-/* $Id: depth.c,v 1.11 1999/12/10 19:09:22 brianp Exp $ */
+/* $Id: depth.c,v 1.24 2000/11/22 07:32:16 joukj Exp $ */
/*
* Mesa 3-D graphics library
* Version: 3.3
- *
- * Copyright (C) 1999 Brian Paul All Rights Reserved.
- *
+ *
+ * Copyright (C) 1999-2000 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
#include "context.h"
#include "enums.h"
#include "depth.h"
+#include "macros.h"
#include "mem.h"
-#include "pb.h"
-#include "types.h"
+#include "mtypes.h"
#endif
ctx->Depth.Clear = (GLfloat) CLAMP( depth, 0.0, 1.0 );
if (ctx->Driver.ClearDepth)
(*ctx->Driver.ClearDepth)( ctx, ctx->Depth.Clear );
+ ctx->NewState |= _NEW_DEPTH;
}
case GL_ALWAYS:
if (ctx->Depth.Func != func) {
ctx->Depth.Func = func;
- ctx->NewState |= NEW_RASTER_OPS;
- ctx->TriangleCaps &= ~DD_Z_NEVER;
+ ctx->NewState |= _NEW_DEPTH;
+ ctx->_TriangleCaps &= ~DD_Z_NEVER;
if (ctx->Driver.DepthFunc) {
(*ctx->Driver.DepthFunc)( ctx, func );
}
case GL_NEVER:
if (ctx->Depth.Func != func) {
ctx->Depth.Func = func;
- ctx->NewState |= NEW_RASTER_OPS;
- ctx->TriangleCaps |= DD_Z_NEVER;
+ ctx->NewState |= _NEW_DEPTH;
+ ctx->_TriangleCaps |= DD_Z_NEVER;
if (ctx->Driver.DepthFunc) {
(*ctx->Driver.DepthFunc)( ctx, func );
}
*/
if (ctx->Depth.Mask != flag) {
ctx->Depth.Mask = flag;
- ctx->NewState |= NEW_RASTER_OPS;
+ ctx->NewState |= _NEW_DEPTH;
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;
-}
-
-
-
-
-/*
- * 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");
- }
-}
-
-
-
-/*
- * 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.
- */
-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 */
- 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);
-
- hardware_depth_test_pixels( ctx, n, zbuffer, z, mask );
-
- /* 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);
- }
-}
-
-
-
-
-
-/**********************************************************************/
-/***** Read Depth Buffer *****/
-/**********************************************************************/
-
-
-/*
- * 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->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));
- }
-}
-
-
-
-/**********************************************************************/
-/***** Allocate and Clear Depth Buffer *****/
-/**********************************************************************/
-
-
-
-/*
- * 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 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 )
-{
- 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--;
- }
- }
- }
-}