X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fmesa%2Fmain%2Fdepth.c;h=f187205b978356c823a2dcc7ab5ac80910d4afc8;hb=16e91d4c0e1088f5c4098b01b4b7bf670cd66c4a;hp=88a0a1a69db3720aec153813942bf081e773db7e;hpb=941dcc797e1a6317808c1ec43476817286d576ba;p=mesa.git

diff --git a/src/mesa/main/depth.c b/src/mesa/main/depth.c
index 88a0a1a69db..f187205b978 100644
--- a/src/mesa/main/depth.c
+++ b/src/mesa/main/depth.c
@@ -1,21 +1,19 @@
-/* $Id: depth.c,v 1.16 2000/04/04 00:54:23 brianp Exp $ */
-
 /*
  * Mesa 3-D graphics library
- * Version:  3.3
- * 
- * Copyright (C) 1999-2000  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
@@ -25,18 +23,13 @@
  */
 
 
-#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"
 
 
 /**********************************************************************/
@@ -45,1584 +38,125 @@
 
 
 
-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 );
+   ASSERT_OUTSIDE_BEGIN_END(ctx);
+
+   depth = CLAMP( depth, 0.0, 1.0 );
+
+   if (ctx->Depth.Clear == depth)
+      return;
+
+   FLUSH_VERTICES(ctx, _NEW_DEPTH);
+   ctx->Depth.Clear = depth;
    if (ctx->Driver.ClearDepth)
       (*ctx->Driver.ClearDepth)( ctx, ctx->Depth.Clear );
 }
 
 
 
-void
+void GLAPIENTRY
 _mesa_DepthFunc( GLenum func )
 {
    GET_CURRENT_CONTEXT(ctx);
-   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glDepthFunc");
+   ASSERT_OUTSIDE_BEGIN_END(ctx);
 
-   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");
+   ASSERT_OUTSIDE_BEGIN_END(ctx);
 
-   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 );
-      }
-   }
-}
-
-
-
-/**********************************************************************/
-/*****                           Misc                             *****/
-/**********************************************************************/
-
-/*
- * Return address of depth buffer value for given window coord.
- */
-GLvoid *
-_mesa_zbuffer_address(GLcontext *ctx, GLint x, GLint y)
-{
-   if (ctx->Visual->DepthBits <= 16)
-      return (GLushort *) ctx->DrawBuffer->DepthBuffer + ctx->DrawBuffer->Width * y + x;
-   else
-      return (GLuint *) ctx->DrawBuffer->DepthBuffer + ctx->DrawBuffer->Width * y + x;
-}
-
-
-#define Z_ADDRESS16( CTX, X, Y )				\
-            ( ((GLushort *) (CTX)->DrawBuffer->DepthBuffer)	\
-              + (CTX)->DrawBuffer->Width * (Y) + (X) )
-
-#define Z_ADDRESS32( CTX, X, Y )				\
-            ( ((GLuint *) (CTX)->DrawBuffer->DepthBuffer)	\
-              + (CTX)->DrawBuffer->Width * (Y) + (X) )
-
-
-
-/**********************************************************************/
-/*****                   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_span16( GLcontext *ctx, GLuint n, GLint x, GLint y,
-                   GLushort 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:
-         BZERO(mask, n * sizeof(GLubyte));
-	 break;
-      default:
-         gl_problem(ctx, "Bad depth func in depth_test_span16");
-   }
-
-   return passed;
-}
-
-
-static GLuint
-depth_test_span32( GLcontext *ctx, GLuint n, GLint x, GLint y,
-                   GLuint 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:
-         BZERO(mask, n * sizeof(GLubyte));
-	 break;
-      default:
-         gl_problem(ctx, "Bad depth func in depth_test_span32");
-   }
-
-   return passed;
-}
-
-
-
-/*
- * Apply depth test to span of fragments.  Hardware or software z buffer.
- */
-GLuint
-_mesa_depth_test_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
-                       const GLdepth z[], GLubyte mask[] )
-{
-   if (ctx->Driver.ReadDepthSpan) {
-      /* hardware-based depth buffer */
-      GLdepth zbuffer[MAX_WIDTH];
-      GLuint passed;
-      (*ctx->Driver.ReadDepthSpan)(ctx, n, x, y, zbuffer);
-      passed = depth_test_span32(ctx, n, x, y, zbuffer, z, mask);
-      assert(ctx->Driver.WriteDepthSpan);
-      (*ctx->Driver.WriteDepthSpan)(ctx, n, x, y, zbuffer, mask);
-      return passed;
-   }
-   else {
-      /* software depth buffer */
-      if (ctx->Visual->DepthBits <= 16) {
-         GLushort *zptr = (GLushort *) Z_ADDRESS16(ctx, x, y);
-         GLuint passed = depth_test_span16(ctx, n, x, y, zptr, z, mask);
-         return passed;
-      }
-      else {
-         GLuint *zptr = (GLuint *) Z_ADDRESS32(ctx, x, y);
-         GLuint passed = depth_test_span32(ctx, n, x, y, zptr, z, mask);
-         return passed;
-      }
-   }
-}
-
-
-
-
-/*
- * Do depth testing for an array of fragments using software Z buffer.
- */
-static void
-software_depth_test_pixels16( 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]) {
-		  GLushort *zptr = Z_ADDRESS16(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]) {
-		  GLushort *zptr = Z_ADDRESS16(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]) {
-		  GLushort *zptr = Z_ADDRESS16(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]) {
-		  GLushort *zptr = Z_ADDRESS16(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]) {
-		  GLushort *zptr = Z_ADDRESS16(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]) {
-		  GLushort *zptr = Z_ADDRESS16(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]) {
-		  GLushort *zptr = Z_ADDRESS16(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]) {
-		  GLushort *zptr = Z_ADDRESS16(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]) {
-		  GLushort *zptr = Z_ADDRESS16(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]) {
-		  GLushort *zptr = Z_ADDRESS16(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]) {
-		  GLushort *zptr = Z_ADDRESS16(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]) {
-		  GLushort *zptr = Z_ADDRESS16(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]) {
-		  GLushort *zptr = Z_ADDRESS16(ctx,x[i],y[i]);
-		  *zptr = z[i];
-	       }
-	    }
-	 }
-	 else {
-	    /* Don't update Z buffer or mask */
-	 }
-	 break;
-      case GL_NEVER:
-	 /* depth test never passes */
-         BZERO(mask, n * sizeof(GLubyte));
-	 break;
-      default:
-         gl_problem(ctx, "Bad depth func in software_depth_test_pixels");
-   }
-}
-
+   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_pixels32( 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]) {
-		  GLuint *zptr = Z_ADDRESS32(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]) {
-		  GLuint *zptr = Z_ADDRESS32(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]) {
-		  GLuint *zptr = Z_ADDRESS32(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]) {
-		  GLuint *zptr = Z_ADDRESS32(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]) {
-		  GLuint *zptr = Z_ADDRESS32(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]) {
-		  GLuint *zptr = Z_ADDRESS32(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]) {
-		  GLuint *zptr = Z_ADDRESS32(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]) {
-		  GLuint *zptr = Z_ADDRESS32(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]) {
-		  GLuint *zptr = Z_ADDRESS32(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]) {
-		  GLuint *zptr = Z_ADDRESS32(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]) {
-		  GLuint *zptr = Z_ADDRESS32(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]) {
-		  GLuint *zptr = Z_ADDRESS32(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]) {
-		  GLuint *zptr = Z_ADDRESS32(ctx,x[i],y[i]);
-		  *zptr = z[i];
-	       }
-	    }
-	 }
-	 else {
-	    /* Don't update Z buffer or mask */
-	 }
-	 break;
-      case GL_NEVER:
-	 /* depth test never passes */
-         BZERO(mask, 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[] )
-{
-   /* 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 */
-         BZERO(mask, n * sizeof(GLubyte));
-	 break;
-      default:
-         gl_problem(ctx, "Bad depth func in hardware_depth_test_pixels");
-   }
-}
-
-
-
-void
-_mesa_depth_test_pixels( GLcontext *ctx,
-                         GLuint n, const GLint x[], const GLint y[],
-                         const GLdepth z[], GLubyte mask[] )
+void GLAPIENTRY
+_mesa_DepthBoundsEXT( GLclampd zmin, GLclampd zmax )
 {
-   if (ctx->Driver.ReadDepthPixels) {
-      /* read depth values from hardware Z buffer */
-      GLdepth zbuffer[PB_SIZE];
-      (*ctx->Driver.ReadDepthPixels)(ctx, n, x, y, zbuffer);
-
-      hardware_depth_test_pixels( ctx, n, zbuffer, z, mask );
+   GET_CURRENT_CONTEXT(ctx);
+   ASSERT_OUTSIDE_BEGIN_END(ctx);
 
-      /* update hardware Z buffer with new values */
-      assert(ctx->Driver.WriteDepthPixels);
-      (*ctx->Driver.WriteDepthPixels)(ctx, n, x, y, zbuffer, mask );
-   }
-   else {
-      /* software depth testing */
-      if (ctx->Visual->DepthBits <= 16)
-         software_depth_test_pixels16(ctx, n, x, y, z, mask);
-      else
-         software_depth_test_pixels32(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
-_mesa_read_depth_span_float( GLcontext* ctx,
-                             GLuint n, GLint x, GLint y, GLfloat depth[] )
-{
-   const GLfloat scale = 1.0F / ctx->Visual->DepthMaxF;
+   if (ctx->Depth.BoundsMin == zmin && ctx->Depth.BoundsMax == zmax)
+      return;
 
-   if (ctx->DrawBuffer->DepthBuffer) {
-      /* read from software depth buffer */
-      if (ctx->Visual->DepthBits <= 16) {
-         const GLushort *zptr = Z_ADDRESS16( ctx, x, y );
-         GLuint i;
-         for (i = 0; i < n; i++) {
-            depth[i] = (GLfloat) zptr[i] * scale;
-         }
-      }
-      else {
-         const GLuint *zptr = Z_ADDRESS32( 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 */
-      BZERO(depth, 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.
- */
-void
-_mesa_alloc_depth_buffer( GLcontext *ctx )
-{
-   /* deallocate current depth buffer if present */
-   if (ctx->DrawBuffer->UseSoftwareDepthBuffer) {
-      GLint bytesPerValue;
-
-      if (ctx->DrawBuffer->DepthBuffer) {
-         FREE(ctx->DrawBuffer->DepthBuffer);
-         ctx->DrawBuffer->DepthBuffer = NULL;
-      }
-
-      /* allocate new depth buffer, but don't initialize it */
-      if (ctx->Visual->DepthBits <= 16)
-         bytesPerValue = sizeof(GLushort);
-      else
-         bytesPerValue = sizeof(GLuint);
-
-      ctx->DrawBuffer->DepthBuffer = MALLOC( ctx->DrawBuffer->Width
-                                             * ctx->DrawBuffer->Height
-                                             * bytesPerValue );
-
-      if (!ctx->DrawBuffer->DepthBuffer) {
-         /* 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.
+/**
+ * Initialize the depth buffer attribute group in the given context.
  */
 void
-_mesa_clear_depth_buffer( GLcontext *ctx )
+_mesa_init_depth(GLcontext *ctx)
 {
-   if (ctx->Visual->DepthBits == 0
-       || !ctx->DrawBuffer->DepthBuffer
-       || !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 */
-      if (ctx->Visual->DepthBits <= 16) {
-         const GLushort clearValue = (GLushort) (ctx->Depth.Clear * ctx->Visual->DepthMax);
-         const GLint rows = ctx->DrawBuffer->Ymax - ctx->DrawBuffer->Ymin + 1;
-         const GLint width = ctx->DrawBuffer->Width;
-         GLushort *dRow = (GLushort *) ctx->DrawBuffer->DepthBuffer
-            + ctx->DrawBuffer->Ymin * width + ctx->DrawBuffer->Xmin;
-         GLint i, j;
-         for (i = 0; i < rows; i++) {
-            for (j = 0; j < width; j++) {
-               dRow[j] = clearValue;
-            }
-            dRow += width;
-         }
-      }
-      else {
-         const GLuint clearValue = (GLuint) (ctx->Depth.Clear * ctx->Visual->DepthMax);
-         const GLint rows = ctx->DrawBuffer->Ymax - ctx->DrawBuffer->Ymin + 1;
-         const GLint width = ctx->DrawBuffer->Width;
-         GLuint *dRow = (GLuint *) ctx->DrawBuffer->DepthBuffer
-            + ctx->DrawBuffer->Ymin * width + ctx->DrawBuffer->Xmin;
-         GLint i, j;
-         for (i = 0; i < rows; i++) {
-            for (j = 0; j < width; j++) {
-               dRow[j] = clearValue;
-            }
-            dRow += width;
-         }
-      }
-   }
-   else {
-      /* clear whole buffer */
-      if (ctx->Visual->DepthBits <= 16) {
-         const GLushort clearValue = (GLushort) (ctx->Depth.Clear * ctx->Visual->DepthMax);
-         if ((clearValue & 0xff) == (clearValue >> 8)) {
-            if (clearValue == 0) {
-               BZERO(ctx->DrawBuffer->DepthBuffer,
-                     2*ctx->DrawBuffer->Width*ctx->DrawBuffer->Height);
-            }
-            else {
-               /* lower and upper bytes of clear_value are same, use MEMSET */
-               MEMSET( ctx->DrawBuffer->DepthBuffer, clearValue & 0xff,
-                       2 * ctx->DrawBuffer->Width * ctx->DrawBuffer->Height);
-            }
-         }
-         else {
-            GLushort *d = (GLushort *) ctx->DrawBuffer->DepthBuffer;
-            GLint n = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height;
-            while (n >= 16) {
-               d[0] = clearValue;    d[1] = clearValue;
-               d[2] = clearValue;    d[3] = clearValue;
-               d[4] = clearValue;    d[5] = clearValue;
-               d[6] = clearValue;    d[7] = clearValue;
-               d[8] = clearValue;    d[9] = clearValue;
-               d[10] = clearValue;   d[11] = clearValue;
-               d[12] = clearValue;   d[13] = clearValue;
-               d[14] = clearValue;   d[15] = clearValue;
-               d += 16;
-               n -= 16;
-            }
-            while (n > 0) {
-               *d++ = clearValue;
-               n--;
-            }
-         }
-      }
-      else {
-         /* >16 bit depth buffer */
-         const GLuint clearValue = (GLuint) (ctx->Depth.Clear * ctx->Visual->DepthMax);
-         if (clearValue == 0) {
-            BZERO(ctx->DrawBuffer->DepthBuffer,
-                ctx->DrawBuffer->Width*ctx->DrawBuffer->Height*sizeof(GLuint));
-         }
-         else {
-            GLint n = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height;
-            GLuint *d = (GLuint *) ctx->DrawBuffer->DepthBuffer;
-            while (n >= 16) {
-               d[0] = clearValue;    d[1] = clearValue;
-               d[2] = clearValue;    d[3] = clearValue;
-               d[4] = clearValue;    d[5] = clearValue;
-               d[6] = clearValue;    d[7] = clearValue;
-               d[8] = clearValue;    d[9] = clearValue;
-               d[10] = clearValue;   d[11] = clearValue;
-               d[12] = clearValue;   d[13] = clearValue;
-               d[14] = clearValue;   d[15] = clearValue;
-               d += 16;
-               n -= 16;
-            }
-            while (n > 0) {
-               *d++ = clearValue;
-               n--;
-            }
-         }
-      }
-   }
+   ctx->Depth.Test = GL_FALSE;
+   ctx->Depth.Clear = 1.0;
+   ctx->Depth.Func = GL_LESS;
+   ctx->Depth.Mask = GL_TRUE;
 }