rgba);
+   }
+}
+
+
+
+/*
+ * Return the texture sample for coordinate (s,t,r) using GL_LINEAR filter.
+ */
+static void
+sample_3d_linear(GLcontext *ctx,
+                 const struct gl_texture_object *tObj,
+                 const struct gl_texture_image *img,
+                 const GLfloat texcoord[4],
+                 GLchan rgba[4])
+{
+   const GLint width = img->Width2;
+   const GLint height = img->Height2;
+   const GLint depth = img->Depth2;
+   GLint i0, j0, k0, i1, j1, k1;
+   GLuint useBorderColor;
+   GLfloat u, v, w;
+   (void) ctx;
+
+   COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapS, texcoord[0], u, width,  i0, i1);
+   COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapT, texcoord[1], v, height, j0, j1);
+   COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapR, texcoord[2], w, depth,  k0, k1);
+
+   useBorderColor = 0;
+   if (img->Border) {
+      i0 += img->Border;
+      i1 += img->Border;
+      j0 += img->Border;
+      j1 += img->Border;
+      k0 += img->Border;
+      k1 += img->Border;
+   }
+   else {
+      /* check if sampling texture border color */
+      if (i0 < 0 || i0 >= width)   useBorderColor |= I0BIT;
+      if (i1 < 0 || i1 >= width)   useBorderColor |= I1BIT;
+      if (j0 < 0 || j0 >= height)  useBorderColor |= J0BIT;
+      if (j1 < 0 || j1 >= height)  useBorderColor |= J1BIT;
+      if (k0 < 0 || k0 >= depth)   useBorderColor |= K0BIT;
+      if (k1 < 0 || k1 >= depth)   useBorderColor |= K1BIT;
+   }
+
+   {
+      const GLfloat a = FRAC(u);
+      const GLfloat b = FRAC(v);
+      const GLfloat c = FRAC(w);
+#if CHAN_TYPE == GL_UNSIGNED_BYTE
+      const GLint ia = IROUND_POS(a * ILERP_SCALE);
+      const GLint ib = IROUND_POS(b * ILERP_SCALE);
+      const GLint ic = IROUND_POS(c * ILERP_SCALE);
+#endif
+      GLchan t000[4], t010[4], t001[4], t011[4];
+      GLchan t100[4], t110[4], t101[4], t111[4];
+
+      /* Fetch texels */
+      if (useBorderColor & (I0BIT | J0BIT | K0BIT)) {
+         COPY_CHAN4(t000, tObj->_BorderChan);
+      }
+      else {
+         img->FetchTexelc(img, i0, j0, k0, t000);
+      }
+      if (useBorderColor & (I1BIT | J0BIT | K0BIT)) {
+         COPY_CHAN4(t100, tObj->_BorderChan);
+      }
+      else {
+         img->FetchTexelc(img, i1, j0, k0, t100);
+      }
+      if (useBorderColor & (I0BIT | J1BIT | K0BIT)) {
+         COPY_CHAN4(t010, tObj->_BorderChan);
+      }
+      else {
+         img->FetchTexelc(img, i0, j1, k0, t010);
+      }
+      if (useBorderColor & (I1BIT | J1BIT | K0BIT)) {
+         COPY_CHAN4(t110, tObj->_BorderChan);
+      }
+      else {
+         img->FetchTexelc(img, i1, j1, k0, t110);
+      }
+
+      if (useBorderColor & (I0BIT | J0BIT | K1BIT)) {
+         COPY_CHAN4(t001, tObj->_BorderChan);
+      }
+      else {
+         img->FetchTexelc(img, i0, j0, k1, t001);
+      }
+      if (useBorderColor & (I1BIT | J0BIT | K1BIT)) {
+         COPY_CHAN4(t101, tObj->_BorderChan);
+      }
+      else {
+         img->FetchTexelc(img, i1, j0, k1, t101);
+      }
+      if (useBorderColor & (I0BIT | J1BIT | K1BIT)) {
+         COPY_CHAN4(t011, tObj->_BorderChan);
+      }
+      else {
+         img->FetchTexelc(img, i0, j1, k1, t011);
+      }
+      if (useBorderColor & (I1BIT | J1BIT | K1BIT)) {
+         COPY_CHAN4(t111, tObj->_BorderChan);
+      }
+      else {
+         img->FetchTexelc(img, i1, j1, k1, t111);
+      }
+
+      /* trilinear interpolation of samples */
+#if CHAN_TYPE == GL_FLOAT
+      rgba[0] = lerp_3d(a, b, c,
+                        t000[0], t100[0], t010[0], t110[0],
+                        t001[0], t101[0], t011[0], t111[0]);
+      rgba[1] = lerp_3d(a, b, c,
+                        t000[1], t100[1], t010[1], t110[1],
+                        t001[1], t101[1], t011[1], t111[1]);
+      rgba[2] = lerp_3d(a, b, c,
+                        t000[2], t100[2], t010[2], t110[2],
+                        t001[2], t101[2], t011[2], t111[2]);
+      rgba[3] = lerp_3d(a, b, c,
+                        t000[3], t100[3], t010[3], t110[3],
+                        t001[3], t101[3], t011[3], t111[3]);
+#elif CHAN_TYPE == GL_UNSIGNED_SHORT
+      rgba[0] = (GLchan) (lerp_3d(a, b, c,
+                                  t000[0], t100[0], t010[0], t110[0],
+                                  t001[0], t101[0], t011[0], t111[0]) + 0.5F);
+      rgba[1] = (GLchan) (lerp_3d(a, b, c,
+                                  t000[1], t100[1], t010[1], t110[1],
+                                  t001[1], t101[1], t011[1], t111[1]) + 0.5F);
+      rgba[2] = (GLchan) (lerp_3d(a, b, c,
+                                  t000[2], t100[2], t010[2], t110[2],
+                                  t001[2], t101[2], t011[2], t111[2]) + 0.5F);
+      rgba[3] = (GLchan) (lerp_3d(a, b, c,
+                                  t000[3], t100[3], t010[3], t110[3],
+                                  t001[3], t101[3], t011[3], t111[3]) + 0.5F);
+#else
+      ASSERT(CHAN_TYPE == GL_UNSIGNED_BYTE);
+      rgba[0] = ilerp_3d(ia, ib, ic,
+                         t000[0], t100[0], t010[0], t110[0],
+                         t001[0], t101[0], t011[0], t111[0]);
+      rgba[1] = ilerp_3d(ia, ib, ic,
+                         t000[1], t100[1], t010[1], t110[1],
+                         t001[1], t101[1], t011[1], t111[1]);
+      rgba[2] = ilerp_3d(ia, ib, ic,
+                         t000[2], t100[2], t010[2], t110[2],
+                         t001[2], t101[2], t011[2], t111[2]);
+      rgba[3] = ilerp_3d(ia, ib, ic,
+                         t000[3], t100[3], t010[3], t110[3],
+                         t001[3], t101[3], t011[3], t111[3]);
+#endif
+   }
+}
+
+
+
+static void
+sample_3d_nearest_mipmap_nearest(GLcontext *ctx,
+                                 const struct gl_texture_object *tObj,
+                                 GLuint n, const GLfloat texcoord[][4],
+                                 const GLfloat lambda[], GLchan rgba[][4] )
+{
+   GLuint i;
+   for (i = 0; i < n; i++) {
+      GLint level;
+      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
+      sample_3d_nearest(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]);
+   }
+}
+
+
+static void
+sample_3d_linear_mipmap_nearest(GLcontext *ctx,
+                                const struct gl_texture_object *tObj,
+                                GLuint n, const GLfloat texcoord[][4],
+                                const GLfloat lambda[], GLchan rgba[][4])
+{
+   GLuint i;
+   ASSERT(lambda != NULL);
+   for (i = 0; i < n; i++) {
+      GLint level;
+      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
+      sample_3d_linear(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]);
+   }
+}
+
+
+static void
+sample_3d_nearest_mipmap_linear(GLcontext *ctx,
+                                const struct gl_texture_object *tObj,
+                                GLuint n, const GLfloat texcoord[][4],
+                                const GLfloat lambda[], GLchan rgba[][4])
+{
+   GLuint i;
+   ASSERT(lambda != NULL);
+   for (i = 0; i < n; i++) {
+      GLint level;
+      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
+      if (level >= tObj->_MaxLevel) {
+         sample_3d_nearest(ctx, tObj, tObj->Image[0][tObj->_MaxLevel],
+                           texcoord[i], rgba[i]);
+      }
+      else {
+         GLchan t0[4], t1[4];  /* texels */
+         const GLfloat f = FRAC(lambda[i]);
+         sample_3d_nearest(ctx, tObj, tObj->Image[0][level  ], texcoord[i], t0);
+         sample_3d_nearest(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1);
+         lerp_rgba(rgba[i], f, t0, t1);
+      }
+   }
+}
+
+
+static void
+sample_3d_linear_mipmap_linear(GLcontext *ctx,
+                               const struct gl_texture_object *tObj,
+                               GLuint n, const GLfloat texcoord[][4],
+                               const GLfloat lambda[], GLchan rgba[][4])
+{
+   GLuint i;
+   ASSERT(lambda != NULL);
+   for (i = 0; i < n; i++) {
+      GLint level;
+      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
+      if (level >= tObj->_MaxLevel) {
+         sample_3d_linear(ctx, tObj, tObj->Image[0][tObj->_MaxLevel],
+                          texcoord[i], rgba[i]);
+      }
+      else {
+         GLchan t0[4], t1[4];  /* texels */
+         const GLfloat f = FRAC(lambda[i]);
+         sample_3d_linear(ctx, tObj, tObj->Image[0][level  ], texcoord[i], t0);
+         sample_3d_linear(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1);
+         lerp_rgba(rgba[i], f, t0, t1);
+      }
+   }
+}
+
+
+static void
+sample_nearest_3d(GLcontext *ctx, GLuint texUnit,
+                  const struct gl_texture_object *tObj, GLuint n,
+                  const GLfloat texcoords[][4], const GLfloat lambda[],
+                  GLchan rgba[][4])
+{
+   GLuint i;
+   struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel];
+   (void) texUnit;
+   (void) lambda;
+   for (i=0;i<n;i++) {
+      sample_3d_nearest(ctx, tObj, image, texcoords[i], rgba[i]);
+   }
+}
+
+
+
+static void
+sample_linear_3d( GLcontext *ctx, GLuint texUnit,
+                  const struct gl_texture_object *tObj, GLuint n,
+                  const GLfloat texcoords[][4],
+                 const GLfloat lambda[], GLchan rgba[][4] )
+{
+   GLuint i;
+   struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel];
+   (void) texUnit;
+   (void) lambda;
+   for (i=0;i<n;i++) {
+      sample_3d_linear(ctx, tObj, image, texcoords[i], rgba[i]);
+   }
+}
+
+
+/*
+ * Given an (s,t,r) texture coordinate and lambda (level of detail) value,
+ * return a texture sample.
+ */
+static void
+sample_lambda_3d( GLcontext *ctx, GLuint texUnit,
+                  const struct gl_texture_object *tObj, GLuint n,
+                  const GLfloat texcoords[][4], const GLfloat lambda[],
+                  GLchan rgba[][4] )
+{
+   GLuint minStart, minEnd;  /* texels with minification */
+   GLuint magStart, magEnd;  /* texels with magnification */
+   GLuint i;
+
+   ASSERT(lambda != NULL);
+   compute_min_mag_ranges(SWRAST_CONTEXT(ctx)->_MinMagThresh[texUnit],
+                          n, lambda, &minStart, &minEnd, &magStart, &magEnd);
+
+   if (minStart < minEnd) {
+      /* do the minified texels */
+      GLuint m = minEnd - minStart;
+      switch (tObj->MinFilter) {
+      case GL_NEAREST:
+         for (i = minStart; i < minEnd; i++)
+            sample_3d_nearest(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
+                              texcoords[i], rgba[i]);
+         break;
+      case GL_LINEAR:
+         for (i = minStart; i < minEnd; i++)
+            sample_3d_linear(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
+                             texcoords[i], rgba[i]);
+         break;
+      case GL_NEAREST_MIPMAP_NEAREST:
+         sample_3d_nearest_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
+                                          lambda + minStart, rgba + minStart);
+         break;
+      case GL_LINEAR_MIPMAP_NEAREST:
+         sample_3d_linear_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
+                                         lambda + minStart, rgba + minStart);
+         break;
+      case GL_NEAREST_MIPMAP_LINEAR:
+         sample_3d_nearest_mipmap_linear(ctx, tObj, m, texcoords + minStart,
+                                         lambda + minStart, rgba + minStart);
+         break;
+      case GL_LINEAR_MIPMAP_LINEAR:
+         sample_3d_linear_mipmap_linear(ctx, tObj, m, texcoords + minStart,
+                                        lambda + minStart, rgba + minStart);
+         break;
+      default:
+         _mesa_problem(ctx, "Bad min filter in sample_3d_texture");
+         return;
+      }
+   }
+
+   if (magStart < magEnd) {
+      /* do the magnified texels */
+      switch (tObj->MagFilter) {
+      case GL_NEAREST:
+         for (i = magStart; i < magEnd; i++)
+            sample_3d_nearest(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
+                              texcoords[i], rgba[i]);
+         break;
+      case GL_LINEAR:
+         for (i = magStart; i < magEnd; i++)
+            sample_3d_linear(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
+                             texcoords[i], rgba[i]);
+         break;
+      default:
+         _mesa_problem(ctx, "Bad mag filter in sample_3d_texture");
+         return;
+      }
+   }
+}
+
+
+/**********************************************************************/
+/*                Texture Cube Map Sampling Functions                 */
+/**********************************************************************/
+
+/**
+ * Choose one of six sides of a texture cube map given the texture
+ * coord (rx,ry,rz).  Return pointer to corresponding array of texture
+ * images.
+ */
+static const struct gl_texture_image **
+choose_cube_face(const struct gl_texture_object *texObj,
+                 const GLfloat texcoord[4], GLfloat newCoord[4])
+{
+   /*
+      major axis
+      direction     target                             sc     tc    ma
+      ----------    -------------------------------    ---    ---   ---
+       +rx          TEXTURE_CUBE_MAP_POSITIVE_X_EXT    -rz    -ry   rx
+       -rx          TEXTURE_CUBE_MAP_NEGATIVE_X_EXT    +rz    -ry   rx
+       +ry          TEXTURE_CUBE_MAP_POSITIVE_Y_EXT    +rx    +rz   ry
+       -ry          TEXTURE_CUBE_MAP_NEGATIVE_Y_EXT    +rx    -rz   ry
+       +rz          TEXTURE_CUBE_MAP_POSITIVE_Z_EXT    +rx    -ry   rz
+       -rz          TEXTURE_CUBE_MAP_NEGATIVE_Z_EXT    -rx    -ry   rz
+   */
+   const GLfloat rx = texcoord[0];
+   const GLfloat ry = texcoord[1];
+   const GLfloat rz = texcoord[2];
+   const GLfloat arx = FABSF(rx), ary = FABSF(ry), arz = FABSF(rz);
+   GLuint face;
+   GLfloat sc, tc, ma;
+
+   if (arx > ary && arx > arz) {
+      if (rx >= 0.0F) {
+         face = FACE_POS_X;
+         sc = -rz;
+         tc = -ry;
+         ma = arx;
+      }
+      else {
+         face = FACE_NEG_X;
+         sc = rz;
+         tc = -ry;
+         ma = arx;
+      }
+   }
+   else if (ary > arx && ary > arz) {
+      if (ry >= 0.0F) {
+         face = FACE_POS_Y;
+         sc = rx;
+         tc = rz;
+         ma = ary;
+      }
+      else {
+         face = FACE_NEG_Y;
+         sc = rx;
+         tc = -rz;
+         ma = ary;
+      }
+   }
+   else {
+      if (rz > 0.0F) {
+         face = FACE_POS_Z;
+         sc = rx;
+         tc = -ry;
+         ma = arz;
+      }
+      else {
+         face = FACE_NEG_Z;
+         sc = -rx;
+         tc = -ry;
+         ma = arz;
+      }
+   }
+
+   newCoord[0] = ( sc / ma + 1.0F ) * 0.5F;
+   newCoord[1] = ( tc / ma + 1.0F ) * 0.5F;
+   return (const struct gl_texture_image **) texObj->Image[face];
+}
+
+
+static void
+sample_nearest_cube(GLcontext *ctx, GLuint texUnit,
+                   const struct gl_texture_object *tObj, GLuint n,
+                    const GLfloat texcoords[][4], const GLfloat lambda[],
+                    GLchan rgba[][4])
+{
+   GLuint i;
+   (void) texUnit;
+   (void) lambda;
+   for (i = 0; i < n; i++) {
+      const struct gl_texture_image **images;
+      GLfloat newCoord[4];
+      images = choose_cube_face(tObj, texcoords[i], newCoord);
+      sample_2d_nearest(ctx, tObj, images[tObj->BaseLevel],
+                        newCoord, rgba[i]);
+   }
+}
+
+
+static void
+sample_linear_cube(GLcontext *ctx, GLuint texUnit,
+                  const struct gl_texture_object *tObj, GLuint n,
+                   const GLfloat texcoords[][4],
+                  const GLfloat lambda[], GLchan rgba[][4])
+{
+   GLuint i;
+   (void) texUnit;
+   (void) lambda;
+   for (i = 0; i < n; i++) {
+      const struct gl_texture_image **images;
+      GLfloat newCoord[4];
+      images = choose_cube_face(tObj, texcoords[i], newCoord);
+      sample_2d_linear(ctx, tObj, images[tObj->BaseLevel],
+                       newCoord, rgba[i]);
+   }
+}
+
+
+static void
+sample_cube_nearest_mipmap_nearest(GLcontext *ctx, GLuint texUnit,
+                                   const struct gl_texture_object *tObj,
+                                   GLuint n, const GLfloat texcoord[][4],
+                                   const GLfloat lambda[], GLchan rgba[][4])
+{
+   GLuint i;
+   (void) texUnit;
+   ASSERT(lambda != NULL);
+   for (i = 0; i < n; i++) {
+      const struct gl_texture_image **images;
+      GLfloat newCoord[4];
+      GLint level;
+      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
+      images = choose_cube_face(tObj, texcoord[i], newCoord);
+      sample_2d_nearest(ctx, tObj, images[level], newCoord, rgba[i]);
+   }
+}
+
+
+static void
+sample_cube_linear_mipmap_nearest(GLcontext *ctx, GLuint texUnit,
+                                  const struct gl_texture_object *tObj,
+                                  GLuint n, const GLfloat texcoord[][4],
+                                  const GLfloat lambda[], GLchan rgba[][4])
+{
+   GLuint i;
+   (void) texUnit;
+   ASSERT(lambda != NULL);
+   for (i = 0; i < n; i++) {
+      const struct gl_texture_image **images;
+      GLfloat newCoord[4];
+      GLint level;
+      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
+      images = choose_cube_face(tObj, texcoord[i], newCoord);
+      sample_2d_linear(ctx, tObj, images[level], newCoord, rgba[i]);
+   }
+}
+
+
+static void
+sample_cube_nearest_mipmap_linear(GLcontext *ctx, GLuint texUnit,
+                                  const struct gl_texture_object *tObj,
+                                  GLuint n, const GLfloat texcoord[][4],
+                                  const GLfloat lambda[], GLchan rgba[][4])
+{
+   GLuint i;
+   (void) texUnit;
+   ASSERT(lambda != NULL);
+   for (i = 0; i < n; i++) {
+      const struct gl_texture_image **images;
+      GLfloat newCoord[4];
+      GLint level;
+      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
+      images = choose_cube_face(tObj, texcoord[i], newCoord);
+      if (level >= tObj->_MaxLevel) {
+         sample_2d_nearest(ctx, tObj, images[tObj->_MaxLevel],
+                           newCoord, rgba[i]);
+      }
+      else {
+         GLchan t0[4], t1[4];  /* texels */
+         const GLfloat f = FRAC(lambda[i]);
+         sample_2d_nearest(ctx, tObj, images[level  ], newCoord, t0);
+         sample_2d_nearest(ctx, tObj, images[level+1], newCoord, t1);
+         lerp_rgba(rgba[i], f, t0, t1);
+      }
+   }
+}
+
+
+static void
+sample_cube_linear_mipmap_linear(GLcontext *ctx, GLuint texUnit,
+                                 const struct gl_texture_object *tObj,
+                                 GLuint n, const GLfloat texcoord[][4],
+                                 const GLfloat lambda[], GLchan rgba[][4])
+{
+   GLuint i;
+   (void) texUnit;
+   ASSERT(lambda != NULL);
+   for (i = 0; i < n; i++) {
+      const struct gl_texture_image **images;
+      GLfloat newCoord[4];
+      GLint level;
+      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
+      images = choose_cube_face(tObj, texcoord[i], newCoord);
+      if (level >= tObj->_MaxLevel) {
+         sample_2d_linear(ctx, tObj, images[tObj->_MaxLevel],
+                          newCoord, rgba[i]);
+      }
+      else {
+         GLchan t0[4], t1[4];
+         const GLfloat f = FRAC(lambda[i]);
+         sample_2d_linear(ctx, tObj, images[level  ], newCoord, t0);
+         sample_2d_linear(ctx, tObj, images[level+1], newCoord, t1);
+         lerp_rgba(rgba[i], f, t0, t1);
+      }
+   }
+}
+
+
+static void
+sample_lambda_cube( GLcontext *ctx, GLuint texUnit,
+                   const struct gl_texture_object *tObj, GLuint n,
+                   const GLfloat texcoords[][4], const GLfloat lambda[],
+                   GLchan rgba[][4])
+{
+   GLuint minStart, minEnd;  /* texels with minification */
+   GLuint magStart, magEnd;  /* texels with magnification */
+
+   ASSERT(lambda != NULL);
+   compute_min_mag_ranges(SWRAST_CONTEXT(ctx)->_MinMagThresh[texUnit],
+                          n, lambda, &minStart, &minEnd, &magStart, &magEnd);
+
+   if (minStart < minEnd) {
+      /* do the minified texels */
+      const GLuint m = minEnd - minStart;
+      switch (tObj->MinFilter) {
+      case GL_NEAREST:
+         sample_nearest_cube(ctx, texUnit, tObj, m, texcoords + minStart,
+                             lambda + minStart, rgba + minStart);
+         break;
+      case GL_LINEAR:
+         sample_linear_cube(ctx, texUnit, tObj, m, texcoords + minStart,
+                            lambda + minStart, rgba + minStart);
+         break;
+      case GL_NEAREST_MIPMAP_NEAREST:
+         sample_cube_nearest_mipmap_nearest(ctx, texUnit, tObj, m,
+                                            texcoords + minStart,
+                                           lambda + minStart, rgba + minStart);
+         break;
+      case GL_LINEAR_MIPMAP_NEAREST:
+         sample_cube_linear_mipmap_nearest(ctx, texUnit, tObj, m,
+                                           texcoords + minStart,
+                                           lambda + minStart, rgba + minStart);
+         break;
+      case GL_NEAREST_MIPMAP_LINEAR:
+         sample_cube_nearest_mipmap_linear(ctx, texUnit, tObj, m,
+                                           texcoords + minStart,
+                                           lambda + minStart, rgba + minStart);
+         break;
+      case GL_LINEAR_MIPMAP_LINEAR:
+         sample_cube_linear_mipmap_linear(ctx, texUnit, tObj, m,
+                                          texcoords + minStart,
+                                          lambda + minStart, rgba + minStart);
+         break;
+      default:
+         _mesa_problem(ctx, "Bad min filter in sample_lambda_cube");
+      }
+   }
+
+   if (magStart < magEnd) {
+      /* do the magnified texels */
+      const GLuint m = magEnd - magStart;
+      switch (tObj->MagFilter) {
+      case GL_NEAREST:
+         sample_nearest_cube(ctx, texUnit, tObj, m, texcoords + magStart,
+                             lambda + magStart, rgba + magStart);
+         break;
+      case GL_LINEAR:
+         sample_linear_cube(ctx, texUnit, tObj, m, texcoords + magStart,
+                            lambda + magStart, rgba + magStart);
+         break;
+      default:
+         _mesa_problem(ctx, "Bad mag filter in sample_lambda_cube");
+      }
+   }
+}
+
+
+/**********************************************************************/
+/*               Texture Rectangle Sampling Functions                 */
+/**********************************************************************/
+
+static void
+sample_nearest_rect(GLcontext *ctx, GLuint texUnit,
+                   const struct gl_texture_object *tObj, GLuint n,
+                    const GLfloat texcoords[][4], const GLfloat lambda[],
+                    GLchan rgba[][4])
+{
+   const struct gl_texture_image *img = tObj->Image[0][0];
+   const GLfloat width = (GLfloat) img->Width;
+   const GLfloat height = (GLfloat) img->Height;
+   const GLint width_minus_1 = img->Width - 1;
+   const GLint height_minus_1 = img->Height - 1;
+   GLuint i;
+
+   (void) ctx;
+   (void) texUnit;
+   (void) lambda;
+
+   ASSERT(tObj->WrapS == GL_CLAMP ||
+          tObj->WrapS == GL_CLAMP_TO_EDGE ||
+          tObj->WrapS == GL_CLAMP_TO_BORDER);
+   ASSERT(tObj->WrapT == GL_CLAMP ||
+          tObj->WrapT == GL_CLAMP_TO_EDGE ||
+          tObj->WrapT == GL_CLAMP_TO_BORDER);
+   ASSERT(img->Format != GL_COLOR_INDEX);
+
+   /* XXX move Wrap mode tests outside of loops for common cases */
+   for (i = 0; i < n; i++) {
+      GLint row, col;
+      /* NOTE: we DO NOT use [0, 1] texture coordinates! */
+      if (tObj->WrapS == GL_CLAMP) {
+         col = IFLOOR( CLAMP(texcoords[i][0], 0.0F, width - 1) );
+      }
+      else if (tObj->WrapS == GL_CLAMP_TO_EDGE) {
+         col = IFLOOR( CLAMP(texcoords[i][0], 0.5F, width - 0.5F) );
+      }
+      else {
+         col = IFLOOR( CLAMP(texcoords[i][0], -0.5F, width + 0.5F) );
+      }
+      if (tObj->WrapT == GL_CLAMP) {
+         row = IFLOOR( CLAMP(texcoords[i][1], 0.0F, height - 1) );
+      }
+      else if (tObj->WrapT == GL_CLAMP_TO_EDGE) {
+         row = IFLOOR( CLAMP(texcoords[i][1], 0.5F, height - 0.5F) );
+      }
+      else {
+         row = IFLOOR( CLAMP(texcoords[i][1], -0.5F, height + 0.5F) );
+      }
+
+      if (col < 0 || col > width_minus_1 || row < 0 || row > height_minus_1)
+         COPY_CHAN4(rgba[i], tObj->_BorderChan);
+      else
+         img->FetchTexelc(img, col, row, 0, rgba[i]);
+   }
+}
+
+
+static void
+sample_linear_rect(GLcontext *ctx, GLuint texUnit,
+                  const struct gl_texture_object *tObj, GLuint n,
+                   const GLfloat texcoords[][4],
+                  const GLfloat lambda[], GLchan rgba[][4])
+{
+   const struct gl_texture_image *img = tObj->Image[0][0];
+   const GLfloat width = (GLfloat) img->Width;
+   const GLfloat height = (GLfloat) img->Height;
+   const GLint width_minus_1 = img->Width - 1;
+   const GLint height_minus_1 = img->Height - 1;
+   GLuint i;
+
+   (void) ctx;
+   (void) texUnit;
+   (void) lambda;
+
+   ASSERT(tObj->WrapS == GL_CLAMP ||
+          tObj->WrapS == GL_CLAMP_TO_EDGE ||
+          tObj->WrapS == GL_CLAMP_TO_BORDER);
+   ASSERT(tObj->WrapT == GL_CLAMP ||
+          tObj->WrapT == GL_CLAMP_TO_EDGE ||
+          tObj->WrapT == GL_CLAMP_TO_BORDER);
+   ASSERT(img->Format != GL_COLOR_INDEX);
+
+   /* XXX lots of opportunity for optimization in this loop */
+   for (i = 0; i < n; i++) {
+      GLfloat frow, fcol;
+      GLint i0, j0, i1, j1;
+      GLchan t00[4], t01[4], t10[4], t11[4];
+      GLfloat a, b;
+      GLuint useBorderColor = 0;
+
+      /* NOTE: we DO NOT use [0, 1] texture coordinates! */
+      if (tObj->WrapS == GL_CLAMP) {
+         /* Not exactly what the spec says, but it matches NVIDIA output */
+         fcol = CLAMP(texcoords[i][0] - 0.5F, 0.0, width_minus_1);
+         i0 = IFLOOR(fcol);
+         i1 = i0 + 1;
+      }
+      else if (tObj->WrapS == GL_CLAMP_TO_EDGE) {
+         fcol = CLAMP(texcoords[i][0], 0.5F, width - 0.5F);
+         fcol -= 0.5F;
+         i0 = IFLOOR(fcol);
+         i1 = i0 + 1;
+         if (i1 > width_minus_1)
+            i1 = width_minus_1;
+      }
+      else {
+         ASSERT(tObj->WrapS == GL_CLAMP_TO_BORDER);
+         fcol = CLAMP(texcoords[i][0], -0.5F, width + 0.5F);
+         fcol -= 0.5F;
+         i0 = IFLOOR(fcol);
+         i1 = i0 + 1;
+      }
+
+      if (tObj->WrapT == GL_CLAMP) {
+         /* Not exactly what the spec says, but it matches NVIDIA output */
+         frow = CLAMP(texcoords[i][1] - 0.5F, 0.0, width_minus_1);
+         j0 = IFLOOR(frow);
+         j1 = j0 + 1;
+      }
+      else if (tObj->WrapT == GL_CLAMP_TO_EDGE) {
+         frow = CLAMP(texcoords[i][1], 0.5F, height - 0.5F);
+         frow -= 0.5F;
+         j0 = IFLOOR(frow);
+         j1 = j0 + 1;
+         if (j1 > height_minus_1)
+            j1 = height_minus_1;
+      }
+      else {
+         ASSERT(tObj->WrapT == GL_CLAMP_TO_BORDER);
+         frow = CLAMP(texcoords[i][1], -0.5F, height + 0.5F);
+         frow -= 0.5F;
+         j0 = IFLOOR(frow);
+         j1 = j0 + 1;
+      }
+
+      /* compute integer rows/columns */
+      if (i0 < 0 || i0 > width_minus_1)   useBorderColor |= I0BIT;
+      if (i1 < 0 || i1 > width_minus_1)   useBorderColor |= I1BIT;
+      if (j0 < 0 || j0 > height_minus_1)  useBorderColor |= J0BIT;
+      if (j1 < 0 || j1 > height_minus_1)  useBorderColor |= J1BIT;
+
+      /* get four texel samples */
+      if (useBorderColor & (I0BIT | J0BIT))
+         COPY_CHAN4(t00, tObj->_BorderChan);
+      else
+         img->FetchTexelc(img, i0, j0, 0, t00);
+
+      if (useBorderColor & (I1BIT | J0BIT))
+         COPY_CHAN4(t10, tObj->_BorderChan);
+      else
+         img->FetchTexelc(img, i1, j0, 0, t10);
+
+      if (useBorderColor & (I0BIT | J1BIT))
+         COPY_CHAN4(t01, tObj->_BorderChan);
+      else
+         img->FetchTexelc(img, i0, j1, 0, t01);
+
+      if (useBorderColor & (I1BIT | J1BIT))
+         COPY_CHAN4(t11, tObj->_BorderChan);
+      else
+         img->FetchTexelc(img, i1, j1, 0, t11);
+
+      /* compute interpolants */
+      a = FRAC(fcol);
+      b = FRAC(frow);
+
+      lerp_rgba_2d(rgba[i], a, b, t00, t10, t01, t11);
+   }
+}
+
+
+static void
+sample_lambda_rect( GLcontext *ctx, GLuint texUnit,
+                   const struct gl_texture_object *tObj, GLuint n,
+                   const GLfloat texcoords[][4], const GLfloat lambda[],
+                   GLchan rgba[][4])
+{
+   GLuint minStart, minEnd, magStart, magEnd;
+
+   /* We only need lambda to decide between minification and magnification.
+    * There is no mipmapping with rectangular textures.
+    */
+   compute_min_mag_ranges(SWRAST_CONTEXT(ctx)->_MinMagThresh[texUnit],
+                          n, lambda, &minStart, &minEnd, &magStart, &magEnd);
+
+   if (minStart < minEnd) {
+      if (tObj->MinFilter == GL_NEAREST) {
+         sample_nearest_rect( ctx, texUnit, tObj, minEnd - minStart,
+                              texcoords + minStart, NULL, rgba + minStart);
+      }
+      else {
+         sample_linear_rect( ctx, texUnit, tObj, minEnd - minStart,
+                             texcoords + minStart, NULL, rgba + minStart);
+      }
+   }
+   if (magStart < magEnd) {
+      if (tObj->MagFilter == GL_NEAREST) {
+         sample_nearest_rect( ctx, texUnit, tObj, magEnd - magStart,
+                              texcoords + magStart, NULL, rgba + magStart);
+      }
+      else {
+         sample_linear_rect( ctx, texUnit, tObj, magEnd - magStart,
+                             texcoords + magStart, NULL, rgba + magStart);
+      }
+   }
+}
+
+
+
+/*
+ * Sample a shadow/depth texture.
+ */
+static void
+sample_depth_texture( GLcontext *ctx, GLuint unit,
+                      const struct gl_texture_object *tObj, GLuint n,
+                      const GLfloat texcoords[][4], const GLfloat lambda[],
+                      GLchan texel[][4] )
+{
+   const GLint baseLevel = tObj->BaseLevel;
+   const struct gl_texture_image *texImage = tObj->Image[0][baseLevel];
+   const GLuint width = texImage->Width;
+   const GLuint height = texImage->Height;
+   GLchan ambient;
+   GLenum function;
+   GLchan result;
+
+   (void) lambda;
+   (void) unit;
+
+   ASSERT(tObj->Image[0][tObj->BaseLevel]->Format == GL_DEPTH_COMPONENT);
+   ASSERT(tObj->Target == GL_TEXTURE_1D ||
+          tObj->Target == GL_TEXTURE_2D ||
+          tObj->Target == GL_TEXTURE_RECTANGLE_NV);
+
+   UNCLAMPED_FLOAT_TO_CHAN(ambient, tObj->ShadowAmbient);
+
+   /* XXXX if tObj->MinFilter != tObj->MagFilter, we're ignoring lambda */
+
+   /* XXX this could be precomputed and saved in the texture object */
+   if (tObj->CompareFlag) {
+      /* GL_SGIX_shadow */
+      if (tObj->CompareOperator == GL_TEXTURE_LEQUAL_R_SGIX) {
+         function = GL_LEQUAL;
+      }
+      else {
+         ASSERT(tObj->CompareOperator == GL_TEXTURE_GEQUAL_R_SGIX);
+         function = GL_GEQUAL;
+      }
+   }
+   else if (tObj->CompareMode == GL_COMPARE_R_TO_TEXTURE_ARB) {
+      /* GL_ARB_shadow */
+      function = tObj->CompareFunc;
+   }
+   else {
+      function = GL_NONE;  /* pass depth through as grayscale */
+   }
+
+   if (tObj->MagFilter == GL_NEAREST) {
+      GLuint i;
+      for (i = 0; i < n; i++) {
+         GLfloat depthSample;
+         GLint col, row;
+         /* XXX fix for texture rectangle! */
+         COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapS, texcoords[i][0], width, col);
+         COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapT, texcoords[i][1], height, row);
+         texImage->FetchTexelf(texImage, col, row, 0, &depthSample);
+
+         switch (function) {
+         case GL_LEQUAL:
+            result = (texcoords[i][2] <= depthSample) ? CHAN_MAX : ambient;
+            break;
+         case GL_GEQUAL:
+            result = (texcoords[i][2] >= depthSample) ? CHAN_MAX : ambient;
+            break;
+         case GL_LESS:
+            result = (texcoords[i][2] < depthSample) ? CHAN_MAX : ambient;
+            break;
+         case GL_GREATER:
+            result = (texcoords[i][2] > depthSample) ? CHAN_MAX : ambient;
+            break;
+         case GL_EQUAL:
+            result = (texcoords[i][2] == depthSample) ? CHAN_MAX : ambient;
+            break;
+         case GL_NOTEQUAL:
+            result = (texcoords[i][2] != depthSample) ? CHAN_MAX : ambient;
+            break;
+         case GL_ALWAYS:
+            result = CHAN_MAX;
+            break;
+         case GL_NEVER:
+            result = ambient;
+            break;
+         case GL_NONE:
+            CLAMPED_FLOAT_TO_CHAN(result, depthSample);
+            break;
+         default:
+            _mesa_problem(ctx, "Bad compare func in sample_depth_texture");
+            return;
+         }
+
+         switch (tObj->DepthMode) {
+         case GL_LUMINANCE:
+            texel[i][RCOMP] = result;
+            texel[i][GCOMP] = result;
+            texel[i][BCOMP] = result;
+            texel[i][ACOMP] = CHAN_MAX;
+            break;
+         case GL_INTENSITY:
+            texel[i][RCOMP] = result;
+            texel[i][GCOMP] = result;
+            texel[i][BCOMP] = result;
+            texel[i][ACOMP] = result;
+            break;
+         case GL_ALPHA:
+            texel[i][RCOMP] = 0;
+            texel[i][GCOMP] = 0;
+            texel[i][BCOMP] = 0;
+            texel[i][ACOMP] = result;
+            break;
+         default:
+            _mesa_problem(ctx, "Bad depth texture mode");
+         }
+      }
+   }
+   else {
+      GLuint i;
+      ASSERT(tObj->MagFilter == GL_LINEAR);
+      for (i = 0; i < n; i++) {
+         GLfloat depth00, depth01, depth10, depth11;
+         GLint i0, i1, j0, j1;
+         GLfloat u, v;
+         GLuint useBorderTexel;
+
+         /* XXX fix for texture rectangle! */
+         COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapS, texcoords[i][0], u, width, i0, i1);
+         COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapT, texcoords[i][1], v, height,j0, j1);
+
+         useBorderTexel = 0;
+         if (texImage->Border) {
+            i0 += texImage->Border;
+            i1 += texImage->Border;
+            j0 += texImage->Border;
+            j1 += texImage->Border;
+         }
+         else {
+            if (i0 < 0 || i0 >= (GLint) width)   useBorderTexel |= I0BIT;
+            if (i1 < 0 || i1 >= (GLint) width)   useBorderTexel |= I1BIT;
+            if (j0 < 0 || j0 >= (GLint) height)  useBorderTexel |= J0BIT;
+            if (j1 < 0 || j1 >= (GLint) height)  useBorderTexel |= J1BIT;
+         }
+
+         /* get four depth samples from the texture */
+         if (useBorderTexel & (I0BIT | J0BIT)) {
+            depth00 = 1.0;
+         }
+         else {
+            texImage->FetchTexelf(texImage, i0, j0, 0, &depth00);
+         }
+         if (useBorderTexel & (I1BIT | J0BIT)) {
+            depth10 = 1.0;
+         }
+         else {
+            texImage->FetchTexelf(texImage, i1, j0, 0, &depth10);
+         }
+         if (useBorderTexel & (I0BIT | J1BIT)) {
+            depth01 = 1.0;
+         }
+         else {
+            texImage->FetchTexelf(texImage, i0, j1, 0, &depth01);
+         }
+         if (useBorderTexel & (I1BIT | J1BIT)) {
+            depth11 = 1.0;
+         }
+         else {
+            texImage->FetchTexelf(texImage, i1, j1, 0, &depth11);
+         }
+
+         if (0) {
+            /* compute a single weighted depth sample and do one comparison */
+            const GLfloat a = FRAC(u + 1.0F);
+            const GLfloat b = FRAC(v + 1.0F);
+            const GLfloat depthSample
+               = lerp_2d(a, b, depth00, depth10, depth01, depth11);
+            if ((depthSample <= texcoords[i][2] && function == GL_LEQUAL) ||
+                (depthSample >= texcoords[i][2] && function == GL_GEQUAL)) {
+               result  = ambient;
+            }
+            else {
+               result = CHAN_MAX;
+            }
+         }
+         else {
+            /* Do four depth/R comparisons and compute a weighted result.
+             * If this touches on somebody's I.P., I'll remove this code
+             * upon request.
+             */
+            const GLfloat d = (CHAN_MAXF - (GLfloat) ambient) * 0.25F;
+            GLfloat luminance = CHAN_MAXF;
+
+            switch (function) {
+            case GL_LEQUAL:
+               if (depth00 <= texcoords[i][2])  luminance -= d;
+               if (depth01 <= texcoords[i][2])  luminance -= d;
+               if (depth10 <= texcoords[i][2])  luminance -= d;
+               if (depth11 <= texcoords[i][2])  luminance -= d;
+               result = (GLchan) luminance;
+               break;
+            case GL_GEQUAL:
+               if (depth00 >= texcoords[i][2])  luminance -= d;
+               if (depth01 >= texcoords[i][2])  luminance -= d;
+               if (depth10 >= texcoords[i][2])  luminance -= d;
+               if (depth11 >= texcoords[i][2])  luminance -= d;
+               result = (GLchan) luminance;
+               break;
+            case GL_LESS:
+               if (depth00 < texcoords[i][2])  luminance -= d;
+               if (depth01 < texcoords[i][2])  luminance -= d;
+               if (depth10 < texcoords[i][2])  luminance -= d;
+               if (depth11 < texcoords[i][2])  luminance -= d;
+               result = (GLchan) luminance;
+               break;
+            case GL_GREATER:
+               if (depth00 > texcoords[i][2])  luminance -= d;
+               if (depth01 > texcoords[i][2])  luminance -= d;
+               if (depth10 > texcoords[i][2])  luminance -= d;
+               if (depth11 > texcoords[i][2])  luminance -= d;
+               result = (GLchan) luminance;
+               break;
+            case GL_EQUAL:
+               if (depth00 == texcoords[i][2])  luminance -= d;
+               if (depth01 == texcoords[i][2])  luminance -= d;
+               if (depth10 == texcoords[i][2])  luminance -= d;
+               if (depth11 == texcoords[i][2])  luminance -= d;
+               result = (GLchan) luminance;
+               break;
+            case GL_NOTEQUAL:
+               if (depth00 != texcoords[i][2])  luminance -= d;
+               if (depth01 != texcoords[i][2])  luminance -= d;
+               if (depth10 != texcoords[i][2])  luminance -= d;
+               if (depth11 != texcoords[i][2])  luminance -= d;
+               result = (GLchan) luminance;
+               break;
+            case GL_ALWAYS:
+               result = 0;
+               break;
+            case GL_NEVER:
+               result = CHAN_MAX;
+               break;
+            case GL_NONE:
+               /* ordinary bilinear filtering */
+               {
+                  const GLfloat a = FRAC(u + 1.0F);
+                  const GLfloat b = FRAC(v + 1.0F);
+                  const GLfloat depthSample
+                     = lerp_2d(a, b, depth00, depth10, depth01, depth11);
+                  CLAMPED_FLOAT_TO_CHAN(result, depthSample);
+               }
+               break;
+            default:
+               _mesa_problem(ctx, "Bad compare func in sample_depth_texture");
+               return;
+            }
+         }
+
+         switch (tObj->DepthMode) {
+         case GL_LUMINANCE:
+            texel[i][RCOMP] = result;
+            texel[i][GCOMP] = result;
+            texel[i][BCOMP] = result;
+            texel[i][ACOMP] = CHAN_MAX;
+            break;
+         case GL_INTENSITY:
+            texel[i][RCOMP] = result;
+            texel[i][GCOMP] = result;
+            texel[i][BCOMP] = result;
+            texel[i][ACOMP] = result;
+            break;
+         case GL_ALPHA:
+            texel[i][RCOMP] = 0;
+            texel[i][GCOMP] = 0;
+            texel[i][BCOMP] = 0;
+            texel[i][ACOMP] = result;
+            break;
+         default:
+            _mesa_problem(ctx, "Bad depth texture mode");
+         }
+      }  /* for */
+   }  /* if filter */
+}
+
+
+#if 0
+/*
+ * Experimental depth texture sampling function.
+ */
+static void
+sample_depth_texture2(const GLcontext *ctx,
+                     const struct gl_texture_unit *texUnit,
+                     GLuint n, const GLfloat texcoords[][4],
+                     GLchan texel[][4])
+{
+   const struct gl_texture_object *texObj = texUnit->_Current;
+   const GLint baseLevel = texObj->BaseLevel;
+   const struct gl_texture_image *texImage = texObj->Image[0][baseLevel];
+   const GLuint width = texImage->Width;
+   const GLuint height = texImage->Height;
+   GLchan ambient;
+   GLboolean lequal, gequal;
+
+   if (texObj->Target != GL_TEXTURE_2D) {
+      _mesa_problem(ctx, "only 2-D depth textures supported at this time");
+      return;
+   }
+
+   if (texObj->MinFilter != texObj->MagFilter) {
+      _mesa_problem(ctx, "mipmapped depth textures not supported at this time");
+      return;
+   }
+
+   /* XXX the GL_SGIX_shadow extension spec doesn't say what to do if
+    * GL_TEXTURE_COMPARE_SGIX == GL_TRUE but the current texture object
+    * isn't a depth texture.
+    */
+   if (texImage->Format != GL_DEPTH_COMPONENT) {
+      _mesa_problem(ctx,"GL_TEXTURE_COMPARE_SGIX enabled with non-depth texture");
+      return;
+   }
+
+   UNCLAMPED_FLOAT_TO_CHAN(ambient, tObj->ShadowAmbient);
+
+   if (texObj->CompareOperator == GL_TEXTURE_LEQUAL_R_SGIX) {
+      lequal = GL_TRUE;
+      gequal = GL_FALSE;
+   }
+   else {
+      lequal = GL_FALSE;
+      gequal = GL_TRUE;
+   }
+
+   {
+      GLuint i;
+      for (i = 0; i < n; i++) {
+         const GLint K = 3;
+         GLint col, row, ii, jj, imin, imax, jmin, jmax, samples, count;
+         GLfloat w;
+         GLchan lum;
+         COMPUTE_NEAREST_TEXEL_LOCATION(texObj->WrapS, texcoords[i][0],
+                                       width, col);
+         COMPUTE_NEAREST_TEXEL_LOCATION(texObj->WrapT, texcoords[i][1],
+                                       height, row);
+
+         imin = col - K;
+         imax = col + K;
+         jmin = row - K;
+         jmax = row + K;
+
+         if (imin < 0)  imin = 0;
+         if (imax >= width)  imax = width - 1;
+         if (jmin < 0)  jmin = 0;
+         if (jmax >= height) jmax = height - 1;
+
+         samples = (imax - imin + 1) * (jmax - jmin + 1);
+         count = 0;
+         for (jj = jmin; jj <= jmax; jj++) {
+            for (ii = imin; ii <= imax; ii++) {
+               GLfloat depthSample;
+               texImage->FetchTexelf(texImage, ii, jj, 0, &depthSample);
+               if ((depthSample <= r[i] && lequal) ||
+                   (depthSample >= r[i] && gequal)) {
+                  count++;
+               }
+            }
+         }
+
+         w = (GLfloat) count / (GLfloat) samples;
+         w = CHAN_MAXF - w * (CHAN_MAXF - (GLfloat) ambient);
+         lum = (GLint) w;
+
+         texel[i][RCOMP] = lum;
+         texel[i][GCOMP] = lum;
+         texel[i][BCOMP] = lum;
+         texel[i][ACOMP] = CHAN_MAX;
+      }
+   }
+}
+#endif
+
+
+/**
+ * We use this function when a texture object is in an "incomplete" state.
+ * When a fragment program attempts to sample an incomplete texture we
+ * return black (see issue 23 in GL_ARB_fragment_program spec).
+ * Note: fragment programss don't observe the texture enable/disable flags.
+ */
+static void
+null_sample_func( GLcontext *ctx, GLuint texUnit,
+                 const struct gl_texture_object *tObj, GLuint n,
+                 const GLfloat texcoords[][4], const GLfloat lambda[],
+                 GLchan rgba[][4])
+{
+   GLuint i;
+   (void) ctx;
+   (void) texUnit;
+   (void) tObj;
+   (void) texcoords;
+   (void) lambda;
+   for (i = 0; i < n; i++) {
+      rgba[i][RCOMP] = 0;
+      rgba[i][GCOMP] = 0;
+      rgba[i][BCOMP] = 0;
+      rgba[i][ACOMP] = CHAN_MAX;
+   }
+}
+
+
+/**
+ * Choose the texture sampling function for the given texture object.
+ */
+texture_sample_func
+_swrast_choose_texture_sample_func( GLcontext *ctx,
+                                   const struct gl_texture_object *t )
+{
+   if (!t || !t->Complete) {
+      return &null_sample_func;
+   }
+   else {
+      const GLboolean needLambda = (GLboolean) (t->MinFilter != t->MagFilter);
+      const GLenum format = t->Image[0][t->BaseLevel]->Format;
+
+      switch (t->Target) {
+      case GL_TEXTURE_1D:
+         if (format == GL_DEPTH_COMPONENT) {
+            return &sample_depth_texture;
+         }
+         else if (needLambda) {
+            return &sample_lambda_1d;
+         }
+         else if (t->MinFilter == GL_LINEAR) {
+            return &sample_linear_1d;
+         }
+         else {
+            ASSERT(t->MinFilter == GL_NEAREST);
+            return &sample_nearest_1d;
+         }
+      case GL_TEXTURE_2D:
+         if (format == GL_DEPTH_COMPONENT) {
+            return &sample_depth_texture;
+         }
+         else if (needLambda) {
+            return &sample_lambda_2d;
+         }
+         else if (t->MinFilter == GL_LINEAR) {
+            return &sample_linear_2d;
+         }
+         else {
+            GLint baseLevel = t->BaseLevel;
+            ASSERT(t->MinFilter == GL_NEAREST);
+            if (t->WrapS == GL_REPEAT &&
+                t->WrapT == GL_REPEAT &&
+                t->_IsPowerOfTwo &&
+                t->Image[0][baseLevel]->Border == 0 &&
+                t->Image[0][baseLevel]->TexFormat->MesaFormat == MESA_FORMAT_RGB) {
+               return &opt_sample_rgb_2d;
+            }
+            else if (t->WrapS == GL_REPEAT &&
+                     t->WrapT == GL_REPEAT &&
+                     t->_IsPowerOfTwo &&
+                     t->Image[0][baseLevel]->Border == 0 &&
+                     t->Image[0][baseLevel]->TexFormat->MesaFormat == MESA_FORMAT_RGBA) {
+               return &opt_sample_rgba_2d;
+            }
+            else {
+               return &sample_nearest_2d;
+            }
+         }
+      case GL_TEXTURE_3D:
+         if (needLambda) {
+            return &sample_lambda_3d;
+         }
+         else if (t->MinFilter == GL_LINEAR) {
+            return &sample_linear_3d;
+         }
+         else {
+            ASSERT(t->MinFilter == GL_NEAREST);
+            return &sample_nearest_3d;
+         }
+      case GL_TEXTURE_CUBE_MAP:
+         if (needLambda) {
+            return &sample_lambda_cube;
+         }
+         else if (t->MinFilter == GL_LINEAR) {
+            return &sample_linear_cube;
+         }
+         else {
+            ASSERT(t->MinFilter == GL_NEAREST);
+            return &sample_nearest_cube;
+         }
+      case GL_TEXTURE_RECTANGLE_NV:
+         if (needLambda) {
+            return &sample_lambda_rect;
+         }
+         else if (t->MinFilter == GL_LINEAR) {
+            return &sample_linear_rect;
+         }
+         else {
+            ASSERT(t->MinFilter == GL_NEAREST);
+            return &sample_nearest_rect;
+         }
+      default:
+         _mesa_problem(ctx,
+                       "invalid target in _swrast_choose_texture_sample_func");
+         return &null_sample_func;
+      }
+   }
+}
diff --git a/src/mesa/swrast/s_texfilter.h b/src/mesa/swrast/s_texfilter.h
new file mode 100644 (file)
index 0000000..e4445e7
--- /dev/null
@@ -0,0 +1,39 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  6.5
+ *
+ * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+#ifndef S_TEXFILTER_H
+#define S_TEXFILTER_H
+
+
+#include "mtypes.h"
+#include "swrast.h"
+
+
+extern texture_sample_func
+_swrast_choose_texture_sample_func( GLcontext *ctx,
+                                   const struct gl_texture_object *tObj );
+
+
+#endif
diff --git a/src/mesa/swrast/s_texture.c b/src/mesa/swrast/s_texture.c
deleted file mode 100644 (file)
index 04a4996..0000000
+++ /dev/null
@@ -1,3958 +0,0 @@
-/*
- * Mesa 3-D graphics library
- * Version:  6.5
- *
- * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included
- * in all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
- * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
- * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
- * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
- * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- */
-
-
-#include "glheader.h"
-#include "context.h"
-#include "colormac.h"
-#include "macros.h"
-#include "imports.h"
-#include "pixel.h"
-#include "texformat.h"
-#include "teximage.h"
-
-#include "s_context.h"
-#include "s_texture.h"
-
-
-/**
- * Constants for integer linear interpolation.
- */
-#define ILERP_SCALE 65536.0F
-#define ILERP_SHIFT 16
-
-
-/**
- * Linear interpolation macros
- */
-#define LERP(T, A, B)  ( (A) + (T) * ((B) - (A)) )
-#define ILERP(IT, A, B)  ( (A) + (((IT) * ((B) - (A))) >> ILERP_SHIFT) )
-
-
-/**
- * Do 2D/biliner interpolation of float values.
- * v00, v10, v01 and v11 are typically four texture samples in a square/box.
- * a and b are the horizontal and vertical interpolants.
- * It's important that this function is inlined when compiled with
- * optimization!  If we find that's not true on some systems, convert
- * to a macro.
- */
-static INLINE GLfloat
-lerp_2d(GLfloat a, GLfloat b,
-        GLfloat v00, GLfloat v10, GLfloat v01, GLfloat v11)
-{
-   const GLfloat temp0 = LERP(a, v00, v10);
-   const GLfloat temp1 = LERP(a, v01, v11);
-   return LERP(b, temp0, temp1);
-}
-
-
-/**
- * Do 2D/biliner interpolation of integer values.
- * \sa lerp_2d
- */
-static INLINE GLint
-ilerp_2d(GLint ia, GLint ib,
-         GLint v00, GLint v10, GLint v01, GLint v11)
-{
-   /* fixed point interpolants in [0, ILERP_SCALE] */
-   const GLint temp0 = ILERP(ia, v00, v10);
-   const GLint temp1 = ILERP(ia, v01, v11);
-   return ILERP(ib, temp0, temp1);
-}
-
-
-/**
- * Do 3D/trilinear interpolation of float values.
- * \sa lerp_2d
- */
-static INLINE GLfloat
-lerp_3d(GLfloat a, GLfloat b, GLfloat c,
-        GLfloat v000, GLfloat v100, GLfloat v010, GLfloat v110,
-        GLfloat v001, GLfloat v101, GLfloat v011, GLfloat v111)
-{
-   const GLfloat temp00 = LERP(a, v000, v100);
-   const GLfloat temp10 = LERP(a, v010, v110);
-   const GLfloat temp01 = LERP(a, v001, v101);
-   const GLfloat temp11 = LERP(a, v011, v111);
-   const GLfloat temp0 = LERP(b, temp00, temp10);
-   const GLfloat temp1 = LERP(b, temp01, temp11);
-   return LERP(c, temp0, temp1);
-}
-
-
-/**
- * Do 3D/trilinear interpolation of integer values.
- * \sa lerp_2d
- */
-static INLINE GLint
-ilerp_3d(GLint ia, GLint ib, GLint ic,
-         GLint v000, GLint v100, GLint v010, GLint v110,
-         GLint v001, GLint v101, GLint v011, GLint v111)
-{
-   /* fixed point interpolants in [0, ILERP_SCALE] */
-   const GLint temp00 = ILERP(ia, v000, v100);
-   const GLint temp10 = ILERP(ia, v010, v110);
-   const GLint temp01 = ILERP(ia, v001, v101);
-   const GLint temp11 = ILERP(ia, v011, v111);
-   const GLint temp0 = ILERP(ib, temp00, temp10);
-   const GLint temp1 = ILERP(ib, temp01, temp11);
-   return ILERP(ic, temp0, temp1);
-}
-
-
-
-/**
- * Compute the remainder of a divided by b, but be careful with
- * negative values so that GL_REPEAT mode works right.
- */
-static INLINE GLint
-repeat_remainder(GLint a, GLint b)
-{
-   if (a >= 0)
-      return a % b;
-   else
-      return (a + 1) % b + b - 1;
-}
-
-
-/**
- * Used to compute texel locations for linear sampling.
- * Input:
- *    wrapMode = GL_REPEAT, GL_CLAMP, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_BORDER
- *    S = texcoord in [0,1]
- *    SIZE = width (or height or depth) of texture
- * Output:
- *    U = texcoord in [0, width]
- *    I0, I1 = two nearest texel indexes
- */
-#define COMPUTE_LINEAR_TEXEL_LOCATIONS(wrapMode, S, U, SIZE, I0, I1)   \
-{                                                                      \
-   if (wrapMode == GL_REPEAT) {                                                \
-      U = S * SIZE - 0.5F;                                             \
-      if (tObj->_IsPowerOfTwo) {                                       \
-         I0 = IFLOOR(U) & (SIZE - 1);                                  \
-         I1 = (I0 + 1) & (SIZE - 1);                                   \
-      }                                                                        \
-      else {                                                           \
-         I0 = repeat_remainder(IFLOOR(U), SIZE);                       \
-         I1 = repeat_remainder(I0 + 1, SIZE);                          \
-      }                                                                        \
-   }                                                                   \
-   else if (wrapMode == GL_CLAMP_TO_EDGE) {                            \
-      if (S <= 0.0F)                                                   \
-         U = 0.0F;                                                     \
-      else if (S >= 1.0F)                                              \
-         U = (GLfloat) SIZE;                                           \
-      else                                                             \
-         U = S * SIZE;                                                 \
-      U -= 0.5F;                                                       \
-      I0 = IFLOOR(U);                                                  \
-      I1 = I0 + 1;                                                     \
-      if (I0 < 0)                                                      \
-         I0 = 0;                                                       \
-      if (I1 >= (GLint) SIZE)                                          \
-         I1 = SIZE - 1;                                                        \
-   }                                                                   \
-   else if (wrapMode == GL_CLAMP_TO_BORDER) {                          \
-      const GLfloat min = -1.0F / (2.0F * SIZE);                       \
-      const GLfloat max = 1.0F - min;                                  \
-      if (S <= min)                                                    \
-         U = min * SIZE;                                               \
-      else if (S >= max)                                               \
-         U = max * SIZE;                                               \
-      else                                                             \
-         U = S * SIZE;                                                 \
-      U -= 0.5F;                                                       \
-      I0 = IFLOOR(U);                                                  \
-      I1 = I0 + 1;                                                     \
-   }                                                                   \
-   else if (wrapMode == GL_MIRRORED_REPEAT) {                          \
-      const GLint flr = IFLOOR(S);                                     \
-      if (flr & 1)                                                     \
-         U = 1.0F - (S - (GLfloat) flr);       /* flr is odd */        \
-      else                                                             \
-         U = S - (GLfloat) flr;                /* flr is even */               \
-      U = (U * SIZE) - 0.5F;                                           \
-      I0 = IFLOOR(U);                                                  \
-      I1 = I0 + 1;                                                     \
-      if (I0 < 0)                                                      \
-         I0 = 0;                                                       \
-      if (I1 >= (GLint) SIZE)                                          \
-         I1 = SIZE - 1;                                                        \
-   }                                                                   \
-   else if (wrapMode == GL_MIRROR_CLAMP_EXT) {                         \
-      U = (GLfloat) fabs(S);                                           \
-      if (U >= 1.0F)                                                   \
-         U = (GLfloat) SIZE;                                           \
-      else                                                             \
-         U *= SIZE;                                                    \
-      U -= 0.5F;                                                       \
-      I0 = IFLOOR(U);                                                  \
-      I1 = I0 + 1;                                                     \
-   }                                                                   \
-   else if (wrapMode == GL_MIRROR_CLAMP_TO_EDGE_EXT) {                 \
-      U = (GLfloat) fabs(S);                                           \
-      if (U >= 1.0F)                                                   \
-         U = (GLfloat) SIZE;                                           \
-      else                                                             \
-         U *= SIZE;                                                    \
-      U -= 0.5F;                                                       \
-      I0 = IFLOOR(U);                                                  \
-      I1 = I0 + 1;                                                     \
-      if (I0 < 0)                                                      \
-         I0 = 0;                                                       \
-      if (I1 >= (GLint) SIZE)                                          \
-         I1 = SIZE - 1;                                                        \
-   }                                                                   \
-   else if (wrapMode == GL_MIRROR_CLAMP_TO_BORDER_EXT) {               \
-      const GLfloat min = -1.0F / (2.0F * SIZE);                       \
-      const GLfloat max = 1.0F - min;                                  \
-      U = (GLfloat) fabs(S);                                           \
-      if (U <= min)                                                    \
-         U = min * SIZE;                                               \
-      else if (U >= max)                                               \
-         U = max * SIZE;                                               \
-      else                                                             \
-         U *= SIZE;                                                    \
-      U -= 0.5F;                                                       \
-      I0 = IFLOOR(U);                                                  \
-      I1 = I0 + 1;                                                     \
-   }                                                                   \
-   else {                                                              \
-      ASSERT(wrapMode == GL_CLAMP);                                    \
-      if (S <= 0.0F)                                                   \
-         U = 0.0F;                                                     \
-      else if (S >= 1.0F)                                              \
-         U = (GLfloat) SIZE;                                           \
-      else                                                             \
-         U = S * SIZE;                                                 \
-      U -= 0.5F;                                                       \
-      I0 = IFLOOR(U);                                                  \
-      I1 = I0 + 1;                                                     \
-   }                                                                   \
-}
-
-
-/**
- * Used to compute texel location for nearest sampling.
- */
-#define COMPUTE_NEAREST_TEXEL_LOCATION(wrapMode, S, SIZE, I)           \
-{                                                                      \
-   if (wrapMode == GL_REPEAT) {                                                \
-      /* s limited to [0,1) */                                         \
-      /* i limited to [0,size-1] */                                    \
-      I = IFLOOR(S * SIZE);                                            \
-      if (tObj->_IsPowerOfTwo)                                         \
-         I &= (SIZE - 1);                                              \
-      else                                                             \
-         I = repeat_remainder(I, SIZE);                                        \
-   }                                                                   \
-   else if (wrapMode == GL_CLAMP_TO_EDGE) {                            \
-      /* s limited to [min,max] */                                     \
-      /* i limited to [0, size-1] */                                   \
-      const GLfloat min = 1.0F / (2.0F * SIZE);                                \
-      const GLfloat max = 1.0F - min;                                  \
-      if (S < min)                                                     \
-         I = 0;                                                                \
-      else if (S > max)                                                        \
-         I = SIZE - 1;                                                 \
-      else                                                             \
-         I = IFLOOR(S * SIZE);                                         \
-   }                                                                   \
-   else if (wrapMode == GL_CLAMP_TO_BORDER) {                          \
-      /* s limited to [min,max] */                                     \
-      /* i limited to [-1, size] */                                    \
-      const GLfloat min = -1.0F / (2.0F * SIZE);                       \
-      const GLfloat max = 1.0F - min;                                  \
-      if (S <= min)                                                    \
-         I = -1;                                                       \
-      else if (S >= max)                                               \
-         I = SIZE;                                                     \
-      else                                                             \
-         I = IFLOOR(S * SIZE);                                         \
-   }                                                                   \
-   else if (wrapMode == GL_MIRRORED_REPEAT) {                          \
-      const GLfloat min = 1.0F / (2.0F * SIZE);                                \
-      const GLfloat max = 1.0F - min;                                  \
-      const GLint flr = IFLOOR(S);                                     \
-      GLfloat u;                                                       \
-      if (flr & 1)                                                     \
-         u = 1.0F - (S - (GLfloat) flr);       /* flr is odd */        \
-      else                                                             \
-         u = S - (GLfloat) flr;                /* flr is even */               \
-      if (u < min)                                                     \
-         I = 0;                                                                \
-      else if (u > max)                                                        \
-         I = SIZE - 1;                                                 \
-      else                                                             \
-         I = IFLOOR(u * SIZE);                                         \
-   }                                                                   \
-   else if (wrapMode == GL_MIRROR_CLAMP_EXT) {                         \
-      /* s limited to [0,1] */                                         \
-      /* i limited to [0,size-1] */                                    \
-      const GLfloat u = (GLfloat) fabs(S);                             \
-      if (u <= 0.0F)                                                   \
-         I = 0;                                                                \
-      else if (u >= 1.0F)                                              \
-         I = SIZE - 1;                                                 \
-      else                                                             \
-         I = IFLOOR(u * SIZE);                                         \
-   }                                                                   \
-   else if (wrapMode == GL_MIRROR_CLAMP_TO_EDGE_EXT) {                 \
-      /* s limited to [min,max] */                                     \
-      /* i limited to [0, size-1] */                                   \
-      const GLfloat min = 1.0F / (2.0F * SIZE);                                \
-      const GLfloat max = 1.0F - min;                                  \
-      const GLfloat u = (GLfloat) fabs(S);                             \
-      if (u < min)                                                     \
-         I = 0;                                                                \
-      else if (u > max)                                                        \
-         I = SIZE - 1;                                                 \
-      else                                                             \
-         I = IFLOOR(u * SIZE);                                         \
-   }                                                                   \
-   else if (wrapMode == GL_MIRROR_CLAMP_TO_BORDER_EXT) {               \
-      /* s limited to [min,max] */                                     \
-      /* i limited to [0, size-1] */                                   \
-      const GLfloat min = -1.0F / (2.0F * SIZE);                       \
-      const GLfloat max = 1.0F - min;                                  \
-      const GLfloat u = (GLfloat) fabs(S);                             \
-      if (u < min)                                                     \
-         I = -1;                                                       \
-      else if (u > max)                                                        \
-         I = SIZE;                                                     \
-      else                                                             \
-         I = IFLOOR(u * SIZE);                                         \
-   }                                                                   \
-   else {                                                              \
-      ASSERT(wrapMode == GL_CLAMP);                                    \
-      /* s limited to [0,1] */                                         \
-      /* i limited to [0,size-1] */                                    \
-      if (S <= 0.0F)                                                   \
-         I = 0;                                                                \
-      else if (S >= 1.0F)                                              \
-         I = SIZE - 1;                                                 \
-      else                                                             \
-         I = IFLOOR(S * SIZE);                                         \
-   }                                                                   \
-}
-
-
-/* Power of two image sizes only */
-#define COMPUTE_LINEAR_REPEAT_TEXEL_LOCATION(S, U, SIZE, I0, I1)       \
-{                                                                      \
-   U = S * SIZE - 0.5F;                                                        \
-   I0 = IFLOOR(U) & (SIZE - 1);                                                \
-   I1 = (I0 + 1) & (SIZE - 1);                                         \
-}
-
-
-/*
- * Compute linear mipmap levels for given lambda.
- */
-#define COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda, level)       \
-{                                                              \
-   if (lambda < 0.0F)                                          \
-      level = tObj->BaseLevel;                                 \
-   else if (lambda > tObj->_MaxLambda)                         \
-      level = (GLint) (tObj->BaseLevel + tObj->_MaxLambda);    \
-   else                                                                \
-      level = (GLint) (tObj->BaseLevel + lambda);              \
-}
-
-
-/*
- * Compute nearest mipmap level for given lambda.
- */
-#define COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda, level)      \
-{                                                              \
-   GLfloat l;                                                  \
-   if (lambda <= 0.5F)                                         \
-      l = 0.0F;                                                        \
-   else if (lambda > tObj->_MaxLambda + 0.4999F)               \
-      l = tObj->_MaxLambda + 0.4999F;                          \
-   else                                                                \
-      l = lambda;                                              \
-   level = (GLint) (tObj->BaseLevel + l + 0.5F);               \
-   if (level > tObj->_MaxLevel)                                        \
-      level = tObj->_MaxLevel;                                 \
-}
-
-
-
-/*
- * Note, the FRAC macro has to work perfectly.  Otherwise you'll sometimes
- * see 1-pixel bands of improperly weighted linear-sampled texels.  The
- * tests/texwrap.c demo is a good test.
- * Also note, FRAC(x) doesn't truly return the fractional part of x for x < 0.
- * Instead, if x < 0 then FRAC(x) = 1 - true_frac(x).
- */
-#define FRAC(f)  ((f) - IFLOOR(f))
-
-
-
-/*
- * Bitflags for texture border color sampling.
- */
-#define I0BIT   1
-#define I1BIT   2
-#define J0BIT   4
-#define J1BIT   8
-#define K0BIT  16
-#define K1BIT  32
-
-
-
-/*
- * The lambda[] array values are always monotonic.  Either the whole span
- * will be minified, magnified, or split between the two.  This function
- * determines the subranges in [0, n-1] that are to be minified or magnified.
- */
-static INLINE void
-compute_min_mag_ranges( GLfloat minMagThresh, GLuint n, const GLfloat lambda[],
-                        GLuint *minStart, GLuint *minEnd,
-                        GLuint *magStart, GLuint *magEnd )
-{
-   ASSERT(lambda != NULL);
-#if 0
-   /* Verify that lambda[] is monotonous.
-    * We can't really use this because the inaccuracy in the LOG2 function
-    * causes this test to fail, yet the resulting texturing is correct.
-    */
-   if (n > 1) {
-      GLuint i;
-      printf("lambda delta = %g\n", lambda[0] - lambda[n-1]);
-      if (lambda[0] >= lambda[n-1]) { /* decreasing */
-         for (i = 0; i < n - 1; i++) {
-            ASSERT((GLint) (lambda[i] * 10) >= (GLint) (lambda[i+1] * 10));
-         }
-      }
-      else { /* increasing */
-         for (i = 0; i < n - 1; i++) {
-            ASSERT((GLint) (lambda[i] * 10) <= (GLint) (lambda[i+1] * 10));
-         }
-      }
-   }
-#endif /* DEBUG */
-
-   /* since lambda is monotonous-array use this check first */
-   if (lambda[0] <= minMagThresh && lambda[n-1] <= minMagThresh) {
-      /* magnification for whole span */
-      *magStart = 0;
-      *magEnd = n;
-      *minStart = *minEnd = 0;
-   }
-   else if (lambda[0] > minMagThresh && lambda[n-1] > minMagThresh) {
-      /* minification for whole span */
-      *minStart = 0;
-      *minEnd = n;
-      *magStart = *magEnd = 0;
-   }
-   else {
-      /* a mix of minification and magnification */
-      GLuint i;
-      if (lambda[0] > minMagThresh) {
-         /* start with minification */
-         for (i = 1; i < n; i++) {
-            if (lambda[i] <= minMagThresh)
-               break;
-         }
-         *minStart = 0;
-         *minEnd = i;
-         *magStart = i;
-         *magEnd = n;
-      }
-      else {
-         /* start with magnification */
-         for (i = 1; i < n; i++) {
-            if (lambda[i] > minMagThresh)
-               break;
-         }
-         *magStart = 0;
-         *magEnd = i;
-         *minStart = i;
-         *minEnd = n;
-      }
-   }
-
-#if 0
-   /* Verify the min/mag Start/End values
-    * We don't use this either (see above)
-    */
-   {
-      GLint i;
-      for (i = 0; i < n; i++) {
-         if (lambda[i] > minMagThresh) {
-            /* minification */
-            ASSERT(i >= *minStart);
-            ASSERT(i < *minEnd);
-         }
-         else {
-            /* magnification */
-            ASSERT(i >= *magStart);
-            ASSERT(i < *magEnd);
-         }
-      }
-   }
-#endif
-}
-
-
-/**********************************************************************/
-/*                    1-D Texture Sampling Functions                  */
-/**********************************************************************/
-
-/*
- * Return the texture sample for coordinate (s) using GL_NEAREST filter.
- */
-static void
-sample_1d_nearest(GLcontext *ctx,
-                  const struct gl_texture_object *tObj,
-                  const struct gl_texture_image *img,
-                  const GLfloat texcoord[4], GLchan rgba[4])
-{
-   const GLint width = img->Width2;  /* without border, power of two */
-   GLint i;
-   (void) ctx;
-
-   COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapS, texcoord[0], width, i);
-
-   /* skip over the border, if any */
-   i += img->Border;
-
-   if (i < 0 || i >= (GLint) img->Width) {
-      /* Need this test for GL_CLAMP_TO_BORDER mode */
-      COPY_CHAN4(rgba, tObj->_BorderChan);
-   }
-   else {
-      img->FetchTexelc(img, i, 0, 0, rgba);
-   }
-}
-
-
-
-/*
- * Return the texture sample for coordinate (s) using GL_LINEAR filter.
- */
-static void
-sample_1d_linear(GLcontext *ctx,
-                 const struct gl_texture_object *tObj,
-                 const struct gl_texture_image *img,
-                 const GLfloat texcoord[4], GLchan rgba[4])
-{
-   const GLint width = img->Width2;
-   GLint i0, i1;
-   GLfloat u;
-   GLuint useBorderColor;
-   (void) ctx;
-
-   COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapS, texcoord[0], u, width, i0, i1);
-
-   useBorderColor = 0;
-   if (img->Border) {
-      i0 += img->Border;
-      i1 += img->Border;
-   }
-   else {
-      if (i0 < 0 || i0 >= width)   useBorderColor |= I0BIT;
-      if (i1 < 0 || i1 >= width)   useBorderColor |= I1BIT;
-   }
-
-   {
-      const GLfloat a = FRAC(u);
-      GLchan t0[4], t1[4];  /* texels */
-
-      /* fetch texel colors */
-      if (useBorderColor & I0BIT) {
-         COPY_CHAN4(t0, tObj->_BorderChan);
-      }
-      else {
-         img->FetchTexelc(img, i0, 0, 0, t0);
-      }
-      if (useBorderColor & I1BIT) {
-         COPY_CHAN4(t1, tObj->_BorderChan);
-      }
-      else {
-         img->FetchTexelc(img, i1, 0, 0, t1);
-      }
-
-      /* do linear interpolation of texel colors */
-#if CHAN_TYPE == GL_FLOAT
-      rgba[0] = LERP(a, t0[0], t1[0]);
-      rgba[1] = LERP(a, t0[1], t1[1]);
-      rgba[2] = LERP(a, t0[2], t1[2]);
-      rgba[3] = LERP(a, t0[3], t1[3]);
-#elif CHAN_TYPE == GL_UNSIGNED_SHORT
-      rgba[0] = (GLchan) (LERP(a, t0[0], t1[0]) + 0.5);
-      rgba[1] = (GLchan) (LERP(a, t0[1], t1[1]) + 0.5);
-      rgba[2] = (GLchan) (LERP(a, t0[2], t1[2]) + 0.5);
-      rgba[3] = (GLchan) (LERP(a, t0[3], t1[3]) + 0.5);
-#else
-      ASSERT(CHAN_TYPE == GL_UNSIGNED_BYTE);
-      {
-         /* fixed point interpolants in [0, ILERP_SCALE] */
-         const GLint ia = IROUND_POS(a * ILERP_SCALE);
-         rgba[0] = ILERP(ia, t0[0], t1[0]);
-         rgba[1] = ILERP(ia, t0[1], t1[1]);
-         rgba[2] = ILERP(ia, t0[2], t1[2]);
-         rgba[3] = ILERP(ia, t0[3], t1[3]);
-      }
-#endif
-   }
-}
-
-
-static void
-sample_1d_nearest_mipmap_nearest(GLcontext *ctx,
-                                 const struct gl_texture_object *tObj,
-                                 GLuint n, const GLfloat texcoord[][4],
-                                 const GLfloat lambda[], GLchan rgba[][4])
-{
-   GLuint i;
-   ASSERT(lambda != NULL);
-   for (i = 0; i < n; i++) {
-      GLint level;
-      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
-      sample_1d_nearest(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]);
-   }
-}
-
-
-static void
-sample_1d_linear_mipmap_nearest(GLcontext *ctx,
-                                const struct gl_texture_object *tObj,
-                                GLuint n, const GLfloat texcoord[][4],
-                                const GLfloat lambda[], GLchan rgba[][4])
-{
-   GLuint i;
-   ASSERT(lambda != NULL);
-   for (i = 0; i < n; i++) {
-      GLint level;
-      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
-      sample_1d_linear(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]);
-   }
-}
-
-
-
-/*
- * This is really just needed in order to prevent warnings with some compilers.
- */
-#if CHAN_TYPE == GL_FLOAT
-#define CHAN_CAST
-#else
-#define CHAN_CAST (GLchan) (GLint)
-#endif
-
-
-static void
-sample_1d_nearest_mipmap_linear(GLcontext *ctx,
-                                const struct gl_texture_object *tObj,
-                                GLuint n, const GLfloat texcoord[][4],
-                                const GLfloat lambda[], GLchan rgba[][4])
-{
-   GLuint i;
-   ASSERT(lambda != NULL);
-   for (i = 0; i < n; i++) {
-      GLint level;
-      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
-      if (level >= tObj->_MaxLevel) {
-         sample_1d_nearest(ctx, tObj, tObj->Image[0][tObj->_MaxLevel],
-                           texcoord[i], rgba[i]);
-      }
-      else {
-         GLchan t0[4], t1[4];
-         const GLfloat f = FRAC(lambda[i]);
-         sample_1d_nearest(ctx, tObj, tObj->Image[0][level  ], texcoord[i], t0);
-         sample_1d_nearest(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1);
-         rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
-         rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
-         rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
-         rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
-      }
-   }
-}
-
-
-
-static void
-sample_1d_linear_mipmap_linear(GLcontext *ctx,
-                               const struct gl_texture_object *tObj,
-                               GLuint n, const GLfloat texcoord[][4],
-                               const GLfloat lambda[], GLchan rgba[][4])
-{
-   GLuint i;
-   ASSERT(lambda != NULL);
-   for (i = 0; i < n; i++) {
-      GLint level;
-      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
-      if (level >= tObj->_MaxLevel) {
-         sample_1d_linear(ctx, tObj, tObj->Image[0][tObj->_MaxLevel],
-                          texcoord[i], rgba[i]);
-      }
-      else {
-         GLchan t0[4], t1[4];
-         const GLfloat f = FRAC(lambda[i]);
-         sample_1d_linear(ctx, tObj, tObj->Image[0][level  ], texcoord[i], t0);
-         sample_1d_linear(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1);
-         rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
-         rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
-         rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
-         rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
-      }
-   }
-}
-
-
-
-static void
-sample_nearest_1d( GLcontext *ctx, GLuint texUnit,
-                   const struct gl_texture_object *tObj, GLuint n,
-                   const GLfloat texcoords[][4], const GLfloat lambda[],
-                   GLchan rgba[][4] )
-{
-   GLuint i;
-   struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel];
-   (void) texUnit;
-   (void) lambda;
-   for (i=0;i<n;i++) {
-      sample_1d_nearest(ctx, tObj, image, texcoords[i], rgba[i]);
-   }
-}
-
-
-
-static void
-sample_linear_1d( GLcontext *ctx, GLuint texUnit,
-                  const struct gl_texture_object *tObj, GLuint n,
-                  const GLfloat texcoords[][4], const GLfloat lambda[],
-                  GLchan rgba[][4] )
-{
-   GLuint i;
-   struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel];
-   (void) texUnit;
-   (void) lambda;
-   for (i=0;i<n;i++) {
-      sample_1d_linear(ctx, tObj, image, texcoords[i], rgba[i]);
-   }
-}
-
-
-/*
- * Given an (s) texture coordinate and lambda (level of detail) value,
- * return a texture sample.
- *
- */
-static void
-sample_lambda_1d( GLcontext *ctx, GLuint texUnit,
-                  const struct gl_texture_object *tObj, GLuint n,
-                  const GLfloat texcoords[][4],
-                  const GLfloat lambda[], GLchan rgba[][4] )
-{
-   GLuint minStart, minEnd;  /* texels with minification */
-   GLuint magStart, magEnd;  /* texels with magnification */
-   GLuint i;
-
-   ASSERT(lambda != NULL);
-   compute_min_mag_ranges(SWRAST_CONTEXT(ctx)->_MinMagThresh[texUnit],
-                          n, lambda, &minStart, &minEnd, &magStart, &magEnd);
-
-   if (minStart < minEnd) {
-      /* do the minified texels */
-      const GLuint m = minEnd - minStart;
-      switch (tObj->MinFilter) {
-      case GL_NEAREST:
-         for (i = minStart; i < minEnd; i++)
-            sample_1d_nearest(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
-                              texcoords[i], rgba[i]);
-         break;
-      case GL_LINEAR:
-         for (i = minStart; i < minEnd; i++)
-            sample_1d_linear(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
-                             texcoords[i], rgba[i]);
-         break;
-      case GL_NEAREST_MIPMAP_NEAREST:
-         sample_1d_nearest_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
-                                          lambda + minStart, rgba + minStart);
-         break;
-      case GL_LINEAR_MIPMAP_NEAREST:
-         sample_1d_linear_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
-                                         lambda + minStart, rgba + minStart);
-         break;
-      case GL_NEAREST_MIPMAP_LINEAR:
-         sample_1d_nearest_mipmap_linear(ctx, tObj, m, texcoords + minStart,
-                                         lambda + minStart, rgba + minStart);
-         break;
-      case GL_LINEAR_MIPMAP_LINEAR:
-         sample_1d_linear_mipmap_linear(ctx, tObj, m, texcoords + minStart,
-                                        lambda + minStart, rgba + minStart);
-         break;
-      default:
-         _mesa_problem(ctx, "Bad min filter in sample_1d_texture");
-         return;
-      }
-   }
-
-   if (magStart < magEnd) {
-      /* do the magnified texels */
-      switch (tObj->MagFilter) {
-      case GL_NEAREST:
-         for (i = magStart; i < magEnd; i++)
-            sample_1d_nearest(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
-                              texcoords[i], rgba[i]);
-         break;
-      case GL_LINEAR:
-         for (i = magStart; i < magEnd; i++)
-            sample_1d_linear(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
-                             texcoords[i], rgba[i]);
-         break;
-      default:
-         _mesa_problem(ctx, "Bad mag filter in sample_1d_texture");
-         return;
-      }
-   }
-}
-
-
-/**********************************************************************/
-/*                    2-D Texture Sampling Functions                  */
-/**********************************************************************/
-
-
-/*
- * Return the texture sample for coordinate (s,t) using GL_NEAREST filter.
- */
-static INLINE void
-sample_2d_nearest(GLcontext *ctx,
-                  const struct gl_texture_object *tObj,
-                  const struct gl_texture_image *img,
-                  const GLfloat texcoord[4],
-                  GLchan rgba[])
-{
-   const GLint width = img->Width2;    /* without border, power of two */
-   const GLint height = img->Height2;  /* without border, power of two */
-   GLint i, j;
-   (void) ctx;
-
-   COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapS, texcoord[0], width,  i);
-   COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapT, texcoord[1], height, j);
-
-   /* skip over the border, if any */
-   i += img->Border;
-   j += img->Border;
-
-   if (i < 0 || i >= (GLint) img->Width || j < 0 || j >= (GLint) img->Height) {
-      /* Need this test for GL_CLAMP_TO_BORDER mode */
-      COPY_CHAN4(rgba, tObj->_BorderChan);
-   }
-   else {
-      img->FetchTexelc(img, i, j, 0, rgba);
-   }
-}
-
-
-
-/**
- * Return the texture sample for coordinate (s,t) using GL_LINEAR filter.
- * New sampling code contributed by Lynn Quam <quam@ai.sri.com>.
- */
-static INLINE void
-sample_2d_linear(GLcontext *ctx,
-                 const struct gl_texture_object *tObj,
-                 const struct gl_texture_image *img,
-                 const GLfloat texcoord[4],
-                 GLchan rgba[])
-{
-   const GLint width = img->Width2;
-   const GLint height = img->Height2;
-   GLint i0, j0, i1, j1;
-   GLuint useBorderColor;
-   GLfloat u, v;
-   (void) ctx;
-
-   COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapS, texcoord[0], u, width,  i0, i1);
-   COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapT, texcoord[1], v, height, j0, j1);
-
-   useBorderColor = 0;
-   if (img->Border) {
-      i0 += img->Border;
-      i1 += img->Border;
-      j0 += img->Border;
-      j1 += img->Border;
-   }
-   else {
-      if (i0 < 0 || i0 >= width)   useBorderColor |= I0BIT;
-      if (i1 < 0 || i1 >= width)   useBorderColor |= I1BIT;
-      if (j0 < 0 || j0 >= height)  useBorderColor |= J0BIT;
-      if (j1 < 0 || j1 >= height)  useBorderColor |= J1BIT;
-   }
-
-   {
-      const GLfloat a = FRAC(u);
-      const GLfloat b = FRAC(v);
-#if CHAN_TYPE == GL_UNSIGNED_BYTE
-      const GLint ia = IROUND_POS(a * ILERP_SCALE);
-      const GLint ib = IROUND_POS(b * ILERP_SCALE);
-#endif
-      GLchan t00[4], t10[4], t01[4], t11[4]; /* sampled texel colors */
-
-      /* fetch four texel colors */
-      if (useBorderColor & (I0BIT | J0BIT)) {
-         COPY_CHAN4(t00, tObj->_BorderChan);
-      }
-      else {
-         img->FetchTexelc(img, i0, j0, 0, t00);
-      }
-      if (useBorderColor & (I1BIT | J0BIT)) {
-         COPY_CHAN4(t10, tObj->_BorderChan);
-      }
-      else {
-         img->FetchTexelc(img, i1, j0, 0, t10);
-      }
-      if (useBorderColor & (I0BIT | J1BIT)) {
-         COPY_CHAN4(t01, tObj->_BorderChan);
-      }
-      else {
-         img->FetchTexelc(img, i0, j1, 0, t01);
-      }
-      if (useBorderColor & (I1BIT | J1BIT)) {
-         COPY_CHAN4(t11, tObj->_BorderChan);
-      }
-      else {
-         img->FetchTexelc(img, i1, j1, 0, t11);
-      }
-
-      /* do bilinear interpolation of texel colors */
-#if CHAN_TYPE == GL_FLOAT
-      rgba[0] = lerp_2d(a, b, t00[0], t10[0], t01[0], t11[0]);
-      rgba[1] = lerp_2d(a, b, t00[1], t10[1], t01[1], t11[1]);
-      rgba[2] = lerp_2d(a, b, t00[2], t10[2], t01[2], t11[2]);
-      rgba[3] = lerp_2d(a, b, t00[3], t10[3], t01[3], t11[3]);
-#elif CHAN_TYPE == GL_UNSIGNED_SHORT
-      rgba[0] = (GLchan) (lerp_2d(a, b, t00[0], t10[0], t01[0], t11[0]) + 0.5);
-      rgba[1] = (GLchan) (lerp_2d(a, b, t00[1], t10[1], t01[1], t11[1]) + 0.5);
-      rgba[2] = (GLchan) (lerp_2d(a, b, t00[2], t10[2], t01[2], t11[2]) + 0.5);
-      rgba[3] = (GLchan) (lerp_2d(a, b, t00[3], t10[3], t01[3], t11[3]) + 0.5);
-#else
-      ASSERT(CHAN_TYPE == GL_UNSIGNED_BYTE);
-      rgba[0] = ilerp_2d(ia, ib, t00[0], t10[0], t01[0], t11[0]);
-      rgba[1] = ilerp_2d(ia, ib, t00[1], t10[1], t01[1], t11[1]);
-      rgba[2] = ilerp_2d(ia, ib, t00[2], t10[2], t01[2], t11[2]);
-      rgba[3] = ilerp_2d(ia, ib, t00[3], t10[3], t01[3], t11[3]);
-#endif
-   }
-}
-
-
-/*
- * As above, but we know WRAP_S == REPEAT and WRAP_T == REPEAT.
- */
-static INLINE void
-sample_2d_linear_repeat(GLcontext *ctx,
-                        const struct gl_texture_object *tObj,
-                        const struct gl_texture_image *img,
-                        const GLfloat texcoord[4],
-                        GLchan rgba[])
-{
-   const GLint width = img->Width2;
-   const GLint height = img->Height2;
-   GLint i0, j0, i1, j1;
-   GLfloat u, v;
-   (void) ctx;
-   (void) tObj;
-   
-   ASSERT(tObj->WrapS == GL_REPEAT);
-   ASSERT(tObj->WrapT == GL_REPEAT);
-   ASSERT(img->Border == 0);
-   ASSERT(img->Format != GL_COLOR_INDEX);
-   ASSERT(img->_IsPowerOfTwo);
-
-   COMPUTE_LINEAR_REPEAT_TEXEL_LOCATION(texcoord[0], u, width,  i0, i1);
-   COMPUTE_LINEAR_REPEAT_TEXEL_LOCATION(texcoord[1], v, height, j0, j1);
-
-   {
-      const GLfloat a = FRAC(u);
-      const GLfloat b = FRAC(v);
-#if CHAN_TYPE == GL_UNSIGNED_BYTE
-      const GLint ia = IROUND_POS(a * ILERP_SCALE);
-      const GLint ib = IROUND_POS(b * ILERP_SCALE);
-#endif
-      GLchan t00[4], t10[4], t01[4], t11[4]; /* sampled texel colors */
-
-      img->FetchTexelc(img, i0, j0, 0, t00);
-      img->FetchTexelc(img, i1, j0, 0, t10);
-      img->FetchTexelc(img, i0, j1, 0, t01);
-      img->FetchTexelc(img, i1, j1, 0, t11);
-
-      /* do bilinear interpolation of texel colors */
-#if CHAN_TYPE == GL_FLOAT
-      rgba[0] = lerp_2d(a, b, t00[0], t10[0], t01[0], t11[0]);
-      rgba[1] = lerp_2d(a, b, t00[1], t10[1], t01[1], t11[1]);
-      rgba[2] = lerp_2d(a, b, t00[2], t10[2], t01[2], t11[2]);
-      rgba[3] = lerp_2d(a, b, t00[3], t10[3], t01[3], t11[3]);
-#elif CHAN_TYPE == GL_UNSIGNED_SHORT
-      rgba[0] = (GLchan) (lerp_2d(a, b, t00[0], t10[0], t01[0], t11[0]) + 0.5);
-      rgba[1] = (GLchan) (lerp_2d(a, b, t00[1], t10[1], t01[1], t11[1]) + 0.5);
-      rgba[2] = (GLchan) (lerp_2d(a, b, t00[2], t10[2], t01[2], t11[2]) + 0.5);
-      rgba[3] = (GLchan) (lerp_2d(a, b, t00[3], t10[3], t01[3], t11[3]) + 0.5);
-#else
-      ASSERT(CHAN_TYPE == GL_UNSIGNED_BYTE);
-      rgba[0] = ilerp_2d(ia, ib, t00[0], t10[0], t01[0], t11[0]);
-      rgba[1] = ilerp_2d(ia, ib, t00[1], t10[1], t01[1], t11[1]);
-      rgba[2] = ilerp_2d(ia, ib, t00[2], t10[2], t01[2], t11[2]);
-      rgba[3] = ilerp_2d(ia, ib, t00[3], t10[3], t01[3], t11[3]);
-#endif
-   }
-}
-
-
-
-static void
-sample_2d_nearest_mipmap_nearest(GLcontext *ctx,
-                                 const struct gl_texture_object *tObj,
-                                 GLuint n, const GLfloat texcoord[][4],
-                                 const GLfloat lambda[], GLchan rgba[][4])
-{
-   GLuint i;
-   for (i = 0; i < n; i++) {
-      GLint level;
-      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
-      sample_2d_nearest(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]);
-   }
-}
-
-
-
-static void
-sample_2d_linear_mipmap_nearest(GLcontext *ctx,
-                                const struct gl_texture_object *tObj,
-                                GLuint n, const GLfloat texcoord[][4],
-                                const GLfloat lambda[], GLchan rgba[][4])
-{
-   GLuint i;
-   ASSERT(lambda != NULL);
-   for (i = 0; i < n; i++) {
-      GLint level;
-      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
-      sample_2d_linear(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]);
-   }
-}
-
-
-
-static void
-sample_2d_nearest_mipmap_linear(GLcontext *ctx,
-                                const struct gl_texture_object *tObj,
-                                GLuint n, const GLfloat texcoord[][4],
-                                const GLfloat lambda[], GLchan rgba[][4])
-{
-   GLuint i;
-   ASSERT(lambda != NULL);
-   for (i = 0; i < n; i++) {
-      GLint level;
-      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
-      if (level >= tObj->_MaxLevel) {
-         sample_2d_nearest(ctx, tObj, tObj->Image[0][tObj->_MaxLevel],
-                           texcoord[i], rgba[i]);
-      }
-      else {
-         GLchan t0[4], t1[4];  /* texels */
-         const GLfloat f = FRAC(lambda[i]);
-         sample_2d_nearest(ctx, tObj, tObj->Image[0][level  ], texcoord[i], t0);
-         sample_2d_nearest(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1);
-         rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
-         rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
-         rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
-         rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
-      }
-   }
-}
-
-
-
-/* Trilinear filtering */
-static void
-sample_2d_linear_mipmap_linear( GLcontext *ctx,
-                                const struct gl_texture_object *tObj,
-                                GLuint n, const GLfloat texcoord[][4],
-                                const GLfloat lambda[], GLchan rgba[][4] )
-{
-   GLuint i;
-   ASSERT(lambda != NULL);
-   for (i = 0; i < n; i++) {
-      GLint level;
-      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
-      if (level >= tObj->_MaxLevel) {
-         sample_2d_linear(ctx, tObj, tObj->Image[0][tObj->_MaxLevel],
-                          texcoord[i], rgba[i]);
-      }
-      else {
-         GLchan t0[4], t1[4];  /* texels */
-         const GLfloat f = FRAC(lambda[i]);
-         sample_2d_linear(ctx, tObj, tObj->Image[0][level  ], texcoord[i], t0);
-         sample_2d_linear(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1);
-         rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
-         rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
-         rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
-         rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
-      }
-   }
-}
-
-
-static void
-sample_2d_linear_mipmap_linear_repeat( GLcontext *ctx,
-                                       const struct gl_texture_object *tObj,
-                                       GLuint n, const GLfloat texcoord[][4],
-                                       const GLfloat lambda[], GLchan rgba[][4] )
-{
-   GLuint i;
-   ASSERT(lambda != NULL);
-   ASSERT(tObj->WrapS == GL_REPEAT);
-   ASSERT(tObj->WrapT == GL_REPEAT);
-   ASSERT(tObj->_IsPowerOfTwo);
-   for (i = 0; i < n; i++) {
-      GLint level;
-      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
-      if (level >= tObj->_MaxLevel) {
-         sample_2d_linear_repeat(ctx, tObj, tObj->Image[0][tObj->_MaxLevel],
-                                 texcoord[i], rgba[i]);
-      }
-      else {
-         GLchan t0[4], t1[4];  /* texels */
-         const GLfloat f = FRAC(lambda[i]);
-         sample_2d_linear_repeat(ctx, tObj, tObj->Image[0][level  ], texcoord[i], t0);
-         sample_2d_linear_repeat(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1);
-         rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
-         rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
-         rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
-         rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
-      }
-   }
-}
-
-
-static void
-sample_nearest_2d( GLcontext *ctx, GLuint texUnit,
-                   const struct gl_texture_object *tObj, GLuint n,
-                   const GLfloat texcoords[][4],
-                   const GLfloat lambda[], GLchan rgba[][4] )
-{
-   GLuint i;
-   struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel];
-   (void) texUnit;
-   (void) lambda;
-   for (i=0;i<n;i++) {
-      sample_2d_nearest(ctx, tObj, image, texcoords[i], rgba[i]);
-   }
-}
-
-
-
-static void
-sample_linear_2d( GLcontext *ctx, GLuint texUnit,
-                  const struct gl_texture_object *tObj, GLuint n,
-                  const GLfloat texcoords[][4],
-                  const GLfloat lambda[], GLchan rgba[][4] )
-{
-   GLuint i;
-   struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel];
-   (void) texUnit;
-   (void) lambda;
-   if (tObj->WrapS == GL_REPEAT && tObj->WrapT == GL_REPEAT
-       && image->Border == 0) {
-      for (i=0;i<n;i++) {
-         sample_2d_linear_repeat(ctx, tObj, image, texcoords[i], rgba[i]);
-      }
-   }
-   else {
-      for (i=0;i<n;i++) {
-         sample_2d_linear(ctx, tObj, image, texcoords[i], rgba[i]);
-      }
-   }
-}
-
-
-/*
- * Optimized 2-D texture sampling:
- *    S and T wrap mode == GL_REPEAT
- *    GL_NEAREST min/mag filter
- *    No border, 
- *    RowStride == Width,
- *    Format = GL_RGB
- */
-static void
-opt_sample_rgb_2d( GLcontext *ctx, GLuint texUnit,
-                   const struct gl_texture_object *tObj,
-                   GLuint n, const GLfloat texcoords[][4],
-                   const GLfloat lambda[], GLchan rgba[][4] )
-{
-   const struct gl_texture_image *img = tObj->Image[0][tObj->BaseLevel];
-   const GLfloat width = (GLfloat) img->Width;
-   const GLfloat height = (GLfloat) img->Height;
-   const GLint colMask = img->Width - 1;
-   const GLint rowMask = img->Height - 1;
-   const GLint shift = img->WidthLog2;
-   GLuint k;
-   (void) ctx;
-   (void) texUnit;
-   (void) lambda;
-   ASSERT(tObj->WrapS==GL_REPEAT);
-   ASSERT(tObj->WrapT==GL_REPEAT);
-   ASSERT(img->Border==0);
-   ASSERT(img->Format==GL_RGB);
-   ASSERT(img->_IsPowerOfTwo);
-
-   for (k=0; k<n; k++) {
-      GLint i = IFLOOR(texcoords[k][0] * width) & colMask;
-      GLint j = IFLOOR(texcoords[k][1] * height) & rowMask;
-      GLint pos = (j << shift) | i;
-      GLchan *texel = ((GLchan *) img->Data) + 3*pos;
-      rgba[k][RCOMP] = texel[0];
-      rgba[k][GCOMP] = texel[1];
-      rgba[k][BCOMP] = texel[2];
-   }
-}
-
-
-/*
- * Optimized 2-D texture sampling:
- *    S and T wrap mode == GL_REPEAT
- *    GL_NEAREST min/mag filter
- *    No border
- *    RowStride == Width,
- *    Format = GL_RGBA
- */
-static void
-opt_sample_rgba_2d( GLcontext *ctx, GLuint texUnit,
-                    const struct gl_texture_object *tObj,
-                    GLuint n, const GLfloat texcoords[][4],
-                    const GLfloat lambda[], GLchan rgba[][4] )
-{
-   const struct gl_texture_image *img = tObj->Image[0][tObj->BaseLevel];
-   const GLfloat width = (GLfloat) img->Width;
-   const GLfloat height = (GLfloat) img->Height;
-   const GLint colMask = img->Width - 1;
-   const GLint rowMask = img->Height - 1;
-   const GLint shift = img->WidthLog2;
-   GLuint i;
-   (void) ctx;
-   (void) texUnit;
-   (void) lambda;
-   ASSERT(tObj->WrapS==GL_REPEAT);
-   ASSERT(tObj->WrapT==GL_REPEAT);
-   ASSERT(img->Border==0);
-   ASSERT(img->Format==GL_RGBA);
-   ASSERT(img->_IsPowerOfTwo);
-
-   for (i = 0; i < n; i++) {
-      const GLint col = IFLOOR(texcoords[i][0] * width) & colMask;
-      const GLint row = IFLOOR(texcoords[i][1] * height) & rowMask;
-      const GLint pos = (row << shift) | col;
-      const GLchan *texel = ((GLchan *) img->Data) + (pos << 2);    /* pos*4 */
-      COPY_CHAN4(rgba[i], texel);
-   }
-}
-
-
-/*
- * Given an array of texture coordinate and lambda (level of detail)
- * values, return an array of texture sample.
- */
-static void
-sample_lambda_2d( GLcontext *ctx, GLuint texUnit,
-                  const struct gl_texture_object *tObj,
-                  GLuint n, const GLfloat texcoords[][4],
-                  const GLfloat lambda[], GLchan rgba[][4] )
-{
-   const struct gl_texture_image *tImg = tObj->Image[0][tObj->BaseLevel];
-   GLuint minStart, minEnd;  /* texels with minification */
-   GLuint magStart, magEnd;  /* texels with magnification */
-
-   const GLboolean repeatNoBorderPOT = (tObj->WrapS == GL_REPEAT)
-      && (tObj->WrapT == GL_REPEAT)
-      && (tImg->Border == 0 && (tImg->Width == tImg->RowStride))
-      && (tImg->Format != GL_COLOR_INDEX)
-      && tImg->_IsPowerOfTwo;
-
-   ASSERT(lambda != NULL);
-   compute_min_mag_ranges(SWRAST_CONTEXT(ctx)->_MinMagThresh[texUnit],
-                          n, lambda, &minStart, &minEnd, &magStart, &magEnd);
-
-   if (minStart < minEnd) {
-      /* do the minified texels */
-      const GLuint m = minEnd - minStart;
-      switch (tObj->MinFilter) {
-      case GL_NEAREST:
-         if (repeatNoBorderPOT) {
-            switch (tImg->TexFormat->MesaFormat) {
-            case MESA_FORMAT_RGB:
-            case MESA_FORMAT_RGB888:
-            /*case MESA_FORMAT_BGR888:*/
-               opt_sample_rgb_2d(ctx, texUnit, tObj, m, texcoords + minStart,
-                                 NULL, rgba + minStart);
-               break;
-            case MESA_FORMAT_RGBA:
-            case MESA_FORMAT_RGBA8888:
-            case MESA_FORMAT_ARGB8888:
-            /*case MESA_FORMAT_ABGR8888:*/
-            /*case MESA_FORMAT_BGRA8888:*/
-              opt_sample_rgba_2d(ctx, texUnit, tObj, m, texcoords + minStart,
-                                  NULL, rgba + minStart);
-               break;
-            default:
-               sample_nearest_2d(ctx, texUnit, tObj, m, texcoords + minStart,
-                                 NULL, rgba + minStart );
-            }
-         }
-         else {
-            sample_nearest_2d(ctx, texUnit, tObj, m, texcoords + minStart,
-                              NULL, rgba + minStart);
-         }
-         break;
-      case GL_LINEAR:
-        sample_linear_2d(ctx, texUnit, tObj, m, texcoords + minStart,
-                         NULL, rgba + minStart);
-         break;
-      case GL_NEAREST_MIPMAP_NEAREST:
-         sample_2d_nearest_mipmap_nearest(ctx, tObj, m,
-                                          texcoords + minStart,
-                                          lambda + minStart, rgba + minStart);
-         break;
-      case GL_LINEAR_MIPMAP_NEAREST:
-         sample_2d_linear_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
-                                         lambda + minStart, rgba + minStart);
-         break;
-      case GL_NEAREST_MIPMAP_LINEAR:
-         sample_2d_nearest_mipmap_linear(ctx, tObj, m, texcoords + minStart,
-                                         lambda + minStart, rgba + minStart);
-         break;
-      case GL_LINEAR_MIPMAP_LINEAR:
-         if (repeatNoBorderPOT)
-            sample_2d_linear_mipmap_linear_repeat(ctx, tObj, m,
-                  texcoords + minStart, lambda + minStart, rgba + minStart);
-         else
-            sample_2d_linear_mipmap_linear(ctx, tObj, m, texcoords + minStart,
-                                        lambda + minStart, rgba + minStart);
-         break;
-      default:
-         _mesa_problem(ctx, "Bad min filter in sample_2d_texture");
-         return;
-      }
-   }
-
-   if (magStart < magEnd) {
-      /* do the magnified texels */
-      const GLuint m = magEnd - magStart;
-
-      switch (tObj->MagFilter) {
-      case GL_NEAREST:
-         if (repeatNoBorderPOT) {
-            switch (tImg->TexFormat->MesaFormat) {
-            case MESA_FORMAT_RGB:
-            case MESA_FORMAT_RGB888:
-            /*case MESA_FORMAT_BGR888:*/
-               opt_sample_rgb_2d(ctx, texUnit, tObj, m, texcoords + magStart,
-                                 NULL, rgba + magStart);
-               break;
-            case MESA_FORMAT_RGBA:
-            case MESA_FORMAT_RGBA8888:
-            case MESA_FORMAT_ARGB8888:
-            /*case MESA_FORMAT_ABGR8888:*/
-            /*case MESA_FORMAT_BGRA8888:*/
-              opt_sample_rgba_2d(ctx, texUnit, tObj, m, texcoords + magStart,
-                                  NULL, rgba + magStart);
-               break;
-            default:
-               sample_nearest_2d(ctx, texUnit, tObj, m, texcoords + magStart,
-                                 NULL, rgba + magStart );
-            }
-         }
-         else {
-            sample_nearest_2d(ctx, texUnit, tObj, m, texcoords + magStart,
-                              NULL, rgba + magStart);
-         }
-         break;
-      case GL_LINEAR:
-        sample_linear_2d(ctx, texUnit, tObj, m, texcoords + magStart,
-                         NULL, rgba + magStart);
-         break;
-      default:
-         _mesa_problem(ctx, "Bad mag filter in sample_lambda_2d");
-      }
-   }
-}
-
-
-
-/**********************************************************************/
-/*                    3-D Texture Sampling Functions                  */
-/**********************************************************************/
-
-/*
- * Return the texture sample for coordinate (s,t,r) using GL_NEAREST filter.
- */
-static void
-sample_3d_nearest(GLcontext *ctx,
-                  const struct gl_texture_object *tObj,
-                  const struct gl_texture_image *img,
-                  const GLfloat texcoord[4],
-                  GLchan rgba[4])
-{
-   const GLint width = img->Width2;     /* without border, power of two */
-   const GLint height = img->Height2;   /* without border, power of two */
-   const GLint depth = img->Depth2;     /* without border, power of two */
-   GLint i, j, k;
-   (void) ctx;
-
-   COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapS, texcoord[0], width,  i);
-   COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapT, texcoord[1], height, j);
-   COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapR, texcoord[2], depth,  k);
-
-   if (i < 0 || i >= (GLint) img->Width ||
-       j < 0 || j >= (GLint) img->Height ||
-       k < 0 || k >= (GLint) img->Depth) {
-      /* Need this test for GL_CLAMP_TO_BORDER mode */
-      COPY_CHAN4(rgba, tObj->_BorderChan);
-   }
-   else {
-      img->FetchTexelc(img, i, j, k, rgba);
-   }
-}
-
-
-
-/*
- * Return the texture sample for coordinate (s,t,r) using GL_LINEAR filter.
- */
-static void
-sample_3d_linear(GLcontext *ctx,
-                 const struct gl_texture_object *tObj,
-                 const struct gl_texture_image *img,
-                 const GLfloat texcoord[4],
-                 GLchan rgba[4])
-{
-   const GLint width = img->Width2;
-   const GLint height = img->Height2;
-   const GLint depth = img->Depth2;
-   GLint i0, j0, k0, i1, j1, k1;
-   GLuint useBorderColor;
-   GLfloat u, v, w;
-   (void) ctx;
-
-   COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapS, texcoord[0], u, width,  i0, i1);
-   COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapT, texcoord[1], v, height, j0, j1);
-   COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapR, texcoord[2], w, depth,  k0, k1);
-
-   useBorderColor = 0;
-   if (img->Border) {
-      i0 += img->Border;
-      i1 += img->Border;
-      j0 += img->Border;
-      j1 += img->Border;
-      k0 += img->Border;
-      k1 += img->Border;
-   }
-   else {
-      /* check if sampling texture border color */
-      if (i0 < 0 || i0 >= width)   useBorderColor |= I0BIT;
-      if (i1 < 0 || i1 >= width)   useBorderColor |= I1BIT;
-      if (j0 < 0 || j0 >= height)  useBorderColor |= J0BIT;
-      if (j1 < 0 || j1 >= height)  useBorderColor |= J1BIT;
-      if (k0 < 0 || k0 >= depth)   useBorderColor |= K0BIT;
-      if (k1 < 0 || k1 >= depth)   useBorderColor |= K1BIT;
-   }
-
-   {
-      const GLfloat a = FRAC(u);
-      const GLfloat b = FRAC(v);
-      const GLfloat c = FRAC(w);
-#if CHAN_TYPE == GL_UNSIGNED_BYTE
-      const GLint ia = IROUND_POS(a * ILERP_SCALE);
-      const GLint ib = IROUND_POS(b * ILERP_SCALE);
-      const GLint ic = IROUND_POS(c * ILERP_SCALE);
-#endif
-      GLchan t000[4], t010[4], t001[4], t011[4];
-      GLchan t100[4], t110[4], t101[4], t111[4];
-
-      /* Fetch texels */
-      if (useBorderColor & (I0BIT | J0BIT | K0BIT)) {
-         COPY_CHAN4(t000, tObj->_BorderChan);
-      }
-      else {
-         img->FetchTexelc(img, i0, j0, k0, t000);
-      }
-      if (useBorderColor & (I1BIT | J0BIT | K0BIT)) {
-         COPY_CHAN4(t100, tObj->_BorderChan);
-      }
-      else {
-         img->FetchTexelc(img, i1, j0, k0, t100);
-      }
-      if (useBorderColor & (I0BIT | J1BIT | K0BIT)) {
-         COPY_CHAN4(t010, tObj->_BorderChan);
-      }
-      else {
-         img->FetchTexelc(img, i0, j1, k0, t010);
-      }
-      if (useBorderColor & (I1BIT | J1BIT | K0BIT)) {
-         COPY_CHAN4(t110, tObj->_BorderChan);
-      }
-      else {
-         img->FetchTexelc(img, i1, j1, k0, t110);
-      }
-
-      if (useBorderColor & (I0BIT | J0BIT | K1BIT)) {
-         COPY_CHAN4(t001, tObj->_BorderChan);
-      }
-      else {
-         img->FetchTexelc(img, i0, j0, k1, t001);
-      }
-      if (useBorderColor & (I1BIT | J0BIT | K1BIT)) {
-         COPY_CHAN4(t101, tObj->_BorderChan);
-      }
-      else {
-         img->FetchTexelc(img, i1, j0, k1, t101);
-      }
-      if (useBorderColor & (I0BIT | J1BIT | K1BIT)) {
-         COPY_CHAN4(t011, tObj->_BorderChan);
-      }
-      else {
-         img->FetchTexelc(img, i0, j1, k1, t011);
-      }
-      if (useBorderColor & (I1BIT | J1BIT | K1BIT)) {
-         COPY_CHAN4(t111, tObj->_BorderChan);
-      }
-      else {
-         img->FetchTexelc(img, i1, j1, k1, t111);
-      }
-
-      /* trilinear interpolation of samples */
-#if CHAN_TYPE == GL_FLOAT
-      rgba[0] = lerp_3d(a, b, c,
-                        t000[0], t100[0], t010[0], t110[0],
-                        t001[0], t101[0], t011[0], t111[0]);
-      rgba[1] = lerp_3d(a, b, c,
-                        t000[1], t100[1], t010[1], t110[1],
-                        t001[1], t101[1], t011[1], t111[1]);
-      rgba[2] = lerp_3d(a, b, c,
-                        t000[2], t100[2], t010[2], t110[2],
-                        t001[2], t101[2], t011[2], t111[2]);
-      rgba[3] = lerp_3d(a, b, c,
-                        t000[3], t100[3], t010[3], t110[3],
-                        t001[3], t101[3], t011[3], t111[3]);
-#elif CHAN_TYPE == GL_UNSIGNED_SHORT
-      rgba[0] = (GLchan) (lerp_3d(a, b, c,
-                                  t000[0], t100[0], t010[0], t110[0],
-                                  t001[0], t101[0], t011[0], t111[0]) + 0.5F);
-      rgba[1] = (GLchan) (lerp_3d(a, b, c,
-                                  t000[1], t100[1], t010[1], t110[1],
-                                  t001[1], t101[1], t011[1], t111[1]) + 0.5F);
-      rgba[2] = (GLchan) (lerp_3d(a, b, c,
-                                  t000[2], t100[2], t010[2], t110[2],
-                                  t001[2], t101[2], t011[2], t111[2]) + 0.5F);
-      rgba[3] = (GLchan) (lerp_3d(a, b, c,
-                                  t000[3], t100[3], t010[3], t110[3],
-                                  t001[3], t101[3], t011[3], t111[3]) + 0.5F);
-#else
-      ASSERT(CHAN_TYPE == GL_UNSIGNED_BYTE);
-      rgba[0] = ilerp_3d(ia, ib, ic,
-                         t000[0], t100[0], t010[0], t110[0],
-                         t001[0], t101[0], t011[0], t111[0]);
-      rgba[1] = ilerp_3d(ia, ib, ic,
-                         t000[1], t100[1], t010[1], t110[1],
-                         t001[1], t101[1], t011[1], t111[1]);
-      rgba[2] = ilerp_3d(ia, ib, ic,
-                         t000[2], t100[2], t010[2], t110[2],
-                         t001[2], t101[2], t011[2], t111[2]);
-      rgba[3] = ilerp_3d(ia, ib, ic,
-                         t000[3], t100[3], t010[3], t110[3],
-                         t001[3], t101[3], t011[3], t111[3]);
-#endif
-   }
-}
-
-
-
-static void
-sample_3d_nearest_mipmap_nearest(GLcontext *ctx,
-                                 const struct gl_texture_object *tObj,
-                                 GLuint n, const GLfloat texcoord[][4],
-                                 const GLfloat lambda[], GLchan rgba[][4] )
-{
-   GLuint i;
-   for (i = 0; i < n; i++) {
-      GLint level;
-      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
-      sample_3d_nearest(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]);
-   }
-}
-
-
-static void
-sample_3d_linear_mipmap_nearest(GLcontext *ctx,
-                                const struct gl_texture_object *tObj,
-                                GLuint n, const GLfloat texcoord[][4],
-                                const GLfloat lambda[], GLchan rgba[][4])
-{
-   GLuint i;
-   ASSERT(lambda != NULL);
-   for (i = 0; i < n; i++) {
-      GLint level;
-      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
-      sample_3d_linear(ctx, tObj, tObj->Image[0][level], texcoord[i], rgba[i]);
-   }
-}
-
-
-static void
-sample_3d_nearest_mipmap_linear(GLcontext *ctx,
-                                const struct gl_texture_object *tObj,
-                                GLuint n, const GLfloat texcoord[][4],
-                                const GLfloat lambda[], GLchan rgba[][4])
-{
-   GLuint i;
-   ASSERT(lambda != NULL);
-   for (i = 0; i < n; i++) {
-      GLint level;
-      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
-      if (level >= tObj->_MaxLevel) {
-         sample_3d_nearest(ctx, tObj, tObj->Image[0][tObj->_MaxLevel],
-                           texcoord[i], rgba[i]);
-      }
-      else {
-         GLchan t0[4], t1[4];  /* texels */
-         const GLfloat f = FRAC(lambda[i]);
-         sample_3d_nearest(ctx, tObj, tObj->Image[0][level  ], texcoord[i], t0);
-         sample_3d_nearest(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1);
-         rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
-         rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
-         rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
-         rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
-      }
-   }
-}
-
-
-static void
-sample_3d_linear_mipmap_linear(GLcontext *ctx,
-                               const struct gl_texture_object *tObj,
-                               GLuint n, const GLfloat texcoord[][4],
-                               const GLfloat lambda[], GLchan rgba[][4])
-{
-   GLuint i;
-   ASSERT(lambda != NULL);
-   for (i = 0; i < n; i++) {
-      GLint level;
-      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
-      if (level >= tObj->_MaxLevel) {
-         sample_3d_linear(ctx, tObj, tObj->Image[0][tObj->_MaxLevel],
-                          texcoord[i], rgba[i]);
-      }
-      else {
-         GLchan t0[4], t1[4];  /* texels */
-         const GLfloat f = FRAC(lambda[i]);
-         sample_3d_linear(ctx, tObj, tObj->Image[0][level  ], texcoord[i], t0);
-         sample_3d_linear(ctx, tObj, tObj->Image[0][level+1], texcoord[i], t1);
-         rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
-         rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
-         rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
-         rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
-      }
-   }
-}
-
-
-static void
-sample_nearest_3d(GLcontext *ctx, GLuint texUnit,
-                  const struct gl_texture_object *tObj, GLuint n,
-                  const GLfloat texcoords[][4], const GLfloat lambda[],
-                  GLchan rgba[][4])
-{
-   GLuint i;
-   struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel];
-   (void) texUnit;
-   (void) lambda;
-   for (i=0;i<n;i++) {
-      sample_3d_nearest(ctx, tObj, image, texcoords[i], rgba[i]);
-   }
-}
-
-
-
-static void
-sample_linear_3d( GLcontext *ctx, GLuint texUnit,
-                  const struct gl_texture_object *tObj, GLuint n,
-                  const GLfloat texcoords[][4],
-                 const GLfloat lambda[], GLchan rgba[][4] )
-{
-   GLuint i;
-   struct gl_texture_image *image = tObj->Image[0][tObj->BaseLevel];
-   (void) texUnit;
-   (void) lambda;
-   for (i=0;i<n;i++) {
-      sample_3d_linear(ctx, tObj, image, texcoords[i], rgba[i]);
-   }
-}
-
-
-/*
- * Given an (s,t,r) texture coordinate and lambda (level of detail) value,
- * return a texture sample.
- */
-static void
-sample_lambda_3d( GLcontext *ctx, GLuint texUnit,
-                  const struct gl_texture_object *tObj, GLuint n,
-                  const GLfloat texcoords[][4], const GLfloat lambda[],
-                  GLchan rgba[][4] )
-{
-   GLuint minStart, minEnd;  /* texels with minification */
-   GLuint magStart, magEnd;  /* texels with magnification */
-   GLuint i;
-
-   ASSERT(lambda != NULL);
-   compute_min_mag_ranges(SWRAST_CONTEXT(ctx)->_MinMagThresh[texUnit],
-                          n, lambda, &minStart, &minEnd, &magStart, &magEnd);
-
-   if (minStart < minEnd) {
-      /* do the minified texels */
-      GLuint m = minEnd - minStart;
-      switch (tObj->MinFilter) {
-      case GL_NEAREST:
-         for (i = minStart; i < minEnd; i++)
-            sample_3d_nearest(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
-                              texcoords[i], rgba[i]);
-         break;
-      case GL_LINEAR:
-         for (i = minStart; i < minEnd; i++)
-            sample_3d_linear(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
-                             texcoords[i], rgba[i]);
-         break;
-      case GL_NEAREST_MIPMAP_NEAREST:
-         sample_3d_nearest_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
-                                          lambda + minStart, rgba + minStart);
-         break;
-      case GL_LINEAR_MIPMAP_NEAREST:
-         sample_3d_linear_mipmap_nearest(ctx, tObj, m, texcoords + minStart,
-                                         lambda + minStart, rgba + minStart);
-         break;
-      case GL_NEAREST_MIPMAP_LINEAR:
-         sample_3d_nearest_mipmap_linear(ctx, tObj, m, texcoords + minStart,
-                                         lambda + minStart, rgba + minStart);
-         break;
-      case GL_LINEAR_MIPMAP_LINEAR:
-         sample_3d_linear_mipmap_linear(ctx, tObj, m, texcoords + minStart,
-                                        lambda + minStart, rgba + minStart);
-         break;
-      default:
-         _mesa_problem(ctx, "Bad min filter in sample_3d_texture");
-         return;
-      }
-   }
-
-   if (magStart < magEnd) {
-      /* do the magnified texels */
-      switch (tObj->MagFilter) {
-      case GL_NEAREST:
-         for (i = magStart; i < magEnd; i++)
-            sample_3d_nearest(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
-                              texcoords[i], rgba[i]);
-         break;
-      case GL_LINEAR:
-         for (i = magStart; i < magEnd; i++)
-            sample_3d_linear(ctx, tObj, tObj->Image[0][tObj->BaseLevel],
-                             texcoords[i], rgba[i]);
-         break;
-      default:
-         _mesa_problem(ctx, "Bad mag filter in sample_3d_texture");
-         return;
-      }
-   }
-}
-
-
-/**********************************************************************/
-/*                Texture Cube Map Sampling Functions                 */
-/**********************************************************************/
-
-/*
- * Choose one of six sides of a texture cube map given the texture
- * coord (rx,ry,rz).  Return pointer to corresponding array of texture
- * images.
- */
-static const struct gl_texture_image **
-choose_cube_face(const struct gl_texture_object *texObj,
-                 const GLfloat texcoord[4], GLfloat newCoord[4])
-{
-/*
-      major axis
-      direction     target                             sc     tc    ma
-      ----------    -------------------------------    ---    ---   ---
-       +rx          TEXTURE_CUBE_MAP_POSITIVE_X_EXT    -rz    -ry   rx
-       -rx          TEXTURE_CUBE_MAP_NEGATIVE_X_EXT    +rz    -ry   rx
-       +ry          TEXTURE_CUBE_MAP_POSITIVE_Y_EXT    +rx    +rz   ry
-       -ry          TEXTURE_CUBE_MAP_NEGATIVE_Y_EXT    +rx    -rz   ry
-       +rz          TEXTURE_CUBE_MAP_POSITIVE_Z_EXT    +rx    -ry   rz
-       -rz          TEXTURE_CUBE_MAP_NEGATIVE_Z_EXT    -rx    -ry   rz
-*/
-   const GLfloat rx = texcoord[0];
-   const GLfloat ry = texcoord[1];
-   const GLfloat rz = texcoord[2];
-   const struct gl_texture_image **imgArray;
-   const GLfloat arx = FABSF(rx),   ary = FABSF(ry),   arz = FABSF(rz);
-   GLfloat sc, tc, ma;
-
-   if (arx > ary && arx > arz) {
-      if (rx >= 0.0F) {
-         imgArray = (const struct gl_texture_image **) texObj->Image[FACE_POS_X];
-         sc = -rz;
-         tc = -ry;
-         ma = arx;
-      }
-      else {
-         imgArray = (const struct gl_texture_image **) texObj->Image[FACE_NEG_X];
-         sc = rz;
-         tc = -ry;
-         ma = arx;
-      }
-   }
-   else if (ary > arx && ary > arz) {
-      if (ry >= 0.0F) {
-         imgArray = (const struct gl_texture_image **) texObj->Image[FACE_POS_Y];
-         sc = rx;
-         tc = rz;
-         ma = ary;
-      }
-      else {
-         imgArray = (const struct gl_texture_image **) texObj->Image[FACE_NEG_Y];
-         sc = rx;
-         tc = -rz;
-         ma = ary;
-      }
-   }
-   else {
-      if (rz > 0.0F) {
-         imgArray = (const struct gl_texture_image **) texObj->Image[FACE_POS_Z];
-         sc = rx;
-         tc = -ry;
-         ma = arz;
-      }
-      else {
-         imgArray = (const struct gl_texture_image **) texObj->Image[FACE_NEG_Z];
-         sc = -rx;
-         tc = -ry;
-         ma = arz;
-      }
-   }
-
-   newCoord[0] = ( sc / ma + 1.0F ) * 0.5F;
-   newCoord[1] = ( tc / ma + 1.0F ) * 0.5F;
-   return imgArray;
-}
-
-
-static void
-sample_nearest_cube(GLcontext *ctx, GLuint texUnit,
-                   const struct gl_texture_object *tObj, GLuint n,
-                    const GLfloat texcoords[][4], const GLfloat lambda[],
-                    GLchan rgba[][4])
-{
-   GLuint i;
-   (void) texUnit;
-   (void) lambda;
-   for (i = 0; i < n; i++) {
-      const struct gl_texture_image **images;
-      GLfloat newCoord[4];
-      images = choose_cube_face(tObj, texcoords[i], newCoord);
-      sample_2d_nearest(ctx, tObj, images[tObj->BaseLevel],
-                        newCoord, rgba[i]);
-   }
-}
-
-
-static void
-sample_linear_cube(GLcontext *ctx, GLuint texUnit,
-                  const struct gl_texture_object *tObj, GLuint n,
-                   const GLfloat texcoords[][4],
-                  const GLfloat lambda[], GLchan rgba[][4])
-{
-   GLuint i;
-   (void) texUnit;
-   (void) lambda;
-   for (i = 0; i < n; i++) {
-      const struct gl_texture_image **images;
-      GLfloat newCoord[4];
-      images = choose_cube_face(tObj, texcoords[i], newCoord);
-      sample_2d_linear(ctx, tObj, images[tObj->BaseLevel],
-                       newCoord, rgba[i]);
-   }
-}
-
-
-static void
-sample_cube_nearest_mipmap_nearest(GLcontext *ctx, GLuint texUnit,
-                                   const struct gl_texture_object *tObj,
-                                   GLuint n, const GLfloat texcoord[][4],
-                                   const GLfloat lambda[], GLchan rgba[][4])
-{
-   GLuint i;
-   (void) texUnit;
-   ASSERT(lambda != NULL);
-   for (i = 0; i < n; i++) {
-      const struct gl_texture_image **images;
-      GLfloat newCoord[4];
-      GLint level;
-      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
-      images = choose_cube_face(tObj, texcoord[i], newCoord);
-      sample_2d_nearest(ctx, tObj, images[level], newCoord, rgba[i]);
-   }
-}
-
-
-static void
-sample_cube_linear_mipmap_nearest(GLcontext *ctx, GLuint texUnit,
-                                  const struct gl_texture_object *tObj,
-                                  GLuint n, const GLfloat texcoord[][4],
-                                  const GLfloat lambda[], GLchan rgba[][4])
-{
-   GLuint i;
-   (void) texUnit;
-   ASSERT(lambda != NULL);
-   for (i = 0; i < n; i++) {
-      const struct gl_texture_image **images;
-      GLfloat newCoord[4];
-      GLint level;
-      COMPUTE_NEAREST_MIPMAP_LEVEL(tObj, lambda[i], level);
-      images = choose_cube_face(tObj, texcoord[i], newCoord);
-      sample_2d_linear(ctx, tObj, images[level], newCoord, rgba[i]);
-   }
-}
-
-
-static void
-sample_cube_nearest_mipmap_linear(GLcontext *ctx, GLuint texUnit,
-                                  const struct gl_texture_object *tObj,
-                                  GLuint n, const GLfloat texcoord[][4],
-                                  const GLfloat lambda[], GLchan rgba[][4])
-{
-   GLuint i;
-   (void) texUnit;
-   ASSERT(lambda != NULL);
-   for (i = 0; i < n; i++) {
-      const struct gl_texture_image **images;
-      GLfloat newCoord[4];
-      GLint level;
-      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
-      images = choose_cube_face(tObj, texcoord[i], newCoord);
-      if (level >= tObj->_MaxLevel) {
-         sample_2d_nearest(ctx, tObj, images[tObj->_MaxLevel],
-                           newCoord, rgba[i]);
-      }
-      else {
-         GLchan t0[4], t1[4];  /* texels */
-         const GLfloat f = FRAC(lambda[i]);
-         sample_2d_nearest(ctx, tObj, images[level  ], newCoord, t0);
-         sample_2d_nearest(ctx, tObj, images[level+1], newCoord, t1);
-         rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
-         rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
-         rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
-         rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
-      }
-   }
-}
-
-
-static void
-sample_cube_linear_mipmap_linear(GLcontext *ctx, GLuint texUnit,
-                                 const struct gl_texture_object *tObj,
-                                 GLuint n, const GLfloat texcoord[][4],
-                                 const GLfloat lambda[], GLchan rgba[][4])
-{
-   GLuint i;
-   (void) texUnit;
-   ASSERT(lambda != NULL);
-   for (i = 0; i < n; i++) {
-      const struct gl_texture_image **images;
-      GLfloat newCoord[4];
-      GLint level;
-      COMPUTE_LINEAR_MIPMAP_LEVEL(tObj, lambda[i], level);
-      images = choose_cube_face(tObj, texcoord[i], newCoord);
-      if (level >= tObj->_MaxLevel) {
-         sample_2d_linear(ctx, tObj, images[tObj->_MaxLevel],
-                          newCoord, rgba[i]);
-      }
-      else {
-         GLchan t0[4], t1[4];
-         const GLfloat f = FRAC(lambda[i]);
-         sample_2d_linear(ctx, tObj, images[level  ], newCoord, t0);
-         sample_2d_linear(ctx, tObj, images[level+1], newCoord, t1);
-         rgba[i][RCOMP] = CHAN_CAST ((1.0F-f) * t0[RCOMP] + f * t1[RCOMP]);
-         rgba[i][GCOMP] = CHAN_CAST ((1.0F-f) * t0[GCOMP] + f * t1[GCOMP]);
-         rgba[i][BCOMP] = CHAN_CAST ((1.0F-f) * t0[BCOMP] + f * t1[BCOMP]);
-         rgba[i][ACOMP] = CHAN_CAST ((1.0F-f) * t0[ACOMP] + f * t1[ACOMP]);
-      }
-   }
-}
-
-
-static void
-sample_lambda_cube( GLcontext *ctx, GLuint texUnit,
-                   const struct gl_texture_object *tObj, GLuint n,
-                   const GLfloat texcoords[][4], const GLfloat lambda[],
-                   GLchan rgba[][4])
-{
-   GLuint minStart, minEnd;  /* texels with minification */
-   GLuint magStart, magEnd;  /* texels with magnification */
-
-   ASSERT(lambda != NULL);
-   compute_min_mag_ranges(SWRAST_CONTEXT(ctx)->_MinMagThresh[texUnit],
-                          n, lambda, &minStart, &minEnd, &magStart, &magEnd);
-
-   if (minStart < minEnd) {
-      /* do the minified texels */
-      const GLuint m = minEnd - minStart;
-      switch (tObj->MinFilter) {
-      case GL_NEAREST:
-         sample_nearest_cube(ctx, texUnit, tObj, m, texcoords + minStart,
-                             lambda + minStart, rgba + minStart);
-         break;
-      case GL_LINEAR:
-         sample_linear_cube(ctx, texUnit, tObj, m, texcoords + minStart,
-                            lambda + minStart, rgba + minStart);
-         break;
-      case GL_NEAREST_MIPMAP_NEAREST:
-         sample_cube_nearest_mipmap_nearest(ctx, texUnit, tObj, m,
-                                            texcoords + minStart,
-                                           lambda + minStart, rgba + minStart);
-         break;
-      case GL_LINEAR_MIPMAP_NEAREST:
-         sample_cube_linear_mipmap_nearest(ctx, texUnit, tObj, m,
-                                           texcoords + minStart,
-                                           lambda + minStart, rgba + minStart);
-         break;
-      case GL_NEAREST_MIPMAP_LINEAR:
-         sample_cube_nearest_mipmap_linear(ctx, texUnit, tObj, m,
-                                           texcoords + minStart,
-                                           lambda + minStart, rgba + minStart);
-         break;
-      case GL_LINEAR_MIPMAP_LINEAR:
-         sample_cube_linear_mipmap_linear(ctx, texUnit, tObj, m,
-                                          texcoords + minStart,
-                                          lambda + minStart, rgba + minStart);
-         break;
-      default:
-         _mesa_problem(ctx, "Bad min filter in sample_lambda_cube");
-      }
-   }
-
-   if (magStart < magEnd) {
-      /* do the magnified texels */
-      const GLuint m = magEnd - magStart;
-      switch (tObj->MagFilter) {
-      case GL_NEAREST:
-         sample_nearest_cube(ctx, texUnit, tObj, m, texcoords + magStart,
-                             lambda + magStart, rgba + magStart);
-         break;
-      case GL_LINEAR:
-         sample_linear_cube(ctx, texUnit, tObj, m, texcoords + magStart,
-                            lambda + magStart, rgba + magStart);
-         break;
-      default:
-         _mesa_problem(ctx, "Bad mag filter in sample_lambda_cube");
-      }
-   }
-}
-
-
-/**********************************************************************/
-/*               Texture Rectangle Sampling Functions                 */
-/**********************************************************************/
-
-static void
-sample_nearest_rect(GLcontext *ctx, GLuint texUnit,
-                   const struct gl_texture_object *tObj, GLuint n,
-                    const GLfloat texcoords[][4], const GLfloat lambda[],
-                    GLchan rgba[][4])
-{
-   const struct gl_texture_image *img = tObj->Image[0][0];
-   const GLfloat width = (GLfloat) img->Width;
-   const GLfloat height = (GLfloat) img->Height;
-   const GLint width_minus_1 = img->Width - 1;
-   const GLint height_minus_1 = img->Height - 1;
-   GLuint i;
-
-   (void) ctx;
-   (void) texUnit;
-   (void) lambda;
-
-   ASSERT(tObj->WrapS == GL_CLAMP ||
-          tObj->WrapS == GL_CLAMP_TO_EDGE ||
-          tObj->WrapS == GL_CLAMP_TO_BORDER);
-   ASSERT(tObj->WrapT == GL_CLAMP ||
-          tObj->WrapT == GL_CLAMP_TO_EDGE ||
-          tObj->WrapT == GL_CLAMP_TO_BORDER);
-   ASSERT(img->Format != GL_COLOR_INDEX);
-
-   /* XXX move Wrap mode tests outside of loops for common cases */
-   for (i = 0; i < n; i++) {
-      GLint row, col;
-      /* NOTE: we DO NOT use [0, 1] texture coordinates! */
-      if (tObj->WrapS == GL_CLAMP) {
-         col = IFLOOR( CLAMP(texcoords[i][0], 0.0F, width - 1) );
-      }
-      else if (tObj->WrapS == GL_CLAMP_TO_EDGE) {
-         col = IFLOOR( CLAMP(texcoords[i][0], 0.5F, width - 0.5F) );
-      }
-      else {
-         col = IFLOOR( CLAMP(texcoords[i][0], -0.5F, width + 0.5F) );
-      }
-      if (tObj->WrapT == GL_CLAMP) {
-         row = IFLOOR( CLAMP(texcoords[i][1], 0.0F, height - 1) );
-      }
-      else if (tObj->WrapT == GL_CLAMP_TO_EDGE) {
-         row = IFLOOR( CLAMP(texcoords[i][1], 0.5F, height - 0.5F) );
-      }
-      else {
-         row = IFLOOR( CLAMP(texcoords[i][1], -0.5F, height + 0.5F) );
-      }
-
-      if (col < 0 || col > width_minus_1 || row < 0 || row > height_minus_1)
-         COPY_CHAN4(rgba[i], tObj->_BorderChan);
-      else
-         img->FetchTexelc(img, col, row, 0, rgba[i]);
-   }
-}
-
-
-static void
-sample_linear_rect(GLcontext *ctx, GLuint texUnit,
-                  const struct gl_texture_object *tObj, GLuint n,
-                   const GLfloat texcoords[][4],
-                  const GLfloat lambda[], GLchan rgba[][4])
-{
-   const struct gl_texture_image *img = tObj->Image[0][0];
-   const GLfloat width = (GLfloat) img->Width;
-   const GLfloat height = (GLfloat) img->Height;
-   const GLint width_minus_1 = img->Width - 1;
-   const GLint height_minus_1 = img->Height - 1;
-   GLuint i;
-
-   (void) ctx;
-   (void) texUnit;
-   (void) lambda;
-
-   ASSERT(tObj->WrapS == GL_CLAMP ||
-          tObj->WrapS == GL_CLAMP_TO_EDGE ||
-          tObj->WrapS == GL_CLAMP_TO_BORDER);
-   ASSERT(tObj->WrapT == GL_CLAMP ||
-          tObj->WrapT == GL_CLAMP_TO_EDGE ||
-          tObj->WrapT == GL_CLAMP_TO_BORDER);
-   ASSERT(img->Format != GL_COLOR_INDEX);
-
-   /* XXX lots of opportunity for optimization in this loop */
-   for (i = 0; i < n; i++) {
-      GLfloat frow, fcol;
-      GLint i0, j0, i1, j1;
-      GLchan t00[4], t01[4], t10[4], t11[4];
-      GLfloat a, b;
-      GLuint useBorderColor = 0;
-#if CHAN_TYPE == GL_UNSIGNED_BYTE
-      GLint ia, ib;
-#endif
-
-      /* NOTE: we DO NOT use [0, 1] texture coordinates! */
-      if (tObj->WrapS == GL_CLAMP) {
-         /* Not exactly what the spec says, but it matches NVIDIA output */
-         fcol = CLAMP(texcoords[i][0] - 0.5F, 0.0, width_minus_1);
-         i0 = IFLOOR(fcol);
-         i1 = i0 + 1;
-      }
-      else if (tObj->WrapS == GL_CLAMP_TO_EDGE) {
-         fcol = CLAMP(texcoords[i][0], 0.5F, width - 0.5F);
-         fcol -= 0.5F;
-         i0 = IFLOOR(fcol);
-         i1 = i0 + 1;
-         if (i1 > width_minus_1)
-            i1 = width_minus_1;
-      }
-      else {
-         ASSERT(tObj->WrapS == GL_CLAMP_TO_BORDER);
-         fcol = CLAMP(texcoords[i][0], -0.5F, width + 0.5F);
-         fcol -= 0.5F;
-         i0 = IFLOOR(fcol);
-         i1 = i0 + 1;
-      }
-
-      if (tObj->WrapT == GL_CLAMP) {
-         /* Not exactly what the spec says, but it matches NVIDIA output */
-         frow = CLAMP(texcoords[i][1] - 0.5F, 0.0, width_minus_1);
-         j0 = IFLOOR(frow);
-         j1 = j0 + 1;
-      }
-      else if (tObj->WrapT == GL_CLAMP_TO_EDGE) {
-         frow = CLAMP(texcoords[i][1], 0.5F, height - 0.5F);
-         frow -= 0.5F;
-         j0 = IFLOOR(frow);
-         j1 = j0 + 1;
-         if (j1 > height_minus_1)
-            j1 = height_minus_1;
-      }
-      else {
-         ASSERT(tObj->WrapT == GL_CLAMP_TO_BORDER);
-         frow = CLAMP(texcoords[i][1], -0.5F, height + 0.5F);
-         frow -= 0.5F;
-         j0 = IFLOOR(frow);
-         j1 = j0 + 1;
-      }
-
-      /* compute integer rows/columns */
-      if (i0 < 0 || i0 > width_minus_1)   useBorderColor |= I0BIT;
-      if (i1 < 0 || i1 > width_minus_1)   useBorderColor |= I1BIT;
-      if (j0 < 0 || j0 > height_minus_1)  useBorderColor |= J0BIT;
-      if (j1 < 0 || j1 > height_minus_1)  useBorderColor |= J1BIT;
-
-      /* get four texel samples */
-      if (useBorderColor & (I0BIT | J0BIT))
-         COPY_CHAN4(t00, tObj->_BorderChan);
-      else
-         img->FetchTexelc(img, i0, j0, 0, t00);
-
-      if (useBorderColor & (I1BIT | J0BIT))
-         COPY_CHAN4(t10, tObj->_BorderChan);
-      else
-         img->FetchTexelc(img, i1, j0, 0, t10);
-
-      if (useBorderColor & (I0BIT | J1BIT))
-         COPY_CHAN4(t01, tObj->_BorderChan);
-      else
-         img->FetchTexelc(img, i0, j1, 0, t01);
-
-      if (useBorderColor & (I1BIT | J1BIT))
-         COPY_CHAN4(t11, tObj->_BorderChan);
-      else
-         img->FetchTexelc(img, i1, j1, 0, t11);
-
-      /* compute interpolants */
-      a = FRAC(fcol);
-      b = FRAC(frow);
-#if CHAN_TYPE == GL_UNSIGNED_BYTE
-      ia = IROUND_POS(a * ILERP_SCALE);
-      ib = IROUND_POS(b * ILERP_SCALE);
-#endif
-
-      /* do bilinear interpolation of texel colors */
-#if CHAN_TYPE == GL_FLOAT
-      rgba[i][0] = lerp_2d(a, b, t00[0], t10[0], t01[0], t11[0]);
-      rgba[i][1] = lerp_2d(a, b, t00[1], t10[1], t01[1], t11[1]);
-      rgba[i][2] = lerp_2d(a, b, t00[2], t10[2], t01[2], t11[2]);
-      rgba[i][3] = lerp_2d(a, b, t00[3], t10[3], t01[3], t11[3]);
-#elif CHAN_TYPE == GL_UNSIGNED_SHORT
-      rgba[i][0] = (GLchan) (lerp_2d(a, b, t00[0], t10[0], t01[0], t11[0]) + 0.5);
-      rgba[i][1] = (GLchan) (lerp_2d(a, b, t00[1], t10[1], t01[1], t11[1]) + 0.5);
-      rgba[i][2] = (GLchan) (lerp_2d(a, b, t00[2], t10[2], t01[2], t11[2]) + 0.5);
-      rgba[i][3] = (GLchan) (lerp_2d(a, b, t00[3], t10[3], t01[3], t11[3]) + 0.5);
-#else
-      ASSERT(CHAN_TYPE == GL_UNSIGNED_BYTE);
-      rgba[i][0] = ilerp_2d(ia, ib, t00[0], t10[0], t01[0], t11[0]);
-      rgba[i][1] = ilerp_2d(ia, ib, t00[1], t10[1], t01[1], t11[1]);
-      rgba[i][2] = ilerp_2d(ia, ib, t00[2], t10[2], t01[2], t11[2]);
-      rgba[i][3] = ilerp_2d(ia, ib, t00[3], t10[3], t01[3], t11[3]);
-#endif
-   }
-}
-
-
-static void
-sample_lambda_rect( GLcontext *ctx, GLuint texUnit,
-                   const struct gl_texture_object *tObj, GLuint n,
-                   const GLfloat texcoords[][4], const GLfloat lambda[],
-                   GLchan rgba[][4])
-{
-   GLuint minStart, minEnd, magStart, magEnd;
-
-   /* We only need lambda to decide between minification and magnification.
-    * There is no mipmapping with rectangular textures.
-    */
-   compute_min_mag_ranges(SWRAST_CONTEXT(ctx)->_MinMagThresh[texUnit],
-                          n, lambda, &minStart, &minEnd, &magStart, &magEnd);
-
-   if (minStart < minEnd) {
-      if (tObj->MinFilter == GL_NEAREST) {
-         sample_nearest_rect( ctx, texUnit, tObj, minEnd - minStart,
-                              texcoords + minStart, NULL, rgba + minStart);
-      }
-      else {
-         sample_linear_rect( ctx, texUnit, tObj, minEnd - minStart,
-                             texcoords + minStart, NULL, rgba + minStart);
-      }
-   }
-   if (magStart < magEnd) {
-      if (tObj->MagFilter == GL_NEAREST) {
-         sample_nearest_rect( ctx, texUnit, tObj, magEnd - magStart,
-                              texcoords + magStart, NULL, rgba + magStart);
-      }
-      else {
-         sample_linear_rect( ctx, texUnit, tObj, magEnd - magStart,
-                             texcoords + magStart, NULL, rgba + magStart);
-      }
-   }
-}
-
-
-
-/*
- * Sample a shadow/depth texture.
- */
-static void
-sample_depth_texture( GLcontext *ctx, GLuint unit,
-                      const struct gl_texture_object *tObj, GLuint n,
-                      const GLfloat texcoords[][4], const GLfloat lambda[],
-                      GLchan texel[][4] )
-{
-   const GLint baseLevel = tObj->BaseLevel;
-   const struct gl_texture_image *texImage = tObj->Image[0][baseLevel];
-   const GLuint width = texImage->Width;
-   const GLuint height = texImage->Height;
-   GLchan ambient;
-   GLenum function;
-   GLchan result;
-
-   (void) lambda;
-   (void) unit;
-
-   ASSERT(tObj->Image[0][tObj->BaseLevel]->Format == GL_DEPTH_COMPONENT);
-   ASSERT(tObj->Target == GL_TEXTURE_1D ||
-          tObj->Target == GL_TEXTURE_2D ||
-          tObj->Target == GL_TEXTURE_RECTANGLE_NV);
-
-   UNCLAMPED_FLOAT_TO_CHAN(ambient, tObj->ShadowAmbient);
-
-   /* XXXX if tObj->MinFilter != tObj->MagFilter, we're ignoring lambda */
-
-   /* XXX this could be precomputed and saved in the texture object */
-   if (tObj->CompareFlag) {
-      /* GL_SGIX_shadow */
-      if (tObj->CompareOperator == GL_TEXTURE_LEQUAL_R_SGIX) {
-         function = GL_LEQUAL;
-      }
-      else {
-         ASSERT(tObj->CompareOperator == GL_TEXTURE_GEQUAL_R_SGIX);
-         function = GL_GEQUAL;
-      }
-   }
-   else if (tObj->CompareMode == GL_COMPARE_R_TO_TEXTURE_ARB) {
-      /* GL_ARB_shadow */
-      function = tObj->CompareFunc;
-   }
-   else {
-      function = GL_NONE;  /* pass depth through as grayscale */
-   }
-
-   if (tObj->MagFilter == GL_NEAREST) {
-      GLuint i;
-      for (i = 0; i < n; i++) {
-         GLfloat depthSample;
-         GLint col, row;
-         /* XXX fix for texture rectangle! */
-         COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapS, texcoords[i][0], width, col);
-         COMPUTE_NEAREST_TEXEL_LOCATION(tObj->WrapT, texcoords[i][1], height, row);
-         texImage->FetchTexelf(texImage, col, row, 0, &depthSample);
-
-         switch (function) {
-         case GL_LEQUAL:
-            result = (texcoords[i][2] <= depthSample) ? CHAN_MAX : ambient;
-            break;
-         case GL_GEQUAL:
-            result = (texcoords[i][2] >= depthSample) ? CHAN_MAX : ambient;
-            break;
-         case GL_LESS:
-            result = (texcoords[i][2] < depthSample) ? CHAN_MAX : ambient;
-            break;
-         case GL_GREATER:
-            result = (texcoords[i][2] > depthSample) ? CHAN_MAX : ambient;
-            break;
-         case GL_EQUAL:
-            result = (texcoords[i][2] == depthSample) ? CHAN_MAX : ambient;
-            break;
-         case GL_NOTEQUAL:
-            result = (texcoords[i][2] != depthSample) ? CHAN_MAX : ambient;
-            break;
-         case GL_ALWAYS:
-            result = CHAN_MAX;
-            break;
-         case GL_NEVER:
-            result = ambient;
-            break;
-         case GL_NONE:
-            CLAMPED_FLOAT_TO_CHAN(result, depthSample);
-            break;
-         default:
-            _mesa_problem(ctx, "Bad compare func in sample_depth_texture");
-            return;
-         }
-
-         switch (tObj->DepthMode) {
-         case GL_LUMINANCE:
-            texel[i][RCOMP] = result;
-            texel[i][GCOMP] = result;
-            texel[i][BCOMP] = result;
-            texel[i][ACOMP] = CHAN_MAX;
-            break;
-         case GL_INTENSITY:
-            texel[i][RCOMP] = result;
-            texel[i][GCOMP] = result;
-            texel[i][BCOMP] = result;
-            texel[i][ACOMP] = result;
-            break;
-         case GL_ALPHA:
-            texel[i][RCOMP] = 0;
-            texel[i][GCOMP] = 0;
-            texel[i][BCOMP] = 0;
-            texel[i][ACOMP] = result;
-            break;
-         default:
-            _mesa_problem(ctx, "Bad depth texture mode");
-         }
-      }
-   }
-   else {
-      GLuint i;
-      ASSERT(tObj->MagFilter == GL_LINEAR);
-      for (i = 0; i < n; i++) {
-         GLfloat depth00, depth01, depth10, depth11;
-         GLint i0, i1, j0, j1;
-         GLfloat u, v;
-         GLuint useBorderTexel;
-
-         /* XXX fix for texture rectangle! */
-         COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapS, texcoords[i][0], u, width, i0, i1);
-         COMPUTE_LINEAR_TEXEL_LOCATIONS(tObj->WrapT, texcoords[i][1], v, height,j0, j1);
-
-         useBorderTexel = 0;
-         if (texImage->Border) {
-            i0 += texImage->Border;
-            i1 += texImage->Border;
-            j0 += texImage->Border;
-            j1 += texImage->Border;
-         }
-         else {
-            if (i0 < 0 || i0 >= (GLint) width)   useBorderTexel |= I0BIT;
-            if (i1 < 0 || i1 >= (GLint) width)   useBorderTexel |= I1BIT;
-            if (j0 < 0 || j0 >= (GLint) height)  useBorderTexel |= J0BIT;
-            if (j1 < 0 || j1 >= (GLint) height)  useBorderTexel |= J1BIT;
-         }
-
-         /* get four depth samples from the texture */
-         if (useBorderTexel & (I0BIT | J0BIT)) {
-            depth00 = 1.0;
-         }
-         else {
-            texImage->FetchTexelf(texImage, i0, j0, 0, &depth00);
-         }
-         if (useBorderTexel & (I1BIT | J0BIT)) {
-            depth10 = 1.0;
-         }
-         else {
-            texImage->FetchTexelf(texImage, i1, j0, 0, &depth10);
-         }
-         if (useBorderTexel & (I0BIT | J1BIT)) {
-            depth01 = 1.0;
-         }
-         else {
-            texImage->FetchTexelf(texImage, i0, j1, 0, &depth01);
-         }
-         if (useBorderTexel & (I1BIT | J1BIT)) {
-            depth11 = 1.0;
-         }
-         else {
-            texImage->FetchTexelf(texImage, i1, j1, 0, &depth11);
-         }
-
-         if (0) {
-            /* compute a single weighted depth sample and do one comparison */
-            const GLfloat a = FRAC(u + 1.0F);
-            const GLfloat b = FRAC(v + 1.0F);
-            const GLfloat depthSample
-               = lerp_2d(a, b, depth00, depth10, depth01, depth11);
-            if ((depthSample <= texcoords[i][2] && function == GL_LEQUAL) ||
-                (depthSample >= texcoords[i][2] && function == GL_GEQUAL)) {
-               result  = ambient;
-            }
-            else {
-               result = CHAN_MAX;
-            }
-         }
-         else {
-            /* Do four depth/R comparisons and compute a weighted result.
-             * If this touches on somebody's I.P., I'll remove this code
-             * upon request.
-             */
-            const GLfloat d = (CHAN_MAXF - (GLfloat) ambient) * 0.25F;
-            GLfloat luminance = CHAN_MAXF;
-
-            switch (function) {
-            case GL_LEQUAL:
-               if (depth00 <= texcoords[i][2])  luminance -= d;
-               if (depth01 <= texcoords[i][2])  luminance -= d;
-               if (depth10 <= texcoords[i][2])  luminance -= d;
-               if (depth11 <= texcoords[i][2])  luminance -= d;
-               result = (GLchan) luminance;
-               break;
-            case GL_GEQUAL:
-               if (depth00 >= texcoords[i][2])  luminance -= d;
-               if (depth01 >= texcoords[i][2])  luminance -= d;
-               if (depth10 >= texcoords[i][2])  luminance -= d;
-               if (depth11 >= texcoords[i][2])  luminance -= d;
-               result = (GLchan) luminance;
-               break;
-            case GL_LESS:
-               if (depth00 < texcoords[i][2])  luminance -= d;
-               if (depth01 < texcoords[i][2])  luminance -= d;
-               if (depth10 < texcoords[i][2])  luminance -= d;
-               if (depth11 < texcoords[i][2])  luminance -= d;
-               result = (GLchan) luminance;
-               break;
-            case GL_GREATER:
-               if (depth00 > texcoords[i][2])  luminance -= d;
-               if (depth01 > texcoords[i][2])  luminance -= d;
-               if (depth10 > texcoords[i][2])  luminance -= d;
-               if (depth11 > texcoords[i][2])  luminance -= d;
-               result = (GLchan) luminance;
-               break;
-            case GL_EQUAL:
-               if (depth00 == texcoords[i][2])  luminance -= d;
-               if (depth01 == texcoords[i][2])  luminance -= d;
-               if (depth10 == texcoords[i][2])  luminance -= d;
-               if (depth11 == texcoords[i][2])  luminance -= d;
-               result = (GLchan) luminance;
-               break;
-            case GL_NOTEQUAL:
-               if (depth00 != texcoords[i][2])  luminance -= d;
-               if (depth01 != texcoords[i][2])  luminance -= d;
-               if (depth10 != texcoords[i][2])  luminance -= d;
-               if (depth11 != texcoords[i][2])  luminance -= d;
-               result = (GLchan) luminance;
-               break;
-            case GL_ALWAYS:
-               result = 0;
-               break;
-            case GL_NEVER:
-               result = CHAN_MAX;
-               break;
-            case GL_NONE:
-               /* ordinary bilinear filtering */
-               {
-                  const GLfloat a = FRAC(u + 1.0F);
-                  const GLfloat b = FRAC(v + 1.0F);
-                  const GLfloat depthSample
-                     = lerp_2d(a, b, depth00, depth10, depth01, depth11);
-                  CLAMPED_FLOAT_TO_CHAN(result, depthSample);
-               }
-               break;
-            default:
-               _mesa_problem(ctx, "Bad compare func in sample_depth_texture");
-               return;
-            }
-         }
-
-         switch (tObj->DepthMode) {
-         case GL_LUMINANCE:
-            texel[i][RCOMP] = result;
-            texel[i][GCOMP] = result;
-            texel[i][BCOMP] = result;
-            texel[i][ACOMP] = CHAN_MAX;
-            break;
-         case GL_INTENSITY:
-            texel[i][RCOMP] = result;
-            texel[i][GCOMP] = result;
-            texel[i][BCOMP] = result;
-            texel[i][ACOMP] = result;
-            break;
-         case GL_ALPHA:
-            texel[i][RCOMP] = 0;
-            texel[i][GCOMP] = 0;
-            texel[i][BCOMP] = 0;
-            texel[i][ACOMP] = result;
-            break;
-         default:
-            _mesa_problem(ctx, "Bad depth texture mode");
-         }
-      }  /* for */
-   }  /* if filter */
-}
-
-
-#if 0
-/*
- * Experimental depth texture sampling function.
- */
-static void
-sample_depth_texture2(const GLcontext *ctx,
-                     const struct gl_texture_unit *texUnit,
-                     GLuint n, const GLfloat texcoords[][4],
-                     GLchan texel[][4])
-{
-   const struct gl_texture_object *texObj = texUnit->_Current;
-   const GLint baseLevel = texObj->BaseLevel;
-   const struct gl_texture_image *texImage = texObj->Image[0][baseLevel];
-   const GLuint width = texImage->Width;
-   const GLuint height = texImage->Height;
-   GLchan ambient;
-   GLboolean lequal, gequal;
-
-   if (texObj->Target != GL_TEXTURE_2D) {
-      _mesa_problem(ctx, "only 2-D depth textures supported at this time");
-      return;
-   }
-
-   if (texObj->MinFilter != texObj->MagFilter) {
-      _mesa_problem(ctx, "mipmapped depth textures not supported at this time");
-      return;
-   }
-
-   /* XXX the GL_SGIX_shadow extension spec doesn't say what to do if
-    * GL_TEXTURE_COMPARE_SGIX == GL_TRUE but the current texture object
-    * isn't a depth texture.
-    */
-   if (texImage->Format != GL_DEPTH_COMPONENT) {
-      _mesa_problem(ctx,"GL_TEXTURE_COMPARE_SGIX enabled with non-depth texture");
-      return;
-   }
-
-   UNCLAMPED_FLOAT_TO_CHAN(ambient, tObj->ShadowAmbient);
-
-   if (texObj->CompareOperator == GL_TEXTURE_LEQUAL_R_SGIX) {
-      lequal = GL_TRUE;
-      gequal = GL_FALSE;
-   }
-   else {
-      lequal = GL_FALSE;
-      gequal = GL_TRUE;
-   }
-
-   {
-      GLuint i;
-      for (i = 0; i < n; i++) {
-         const GLint K = 3;
-         GLint col, row, ii, jj, imin, imax, jmin, jmax, samples, count;
-         GLfloat w;
-         GLchan lum;
-         COMPUTE_NEAREST_TEXEL_LOCATION(texObj->WrapS, texcoords[i][0],
-                                       width, col);
-         COMPUTE_NEAREST_TEXEL_LOCATION(texObj->WrapT, texcoords[i][1],
-                                       height, row);
-
-         imin = col - K;
-         imax = col + K;
-         jmin = row - K;
-         jmax = row + K;
-
-         if (imin < 0)  imin = 0;
-         if (imax >= width)  imax = width - 1;
-         if (jmin < 0)  jmin = 0;
-         if (jmax >= height) jmax = height - 1;
-
-         samples = (imax - imin + 1) * (jmax - jmin + 1);
-         count = 0;
-         for (jj = jmin; jj <= jmax; jj++) {
-            for (ii = imin; ii <= imax; ii++) {
-               GLfloat depthSample;
-               texImage->FetchTexelf(texImage, ii, jj, 0, &depthSample);
-               if ((depthSample <= r[i] && lequal) ||
-                   (depthSample >= r[i] && gequal)) {
-                  count++;
-               }
-            }
-         }
-
-         w = (GLfloat) count / (GLfloat) samples;
-         w = CHAN_MAXF - w * (CHAN_MAXF - (GLfloat) ambient);
-         lum = (GLint) w;
-
-         texel[i][RCOMP] = lum;
-         texel[i][GCOMP] = lum;
-         texel[i][BCOMP] = lum;
-         texel[i][ACOMP] = CHAN_MAX;
-      }
-   }
-}
-#endif
-
-
-/**
- * We use this function when a texture object is in an "incomplete" state.
- * When a fragment program attempts to sample an incomplete texture we
- * return black (see issue 23 in GL_ARB_fragment_program spec).
- * Note: fragment programss don't observe the texture enable/disable flags.
- */
-static void
-null_sample_func( GLcontext *ctx, GLuint texUnit,
-                 const struct gl_texture_object *tObj, GLuint n,
-                 const GLfloat texcoords[][4], const GLfloat lambda[],
-                 GLchan rgba[][4])
-{
-   GLuint i;
-   (void) ctx;
-   (void) texUnit;
-   (void) tObj;
-   (void) texcoords;
-   (void) lambda;
-   for (i = 0; i < n; i++) {
-      rgba[i][RCOMP] = 0;
-      rgba[i][GCOMP] = 0;
-      rgba[i][BCOMP] = 0;
-      rgba[i][ACOMP] = CHAN_MAX;
-   }
-}
-
-
-/**
- * Setup the texture sampling function for this texture object.
- */
-texture_sample_func
-_swrast_choose_texture_sample_func( GLcontext *ctx,
-                                   const struct gl_texture_object *t )
-{
-   if (!t || !t->Complete) {
-      return &null_sample_func;
-   }
-   else {
-      const GLboolean needLambda = (GLboolean) (t->MinFilter != t->MagFilter);
-      const GLenum format = t->Image[0][t->BaseLevel]->Format;
-
-      switch (t->Target) {
-      case GL_TEXTURE_1D:
-         if (format == GL_DEPTH_COMPONENT) {
-            return &sample_depth_texture;
-         }
-         else if (needLambda) {
-            return &sample_lambda_1d;
-         }
-         else if (t->MinFilter == GL_LINEAR) {
-            return &sample_linear_1d;
-         }
-         else {
-            ASSERT(t->MinFilter == GL_NEAREST);
-            return &sample_nearest_1d;
-         }
-      case GL_TEXTURE_2D:
-         if (format == GL_DEPTH_COMPONENT) {
-            return &sample_depth_texture;
-         }
-         else if (needLambda) {
-            return &sample_lambda_2d;
-         }
-         else if (t->MinFilter == GL_LINEAR) {
-            return &sample_linear_2d;
-         }
-         else {
-            GLint baseLevel = t->BaseLevel;
-            ASSERT(t->MinFilter == GL_NEAREST);
-            if (t->WrapS == GL_REPEAT &&
-                t->WrapT == GL_REPEAT &&
-                t->_IsPowerOfTwo &&
-                t->Image[0][baseLevel]->Border == 0 &&
-                t->Image[0][baseLevel]->TexFormat->MesaFormat == MESA_FORMAT_RGB) {
-               return &opt_sample_rgb_2d;
-            }
-            else if (t->WrapS == GL_REPEAT &&
-                     t->WrapT == GL_REPEAT &&
-                     t->_IsPowerOfTwo &&
-                     t->Image[0][baseLevel]->Border == 0 &&
-                     t->Image[0][baseLevel]->TexFormat->MesaFormat == MESA_FORMAT_RGBA) {
-               return &opt_sample_rgba_2d;
-            }
-            else {
-               return &sample_nearest_2d;
-            }
-         }
-      case GL_TEXTURE_3D:
-         if (needLambda) {
-            return &sample_lambda_3d;
-         }
-         else if (t->MinFilter == GL_LINEAR) {
-            return &sample_linear_3d;
-         }
-         else {
-            ASSERT(t->MinFilter == GL_NEAREST);
-            return &sample_nearest_3d;
-         }
-      case GL_TEXTURE_CUBE_MAP:
-         if (needLambda) {
-            return &sample_lambda_cube;
-         }
-         else if (t->MinFilter == GL_LINEAR) {
-            return &sample_linear_cube;
-         }
-         else {
-            ASSERT(t->MinFilter == GL_NEAREST);
-            return &sample_nearest_cube;
-         }
-      case GL_TEXTURE_RECTANGLE_NV:
-         if (needLambda) {
-            return &sample_lambda_rect;
-         }
-         else if (t->MinFilter == GL_LINEAR) {
-            return &sample_linear_rect;
-         }
-         else {
-            ASSERT(t->MinFilter == GL_NEAREST);
-            return &sample_nearest_rect;
-         }
-      default:
-         _mesa_problem(ctx,
-                       "invalid target in _swrast_choose_texture_sample_func");
-         return &null_sample_func;
-      }
-   }
-}
-
-
-/* Fixed-point products */
-#define PROD(A,B)   ( (GLuint)(A) * ((GLuint)(B)+1) )
-#define S_PROD(A,B) ( (GLint)(A) * ((GLint)(B)+1) )
-
-
-/**
- * Do texture application for GL_ARB/EXT_texture_env_combine.
- * This function also supports GL_{EXT,ARB}_texture_env_dot3 and
- * GL_ATI_texture_env_combine3.  Since "classic" texture environments are
- * implemented using GL_ARB_texture_env_combine-like state, this same function
- * is used for classic texture environment application as well.
- *
- * \param ctx          rendering context
- * \param textureUnit  the texture unit to apply
- * \param n            number of fragments to process (span width)
- * \param primary_rgba incoming fragment color array
- * \param texelBuffer  pointer to texel colors for all texture units
- * 
- * \param rgba         incoming colors, which get modified here
- */
-static void
-texture_combine( const GLcontext *ctx, GLuint unit, GLuint n,
-                 CONST GLchan (*primary_rgba)[4],
-                 CONST GLchan *texelBuffer,
-                 GLchan (*rgba)[4] )
-{
-   const struct gl_texture_unit *textureUnit = &(ctx->Texture.Unit[unit]);
-   const GLchan (*argRGB [3])[4];
-   const GLchan (*argA [3])[4];
-   const GLuint RGBshift = textureUnit->_CurrentCombine->ScaleShiftRGB;
-   const GLuint Ashift   = textureUnit->_CurrentCombine->ScaleShiftA;
-#if CHAN_TYPE == GL_FLOAT
-   const GLchan RGBmult = (GLfloat) (1 << RGBshift);
-   const GLchan Amult = (GLfloat) (1 << Ashift);
-   static const GLchan one[4] = { 1.0, 1.0, 1.0, 1.0 };
-   static const GLchan zero[4] = { 0.0, 0.0, 0.0, 0.0 };
-#else
-   const GLint half = (CHAN_MAX + 1) / 2;
-   static const GLchan one[4] = { CHAN_MAX, CHAN_MAX, CHAN_MAX, CHAN_MAX };
-   static const GLchan zero[4] = { 0, 0, 0, 0 };
-#endif
-   const GLuint numColorArgs = textureUnit->_CurrentCombine->_NumArgsRGB;
-   const GLuint numAlphaArgs = textureUnit->_CurrentCombine->_NumArgsA;
-   GLchan ccolor[3][MAX_WIDTH][4];
-   GLuint i, j;
-
-   ASSERT(ctx->Extensions.EXT_texture_env_combine ||
-          ctx->Extensions.ARB_texture_env_combine);
-   ASSERT(SWRAST_CONTEXT(ctx)->_AnyTextureCombine);
-
-   /*
-   printf("modeRGB 0x%x  modeA 0x%x  srcRGB1 0x%x  srcA1 0x%x  srcRGB2 0x%x  srcA2 0x%x\n",
-          textureUnit->_CurrentCombine->ModeRGB,
-          textureUnit->_CurrentCombine->ModeA,
-          textureUnit->_CurrentCombine->SourceRGB[0],
-          textureUnit->_CurrentCombine->SourceA[0],
-          textureUnit->_CurrentCombine->SourceRGB[1],
-          textureUnit->_CurrentCombine->SourceA[1]);
-   */
-
-   /*
-    * Do operand setup for up to 3 operands.  Loop over the terms.
-    */
-   for (j = 0; j < numColorArgs; j++) {
-      const GLenum srcRGB = textureUnit->_CurrentCombine->SourceRGB[j];
-
-
-      switch (srcRGB) {
-         case GL_TEXTURE:
-            argRGB[j] = (const GLchan (*)[4])
-               (texelBuffer + unit * (n * 4 * sizeof(GLchan)));
-            break;
-         case GL_PRIMARY_COLOR:
-            argRGB[j] = primary_rgba;
-            break;
-         case GL_PREVIOUS:
-            argRGB[j] = (const GLchan (*)[4]) rgba;
-            break;
-         case GL_CONSTANT:
-            {
-               GLchan (*c)[4] = ccolor[j];
-               GLchan red, green, blue, alpha;
-               UNCLAMPED_FLOAT_TO_CHAN(red,   textureUnit->EnvColor[0]);
-               UNCLAMPED_FLOAT_TO_CHAN(green, textureUnit->EnvColor[1]);
-               UNCLAMPED_FLOAT_TO_CHAN(blue,  textureUnit->EnvColor[2]);
-               UNCLAMPED_FLOAT_TO_CHAN(alpha, textureUnit->EnvColor[3]);
-               for (i = 0; i < n; i++) {
-                  c[i][RCOMP] = red;
-                  c[i][GCOMP] = green;
-                  c[i][BCOMP] = blue;
-                  c[i][ACOMP] = alpha;
-               }
-               argRGB[j] = (const GLchan (*)[4]) ccolor[j];
-            }
-            break;
-        /* GL_ATI_texture_env_combine3 allows GL_ZERO & GL_ONE as sources.
-         */
-        case GL_ZERO:
-            argRGB[j] = & zero;
-            break;
-        case GL_ONE:
-            argRGB[j] = & one;
-            break;
-         default:
-            /* ARB_texture_env_crossbar source */
-            {
-               const GLuint srcUnit = srcRGB - GL_TEXTURE0;
-               ASSERT(srcUnit < ctx->Const.MaxTextureUnits);
-               if (!ctx->Texture.Unit[srcUnit]._ReallyEnabled)
-                  return;
-               argRGB[j] = (const GLchan (*)[4])
-                  (texelBuffer + srcUnit * (n * 4 * sizeof(GLchan)));
-            }
-      }
-
-      if (textureUnit->_CurrentCombine->OperandRGB[j] != GL_SRC_COLOR) {
-         const GLchan (*src)[4] = argRGB[j];
-         GLchan (*dst)[4] = ccolor[j];
-
-         /* point to new arg[j] storage */
-         argRGB[j] = (const GLchan (*)[4]) ccolor[j];
-
-         if (textureUnit->_CurrentCombine->OperandRGB[j] == GL_ONE_MINUS_SRC_COLOR) {
-            for (i = 0; i < n; i++) {
-               dst[i][RCOMP] = CHAN_MAX - src[i][RCOMP];
-               dst[i][GCOMP] = CHAN_MAX - src[i][GCOMP];
-               dst[i][BCOMP] = CHAN_MAX - src[i][BCOMP];
-            }
-         }
-         else if (textureUnit->_CurrentCombine->OperandRGB[j] == GL_SRC_ALPHA) {
-            for (i = 0; i < n; i++) {
-               dst[i][RCOMP] = src[i][ACOMP];
-               dst[i][GCOMP] = src[i][ACOMP];
-               dst[i][BCOMP] = src[i][ACOMP];
-            }
-         }
-         else {
-            ASSERT(textureUnit->_CurrentCombine->OperandRGB[j] ==GL_ONE_MINUS_SRC_ALPHA);
-            for (i = 0; i < n; i++) {
-               dst[i][RCOMP] = CHAN_MAX - src[i][ACOMP];
-               dst[i][GCOMP] = CHAN_MAX - src[i][ACOMP];
-               dst[i][BCOMP] = CHAN_MAX - src[i][ACOMP];
-            }
-         }
-      }
-   }
-
-   /*
-    * Set up the argA[i] pointers
-    */
-   for (j = 0; j < numAlphaArgs; j++) {
-      const GLenum srcA = textureUnit->_CurrentCombine->SourceA[j];
-
-      switch (srcA) {
-         case GL_TEXTURE:
-            argA[j] = (const GLchan (*)[4])
-               (texelBuffer + unit * (n * 4 * sizeof(GLchan)));
-            break;
-         case GL_PRIMARY_COLOR:
-            argA[j] = primary_rgba;
-            break;
-         case GL_PREVIOUS:
-            argA[j] = (const GLchan (*)[4]) rgba;
-            break;
-         case GL_CONSTANT:
-            {
-               GLchan alpha, (*c)[4] = ccolor[j];
-               UNCLAMPED_FLOAT_TO_CHAN(alpha, textureUnit->EnvColor[3]);
-               for (i = 0; i < n; i++)
-                  c[i][ACOMP] = alpha;
-               argA[j] = (const GLchan (*)[4]) ccolor[j];
-            }
-            break;
-        /* GL_ATI_texture_env_combine3 allows GL_ZERO & GL_ONE as sources.
-         */
-        case GL_ZERO:
-            argA[j] = & zero;
-            break;
-        case GL_ONE:
-            argA[j] = & one;
-            break;
-         default:
-            /* ARB_texture_env_crossbar source */
-            {
-               const GLuint srcUnit = srcA - GL_TEXTURE0;
-               ASSERT(srcUnit < ctx->Const.MaxTextureUnits);
-               if (!ctx->Texture.Unit[srcUnit]._ReallyEnabled)
-                  return;
-               argA[j] = (const GLchan (*)[4])
-                  (texelBuffer + srcUnit * (n * 4 * sizeof(GLchan)));
-            }
-      }
-
-      if (textureUnit->_CurrentCombine->OperandA[j] == GL_ONE_MINUS_SRC_ALPHA) {
-         const GLchan (*src)[4] = argA[j];
-         GLchan (*dst)[4] = ccolor[j];
-         argA[j] = (const GLchan (*)[4]) ccolor[j];
-         for (i = 0; i < n; i++) {
-            dst[i][ACOMP] = CHAN_MAX - src[i][ACOMP];
-         }
-      }
-   }
-
-   /*
-    * Do the texture combine.
-    */
-   switch (textureUnit->_CurrentCombine->ModeRGB) {
-      case GL_REPLACE:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
-            if (RGBshift) {
-               for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-                  rgba[i][RCOMP] = arg0[i][RCOMP] * RGBmult;
-                  rgba[i][GCOMP] = arg0[i][GCOMP] * RGBmult;
-                  rgba[i][BCOMP] = arg0[i][BCOMP] * RGBmult;
-#else
-                  GLuint r = (GLuint) arg0[i][RCOMP] << RGBshift;
-                  GLuint g = (GLuint) arg0[i][GCOMP] << RGBshift;
-                  GLuint b = (GLuint) arg0[i][BCOMP] << RGBshift;
-                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
-                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
-                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
-#endif
-               }
-            }
-            else {
-               for (i = 0; i < n; i++) {
-                  rgba[i][RCOMP] = arg0[i][RCOMP];
-                  rgba[i][GCOMP] = arg0[i][GCOMP];
-                  rgba[i][BCOMP] = arg0[i][BCOMP];
-               }
-            }
-         }
-         break;
-      case GL_MODULATE:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
-#if CHAN_TYPE != GL_FLOAT
-            const GLint shift = CHAN_BITS - RGBshift;
-#endif
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][RCOMP] = arg0[i][RCOMP] * arg1[i][RCOMP] * RGBmult;
-               rgba[i][GCOMP] = arg0[i][GCOMP] * arg1[i][GCOMP] * RGBmult;
-               rgba[i][BCOMP] = arg0[i][BCOMP] * arg1[i][BCOMP] * RGBmult;
-#else
-               GLuint r = PROD(arg0[i][RCOMP], arg1[i][RCOMP]) >> shift;
-               GLuint g = PROD(arg0[i][GCOMP], arg1[i][GCOMP]) >> shift;
-               GLuint b = PROD(arg0[i][BCOMP], arg1[i][BCOMP]) >> shift;
-               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
-               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
-               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
-#endif
-            }
-         }
-         break;
-      case GL_ADD:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][RCOMP] = (arg0[i][RCOMP] + arg1[i][RCOMP]) * RGBmult;
-               rgba[i][GCOMP] = (arg0[i][GCOMP] + arg1[i][GCOMP]) * RGBmult;
-               rgba[i][BCOMP] = (arg0[i][BCOMP] + arg1[i][BCOMP]) * RGBmult;
-#else
-               GLint r = ((GLint) arg0[i][RCOMP] + (GLint) arg1[i][RCOMP]) << RGBshift;
-               GLint g = ((GLint) arg0[i][GCOMP] + (GLint) arg1[i][GCOMP]) << RGBshift;
-               GLint b = ((GLint) arg0[i][BCOMP] + (GLint) arg1[i][BCOMP]) << RGBshift;
-               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
-               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
-               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
-#endif
-            }
-         }
-         break;
-      case GL_ADD_SIGNED:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][RCOMP] = (arg0[i][RCOMP] + arg1[i][RCOMP] - 0.5) * RGBmult;
-               rgba[i][GCOMP] = (arg0[i][GCOMP] + arg1[i][GCOMP] - 0.5) * RGBmult;
-               rgba[i][BCOMP] = (arg0[i][BCOMP] + arg1[i][BCOMP] - 0.5) * RGBmult;
-#else
-               GLint r = (GLint) arg0[i][RCOMP] + (GLint) arg1[i][RCOMP] -half;
-               GLint g = (GLint) arg0[i][GCOMP] + (GLint) arg1[i][GCOMP] -half;
-               GLint b = (GLint) arg0[i][BCOMP] + (GLint) arg1[i][BCOMP] -half;
-               r = (r < 0) ? 0 : r << RGBshift;
-               g = (g < 0) ? 0 : g << RGBshift;
-               b = (b < 0) ? 0 : b << RGBshift;
-               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
-               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
-               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
-#endif
-            }
-         }
-         break;
-      case GL_INTERPOLATE:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
-            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
-#if CHAN_TYPE != GL_FLOAT
-            const GLint shift = CHAN_BITS - RGBshift;
-#endif
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][RCOMP] = (arg0[i][RCOMP] * arg2[i][RCOMP] +
-                      arg1[i][RCOMP] * (CHAN_MAXF - arg2[i][RCOMP])) * RGBmult;
-               rgba[i][GCOMP] = (arg0[i][GCOMP] * arg2[i][GCOMP] +
-                      arg1[i][GCOMP] * (CHAN_MAXF - arg2[i][GCOMP])) * RGBmult;
-               rgba[i][BCOMP] = (arg0[i][BCOMP] * arg2[i][BCOMP] +
-                      arg1[i][BCOMP] * (CHAN_MAXF - arg2[i][BCOMP])) * RGBmult;
-#else
-               GLuint r = (PROD(arg0[i][RCOMP], arg2[i][RCOMP])
-                           + PROD(arg1[i][RCOMP], CHAN_MAX - arg2[i][RCOMP]))
-                              >> shift;
-               GLuint g = (PROD(arg0[i][GCOMP], arg2[i][GCOMP])
-                           + PROD(arg1[i][GCOMP], CHAN_MAX - arg2[i][GCOMP]))
-                              >> shift;
-               GLuint b = (PROD(arg0[i][BCOMP], arg2[i][BCOMP])
-                           + PROD(arg1[i][BCOMP], CHAN_MAX - arg2[i][BCOMP]))
-                              >> shift;
-               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
-               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
-               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
-#endif
-            }
-         }
-         break;
-      case GL_SUBTRACT:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][RCOMP] = (arg0[i][RCOMP] - arg1[i][RCOMP]) * RGBmult;
-               rgba[i][GCOMP] = (arg0[i][GCOMP] - arg1[i][GCOMP]) * RGBmult;
-               rgba[i][BCOMP] = (arg0[i][BCOMP] - arg1[i][BCOMP]) * RGBmult;
-#else
-               GLint r = ((GLint) arg0[i][RCOMP] - (GLint) arg1[i][RCOMP]) << RGBshift;
-               GLint g = ((GLint) arg0[i][GCOMP] - (GLint) arg1[i][GCOMP]) << RGBshift;
-               GLint b = ((GLint) arg0[i][BCOMP] - (GLint) arg1[i][BCOMP]) << RGBshift;
-               rgba[i][RCOMP] = (GLchan) CLAMP(r, 0, CHAN_MAX);
-               rgba[i][GCOMP] = (GLchan) CLAMP(g, 0, CHAN_MAX);
-               rgba[i][BCOMP] = (GLchan) CLAMP(b, 0, CHAN_MAX);
-#endif
-            }
-         }
-         break;
-      case GL_DOT3_RGB_EXT:
-      case GL_DOT3_RGBA_EXT:
-         {
-            /* Do not scale the result by 1 2 or 4 */
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               GLchan dot = ((arg0[i][RCOMP]-0.5F) * (arg1[i][RCOMP]-0.5F) +
-                             (arg0[i][GCOMP]-0.5F) * (arg1[i][GCOMP]-0.5F) +
-                             (arg0[i][BCOMP]-0.5F) * (arg1[i][BCOMP]-0.5F))
-                            * 4.0F;
-               dot = CLAMP(dot, 0.0F, CHAN_MAXF);
-#else
-               GLint dot = (S_PROD((GLint)arg0[i][RCOMP] - half,
-                                  (GLint)arg1[i][RCOMP] - half) +
-                           S_PROD((GLint)arg0[i][GCOMP] - half,
-                                  (GLint)arg1[i][GCOMP] - half) +
-                           S_PROD((GLint)arg0[i][BCOMP] - half,
-                                  (GLint)arg1[i][BCOMP] - half)) >> 6;
-               dot = CLAMP(dot, 0, CHAN_MAX);
-#endif
-               rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = (GLchan) dot;
-            }
-         }
-         break;
-      case GL_DOT3_RGB:
-      case GL_DOT3_RGBA:
-         {
-            /* DO scale the result by 1 2 or 4 */
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               GLchan dot = ((arg0[i][RCOMP]-0.5F) * (arg1[i][RCOMP]-0.5F) +
-                             (arg0[i][GCOMP]-0.5F) * (arg1[i][GCOMP]-0.5F) +
-                             (arg0[i][BCOMP]-0.5F) * (arg1[i][BCOMP]-0.5F))
-                            * 4.0F * RGBmult;
-               dot = CLAMP(dot, 0.0, CHAN_MAXF);
-#else
-               GLint dot = (S_PROD((GLint)arg0[i][RCOMP] - half,
-                                  (GLint)arg1[i][RCOMP] - half) +
-                           S_PROD((GLint)arg0[i][GCOMP] - half,
-                                  (GLint)arg1[i][GCOMP] - half) +
-                           S_PROD((GLint)arg0[i][BCOMP] - half,
-                                  (GLint)arg1[i][BCOMP] - half)) >> 6;
-               dot <<= RGBshift;
-               dot = CLAMP(dot, 0, CHAN_MAX);
-#endif
-               rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = (GLchan) dot;
-            }
-         }
-         break;
-      case GL_MODULATE_ADD_ATI:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
-            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
-#if CHAN_TYPE != GL_FLOAT
-            const GLint shift = CHAN_BITS - RGBshift;
-#endif
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][RCOMP] = ((arg0[i][RCOMP] * arg2[i][RCOMP]) + arg1[i][RCOMP]) * RGBmult;
-               rgba[i][GCOMP] = ((arg0[i][GCOMP] * arg2[i][GCOMP]) + arg1[i][GCOMP]) * RGBmult;
-               rgba[i][BCOMP] = ((arg0[i][BCOMP] * arg2[i][BCOMP]) + arg1[i][BCOMP]) * RGBmult;
-#else
-               GLuint r = (PROD(arg0[i][RCOMP], arg2[i][RCOMP])
-                           + ((GLuint) arg1[i][RCOMP] << CHAN_BITS)) >> shift;
-               GLuint g = (PROD(arg0[i][GCOMP], arg2[i][GCOMP])
-                           + ((GLuint) arg1[i][GCOMP] << CHAN_BITS)) >> shift;
-               GLuint b = (PROD(arg0[i][BCOMP], arg2[i][BCOMP])
-                           + ((GLuint) arg1[i][BCOMP] << CHAN_BITS)) >> shift;
-               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
-               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
-               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
-#endif
-            }
-        }
-         break;
-      case GL_MODULATE_SIGNED_ADD_ATI:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
-            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
-#if CHAN_TYPE != GL_FLOAT
-            const GLint shift = CHAN_BITS - RGBshift;
-#endif
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][RCOMP] = ((arg0[i][RCOMP] * arg2[i][RCOMP]) + arg1[i][RCOMP] - 0.5) * RGBmult;
-               rgba[i][GCOMP] = ((arg0[i][GCOMP] * arg2[i][GCOMP]) + arg1[i][GCOMP] - 0.5) * RGBmult;
-               rgba[i][BCOMP] = ((arg0[i][BCOMP] * arg2[i][BCOMP]) + arg1[i][BCOMP] - 0.5) * RGBmult;
-#else
-               GLint r = (S_PROD(arg0[i][RCOMP], arg2[i][RCOMP])
-                         + (((GLint) arg1[i][RCOMP] - half) << CHAN_BITS))
-                   >> shift;
-               GLint g = (S_PROD(arg0[i][GCOMP], arg2[i][GCOMP])
-                         + (((GLint) arg1[i][GCOMP] - half) << CHAN_BITS))
-                   >> shift;
-               GLint b = (S_PROD(arg0[i][BCOMP], arg2[i][BCOMP])
-                         + (((GLint) arg1[i][BCOMP] - half) << CHAN_BITS))
-                   >> shift;
-               rgba[i][RCOMP] = (GLchan) CLAMP(r, 0, CHAN_MAX);
-               rgba[i][GCOMP] = (GLchan) CLAMP(g, 0, CHAN_MAX);
-               rgba[i][BCOMP] = (GLchan) CLAMP(b, 0, CHAN_MAX);
-#endif
-            }
-        }
-         break;
-      case GL_MODULATE_SUBTRACT_ATI:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
-            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
-#if CHAN_TYPE != GL_FLOAT
-            const GLint shift = CHAN_BITS - RGBshift;
-#endif
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][RCOMP] = ((arg0[i][RCOMP] * arg2[i][RCOMP]) - arg1[i][RCOMP]) * RGBmult;
-               rgba[i][GCOMP] = ((arg0[i][GCOMP] * arg2[i][GCOMP]) - arg1[i][GCOMP]) * RGBmult;
-               rgba[i][BCOMP] = ((arg0[i][BCOMP] * arg2[i][BCOMP]) - arg1[i][BCOMP]) * RGBmult;
-#else
-               GLint r = (S_PROD(arg0[i][RCOMP], arg2[i][RCOMP])
-                         - ((GLint) arg1[i][RCOMP] << CHAN_BITS))
-                   >> shift;
-               GLint g = (S_PROD(arg0[i][GCOMP], arg2[i][GCOMP])
-                         - ((GLint) arg1[i][GCOMP] << CHAN_BITS))
-                   >> shift;
-               GLint b = (S_PROD(arg0[i][BCOMP], arg2[i][BCOMP])
-                         - ((GLint) arg1[i][BCOMP] << CHAN_BITS))
-                   >> shift;
-               rgba[i][RCOMP] = (GLchan) CLAMP(r, 0, CHAN_MAX);
-               rgba[i][GCOMP] = (GLchan) CLAMP(g, 0, CHAN_MAX);
-               rgba[i][BCOMP] = (GLchan) CLAMP(b, 0, CHAN_MAX);
-#endif
-            }
-        }
-         break;
-      default:
-         _mesa_problem(ctx, "invalid combine mode");
-   }
-
-   switch (textureUnit->_CurrentCombine->ModeA) {
-      case GL_REPLACE:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
-            if (Ashift) {
-               for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-                  GLchan a = arg0[i][ACOMP] * Amult;
-#else
-                  GLuint a = (GLuint) arg0[i][ACOMP] << Ashift;
-#endif
-                  rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
-               }
-            }
-            else {
-               for (i = 0; i < n; i++) {
-                  rgba[i][ACOMP] = arg0[i][ACOMP];
-               }
-            }
-         }
-         break;
-      case GL_MODULATE:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
-#if CHAN_TYPE != GL_FLOAT
-            const GLint shift = CHAN_BITS - Ashift;
-#endif
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][ACOMP] = arg0[i][ACOMP] * arg1[i][ACOMP] * Amult;
-#else
-               GLuint a = (PROD(arg0[i][ACOMP], arg1[i][ACOMP]) >> shift);
-               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
-#endif
-            }
-         }
-         break;
-      case GL_ADD:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
-            const GLchan  (*arg1)[4] = (const GLchan (*)[4]) argA[1];
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][ACOMP] = (arg0[i][ACOMP] + arg1[i][ACOMP]) * Amult;
-#else
-               GLint a = ((GLint) arg0[i][ACOMP] + arg1[i][ACOMP]) << Ashift;
-               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
-#endif
-            }
-         }
-         break;
-      case GL_ADD_SIGNED:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][ACOMP] = (arg0[i][ACOMP] + arg1[i][ACOMP] - 0.5F) * Amult;
-#else
-               GLint a = (GLint) arg0[i][ACOMP] + (GLint) arg1[i][ACOMP] -half;
-               a = (a < 0) ? 0 : a << Ashift;
-               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
-#endif
-            }
-         }
-         break;
-      case GL_INTERPOLATE:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
-            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
-#if CHAN_TYPE != GL_FLOAT
-            const GLint shift = CHAN_BITS - Ashift;
-#endif
-            for (i=0; i<n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][ACOMP] = (arg0[i][ACOMP] * arg2[i][ACOMP] +
-                                 arg1[i][ACOMP] * (CHAN_MAXF - arg2[i][ACOMP]))
-                                * Amult;
-#else
-               GLuint a = (PROD(arg0[i][ACOMP], arg2[i][ACOMP])
-                           + PROD(arg1[i][ACOMP], CHAN_MAX - arg2[i][ACOMP]))
-                              >> shift;
-               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
-#endif
-            }
-         }
-         break;
-      case GL_SUBTRACT:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][ACOMP] = (arg0[i][ACOMP] - arg1[i][ACOMP]) * Amult;
-#else
-               GLint a = ((GLint) arg0[i][ACOMP] - (GLint) arg1[i][ACOMP]) << Ashift;
-               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
-#endif
-            }
-         }
-         break;
-      case GL_MODULATE_ADD_ATI:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
-            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
-#if CHAN_TYPE != GL_FLOAT
-            const GLint shift = CHAN_BITS - Ashift;
-#endif
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][ACOMP] = ((arg0[i][ACOMP] * arg2[i][ACOMP]) + arg1[i][ACOMP]) * Amult;
-#else
-               GLint a = (PROD(arg0[i][ACOMP], arg2[i][ACOMP])
-                          + ((GLuint) arg1[i][ACOMP] << CHAN_BITS))
-                   >> shift;
-               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
-#endif
-            }
-         }
-         break;
-      case GL_MODULATE_SIGNED_ADD_ATI:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
-            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
-#if CHAN_TYPE != GL_FLOAT
-            const GLint shift = CHAN_BITS - Ashift;
-#endif
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][ACOMP] = ((arg0[i][ACOMP] * arg2[i][ACOMP]) + arg1[i][ACOMP] - 0.5F) * Amult;
-#else
-               GLint a = (S_PROD(arg0[i][ACOMP], arg2[i][ACOMP])
-                         + (((GLint) arg1[i][ACOMP] - half) << CHAN_BITS))
-                   >> shift;
-               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
-#endif
-            }
-         }
-         break;
-      case GL_MODULATE_SUBTRACT_ATI:
-         {
-            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
-            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
-            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
-#if CHAN_TYPE != GL_FLOAT
-            const GLint shift = CHAN_BITS - Ashift;
-#endif
-            for (i = 0; i < n; i++) {
-#if CHAN_TYPE == GL_FLOAT
-               rgba[i][ACOMP] = ((arg0[i][ACOMP] * arg2[i][ACOMP]) - arg1[i][ACOMP]) * Amult;
-#else
-               GLint a = (S_PROD(arg0[i][ACOMP], arg2[i][ACOMP]) 
-                         - ((GLint) arg1[i][ACOMP] << CHAN_BITS))
-                   >> shift;
-               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
-#endif
-            }
-         }
-         break;
-      default:
-         _mesa_problem(ctx, "invalid combine mode");
-   }
-
-   /* Fix the alpha component for GL_DOT3_RGBA_EXT/ARB combining.
-    * This is kind of a kludge.  It would have been better if the spec
-    * were written such that the GL_COMBINE_ALPHA value could be set to
-    * GL_DOT3.
-    */
-   if (textureUnit->_CurrentCombine->ModeRGB == GL_DOT3_RGBA_EXT ||
-       textureUnit->_CurrentCombine->ModeRGB == GL_DOT3_RGBA) {
-      for (i = 0; i < n; i++) {
-        rgba[i][ACOMP] = rgba[i][RCOMP];
-      }
-   }
-}
-#undef PROD
-
-
-/**
- * Apply a conventional OpenGL texture env mode (REPLACE, ADD, BLEND,
- * MODULATE, or DECAL) to an array of fragments.
- * Input:  textureUnit - pointer to texture unit to apply
- *         format - base internal texture format
- *         n - number of fragments
- *         primary_rgba - primary colors (may alias rgba for single texture)
- *         texels - array of texel colors
- * InOut:  rgba - incoming fragment colors modified by texel colors
- *                according to the texture environment mode.
- */
-static void
-texture_apply( const GLcontext *ctx,
-               const struct gl_texture_unit *texUnit,
-               GLuint n,
-               CONST GLchan primary_rgba[][4], CONST GLchan texel[][4],
-               GLchan rgba[][4] )
-{
-   GLint baseLevel;
-   GLuint i;
-   GLint Rc, Gc, Bc, Ac;
-   GLenum format;
-   (void) primary_rgba;
-
-   ASSERT(texUnit);
-   ASSERT(texUnit->_Current);
-
-   baseLevel = texUnit->_Current->BaseLevel;
-   ASSERT(texUnit->_Current->Image[0][baseLevel]);
-
-   format = texUnit->_Current->Image[0][baseLevel]->Format;
-
-   if (format == GL_COLOR_INDEX || format == GL_YCBCR_MESA) {
-      format = GL_RGBA;  /* a bit of a hack */
-   }
-   else if (format == GL_DEPTH_COMPONENT) {
-      format = texUnit->_Current->DepthMode;
-   }
-
-   switch (texUnit->EnvMode) {
-      case GL_REPLACE:
-        switch (format) {
-           case GL_ALPHA:
-              for (i=0;i<n;i++) {
-                 /* Cv = Cf */
-                  /* Av = At */
-                  rgba[i][ACOMP] = texel[i][ACOMP];
-              }
-              break;
-           case GL_LUMINANCE:
-              for (i=0;i<n;i++) {
-                 /* Cv = Lt */
-                  GLchan Lt = texel[i][RCOMP];
-                  rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = Lt;
-                  /* Av = Af */
-              }
-              break;
-           case GL_LUMINANCE_ALPHA:
-              for (i=0;i<n;i++) {
-                  GLchan Lt = texel[i][RCOMP];
-                 /* Cv = Lt */
-                 rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = Lt;
-                 /* Av = At */
-                 rgba[i][ACOMP] = texel[i][ACOMP];
-              }
-              break;
-           case GL_INTENSITY:
-              for (i=0;i<n;i++) {
-                 /* Cv = It */
-                  GLchan It = texel[i][RCOMP];
-                  rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = It;
-                  /* Av = It */
-                  rgba[i][ACOMP] = It;
-              }
-              break;
-           case GL_RGB:
-              for (i=0;i<n;i++) {
-                 /* Cv = Ct */
-                 rgba[i][RCOMP] = texel[i][RCOMP];
-                 rgba[i][GCOMP] = texel[i][GCOMP];
-                 rgba[i][BCOMP] = texel[i][BCOMP];
-                 /* Av = Af */
-              }
-              break;
-           case GL_RGBA:
-              for (i=0;i<n;i++) {
-                 /* Cv = Ct */
-                 rgba[i][RCOMP] = texel[i][RCOMP];
-                 rgba[i][GCOMP] = texel[i][GCOMP];
-                 rgba[i][BCOMP] = texel[i][BCOMP];
-                 /* Av = At */
-                 rgba[i][ACOMP] = texel[i][ACOMP];
-              }
-              break;
-            default:
-               _mesa_problem(ctx, "Bad format (GL_REPLACE) in texture_apply");
-               return;
-        }
-        break;
-
-      case GL_MODULATE:
-         switch (format) {
-           case GL_ALPHA:
-              for (i=0;i<n;i++) {
-                 /* Cv = Cf */
-                 /* Av = AfAt */
-                 rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], texel[i][ACOMP] );
-              }
-              break;
-           case GL_LUMINANCE:
-              for (i=0;i<n;i++) {
-                 /* Cv = LtCf */
-                  GLchan Lt = texel[i][RCOMP];
-                 rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], Lt );
-                 rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], Lt );
-                 rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], Lt );
-                 /* Av = Af */
-              }
-              break;
-           case GL_LUMINANCE_ALPHA:
-              for (i=0;i<n;i++) {
-                 /* Cv = CfLt */
-                  GLchan Lt = texel[i][RCOMP];
-                 rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], Lt );
-                 rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], Lt );
-                 rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], Lt );
-                 /* Av = AfAt */
-                 rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], texel[i][ACOMP] );
-              }
-              break;
-           case GL_INTENSITY:
-              for (i=0;i<n;i++) {
-                 /* Cv = CfIt */
-                  GLchan It = texel[i][RCOMP];
-                 rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], It );
-                 rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], It );
-                 rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], It );
-                 /* Av = AfIt */
-                 rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], It );
-              }
-              break;
-           case GL_RGB:
-              for (i=0;i<n;i++) {
-                 /* Cv = CfCt */
-                 rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], texel[i][RCOMP] );
-                 rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], texel[i][GCOMP] );
-                 rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], texel[i][BCOMP] );
-                 /* Av = Af */
-              }
-              break;
-           case GL_RGBA:
-              for (i=0;i<n;i++) {
-                 /* Cv = CfCt */
-                 rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], texel[i][RCOMP] );
-                 rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], texel[i][GCOMP] );
-                 rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], texel[i][BCOMP] );
-                 /* Av = AfAt */
-                 rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], texel[i][ACOMP] );
-              }
-              break;
-            default:
-               _mesa_problem(ctx, "Bad format (GL_MODULATE) in texture_apply");
-               return;
-        }
-        break;
-
-      case GL_DECAL:
-         switch (format) {
-            case GL_ALPHA:
-            case GL_LUMINANCE:
-            case GL_LUMINANCE_ALPHA:
-            case GL_INTENSITY:
-               /* undefined */
-               break;
-           case GL_RGB:
-              for (i=0;i<n;i++) {
-                 /* Cv = Ct */
-                 rgba[i][RCOMP] = texel[i][RCOMP];
-                 rgba[i][GCOMP] = texel[i][GCOMP];
-                 rgba[i][BCOMP] = texel[i][BCOMP];
-                 /* Av = Af */
-              }
-              break;
-           case GL_RGBA:
-              for (i=0;i<n;i++) {
-                 /* Cv = Cf(1-At) + CtAt */
-                 GLint t = texel[i][ACOMP], s = CHAN_MAX - t;
-                 rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(texel[i][RCOMP],t);
-                 rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(texel[i][GCOMP],t);
-                 rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(texel[i][BCOMP],t);
-                 /* Av = Af */
-              }
-              break;
-            default:
-               _mesa_problem(ctx, "Bad format (GL_DECAL) in texture_apply");
-               return;
-        }
-        break;
-
-      case GL_BLEND:
-         Rc = (GLint) (texUnit->EnvColor[0] * CHAN_MAXF);
-         Gc = (GLint) (texUnit->EnvColor[1] * CHAN_MAXF);
-         Bc = (GLint) (texUnit->EnvColor[2] * CHAN_MAXF);
-         Ac = (GLint) (texUnit->EnvColor[3] * CHAN_MAXF);
-        switch (format) {
-           case GL_ALPHA:
-              for (i=0;i<n;i++) {
-                 /* Cv = Cf */
-                 /* Av = AfAt */
-                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
-              }
-              break;
-            case GL_LUMINANCE:
-              for (i=0;i<n;i++) {
-                 /* Cv = Cf(1-Lt) + CcLt */
-                 GLchan Lt = texel[i][RCOMP], s = CHAN_MAX - Lt;
-                 rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(Rc, Lt);
-                 rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(Gc, Lt);
-                 rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(Bc, Lt);
-                 /* Av = Af */
-              }
-              break;
-           case GL_LUMINANCE_ALPHA:
-              for (i=0;i<n;i++) {
-                 /* Cv = Cf(1-Lt) + CcLt */
-                 GLchan Lt = texel[i][RCOMP], s = CHAN_MAX - Lt;
-                 rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(Rc, Lt);
-                 rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(Gc, Lt);
-                 rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(Bc, Lt);
-                 /* Av = AfAt */
-                 rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP],texel[i][ACOMP]);
-              }
-              break;
-            case GL_INTENSITY:
-              for (i=0;i<n;i++) {
-                 /* Cv = Cf(1-It) + CcIt */
-                 GLchan It = texel[i][RCOMP], s = CHAN_MAX - It;
-                 rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(Rc, It);
-                 rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(Gc, It);
-                 rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(Bc, It);
-                  /* Av = Af(1-It) + Ac*It */
-                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], s) + CHAN_PRODUCT(Ac, It);
-               }
-               break;
-           case GL_RGB:
-              for (i=0;i<n;i++) {
-                 /* Cv = Cf(1-Ct) + CcCt */
-                 rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], (CHAN_MAX-texel[i][RCOMP])) + CHAN_PRODUCT(Rc,texel[i][RCOMP]);
-                 rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], (CHAN_MAX-texel[i][GCOMP])) + CHAN_PRODUCT(Gc,texel[i][GCOMP]);
-                 rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], (CHAN_MAX-texel[i][BCOMP])) + CHAN_PRODUCT(Bc,texel[i][BCOMP]);
-                 /* Av = Af */
-              }
-              break;
-           case GL_RGBA:
-              for (i=0;i<n;i++) {
-                 /* Cv = Cf(1-Ct) + CcCt */
-                 rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], (CHAN_MAX-texel[i][RCOMP])) + CHAN_PRODUCT(Rc,texel[i][RCOMP]);
-                 rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], (CHAN_MAX-texel[i][GCOMP])) + CHAN_PRODUCT(Gc,texel[i][GCOMP]);
-                 rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], (CHAN_MAX-texel[i][BCOMP])) + CHAN_PRODUCT(Bc,texel[i][BCOMP]);
-                 /* Av = AfAt */
-                 rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP],texel[i][ACOMP]);
-              }
-              break;
-            default:
-               _mesa_problem(ctx, "Bad format (GL_BLEND) in texture_apply");
-               return;
-        }
-        break;
-
-     /* XXX don't clamp results if GLchan is float??? */
-
-      case GL_ADD:  /* GL_EXT_texture_add_env */
-         switch (format) {
-            case GL_ALPHA:
-               for (i=0;i<n;i++) {
-                  /* Rv = Rf */
-                  /* Gv = Gf */
-                  /* Bv = Bf */
-                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
-               }
-               break;
-            case GL_LUMINANCE:
-               for (i=0;i<n;i++) {
-                  GLuint Lt = texel[i][RCOMP];
-                  GLuint r = rgba[i][RCOMP] + Lt;
-                  GLuint g = rgba[i][GCOMP] + Lt;
-                  GLuint b = rgba[i][BCOMP] + Lt;
-                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
-                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
-                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
-                  /* Av = Af */
-               }
-               break;
-            case GL_LUMINANCE_ALPHA:
-               for (i=0;i<n;i++) {
-                  GLuint Lt = texel[i][RCOMP];
-                  GLuint r = rgba[i][RCOMP] + Lt;
-                  GLuint g = rgba[i][GCOMP] + Lt;
-                  GLuint b = rgba[i][BCOMP] + Lt;
-                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
-                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
-                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
-                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
-               }
-               break;
-            case GL_INTENSITY:
-               for (i=0;i<n;i++) {
-                  GLchan It = texel[i][RCOMP];
-                  GLuint r = rgba[i][RCOMP] + It;
-                  GLuint g = rgba[i][GCOMP] + It;
-                  GLuint b = rgba[i][BCOMP] + It;
-                  GLuint a = rgba[i][ACOMP] + It;
-                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
-                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
-                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
-                  rgba[i][ACOMP] = MIN2(a, CHAN_MAX);
-               }
-               break;
-           case GL_RGB:
-              for (i=0;i<n;i++) {
-                  GLuint r = rgba[i][RCOMP] + texel[i][RCOMP];
-                  GLuint g = rgba[i][GCOMP] + texel[i][GCOMP];
-                  GLuint b = rgba[i][BCOMP] + texel[i][BCOMP];
-                 rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
-                 rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
-                 rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
-                 /* Av = Af */
-              }
-              break;
-           case GL_RGBA:
-              for (i=0;i<n;i++) {
-                  GLuint r = rgba[i][RCOMP] + texel[i][RCOMP];
-                  GLuint g = rgba[i][GCOMP] + texel[i][GCOMP];
-                  GLuint b = rgba[i][BCOMP] + texel[i][BCOMP];
-                 rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
-                 rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
-                 rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
-                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
-               }
-               break;
-            default:
-               _mesa_problem(ctx, "Bad format (GL_ADD) in texture_apply");
-               return;
-        }
-        break;
-
-      default:
-         _mesa_problem(ctx, "Bad env mode in texture_apply");
-         return;
-   }
-}
-
-
-
-/**
- * Apply texture mapping to a span of fragments.
- */
-void
-_swrast_texture_span( GLcontext *ctx, struct sw_span *span )
-{
-   SWcontext *swrast = SWRAST_CONTEXT(ctx);
-   GLchan primary_rgba[MAX_WIDTH][4];
-   GLuint unit;
-
-   ASSERT(span->end < MAX_WIDTH);
-   ASSERT(span->arrayMask & SPAN_TEXTURE);
-
-   /*
-    * Save copy of the incoming fragment colors (the GL_PRIMARY_COLOR)
-    */
-   if (swrast->_AnyTextureCombine)
-      MEMCPY(primary_rgba, span->array->rgba, 4 * span->end * sizeof(GLchan));
-
-   /*
-    * Must do all texture sampling before combining in order to
-    * accomodate GL_ARB_texture_env_crossbar.
-    */
-   for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
-      if (ctx->Texture.Unit[unit]._ReallyEnabled) {
-         const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
-         const struct gl_texture_object *curObj = texUnit->_Current;
-         GLfloat *lambda = span->array->lambda[unit];
-         GLchan (*texels)[4] = (GLchan (*)[4])
-            (swrast->TexelBuffer + unit * (span->end * 4 * sizeof(GLchan)));
-
-         /* adjust texture lod (lambda) */
-         if (span->arrayMask & SPAN_LAMBDA) {
-            if (texUnit->LodBias + curObj->LodBias != 0.0F) {
-               /* apply LOD bias, but don't clamp yet */
-               const GLfloat bias = CLAMP(texUnit->LodBias + curObj->LodBias,
-                                          -ctx->Const.MaxTextureLodBias,
-                                          ctx->Const.MaxTextureLodBias);
-               GLuint i;
-               for (i = 0; i < span->end; i++) {
-                  lambda[i] += bias;
-               }
-            }
-
-            if (curObj->MinLod != -1000.0 || curObj->MaxLod != 1000.0) {
-               /* apply LOD clamping to lambda */
-               const GLfloat min = curObj->MinLod;
-               const GLfloat max = curObj->MaxLod;
-               GLuint i;
-               for (i = 0; i < span->end; i++) {
-                  GLfloat l = lambda[i];
-                  lambda[i] = CLAMP(l, min, max);
-               }
-            }
-         }
-
-         /* Sample the texture (span->end fragments) */
-         swrast->TextureSample[unit]( ctx, unit, texUnit->_Current, span->end,
-                         (const GLfloat (*)[4]) span->array->texcoords[unit],
-                         lambda, texels );
-
-         /* GL_SGI_texture_color_table */
-         if (texUnit->ColorTableEnabled) {
-            _mesa_lookup_rgba_chan(&texUnit->ColorTable, span->end, texels);
-         }
-      }
-   }
-
-   /*
-    * OK, now apply the texture (aka texture combine/blend).
-    * We modify the span->color.rgba values.
-    */
-   for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
-      if (ctx->Texture.Unit[unit]._ReallyEnabled) {
-         const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
-         if (texUnit->_CurrentCombine != &texUnit->_EnvMode ) {
-            texture_combine( ctx, unit, span->end,
-                             (CONST GLchan (*)[4]) primary_rgba,
-                             swrast->TexelBuffer,
-                             span->array->rgba );
-         }
-         else {
-            /* conventional texture blend */
-            const GLchan (*texels)[4] = (const GLchan (*)[4])
-               (swrast->TexelBuffer + unit *
-                (span->end * 4 * sizeof(GLchan)));
-            texture_apply( ctx, texUnit, span->end,
-                           (CONST GLchan (*)[4]) primary_rgba, texels,
-                           span->array->rgba );
-         }
-      }
-   }
-}
diff --git a/src/mesa/swrast/s_texture.h b/src/mesa/swrast/s_texture.h
deleted file mode 100644 (file)
index 698f363..0000000
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * Mesa 3-D graphics library
- * Version:  6.1
- *
- * Copyright (C) 1999-2004  Brian Paul   All Rights Reserved.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included
- * in all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
- * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
- * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
- * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
- * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- */
-
-
-#ifndef S_TEXTURE_H
-#define S_TEXTURE_H
-
-
-#include "mtypes.h"
-#include "swrast.h"
-
-
-extern texture_sample_func
-_swrast_choose_texture_sample_func( GLcontext *ctx,
-                                   const struct gl_texture_object *tObj );
-
-
-extern void
-_swrast_texture_span( GLcontext *ctx, struct sw_span *span );
-
-#endif