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swrast: Use MapRenderbuffer for glReadPixels(GL_DEPTH_COMPONENT) fast-paths. 

This fixes issues with the code playing fast and loose with types of
buffers, and as a bonus avoids the wrappers that were previously used
to pull bits out of packed depth/stencil buffers.

Reviewed-by: Brian Paul <brianp@vmware.com>
This commit is contained in:
Eric Anholt 2011-10-11 15:08:15 -07:00
parent 789cb3435c
commit 8524be3fb4
1 changed files with 63 additions and 68 deletions
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131
src/mesa/swrast/s_readpix.c
View File

@ -27,6 +27,7 @@
#include "main/colormac.h"
#include "main/feedback.h"
#include "main/formats.h"
#include "main/format_unpack.h"
#include "main/image.h"
#include "main/imports.h"
#include "main/macros.h"
@ -39,6 +40,57 @@
#include "s_span.h"
#include "s_stencil.h"
/**
* Tries to implement glReadPixels() of GL_DEPTH_COMPONENT using memcpy of the
* mapping.
*/
static GLboolean
fast_read_depth_pixels( struct gl_context *ctx,
GLint x, GLint y,
GLsizei width, GLsizei height,
GLenum type, GLvoid *pixels,
const struct gl_pixelstore_attrib *packing )
{
struct gl_framebuffer *fb = ctx->ReadBuffer;
struct gl_renderbuffer *rb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
GLubyte *map, *dst;
int stride, dstStride, j;
if (ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0)
return GL_FALSE;
if (packing->SwapBytes)
return GL_FALSE;
if (_mesa_get_format_datatype(rb->Format) != GL_UNSIGNED_INT)
return GL_FALSE;
if (!((type == GL_UNSIGNED_SHORT && rb->Format == MESA_FORMAT_Z16) ||
type == GL_UNSIGNED_INT))
return GL_FALSE;
ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
&map, &stride);
dstStride = _mesa_image_row_stride(packing, width, GL_DEPTH_COMPONENT, type);
dst = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
GL_DEPTH_COMPONENT, type, 0, 0);
for (j = 0; j < height; j++) {
if (type == GL_UNSIGNED_INT) {
_mesa_unpack_uint_z_row(rb->Format, width, map, (GLuint *)dst);
} else {
ASSERT(type == GL_UNSIGNED_SHORT && rb->Format == MESA_FORMAT_Z16);
memcpy(dst, map, width * 2);
}
map += stride;
dst += dstStride;
}
ctx->Driver.UnmapRenderbuffer(ctx, rb);
return GL_TRUE;
}
/**
* Read pixels for format=GL_DEPTH_COMPONENT.
@ -52,8 +104,7 @@ read_depth_pixels( struct gl_context *ctx,
{
struct gl_framebuffer *fb = ctx->ReadBuffer;
struct gl_renderbuffer *rb = fb->_DepthBuffer;
const GLboolean biasOrScale
= ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0;
GLint j;
if (!rb)
return;
@ -66,72 +117,16 @@ read_depth_pixels( struct gl_context *ctx,
/* width should never be > MAX_WIDTH since we did clipping earlier */
ASSERT(width <= MAX_WIDTH);
if (type == GL_UNSIGNED_SHORT && fb->Visual.depthBits == 16
&& !biasOrScale && !packing->SwapBytes) {
/* Special case: directly read 16-bit unsigned depth values. */
GLint j;
ASSERT(rb->Format == MESA_FORMAT_Z16);
ASSERT(rb->DataType == GL_UNSIGNED_SHORT);
for (j = 0; j < height; j++, y++) {
void *dest =_mesa_image_address2d(packing, pixels, width, height,
GL_DEPTH_COMPONENT, type, j, 0);
rb->GetRow(ctx, rb, width, x, y, dest);
}
}
else if (type == GL_UNSIGNED_INT && fb->Visual.depthBits == 24
&& !biasOrScale && !packing->SwapBytes) {
/* Special case: directly read 24-bit unsigned depth values. */
GLint j;
ASSERT(rb->Format == MESA_FORMAT_X8_Z24 ||
rb->Format == MESA_FORMAT_S8_Z24 ||
rb->Format == MESA_FORMAT_Z24_X8 ||
rb->Format == MESA_FORMAT_Z24_S8);
ASSERT(rb->DataType == GL_UNSIGNED_INT ||
rb->DataType == GL_UNSIGNED_INT_24_8);
for (j = 0; j < height; j++, y++) {
GLuint *dest = (GLuint *)
_mesa_image_address2d(packing, pixels, width, height,
GL_DEPTH_COMPONENT, type, j, 0);
GLint k;
rb->GetRow(ctx, rb, width, x, y, dest);
/* convert range from 24-bit to 32-bit */
if (rb->Format == MESA_FORMAT_X8_Z24 ||
rb->Format == MESA_FORMAT_S8_Z24) {
for (k = 0; k < width; k++) {
/* Note: put MSByte of 24-bit value into LSByte */
dest[k] = (dest[k] << 8) | ((dest[k] >> 16) & 0xff);
}
}
else {
for (k = 0; k < width; k++) {
/* Note: fill in LSByte by replication */
dest[k] = dest[k] | ((dest[k] >> 8) & 0xff);
}
}
}
}
else if (type == GL_UNSIGNED_INT && fb->Visual.depthBits == 32
&& !biasOrScale && !packing->SwapBytes) {
/* Special case: directly read 32-bit unsigned depth values. */
GLint j;
ASSERT(rb->Format == MESA_FORMAT_Z32);
ASSERT(rb->DataType == GL_UNSIGNED_INT);
for (j = 0; j < height; j++, y++) {
void *dest = _mesa_image_address2d(packing, pixels, width, height,
GL_DEPTH_COMPONENT, type, j, 0);
rb->GetRow(ctx, rb, width, x, y, dest);
}
}
else {
/* General case (slower) */
GLint j;
for (j = 0; j < height; j++, y++) {
GLfloat depthValues[MAX_WIDTH];
GLvoid *dest = _mesa_image_address2d(packing, pixels, width, height,
GL_DEPTH_COMPONENT, type, j, 0);
_swrast_read_depth_span_float(ctx, rb, width, x, y, depthValues);
_mesa_pack_depth_span(ctx, width, dest, type, depthValues, packing);
}
if (fast_read_depth_pixels(ctx, x, y, width, height, type, pixels, packing))
return;
/* General case (slower) */
for (j = 0; j < height; j++, y++) {
GLfloat depthValues[MAX_WIDTH];
GLvoid *dest = _mesa_image_address2d(packing, pixels, width, height,
GL_DEPTH_COMPONENT, type, j, 0);
_swrast_read_depth_span_float(ctx, rb, width, x, y, depthValues);
_mesa_pack_depth_span(ctx, width, dest, type, depthValues, packing);
}
}