/*
* Mesa 3-D graphics library
* Version: 7.0.3
*
* 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
* 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/bufferobj.h"
#include "main/colormac.h"
#include "main/feedback.h"
#include "main/formats.h"
#include "main/image.h"
#include "main/imports.h"
#include "main/macros.h"
#include "main/pack.h"
#include "main/state.h"
#include "s_context.h"
#include "s_depth.h"
#include "s_span.h"
#include "s_stencil.h"
/**
* Read pixels for format=GL_DEPTH_COMPONENT.
*/
static void
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->_DepthBuffer;
const GLboolean biasOrScale
= ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0;
if (!rb)
return;
/* clipping should have been done already */
ASSERT(x >= 0);
ASSERT(y >= 0);
ASSERT(x + width <= (GLint) rb->Width);
ASSERT(y + height <= (GLint) rb->Height);
/* 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);
}
}
}
/**
* Read pixels for format=GL_STENCIL_INDEX.
*/
static void
read_stencil_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->_StencilBuffer;
GLint j;
if (!rb)
return;
/* width should never be > MAX_WIDTH since we did clipping earlier */
ASSERT(width <= MAX_WIDTH);
/* process image row by row */
for (j=0;j<height;j++,y++) {
GLvoid *dest;
GLstencil stencil[MAX_WIDTH];
_swrast_read_stencil_span(ctx, rb, width, x, y, stencil);
dest = _mesa_image_address2d(packing, pixels, width, height,
GL_STENCIL_INDEX, type, j, 0);
_mesa_pack_stencil_span(ctx, width, type, dest, stencil, packing);
}
}
/**
* Optimized glReadPixels for particular pixel formats when pixel
* scaling, biasing, mapping, etc. are disabled.
* \return GL_TRUE if success, GL_FALSE if unable to do the readpixels
*/
static GLboolean
fast_read_rgba_pixels( struct gl_context *ctx,
GLint x, GLint y,
GLsizei width, GLsizei height,
GLenum format, GLenum type,
GLvoid *pixels,
const struct gl_pixelstore_attrib *packing,
GLbitfield transferOps)
{
struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
if (!rb)
return GL_FALSE;
ASSERT(rb->_BaseFormat == GL_RGBA || rb->_BaseFormat == GL_RGB ||
rb->_BaseFormat == GL_ALPHA);
/* clipping should have already been done */
ASSERT(x + width <= (GLint) rb->Width);
ASSERT(y + height <= (GLint) rb->Height);
/* check for things we can't handle here */
if (transferOps ||
packing->SwapBytes ||
packing->LsbFirst) {
return GL_FALSE;
}
if (format == GL_RGBA && rb->DataType == type) {
const GLint dstStride = _mesa_image_row_stride(packing, width,
format, type);
GLubyte *dest
= (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
format, type, 0, 0);
GLint row;
ASSERT(rb->GetRow);
for (row = 0; row < height; row++) {
rb->GetRow(ctx, rb, width, x, y + row, dest);
dest += dstStride;
}
return GL_TRUE;
}
if (format == GL_RGB &&
rb->DataType == GL_UNSIGNED_BYTE &&
type == GL_UNSIGNED_BYTE) {
const GLint dstStride = _mesa_image_row_stride(packing, width,
format, type);
GLubyte *dest
= (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
format, type, 0, 0);
GLint row;
ASSERT(rb->GetRow);
for (row = 0; row < height; row++) {
GLubyte tempRow[MAX_WIDTH][4];
GLint col;
rb->GetRow(ctx, rb, width, x, y + row, tempRow);
/* convert RGBA to RGB */
for (col = 0; col < width; col++) {
dest[col * 3 + 0] = tempRow[col][0];
dest[col * 3 + 1] = tempRow[col][1];
dest[col * 3 + 2] = tempRow[col][2];
}
dest += dstStride;
}
return GL_TRUE;
}
/* not handled */
return GL_FALSE;
}
/**
* When we're using a low-precision color buffer (like 16-bit 5/6/5)
* we have to adjust our color values a bit to pass conformance.
* The problem is when a 5 or 6-bit color value is converted to an 8-bit
* value and then a floating point value, the floating point values don't
* increment uniformly as the 5 or 6-bit value is incremented.
*
* This function adjusts floating point values to compensate.
*/
static void
adjust_colors(const struct gl_framebuffer *fb, GLuint n, GLfloat rgba[][4])
{
const GLuint rShift = 8 - fb->Visual.redBits;
const GLuint gShift = 8 - fb->Visual.greenBits;
const GLuint bShift = 8 - fb->Visual.blueBits;
GLfloat rScale = 1.0F / (GLfloat) ((1 << fb->Visual.redBits ) - 1);
GLfloat gScale = 1.0F / (GLfloat) ((1 << fb->Visual.greenBits) - 1);
GLfloat bScale = 1.0F / (GLfloat) ((1 << fb->Visual.blueBits ) - 1);
GLuint i;
if (fb->Visual.redBits == 0)
rScale = 0;
if (fb->Visual.greenBits == 0)
gScale = 0;
if (fb->Visual.blueBits == 0)
bScale = 0;
for (i = 0; i < n; i++) {
GLint r, g, b;
/* convert float back to ubyte */
CLAMPED_FLOAT_TO_UBYTE(r, rgba[i][RCOMP]);
CLAMPED_FLOAT_TO_UBYTE(g, rgba[i][GCOMP]);
CLAMPED_FLOAT_TO_UBYTE(b, rgba[i][BCOMP]);
/* using only the N most significant bits of the ubyte value, convert to
* float in [0,1].
*/
rgba[i][RCOMP] = (GLfloat) (r >> rShift) * rScale;
rgba[i][GCOMP] = (GLfloat) (g >> gShift) * gScale;
rgba[i][BCOMP] = (GLfloat) (b >> bShift) * bScale;
}
}
/*
* Read R, G, B, A, RGB, L, or LA pixels.
*/
static void
read_rgba_pixels( struct gl_context *ctx,
GLint x, GLint y,
GLsizei width, GLsizei height,
GLenum format, GLenum type, GLvoid *pixels,
const struct gl_pixelstore_attrib *packing )
{
SWcontext *swrast = SWRAST_CONTEXT(ctx);
GLbitfield transferOps = ctx->_ImageTransferState;
struct gl_framebuffer *fb = ctx->ReadBuffer;
struct gl_renderbuffer *rb = fb->_ColorReadBuffer;
if (!rb)
return;
if (type == GL_FLOAT && ((ctx->Color.ClampReadColor == GL_TRUE) ||
(ctx->Color.ClampReadColor == GL_FIXED_ONLY_ARB &&
rb->DataType != GL_FLOAT)))
transferOps |= IMAGE_CLAMP_BIT;
/* Try optimized path first */
if (fast_read_rgba_pixels(ctx, x, y, width, height,
format, type, pixels, packing, transferOps)) {
return; /* done! */
}
/* width should never be > MAX_WIDTH since we did clipping earlier */
ASSERT(width <= MAX_WIDTH);
do {
const GLint dstStride
= _mesa_image_row_stride(packing, width, format, type);
GLfloat (*rgba)[4] = swrast->SpanArrays->attribs[FRAG_ATTRIB_COL0];
GLint row;
GLubyte *dst
= (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
format, type, 0, 0);
for (row = 0; row < height; row++, y++) {
/* Get float rgba pixels */
_swrast_read_rgba_span(ctx, rb, width, x, y, GL_FLOAT, rgba);
/* apply fudge factor for shallow color buffers */
if (fb->Visual.redBits < 8 ||
fb->Visual.greenBits < 8 ||
fb->Visual.blueBits < 8) {
adjust_colors(fb, width, rgba);
}
/* pack the row of RGBA pixels into user's buffer */
_mesa_pack_rgba_span_float(ctx, width, rgba, format, type, dst,
packing, transferOps);
dst += dstStride;
}
} while (0);
}
/**
* Read combined depth/stencil values.
* We'll have already done error checking to be sure the expected
* depth and stencil buffers really exist.
*/
static void
read_depth_stencil_pixels(struct gl_context *ctx,
GLint x, GLint y,
GLsizei width, GLsizei height,
GLenum type, GLvoid *pixels,
const struct gl_pixelstore_attrib *packing )
{
const GLboolean scaleOrBias
= ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0;
const GLboolean stencilTransfer = ctx->Pixel.IndexShift
|| ctx->Pixel.IndexOffset || ctx->Pixel.MapStencilFlag;
struct gl_renderbuffer *depthRb, *stencilRb;
depthRb = ctx->ReadBuffer->_DepthBuffer;
stencilRb = ctx->ReadBuffer->_StencilBuffer;
if (!depthRb || !stencilRb)
return;
depthRb = ctx->ReadBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
stencilRb = ctx->ReadBuffer->Attachment[BUFFER_STENCIL].Renderbuffer;
if (depthRb->_BaseFormat == GL_DEPTH_STENCIL_EXT &&
stencilRb->_BaseFormat == GL_DEPTH_STENCIL_EXT &&
depthRb == stencilRb &&
!scaleOrBias &&
!stencilTransfer) {
/* This is the ideal case.
* Reading GL_DEPTH_STENCIL pixels from combined depth/stencil buffer.
* Plus, no pixel transfer ops to worry about!
*/
GLint i;
GLint dstStride = _mesa_image_row_stride(packing, width,
GL_DEPTH_STENCIL_EXT, type);
GLubyte *dst = (GLubyte *) _mesa_image_address2d(packing, pixels,
width, height,
GL_DEPTH_STENCIL_EXT,
type, 0, 0);
for (i = 0; i < height; i++) {
depthRb->GetRow(ctx, depthRb, width, x, y + i, dst);
dst += dstStride;
}
}
else {
/* Reading GL_DEPTH_STENCIL pixels from separate depth/stencil buffers,
* or we need pixel transfer.
*/
GLint i;
depthRb = ctx->ReadBuffer->_DepthBuffer;
stencilRb = ctx->ReadBuffer->_StencilBuffer;
for (i = 0; i < height; i++) {
GLstencil stencilVals[MAX_WIDTH];
GLuint *depthStencilDst = (GLuint *)
_mesa_image_address2d(packing, pixels, width, height,
GL_DEPTH_STENCIL_EXT, type, i, 0);
_swrast_read_stencil_span(ctx, stencilRb, width,
x, y + i, stencilVals);
if (!scaleOrBias && !stencilTransfer
&& ctx->ReadBuffer->Visual.depthBits == 24) {
/* ideal case */
GLuint zVals[MAX_WIDTH]; /* 24-bit values! */
GLint j;
ASSERT(depthRb->DataType == GL_UNSIGNED_INT);
/* note, we've already been clipped */
depthRb->GetRow(ctx, depthRb, width, x, y + i, zVals);
for (j = 0; j < width; j++) {
depthStencilDst[j] = (zVals[j] << 8) | (stencilVals[j] & 0xff);
}
}
else {
/* general case */
GLfloat depthVals[MAX_WIDTH];
_swrast_read_depth_span_float(ctx, depthRb, width, x, y + i,
depthVals);
_mesa_pack_depth_stencil_span(ctx, width, depthStencilDst,
depthVals, stencilVals, packing);
}
}
}
}
/**
* Software fallback routine for ctx->Driver.ReadPixels().
* By time we get here, all error checking will have been done.
*/
void
_swrast_ReadPixels( struct gl_context *ctx,
GLint x, GLint y, GLsizei width, GLsizei height,
GLenum format, GLenum type,
const struct gl_pixelstore_attrib *packing,
GLvoid *pixels )
{
SWcontext *swrast = SWRAST_CONTEXT(ctx);
struct gl_pixelstore_attrib clippedPacking = *packing;
if (ctx->NewState)
_mesa_update_state(ctx);
/* Need to do swrast_render_start() before clipping or anything else
* since this is where a driver may grab the hw lock and get an updated
* window size.
*/
swrast_render_start(ctx);
if (swrast->NewState)
_swrast_validate_derived( ctx );
/* Do all needed clipping here, so that we can forget about it later */
if (_mesa_clip_readpixels(ctx, &x, &y, &width, &height, &clippedPacking)) {
pixels = _mesa_map_pbo_dest(ctx, &clippedPacking, pixels);
if (pixels) {
switch (format) {
case GL_STENCIL_INDEX:
read_stencil_pixels(ctx, x, y, width, height, type, pixels,
&clippedPacking);
break;
case GL_DEPTH_COMPONENT:
read_depth_pixels(ctx, x, y, width, height, type, pixels,
&clippedPacking);
break;
case GL_DEPTH_STENCIL_EXT:
read_depth_stencil_pixels(ctx, x, y, width, height, type, pixels,
&clippedPacking);
break;
default:
/* all other formats should be color formats */
read_rgba_pixels(ctx, x, y, width, height, format, type, pixels,
&clippedPacking);
}
_mesa_unmap_pbo_dest(ctx, &clippedPacking);
}
}
swrast_render_finish(ctx);
}