texcompress.c File Reference

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Detailed Description

Helper functions for texture compression.

#include "glheader.h"
#include "imports.h"
#include "colormac.h"
#include "context.h"
#include "image.h"
#include "mipmap.h"
#include "texcompress.h"
#include "texformat.h"
#include "texstore.h"

Functions
GLuint	_mesa_get_compressed_formats (GLcontext *ctx, GLint *formats, GLboolean all)
	Return list of (and count of) all specific texture compression formats that are supported.
GLuint	_mesa_compressed_texture_size (GLcontext *ctx, GLsizei width, GLsizei height, GLsizei depth, GLuint mesaFormat)
	Return number of bytes needed to store a texture of the given size using the specified compressed format.
GLuint	_mesa_compressed_texture_size_glenum (GLcontext *ctx, GLsizei width, GLsizei height, GLsizei depth, GLenum glformat)
	As above, but format is specified by a GLenum (GL_COMPRESSED_*) token.
GLint	_mesa_compressed_row_stride (GLuint mesaFormat, GLsizei width)
GLubyte *	_mesa_compressed_image_address (GLint col, GLint row, GLint img, GLuint mesaFormat, GLsizei width, const GLubyte *image)

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Function Documentation

GLubyte* _mesa_compressed_image_address	(	GLint	col,
		GLint	row,
		GLint	img,
		GLuint	mesaFormat,
		GLsizei	width,
		const GLubyte *	image
	)

GLint _mesa_compressed_row_stride	(	GLuint	mesaFormat,
		GLsizei	width
	)

GLuint _mesa_compressed_texture_size	(	GLcontext *	ctx,
		GLsizei	width,
		GLsizei	height,
		GLsizei	depth,
		GLuint	mesaFormat
	)

Return number of bytes needed to store a texture of the given size using the specified compressed format.

This is called via the ctx->Driver.CompressedTextureSize function, unless a device driver overrides it.

Parameters:

	width	texture width in texels.
	height	texture height in texels.
	depth	texture depth in texels.
	mesaFormat	one of the MESA_FORMAT_* compressed formats

Returns:

size in bytes, or zero if bad format

GLuint _mesa_compressed_texture_size_glenum	(	GLcontext *	ctx,
		GLsizei	width,
		GLsizei	height,
		GLsizei	depth,
		GLenum	glformat
	)

As above, but format is specified by a GLenum (GL_COMPRESSED_*) token.

Note: This function CAN NOT return a padded hardware texture size. That's why we don't call the ctx->Driver.CompressedTextureSize() function.

We use this function to validate the <imageSize> parameter of glCompressedTex[Sub]Image1/2/3D(), which must be an exact match.

GLuint _mesa_get_compressed_formats	(	GLcontext *	ctx,
		GLint *	formats,
		GLboolean	all
	)

Return list of (and count of) all specific texture compression formats that are supported.

Parameters:

	ctx	the GL context
	formats	the resulting format list (may be NULL).
	all	if true return all formats, even those with some kind of restrictions/limitations (See GL_ARB_texture_compression spec for more info).

Returns:

number of formats.

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