s_readpix.c File Reference

#include "main/glheader.h"
#include "main/bufferobj.h"
#include "main/colormac.h"
#include "main/convolve.h"
#include "main/context.h"
#include "main/feedback.h"
#include "main/image.h"
#include "main/macros.h"
#include "main/imports.h"
#include "main/pixel.h"
#include "main/state.h"
#include "s_context.h"
#include "s_depth.h"
#include "s_span.h"
#include "s_stencil.h"

Functions
static void	read_index_pixels (GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height, GLenum type, GLvoid *pixels, const struct gl_pixelstore_attrib *packing)
static void	read_depth_pixels (GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height, GLenum type, GLvoid *pixels, const struct gl_pixelstore_attrib *packing)
	Read pixels for format=GL_DEPTH_COMPONENT.
static void	read_stencil_pixels (GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height, GLenum type, GLvoid *pixels, const struct gl_pixelstore_attrib *packing)
	Read pixels for format=GL_STENCIL_INDEX.
static GLboolean	fast_read_rgba_pixels (GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, GLvoid *pixels, const struct gl_pixelstore_attrib *packing, GLbitfield transferOps)
	Optimized glReadPixels for particular pixel formats when pixel scaling, biasing, mapping, etc.
static void	adjust_colors (GLcontext *ctx, GLuint n, GLfloat rgba[][4])
	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.
static void	read_rgba_pixels (GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, GLvoid *pixels, const struct gl_pixelstore_attrib *packing)
static void	read_depth_stencil_pixels (GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height, GLenum type, GLvoid *pixels, const struct gl_pixelstore_attrib *packing)
	Read combined depth/stencil values.
void	_swrast_ReadPixels (GLcontext *ctx, GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, const struct gl_pixelstore_attrib *packing, GLvoid *pixels)
	Software fallback routine for ctx->Driver.ReadPixels().

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Function Documentation

void _swrast_ReadPixels	(	GLcontext *	ctx,
		GLint	x,
		GLint	y,
		GLsizei	width,
		GLsizei	height,
		GLenum	format,
		GLenum	type,
		const struct gl_pixelstore_attrib *	packing,
		GLvoid *	pixels
	)

Software fallback routine for ctx->Driver.ReadPixels().

By time we get here, all error checking will have been done.

static void adjust_colors	(	GLcontext *	ctx,
		GLuint	n,
		GLfloat	rgba[][4]
	)			[static]

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 convert 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 GLboolean fast_read_rgba_pixels	(	GLcontext *	ctx,
		GLint	x,
		GLint	y,
		GLsizei	width,
		GLsizei	height,
		GLenum	format,
		GLenum	type,
		GLvoid *	pixels,
		const struct gl_pixelstore_attrib *	packing,
		GLbitfield	transferOps
	)			[static]

Optimized glReadPixels for particular pixel formats when pixel scaling, biasing, mapping, etc.

are disabled.

Returns:

GL_TRUE if success, GL_FALSE if unable to do the readpixels

static void read_depth_pixels	(	GLcontext *	ctx,
		GLint	x,
		GLint	y,
		GLsizei	width,
		GLsizei	height,
		GLenum	type,
		GLvoid *	pixels,
		const struct gl_pixelstore_attrib *	packing
	)			[static]

Read pixels for format=GL_DEPTH_COMPONENT.

static void read_depth_stencil_pixels	(	GLcontext *	ctx,
		GLint	x,
		GLint	y,
		GLsizei	width,
		GLsizei	height,
		GLenum	type,
		GLvoid *	pixels,
		const struct gl_pixelstore_attrib *	packing
	)			[static]

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_index_pixels	(	GLcontext *	ctx,
		GLint	x,
		GLint	y,
		GLsizei	width,
		GLsizei	height,
		GLenum	type,
		GLvoid *	pixels,
		const struct gl_pixelstore_attrib *	packing
	)			[static]

static void read_rgba_pixels	(	GLcontext *	ctx,
		GLint	x,
		GLint	y,
		GLsizei	width,
		GLsizei	height,
		GLenum	format,
		GLenum	type,
		GLvoid *	pixels,
		const struct gl_pixelstore_attrib *	packing
	)			[static]

static void read_stencil_pixels	(	GLcontext *	ctx,
		GLint	x,
		GLint	y,
		GLsizei	width,
		GLsizei	height,
		GLenum	type,
		GLvoid *	pixels,
		const struct gl_pixelstore_attrib *	packing
	)			[static]

Read pixels for format=GL_STENCIL_INDEX.

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