/*
* Mesa 3-D graphics library
*
* Copyright (C) 1999-2008 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
* THE AUTHORS OR COPYRIGHT HOLDERS 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 "main/glheader.h"
#include "main/context.h"
#include "main/formats.h"
#include "main/format_unpack.h"
#include "main/format_pack.h"
#include "main/macros.h"
#include "main/imports.h"
#include "s_context.h"
#include "s_depth.h"
#include "s_span.h"
#define Z_TEST(COMPARE) \
do { \
GLuint i; \
for (i = 0; i < n; i++) { \
if (mask[i]) { \
if (COMPARE) { \
/* pass */ \
if (write) { \
zbuffer[i] = zfrag[i]; \
} \
passed++; \
} \
else { \
/* fail */ \
mask[i] = 0; \
} \
} \
} \
} while (0)
/**
* Do depth test for an array of 16-bit Z values.
* @param zbuffer array of Z buffer values (16-bit)
* @param zfrag array of fragment Z values (use 16-bit in 32-bit uint)
* @param mask which fragments are alive, killed afterward
* @return number of fragments which pass the test.
*/
static GLuint
depth_test_span16( struct gl_context *ctx, GLuint n,
GLushort zbuffer[], const GLuint zfrag[], GLubyte mask[] )
{
const GLboolean write = ctx->Depth.Mask;
GLuint passed = 0;
/* switch cases ordered from most frequent to less frequent */
switch (ctx->Depth.Func) {
case GL_LESS:
Z_TEST(zfrag[i] < zbuffer[i]);
break;
case GL_LEQUAL:
Z_TEST(zfrag[i] <= zbuffer[i]);
break;
case GL_GEQUAL:
Z_TEST(zfrag[i] >= zbuffer[i]);
break;
case GL_GREATER:
Z_TEST(zfrag[i] > zbuffer[i]);
break;
case GL_NOTEQUAL:
Z_TEST(zfrag[i] != zbuffer[i]);
break;
case GL_EQUAL:
Z_TEST(zfrag[i] == zbuffer[i]);
break;
case GL_ALWAYS:
Z_TEST(1);
break;
case GL_NEVER:
memset(mask, 0, n * sizeof(GLubyte));
break;
default:
_mesa_problem(ctx, "Bad depth func in depth_test_span16");
}
return passed;
}
/**
* Do depth test for an array of 32-bit Z values.
* @param zbuffer array of Z buffer values (32-bit)
* @param zfrag array of fragment Z values (use 32-bits in 32-bit uint)
* @param mask which fragments are alive, killed afterward
* @return number of fragments which pass the test.
*/
static GLuint
depth_test_span32( struct gl_context *ctx, GLuint n,
GLuint zbuffer[], const GLuint zfrag[], GLubyte mask[])
{
const GLboolean write = ctx->Depth.Mask;
GLuint passed = 0;
/* switch cases ordered from most frequent to less frequent */
switch (ctx->Depth.Func) {
case GL_LESS:
Z_TEST(zfrag[i] < zbuffer[i]);
break;
case GL_LEQUAL:
Z_TEST(zfrag[i] <= zbuffer[i]);
break;
case GL_GEQUAL:
Z_TEST(zfrag[i] >= zbuffer[i]);
break;
case GL_GREATER:
Z_TEST(zfrag[i] > zbuffer[i]);
break;
case GL_NOTEQUAL:
Z_TEST(zfrag[i] != zbuffer[i]);
break;
case GL_EQUAL:
Z_TEST(zfrag[i] == zbuffer[i]);
break;
case GL_ALWAYS:
Z_TEST(1);
break;
case GL_NEVER:
memset(mask, 0, n * sizeof(GLubyte));
break;
default:
_mesa_problem(ctx, "Bad depth func in depth_test_span32");
}
return passed;
}
/**
* Clamp fragment Z values to the depth near/far range (glDepthRange()).
* This is used when GL_ARB_depth_clamp/GL_DEPTH_CLAMP is turned on.
* In that case, vertexes are not clipped against the near/far planes
* so rasterization will produce fragment Z values outside the usual
* [0,1] range.
*/
void
_swrast_depth_clamp_span( struct gl_context *ctx, SWspan *span )
{
struct gl_framebuffer *fb = ctx->DrawBuffer;
const GLuint count = span->end;
GLint *zValues = (GLint *) span->array->z; /* sign change */
GLint min, max;
GLfloat min_f, max_f;
GLuint i;
if (ctx->ViewportArray[0].Near < ctx->ViewportArray[0].Far) {
min_f = ctx->ViewportArray[0].Near;
max_f = ctx->ViewportArray[0].Far;
} else {
min_f = ctx->ViewportArray[0].Far;
max_f = ctx->ViewportArray[0].Near;
}
/* Convert floating point values in [0,1] to device Z coordinates in
* [0, DepthMax].
* ex: If the Z buffer has 24 bits, DepthMax = 0xffffff.
*
* XXX this all falls apart if we have 31 or more bits of Z because
* the triangle rasterization code produces unsigned Z values. Negative
* vertex Z values come out as large fragment Z uints.
*/
min = (GLint) (min_f * fb->_DepthMaxF);
max = (GLint) (max_f * fb->_DepthMaxF);
if (max < 0)
max = 0x7fffffff; /* catch over flow for 30-bit z */
/* Note that we do the comparisons here using signed integers.
*/
for (i = 0; i < count; i++) {
if (zValues[i] < min)
zValues[i] = min;
if (zValues[i] > max)
zValues[i] = max;
}
}
/**
* Get array of 32-bit z values from the depth buffer. With clipping.
* Note: the returned values are always in the range [0, 2^32-1].
*/
static void
get_z32_values(struct gl_context *ctx, struct gl_renderbuffer *rb,
GLuint count, const GLint x[], const GLint y[],
GLuint zbuffer[])
{
struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
const GLint w = rb->Width, h = rb->Height;
const GLubyte *map = _swrast_pixel_address(rb, 0, 0);
GLuint i;
if (rb->Format == MESA_FORMAT_Z_UNORM32) {
const GLint rowStride = srb->RowStride;
for (i = 0; i < count; i++) {
if (x[i] >= 0 && y[i] >= 0 && x[i] < w && y[i] < h) {
zbuffer[i] = *((GLuint *) (map + y[i] * rowStride + x[i] * 4));
}
}
}
else {
const GLint bpp = _mesa_get_format_bytes(rb->Format);
const GLint rowStride = srb->RowStride;
for (i = 0; i < count; i++) {
if (x[i] >= 0 && y[i] >= 0 && x[i] < w && y[i] < h) {
const GLubyte *src = map + y[i] * rowStride+ x[i] * bpp;
_mesa_unpack_uint_z_row(rb->Format, 1, src, &zbuffer[i]);
}
}
}
}
/**
* Put an array of 32-bit z values into the depth buffer.
* Note: the z values are always in the range [0, 2^32-1].
*/
static void
put_z32_values(struct gl_context *ctx, struct gl_renderbuffer *rb,
GLuint count, const GLint x[], const GLint y[],
const GLuint zvalues[], const GLubyte mask[])
{
struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
const GLint w = rb->Width, h = rb->Height;
GLubyte *map = _swrast_pixel_address(rb, 0, 0);
GLuint i;
if (rb->Format == MESA_FORMAT_Z_UNORM32) {
const GLint rowStride = srb->RowStride;
for (i = 0; i < count; i++) {
if (mask[i] && x[i] >= 0 && y[i] >= 0 && x[i] < w && y[i] < h) {
GLuint *dst = (GLuint *) (map + y[i] * rowStride + x[i] * 4);
*dst = zvalues[i];
}
}
}
else {
gl_pack_uint_z_func packZ = _mesa_get_pack_uint_z_func(rb->Format);
const GLint bpp = _mesa_get_format_bytes(rb->Format);
const GLint rowStride = srb->RowStride;
for (i = 0; i < count; i++) {
if (mask[i] && x[i] >= 0 && y[i] >= 0 && x[i] < w && y[i] < h) {
void *dst = map + y[i] * rowStride + x[i] * bpp;
packZ(zvalues + i, dst);
}
}
}
}
/**
* Apply depth (Z) buffer testing to the span.
* \return approx number of pixels that passed (only zero is reliable)
*/
GLuint
_swrast_depth_test_span(struct gl_context *ctx, SWspan *span)
{
struct gl_framebuffer *fb = ctx->DrawBuffer;
struct gl_renderbuffer *rb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
const GLint bpp = _mesa_get_format_bytes(rb->Format);
void *zStart;
const GLuint count = span->end;
const GLuint *fragZ = span->array->z;
GLubyte *mask = span->array->mask;
void *zBufferVals;
GLuint *zBufferTemp = NULL;
GLuint passed;
GLuint zBits = _mesa_get_format_bits(rb->Format, GL_DEPTH_BITS);
GLboolean ztest16 = GL_FALSE;
if (span->arrayMask & SPAN_XY)
zStart = NULL;
else
zStart = _swrast_pixel_address(rb, span->x, span->y);
if (rb->Format == MESA_FORMAT_Z_UNORM16 && !(span->arrayMask & SPAN_XY)) {
/* directly read/write row of 16-bit Z values */
zBufferVals = zStart;
ztest16 = GL_TRUE;
}
else if (rb->Format == MESA_FORMAT_Z_UNORM32 && !(span->arrayMask & SPAN_XY)) {
/* directly read/write row of 32-bit Z values */
zBufferVals = zStart;
}
else {
if (_mesa_get_format_datatype(rb->Format) != GL_UNSIGNED_NORMALIZED) {
_mesa_problem(ctx, "Incorrectly writing swrast's integer depth "
"values to %s depth buffer",
_mesa_get_format_name(rb->Format));
}
/* copy Z buffer values into temp buffer (32-bit Z values) */
zBufferTemp = malloc(count * sizeof(GLuint));
if (!zBufferTemp)
return 0;
if (span->arrayMask & SPAN_XY) {
get_z32_values(ctx, rb, count,
span->array->x, span->array->y, zBufferTemp);
}
else {
_mesa_unpack_uint_z_row(rb->Format, count, zStart, zBufferTemp);
}
if (zBits == 24) {
GLuint i;
/* Convert depth buffer values from 32 to 24 bits to match the
* fragment Z values generated by rasterization.
*/
for (i = 0; i < count; i++) {
zBufferTemp[i] >>= 8;
}
}
else if (zBits == 16) {
GLuint i;
/* Convert depth buffer values from 32 to 16 bits */
for (i = 0; i < count; i++) {
zBufferTemp[i] >>= 16;
}
}
else {
assert(zBits == 32);
}
zBufferVals = zBufferTemp;
}
/* do the depth test either with 16 or 32-bit values */
if (ztest16)
passed = depth_test_span16(ctx, count, zBufferVals, fragZ, mask);
else
passed = depth_test_span32(ctx, count, zBufferVals, fragZ, mask);
if (zBufferTemp) {
/* need to write temp Z values back into the buffer */
/* Convert depth buffer values back to 32-bit values. The least
* significant bits don't matter since they'll get dropped when
* they're packed back into the depth buffer.
*/
if (zBits == 24) {
GLuint i;
for (i = 0; i < count; i++) {
zBufferTemp[i] = (zBufferTemp[i] << 8);
}
}
else if (zBits == 16) {
GLuint i;
for (i = 0; i < count; i++) {
zBufferTemp[i] = zBufferTemp[i] << 16;
}
}
if (span->arrayMask & SPAN_XY) {
/* random locations */
put_z32_values(ctx, rb, count, span->array->x, span->array->y,
zBufferTemp, mask);
}
else {
/* horizontal row */
gl_pack_uint_z_func packZ = _mesa_get_pack_uint_z_func(rb->Format);
GLubyte *dst = zStart;
GLuint i;
for (i = 0; i < count; i++) {
if (mask[i]) {
packZ(&zBufferTemp[i], dst);
}
dst += bpp;
}
}
free(zBufferTemp);
}
if (passed < count) {
span->writeAll = GL_FALSE;
}
return passed;
}
/**
* GL_EXT_depth_bounds_test extension.
* Discard fragments depending on whether the corresponding Z-buffer
* values are outside the depth bounds test range.
* Note: we test the Z buffer values, not the fragment Z values!
* \return GL_TRUE if any fragments pass, GL_FALSE if no fragments pass
*/
GLboolean
_swrast_depth_bounds_test( struct gl_context *ctx, SWspan *span )
{
struct gl_framebuffer *fb = ctx->DrawBuffer;
struct gl_renderbuffer *rb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
GLubyte *zStart;
GLuint zMin = (GLuint)((double)ctx->Depth.BoundsMin * 0xffffffff);
GLuint zMax = (GLuint)((double)ctx->Depth.BoundsMax * 0xffffffff);
GLubyte *mask = span->array->mask;
const GLuint count = span->end;
GLuint i;
GLboolean anyPass = GL_FALSE;
GLuint *zBufferTemp;
const GLuint *zBufferVals;
zBufferTemp = malloc(count * sizeof(GLuint));
if (!zBufferTemp) {
/* don't generate a stream of OUT_OF_MEMORY errors here */
return GL_FALSE;
}
if (span->arrayMask & SPAN_XY)
zStart = NULL;
else
zStart = _swrast_pixel_address(rb, span->x, span->y);
if (rb->Format == MESA_FORMAT_Z_UNORM32 && !(span->arrayMask & SPAN_XY)) {
/* directly access 32-bit values in the depth buffer */
zBufferVals = (const GLuint *) zStart;
}
else {
/* Round the bounds to the precision of the zbuffer. */
if (rb->Format == MESA_FORMAT_Z_UNORM16) {
zMin = (zMin & 0xffff0000) | (zMin >> 16);
zMax = (zMax & 0xffff0000) | (zMax >> 16);
} else {
/* 24 bits */
zMin = (zMin & 0xffffff00) | (zMin >> 24);
zMax = (zMax & 0xffffff00) | (zMax >> 24);
}
/* unpack Z values into a temporary array */
if (span->arrayMask & SPAN_XY) {
get_z32_values(ctx, rb, count, span->array->x, span->array->y,
zBufferTemp);
}
else {
_mesa_unpack_uint_z_row(rb->Format, count, zStart, zBufferTemp);
}
zBufferVals = zBufferTemp;
}
/* Now do the tests */
for (i = 0; i < count; i++) {
if (mask[i]) {
if (zBufferVals[i] < zMin || zBufferVals[i] > zMax)
mask[i] = GL_FALSE;
else
anyPass = GL_TRUE;
}
}
free(zBufferTemp);
return anyPass;
}
/**********************************************************************/
/***** Read Depth Buffer *****/
/**********************************************************************/
/**
* Read a span of depth values from the given depth renderbuffer, returning
* the values as GLfloats.
* This function does clipping to prevent reading outside the depth buffer's
* bounds.
*/
void
_swrast_read_depth_span_float(struct gl_context *ctx,
struct gl_renderbuffer *rb,
GLint n, GLint x, GLint y, GLfloat depth[])
{
if (!rb) {
/* really only doing this to prevent FP exceptions later */
memset(depth, 0, n * sizeof(GLfloat));
return;
}
if (y < 0 || y >= (GLint) rb->Height ||
x + n <= 0 || x >= (GLint) rb->Width) {
/* span is completely outside framebuffer */
memset(depth, 0, n * sizeof(GLfloat));
return;
}
if (x < 0) {
GLint dx = -x;
GLint i;
for (i = 0; i < dx; i++)
depth[i] = 0.0;
x = 0;
n -= dx;
depth += dx;
}
if (x + n > (GLint) rb->Width) {
GLint dx = x + n - (GLint) rb->Width;
GLint i;
for (i = 0; i < dx; i++)
depth[n - i - 1] = 0.0;
n -= dx;
}
if (n <= 0) {
return;
}
_mesa_unpack_float_z_row(rb->Format, n, _swrast_pixel_address(rb, x, y),
depth);
}
/**
* Clear the given z/depth renderbuffer. If the buffer is a combined
* depth+stencil buffer, only the Z bits will be touched.
*/
void
_swrast_clear_depth_buffer(struct gl_context *ctx)
{
struct gl_renderbuffer *rb =
ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
GLint x, y, width, height;
GLubyte *map;
GLint rowStride, i, j;
GLbitfield mapMode;
if (!rb || !ctx->Depth.Mask) {
/* no depth buffer, or writing to it is disabled */
return;
}
/* compute region to clear */
x = ctx->DrawBuffer->_Xmin;
y = ctx->DrawBuffer->_Ymin;
width = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
mapMode = GL_MAP_WRITE_BIT;
if (rb->Format == MESA_FORMAT_Z24_UNORM_S8_UINT ||
rb->Format == MESA_FORMAT_Z24_UNORM_X8_UINT ||
rb->Format == MESA_FORMAT_S8_UINT_Z24_UNORM ||
rb->Format == MESA_FORMAT_X8_UINT_Z24_UNORM) {
mapMode |= GL_MAP_READ_BIT;
}
ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height,
mapMode, &map, &rowStride);
if (!map) {
_mesa_error(ctx, GL_OUT_OF_MEMORY, "glClear(depth)");
return;
}
switch (rb->Format) {
case MESA_FORMAT_Z_UNORM16:
{
GLfloat clear = (GLfloat) ctx->Depth.Clear;
GLushort clearVal = 0;
_mesa_pack_float_z_row(rb->Format, 1, &clear, &clearVal);
if (clearVal == 0xffff && width * 2 == rowStride) {
/* common case */
memset(map, 0xff, width * height * 2);
}
else {
for (i = 0; i < height; i++) {
GLushort *row = (GLushort *) map;
for (j = 0; j < width; j++) {
row[j] = clearVal;
}
map += rowStride;
}
}
}
break;
case MESA_FORMAT_Z_UNORM32:
case MESA_FORMAT_Z_FLOAT32:
{
GLfloat clear = (GLfloat) ctx->Depth.Clear;
GLuint clearVal = 0;
_mesa_pack_float_z_row(rb->Format, 1, &clear, &clearVal);
for (i = 0; i < height; i++) {
GLuint *row = (GLuint *) map;
for (j = 0; j < width; j++) {
row[j] = clearVal;
}
map += rowStride;
}
}
break;
case MESA_FORMAT_Z24_UNORM_S8_UINT:
case MESA_FORMAT_Z24_UNORM_X8_UINT:
case MESA_FORMAT_S8_UINT_Z24_UNORM:
case MESA_FORMAT_X8_UINT_Z24_UNORM:
{
GLfloat clear = (GLfloat) ctx->Depth.Clear;
GLuint clearVal = 0;
GLuint mask;
if (rb->Format == MESA_FORMAT_Z24_UNORM_S8_UINT ||
rb->Format == MESA_FORMAT_Z24_UNORM_X8_UINT)
mask = 0xff000000;
else
mask = 0xff;
_mesa_pack_float_z_row(rb->Format, 1, &clear, &clearVal);
for (i = 0; i < height; i++) {
GLuint *row = (GLuint *) map;
for (j = 0; j < width; j++) {
row[j] = (row[j] & mask) | clearVal;
}
map += rowStride;
}
}
break;
case MESA_FORMAT_Z32_FLOAT_S8X24_UINT:
/* XXX untested */
{
GLfloat clearVal = (GLfloat) ctx->Depth.Clear;
for (i = 0; i < height; i++) {
GLfloat *row = (GLfloat *) map;
for (j = 0; j < width; j++) {
row[j * 2] = clearVal;
}
map += rowStride;
}
}
break;
default:
_mesa_problem(ctx, "Unexpected depth buffer format %s"
" in _swrast_clear_depth_buffer()",
_mesa_get_format_name(rb->Format));
}
ctx->Driver.UnmapRenderbuffer(ctx, rb);
}
/**
* Clear both depth and stencil values in a combined depth+stencil buffer.
*/
void
_swrast_clear_depth_stencil_buffer(struct gl_context *ctx)
{
const GLubyte stencilBits = ctx->DrawBuffer->Visual.stencilBits;
const GLuint writeMask = ctx->Stencil.WriteMask[0];
const GLuint stencilMax = (1 << stencilBits) - 1;
struct gl_renderbuffer *rb =
ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
GLint x, y, width, height;
GLbitfield mapMode;
GLubyte *map;
GLint rowStride, i, j;
/* check that we really have a combined depth+stencil buffer */
assert(rb == ctx->DrawBuffer->Attachment[BUFFER_STENCIL].Renderbuffer);
/* compute region to clear */
x = ctx->DrawBuffer->_Xmin;
y = ctx->DrawBuffer->_Ymin;
width = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
mapMode = GL_MAP_WRITE_BIT;
if ((writeMask & stencilMax) != stencilMax) {
/* need to mask stencil values */
mapMode |= GL_MAP_READ_BIT;
}
ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height,
mapMode, &map, &rowStride);
if (!map) {
_mesa_error(ctx, GL_OUT_OF_MEMORY, "glClear(depth+stencil)");
return;
}
switch (rb->Format) {
case MESA_FORMAT_Z24_UNORM_S8_UINT:
case MESA_FORMAT_S8_UINT_Z24_UNORM:
{
GLfloat zClear = (GLfloat) ctx->Depth.Clear;
GLuint clear = 0, mask;
_mesa_pack_float_z_row(rb->Format, 1, &zClear, &clear);
if (rb->Format == MESA_FORMAT_Z24_UNORM_S8_UINT) {
mask = ((~writeMask) & 0xff) << 24;
clear |= (ctx->Stencil.Clear & writeMask & 0xff) << 24;
}
else {
mask = ((~writeMask) & 0xff);
clear |= (ctx->Stencil.Clear & writeMask & 0xff);
}
for (i = 0; i < height; i++) {
GLuint *row = (GLuint *) map;
if (mask != 0x0) {
for (j = 0; j < width; j++) {
row[j] = (row[j] & mask) | clear;
}
}
else {
for (j = 0; j < width; j++) {
row[j] = clear;
}
}
map += rowStride;
}
}
break;
case MESA_FORMAT_Z32_FLOAT_S8X24_UINT:
/* XXX untested */
{
const GLfloat zClear = (GLfloat) ctx->Depth.Clear;
const GLuint sClear = ctx->Stencil.Clear & writeMask;
const GLuint sMask = (~writeMask) & 0xff;
for (i = 0; i < height; i++) {
GLfloat *zRow = (GLfloat *) map;
GLuint *sRow = (GLuint *) map;
for (j = 0; j < width; j++) {
zRow[j * 2 + 0] = zClear;
}
if (sMask != 0) {
for (j = 0; j < width; j++) {
sRow[j * 2 + 1] = (sRow[j * 2 + 1] & sMask) | sClear;
}
}
else {
for (j = 0; j < width; j++) {
sRow[j * 2 + 1] = sClear;
}
}
map += rowStride;
}
}
break;
default:
_mesa_problem(ctx, "Unexpected depth buffer format %s"
" in _swrast_clear_depth_buffer()",
_mesa_get_format_name(rb->Format));
}
ctx->Driver.UnmapRenderbuffer(ctx, rb);
}