1991-2006
Silicon Graphics, Inc.
glCompressedTexImage2D
3G
glCompressedTexImage2D
specify a two-dimensional texture image in a compressed format
C Specification
void glCompressedTexImage2D
GLenum target
GLint level
GLenum internalformat
GLsizei width
GLsizei height
GLint border
GLsizei imageSize
const GLvoid * data
Parameters
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.
Description
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.
Notes
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.
Errors
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
log
2
⁢
max
,
where
max
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.
Associated Gets
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
See Also
glActiveTexture,
glCompressedTexSubImage2D,
glCopyTexImage2D,
glCopyTexSubImage2D,
glTexImage2D,
glTexSubImage2D,
glTexParameter
Copyright
Copyright 1991-2006
Silicon Graphics, Inc. This document is licensed under the SGI
Free Software B License. For details, see
http://oss.sgi.com/projects/FreeB/.