mesa: Change "BRIAN PAUL" to "THE AUTHORS" in license text.
[mesa.git] / src / mesa / main / depth.c
index b2fa94757e3afd6f5df6bb21f3e939994a93282d..854ffbec16c40d2a317e81d7e068ea7945c25433 100644 (file)
@@ -1,42 +1,35 @@
-/* $Id: depth.c,v 1.11 1999/12/10 19:09:22 brianp Exp $ */
-
 /*
  * Mesa 3-D graphics library
- * Version:  3.3
- * 
- * Copyright (C) 1999  Brian Paul   All Rights Reserved.
- * 
+ * Version:  7.1
+ *
+ * Copyright (C) 1999-2007  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
+ * THE AUTHORS 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.
  */
 
 
-#ifdef PC_HEADER
-#include "all.h"
-#else
 #include "glheader.h"
+#include "imports.h"
 #include "context.h"
-#include "enums.h"
 #include "depth.h"
-#include "mem.h"
-#include "pb.h"
-#include "types.h"
-#endif
-
+#include "enums.h"
+#include "macros.h"
+#include "mtypes.h"
 
 
 /**********************************************************************/
 
 
 
-void
+void GLAPIENTRY
 _mesa_ClearDepth( GLclampd depth )
 {
    GET_CURRENT_CONTEXT(ctx);
-   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glClearDepth");
-   ctx->Depth.Clear = (GLfloat) CLAMP( depth, 0.0, 1.0 );
-   if (ctx->Driver.ClearDepth)
-      (*ctx->Driver.ClearDepth)( ctx, ctx->Depth.Clear );
+
+   if (MESA_VERBOSE & VERBOSE_API)
+      _mesa_debug(ctx, "glClearDepth(%f)\n", depth);
+
+   ctx->Depth.Clear = CLAMP( depth, 0.0, 1.0 );
 }
 
 
+void GLAPIENTRY
+_mesa_ClearDepthf( GLclampf depth )
+{
+   _mesa_ClearDepth(depth);
+}
 
-void
+
+void GLAPIENTRY
 _mesa_DepthFunc( GLenum func )
 {
    GET_CURRENT_CONTEXT(ctx);
-   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glDepthFunc");
 
-   if (MESA_VERBOSE & (VERBOSE_API|VERBOSE_TEXTURE))
-      fprintf(stderr, "glDepthFunc %s\n", gl_lookup_enum_by_nr(func));
+   if (MESA_VERBOSE & VERBOSE_API)
+      _mesa_debug(ctx, "glDepthFunc %s\n", _mesa_lookup_enum_by_nr(func));
 
    switch (func) {
-      case GL_LESS:    /* (default) pass if incoming z < stored z */
-      case GL_GEQUAL:
-      case GL_LEQUAL:
-      case GL_GREATER:
-      case GL_NOTEQUAL:
-      case GL_EQUAL:
-      case GL_ALWAYS:
-        if (ctx->Depth.Func != func) {
-           ctx->Depth.Func = func;
-           ctx->NewState |= NEW_RASTER_OPS;
-           ctx->TriangleCaps &= ~DD_Z_NEVER;
-           if (ctx->Driver.DepthFunc) {
-              (*ctx->Driver.DepthFunc)( ctx, func );
-           }
-        }
-         break;
-      case GL_NEVER:
-        if (ctx->Depth.Func != func) {
-           ctx->Depth.Func = func;
-           ctx->NewState |= NEW_RASTER_OPS;
-           ctx->TriangleCaps |= DD_Z_NEVER;
-           if (ctx->Driver.DepthFunc) {
-              (*ctx->Driver.DepthFunc)( ctx, func );
-           }
-        }
-         break;
-      default:
-         gl_error( ctx, GL_INVALID_ENUM, "glDepth.Func" );
+   case GL_LESS:    /* (default) pass if incoming z < stored z */
+   case GL_GEQUAL:
+   case GL_LEQUAL:
+   case GL_GREATER:
+   case GL_NOTEQUAL:
+   case GL_EQUAL:
+   case GL_ALWAYS:
+   case GL_NEVER:
+      break;
+   default:
+      _mesa_error( ctx, GL_INVALID_ENUM, "glDepth.Func" );
+      return;
    }
+
+   if (ctx->Depth.Func == func)
+      return;
+
+   FLUSH_VERTICES(ctx, _NEW_DEPTH);
+   ctx->Depth.Func = func;
+
+   if (ctx->Driver.DepthFunc)
+      ctx->Driver.DepthFunc( ctx, func );
 }
 
 
 
-void
+void GLAPIENTRY
 _mesa_DepthMask( GLboolean flag )
 {
    GET_CURRENT_CONTEXT(ctx);
-   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glDepthMask");
 
-   if (MESA_VERBOSE & (VERBOSE_API|VERBOSE_TEXTURE))
-      fprintf(stderr, "glDepthMask %d\n", flag);
+   if (MESA_VERBOSE & VERBOSE_API)
+      _mesa_debug(ctx, "glDepthMask %d\n", flag);
 
    /*
     * GL_TRUE indicates depth buffer writing is enabled (default)
     * GL_FALSE indicates depth buffer writing is disabled
     */
-   if (ctx->Depth.Mask != flag) {
-      ctx->Depth.Mask = flag;
-      ctx->NewState |= NEW_RASTER_OPS;
-      if (ctx->Driver.DepthMask) {
-        (*ctx->Driver.DepthMask)( ctx, flag );
-      }
-   }
-}
-
-
-
-/**********************************************************************/
-/*****                   Depth Testing Functions                  *****/
-/**********************************************************************/
-
-
-/*
- * Do depth test for an array of fragments.  This is used both for
- * software and hardware Z buffers.
- * Input:  zbuffer - array of z values in the zbuffer
- *         z - array of fragment z values
- * Return:  number of fragments which pass the test.
- */
-static GLuint
-depth_test_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
-                 GLdepth zbuffer[], const GLdepth z[], GLubyte mask[] )
-{
-   GLuint passed = 0;
-
-   /* switch cases ordered from most frequent to less frequent */
-   switch (ctx->Depth.Func) {
-      case GL_LESS:
-         if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 if (z[i] < zbuffer[i]) {
-                    /* pass */
-                    zbuffer[i] = z[i];
-                    passed++;
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 if (z[i] < zbuffer[i]) {
-                    /* pass */
-                    passed++;
-                 }
-                 else {
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_LEQUAL:
-        if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0;i<n;i++) {
-              if (mask[i]) {
-                 if (z[i] <= zbuffer[i]) {
-                    zbuffer[i] = z[i];
-                    passed++;
-                 }
-                 else {
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0;i<n;i++) {
-              if (mask[i]) {
-                 if (z[i] <= zbuffer[i]) {
-                    /* pass */
-                    passed++;
-                 }
-                 else {
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_GEQUAL:
-        if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0;i<n;i++) {
-              if (mask[i]) {
-                 if (z[i] >= zbuffer[i]) {
-                    zbuffer[i] = z[i];
-                    passed++;
-                 }
-                 else {
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0;i<n;i++) {
-              if (mask[i]) {
-                 if (z[i] >= zbuffer[i]) {
-                    /* pass */
-                    passed++;
-                 }
-                 else {
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_GREATER:
-        if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0;i<n;i++) {
-              if (mask[i]) {
-                 if (z[i] > zbuffer[i]) {
-                    zbuffer[i] = z[i];
-                    passed++;
-                 }
-                 else {
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0;i<n;i++) {
-              if (mask[i]) {
-                 if (z[i] > zbuffer[i]) {
-                    /* pass */
-                    passed++;
-                 }
-                 else {
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_NOTEQUAL:
-        if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0;i<n;i++) {
-              if (mask[i]) {
-                 if (z[i] != zbuffer[i]) {
-                    zbuffer[i] = z[i];
-                    passed++;
-                 }
-                 else {
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0;i<n;i++) {
-              if (mask[i]) {
-                 if (z[i] != zbuffer[i]) {
-                    /* pass */
-                    passed++;
-                 }
-                 else {
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_EQUAL:
-        if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0;i<n;i++) {
-              if (mask[i]) {
-                 if (z[i] == zbuffer[i]) {
-                    zbuffer[i] = z[i];
-                    passed++;
-                 }
-                 else {
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0;i<n;i++) {
-              if (mask[i]) {
-                 if (z[i] == zbuffer[i]) {
-                    /* pass */
-                    passed++;
-                 }
-                 else {
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_ALWAYS:
-        if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0;i<n;i++) {
-              if (mask[i]) {
-                 zbuffer[i] = z[i];
-                 passed++;
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer or mask */
-           passed = n;
-        }
-        break;
-      case GL_NEVER:
-         MEMSET(mask, 0, n * sizeof(GLubyte));
-        break;
-      default:
-         gl_problem(ctx, "Bad depth func in depth_test_span");
-   }
-
-   return passed;
-}
-
-
-
-/*
- * Apply depth test to span of fragments.  Hardware or software z buffer.
- */
-GLuint
-gl_depth_test_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
-                    const GLdepth z[], GLubyte mask[] )
-{
-   GLdepth zbuffer[MAX_WIDTH];
-   GLdepth *zptr;
-   GLuint passed;
-
-   if (ctx->Driver.ReadDepthSpan) {
-      /* read depth values out of hardware Z buffer */
-      (*ctx->Driver.ReadDepthSpan)(ctx, n, x, y, zbuffer);
-      zptr = zbuffer;
-   }
-   else {
-      /* test against software depth buffer values */
-      zptr = Z_ADDRESS( ctx, x, y );
-   }
-
-   passed = depth_test_span( ctx, n, x, y, zptr, z, mask );
-
-   if (ctx->Driver.WriteDepthSpan) {
-      /* write updated depth values into hardware Z buffer */
-      assert(zptr == zbuffer);
-      (*ctx->Driver.WriteDepthSpan)(ctx, n, x, y, zbuffer, mask);
-   }
-
-   return passed;
-}
-
-
+   if (ctx->Depth.Mask == flag)
+      return;
 
+   FLUSH_VERTICES(ctx, _NEW_DEPTH);
+   ctx->Depth.Mask = flag;
 
-/*
- * Do depth testing for an array of fragments using software Z buffer.
- */
-static void
-software_depth_test_pixels( GLcontext *ctx, GLuint n,
-                            const GLint x[], const GLint y[],
-                            const GLdepth z[], GLubyte mask[] )
-{
-   /* switch cases ordered from most frequent to less frequent */
-   switch (ctx->Depth.Func) {
-      case GL_LESS:
-         if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
-                 if (z[i] < *zptr) {
-                    /* pass */
-                    *zptr = z[i];
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
-                 if (z[i] < *zptr) {
-                    /* pass */
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_LEQUAL:
-         if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
-                 if (z[i] <= *zptr) {
-                    /* pass */
-                    *zptr = z[i];
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
-                 if (z[i] <= *zptr) {
-                    /* pass */
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_GEQUAL:
-         if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
-                 if (z[i] >= *zptr) {
-                    /* pass */
-                    *zptr = z[i];
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
-                 if (z[i] >= *zptr) {
-                    /* pass */
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_GREATER:
-         if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
-                 if (z[i] > *zptr) {
-                    /* pass */
-                    *zptr = z[i];
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
-                 if (z[i] > *zptr) {
-                    /* pass */
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_NOTEQUAL:
-         if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
-                 if (z[i] != *zptr) {
-                    /* pass */
-                    *zptr = z[i];
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
-                 if (z[i] != *zptr) {
-                    /* pass */
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_EQUAL:
-         if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
-                 if (z[i] == *zptr) {
-                    /* pass */
-                    *zptr = z[i];
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
-                 if (z[i] == *zptr) {
-                    /* pass */
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_ALWAYS:
-        if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 GLdepth *zptr = Z_ADDRESS(ctx,x[i],y[i]);
-                 *zptr = z[i];
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer or mask */
-        }
-        break;
-      case GL_NEVER:
-        /* depth test never passes */
-         MEMSET(mask, 0, n * sizeof(GLubyte));
-        break;
-      default:
-         gl_problem(ctx, "Bad depth func in software_depth_test_pixels");
-   }
+   if (ctx->Driver.DepthMask)
+      ctx->Driver.DepthMask( ctx, flag );
 }
 
 
 
-/*
- * Do depth testing for an array of pixels using hardware Z buffer.
- * Input/output:  zbuffer - array of depth values from Z buffer
- * Input:  z - array of fragment z values.
+/**
+ * Specified by the GL_EXT_depth_bounds_test extension.
  */
-static void
-hardware_depth_test_pixels( GLcontext *ctx, GLuint n, GLdepth zbuffer[],
-                            const GLdepth z[], GLubyte mask[] )
+void GLAPIENTRY
+_mesa_DepthBoundsEXT( GLclampd zmin, GLclampd zmax )
 {
-   /* switch cases ordered from most frequent to less frequent */
-   switch (ctx->Depth.Func) {
-      case GL_LESS:
-         if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 if (z[i] < zbuffer[i]) {
-                    /* pass */
-                    zbuffer[i] = z[i];
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 if (z[i] < zbuffer[i]) {
-                    /* pass */
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_LEQUAL:
-         if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 if (z[i] <= zbuffer[i]) {
-                    /* pass */
-                    zbuffer[i] = z[i];
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 if (z[i] <= zbuffer[i]) {
-                    /* pass */
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_GEQUAL:
-         if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 if (z[i] >= zbuffer[i]) {
-                    /* pass */
-                    zbuffer[i] = z[i];
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 if (z[i] >= zbuffer[i]) {
-                    /* pass */
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_GREATER:
-         if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 if (z[i] > zbuffer[i]) {
-                    /* pass */
-                    zbuffer[i] = z[i];
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 if (z[i] > zbuffer[i]) {
-                    /* pass */
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_NOTEQUAL:
-         if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 if (z[i] != zbuffer[i]) {
-                    /* pass */
-                    zbuffer[i] = z[i];
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 if (z[i] != zbuffer[i]) {
-                    /* pass */
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_EQUAL:
-         if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 if (z[i] == zbuffer[i]) {
-                    /* pass */
-                    zbuffer[i] = z[i];
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 if (z[i] == zbuffer[i]) {
-                    /* pass */
-                 }
-                 else {
-                    /* fail */
-                    mask[i] = 0;
-                 }
-              }
-           }
-        }
-        break;
-      case GL_ALWAYS:
-        if (ctx->Depth.Mask) {
-           /* Update Z buffer */
-            GLuint i;
-           for (i=0; i<n; i++) {
-              if (mask[i]) {
-                 zbuffer[i] = z[i];
-              }
-           }
-        }
-        else {
-           /* Don't update Z buffer or mask */
-        }
-        break;
-      case GL_NEVER:
-        /* depth test never passes */
-         MEMSET(mask, 0, n * sizeof(GLubyte));
-        break;
-      default:
-         gl_problem(ctx, "Bad depth func in hardware_depth_test_pixels");
-   }
-}
-
-
-
-void gl_depth_test_pixels( GLcontext *ctx,
-                           GLuint n, const GLint x[], const GLint y[],
-                           const GLdepth z[], GLubyte mask[] )
-{
-   if (ctx->Driver.ReadDepthPixels) {
-      /* read depth values from hardware Z buffer */
-      GLdepth zbuffer[PB_SIZE];
-      (*ctx->Driver.ReadDepthPixels)(ctx, n, x, y, zbuffer);
+   GET_CURRENT_CONTEXT(ctx);
 
-      hardware_depth_test_pixels( ctx, n, zbuffer, z, mask );
+   if (MESA_VERBOSE & VERBOSE_API)
+      _mesa_debug(ctx, "glDepthBounds(%f, %f)\n", zmin, zmax);
 
-      /* update hardware Z buffer with new values */
-      assert(ctx->Driver.WriteDepthPixels);
-      (*ctx->Driver.WriteDepthPixels)(ctx, n, x, y, z, mask );
-   }
-   else {
-      /* software depth testing */
-      software_depth_test_pixels(ctx, n, x, y, z, mask);
+   if (zmin > zmax) {
+      _mesa_error(ctx, GL_INVALID_VALUE, "glDepthBoundsEXT(zmin > zmax)");
+      return;
    }
-}
-
-
-
-
-
-/**********************************************************************/
-/*****                      Read Depth Buffer                     *****/
-/**********************************************************************/
 
+   zmin = CLAMP(zmin, 0.0, 1.0);
+   zmax = CLAMP(zmax, 0.0, 1.0);
 
-/*
- * Return a span of depth values from the depth buffer as floats in [0,1].
- * This is used for both hardware and software depth buffers.
- * Input:  n - how many pixels
- *         x,y - location of first pixel
- * Output:  depth - the array of depth values
- */
-void gl_read_depth_span_float( GLcontext* ctx,
-                               GLuint n, GLint x, GLint y, GLfloat depth[] )
-{
-   const GLfloat scale = 1.0F / DEPTH_SCALE;
+   if (ctx->Depth.BoundsMin == zmin && ctx->Depth.BoundsMax == zmax)
+      return;
 
-   if (ctx->DrawBuffer->Depth) {
-      /* read from software depth buffer */
-      const GLdepth *zptr = Z_ADDRESS( ctx, x, y );
-      GLuint i;
-      for (i = 0; i < n; i++) {
-        depth[i] = (GLfloat) zptr[i] * scale;
-      }
-   }
-   else if (ctx->Driver.ReadDepthSpan) {
-      /* read from hardware depth buffer */
-      GLdepth d[MAX_WIDTH];
-      GLuint i;
-      assert(n <= MAX_WIDTH);
-      (*ctx->Driver.ReadDepthSpan)( ctx, n, x, y, d );
-      for (i = 0; i < n; i++) {
-        depth[i] = d[i] * scale;
-      }
-   }
-   else {
-      /* no depth buffer */
-      MEMSET(depth, 0, n * sizeof(GLfloat));
-   }
+   FLUSH_VERTICES(ctx, _NEW_DEPTH);
+   ctx->Depth.BoundsMin = (GLfloat) zmin;
+   ctx->Depth.BoundsMax = (GLfloat) zmax;
 }
 
 
-
 /**********************************************************************/
-/*****                Allocate and Clear Depth Buffer             *****/
+/*****                      Initialization                        *****/
 /**********************************************************************/
 
 
-
-/*
- * Allocate a new depth buffer.  If there's already a depth buffer allocated
- * it will be free()'d.  The new depth buffer will be uniniitalized.
- * This function is only called through Driver.alloc_depth_buffer.
+/**
+ * Initialize the depth buffer attribute group in the given context.
  */
-void gl_alloc_depth_buffer( GLcontext* ctx )
-{
-   /* deallocate current depth buffer if present */
-   if (ctx->DrawBuffer->UseSoftwareDepthBuffer) {
-      if (ctx->DrawBuffer->Depth) {
-         FREE(ctx->DrawBuffer->Depth);
-         ctx->DrawBuffer->Depth = NULL;
-      }
-
-      /* allocate new depth buffer, but don't initialize it */
-      ctx->DrawBuffer->Depth = (GLdepth *) MALLOC( ctx->DrawBuffer->Width
-                                                   * ctx->DrawBuffer->Height
-                                                   * sizeof(GLdepth) );
-      if (!ctx->DrawBuffer->Depth) {
-         /* out of memory */
-         ctx->Depth.Test = GL_FALSE;
-         ctx->NewState |= NEW_RASTER_OPS;
-         gl_error( ctx, GL_OUT_OF_MEMORY, "Couldn't allocate depth buffer" );
-      }
-   }
-}
-
-
-
-
-/*
- * Clear the depth buffer.  If the depth buffer doesn't exist yet we'll
- * allocate it now.
- * This function is only called through Driver.clear_depth_buffer.
- */
-void gl_clear_depth_buffer( GLcontext* ctx )
+void
+_mesa_init_depth(struct gl_context *ctx)
 {
-   GLdepth clear_value = (GLdepth) (ctx->Depth.Clear * DEPTH_SCALE);
-   
-   if (ctx->Visual->DepthBits==0 || !ctx->DrawBuffer->Depth || !ctx->Depth.Mask) {
-      /* no depth buffer, or writing to it is disabled */
-      return;
-   }
-
-   /* The loops in this function have been written so the IRIX 5.3
-    * C compiler can unroll them.  Hopefully other compilers can too!
-    */
-
-   if (ctx->Scissor.Enabled) {
-      /* only clear scissor region */
-      GLint y;
-      for (y=ctx->DrawBuffer->Ymin; y<=ctx->DrawBuffer->Ymax; y++) {
-         GLdepth *d = Z_ADDRESS( ctx, ctx->DrawBuffer->Xmin, y );
-         GLint n = ctx->DrawBuffer->Xmax - ctx->DrawBuffer->Xmin + 1;
-         do {
-            *d++ = clear_value;
-            n--;
-         } while (n);
-      }
-   }
-   else {
-      /* clear whole buffer */
-      if (sizeof(GLdepth)==2 && (clear_value&0xff)==(clear_value>>8)) {
-         /* lower and upper bytes of clear_value are same, use MEMSET */
-         MEMSET( ctx->DrawBuffer->Depth, clear_value & 0xff,
-                 2*ctx->DrawBuffer->Width * ctx->DrawBuffer->Height);
-      }
-      else {
-         GLdepth *d = ctx->DrawBuffer->Depth;
-         GLint n = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height;
-         while (n>=16) {
-            d[0] = clear_value;    d[1] = clear_value;
-            d[2] = clear_value;    d[3] = clear_value;
-            d[4] = clear_value;    d[5] = clear_value;
-            d[6] = clear_value;    d[7] = clear_value;
-            d[8] = clear_value;    d[9] = clear_value;
-            d[10] = clear_value;   d[11] = clear_value;
-            d[12] = clear_value;   d[13] = clear_value;
-            d[14] = clear_value;   d[15] = clear_value;
-            d += 16;
-            n -= 16;
-         }
-         while (n>0) {
-            *d++ = clear_value;
-            n--;
-         }
-      }
-   }
+   ctx->Depth.Test = GL_FALSE;
+   ctx->Depth.Clear = 1.0;
+   ctx->Depth.Func = GL_LESS;
+   ctx->Depth.Mask = GL_TRUE;
 }