glCompressedTexImage2D — specify a two-dimensional texture image in a compressed format
void glCompressedTexImage2D( | GLenum target, |
GLint level, | |
GLenum internalformat, | |
GLsizei width, | |
GLsizei height, | |
GLint border, | |
GLsizei imageSize, | |
const GLvoid * data) ; |
target
Specifies the target texture of the active texture unit. Must be GL_TEXTURE_2D
, GL_TEXTURE_CUBE_MAP_POSITIVE_X
, GL_TEXTURE_CUBE_MAP_NEGATIVE_X
, GL_TEXTURE_CUBE_MAP_POSITIVE_Y
, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y
, GL_TEXTURE_CUBE_MAP_POSITIVE_Z
, or GL_TEXTURE_CUBE_MAP_NEGATIVE_Z
.
level
Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
internalformat
Specifies the format of the compressed image data stored at address data
.
width
Specifies the width of the texture image. All implementations support 2D texture images that are at least 64 texels wide and cube-mapped texture images that are at least 16 texels wide.
height
Specifies the height of the texture image. All implementations support 2D texture images that are at least 64 texels high and cube-mapped texture images that are at least 16 texels high.
border
Specifies the width of the border. Must be 0.
imageSize
Specifies the number of unsigned bytes of image data starting at the address specified by data
.
data
Specifies a pointer to the compressed image data in memory.
Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is active. Texturing is active when the current fragment shader or vertex shader makes use of built-in texture lookup functions.
glCompressedTexImage2D
defines a two-dimensional texture image or cube-map texture image using compressed image data from client memory. The texture image is decoded according to the extension specification defining the specified internalformat
. OpenGL ES defines no specific compressed texture formats, but does provide a mechanism to obtain symbolic constants for such formats provided by extensions. The number of compressed texture formats supported can be obtained by querying the value of GL_NUM_COMPRESSED_TEXTURE_FORMATS
. The list of specific compressed texture formats supported can be obtained by querying the value of GL_COMPRESSED_TEXTURE_FORMATS
.
A GL implementation may choose to store the texture array at any internal resolution it chooses.
glCompressedTexImage2D
specifies a two-dimensional or cube-map texture for the current texture unit, specified with glActiveTexture.
GL_INVALID_ENUM
is generated if target
is not GL_TEXTURE_2D
, GL_TEXTURE_CUBE_MAP_POSITIVE_X
, GL_TEXTURE_CUBE_MAP_NEGATIVE_X
, GL_TEXTURE_CUBE_MAP_POSITIVE_Y
, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y
, GL_TEXTURE_CUBE_MAP_POSITIVE_Z
, or GL_TEXTURE_CUBE_MAP_NEGATIVE_Z
.
GL_INVALID_ENUM
is generated if internalformat
is not a supported format returned in GL_COMPRESSED_TEXTURE_FORMATS
.
GL_INVALID_VALUE
is generated if level
is less than 0.
GL_INVALID_VALUE
may be generated if level
is greater than , where is the returned value of GL_MAX_TEXTURE_SIZE
when target
is GL_TEXTURE_2D
or GL_MAX_CUBE_MAP_TEXTURE_SIZE
when target
is not GL_TEXTURE_2D
.
GL_INVALID_VALUE
is generated if width
or height
is less than 0 or greater than GL_MAX_TEXTURE_SIZE
when target
is GL_TEXTURE_2D
or GL_MAX_CUBE_MAP_TEXTURE_SIZE
when target
is not GL_TEXTURE_2D
.
GL_INVALID_VALUE
is generated if border
is not 0.
GL_INVALID_VALUE
is generated if imageSize
is not consistent with the format, dimensions, and contents of the specified compressed image data.
GL_INVALID_OPERATION
is generated if parameter combinations are not supported by the specific compressed internal format as specified in the specific texture compression extension.
Undefined results, including abnormal program termination, are generated if data
is not encoded in a manner consistent with the extension specification defining the internal compression format.
glGet with arguments GL_NUM_COMPRESSED_TEXTURE_FORMATS
and GL_COMPRESSED_TEXTURE_FORMATS
glGet with argument GL_MAX_TEXTURE_SIZE
or GL_MAX_CUBE_MAP_TEXTURE_SIZE
glActiveTexture, glCompressedTexSubImage2D, glCopyTexImage2D, glCopyTexSubImage2D, glTexImage2D, glTexSubImage2D, glTexParameter
Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see https://web.archive.org/web/20171022161616/http://oss.sgi.com/projects/FreeB/.