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. Must be GL_TEXTURE_2D
, GL_PROXY_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
, GL_TEXTURE_CUBE_MAP_NEGATIVE_Z
, or GL_PROXY_TEXTURE_CUBE_MAP
.
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 including the border if any. If the GL version does not support non-power-of-two sizes, this value must be for some integer . 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 including the border if any. If the GL version does not support non-power-of-two sizes, this value must be Must be for some integer . 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 either 0 or 1.
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 enabled. To enable and disable two-dimensional texturing, call glEnable and glDisable with argument GL_TEXTURE_2D
. To enable and disable texturing using cube-mapped textures, call glEnable and glDisable with argument GL_TEXTURE_CUBE_MAP
.
glCompressedTexImage2D
loads a previously defined, and retrieved, compressed two-dimensional texture image if target
is GL_TEXTURE_2D
(see glTexImage2D).
If target
is GL_PROXY_TEXTURE_2D
, no data is read from data
, but all of the texture image state is recalculated, checked for consistency, and checked against the implementation's capabilities. If the implementation cannot handle a texture of the requested texture size, it sets all of the image state to 0, but does not generate an error (see glGetError). To query for an entire mipmap array, use an image array level greater than or equal to 1.
internalformat
must be an extension-specified compressed-texture format. When a texture is loaded with glTexImage2D using a generic compressed texture format (e.g., GL_COMPRESSED_RGB
), the GL selects from one of its extensions supporting compressed textures. In order to load the compressed texture image using glCompressedTexImage2D
, query the compressed texture image's size and format using glGetTexLevelParameter.
If a non-zero named buffer object is bound to the GL_PIXEL_UNPACK_BUFFER
target (see glBindBuffer) while a texture image is specified, data
is treated as a byte offset into the buffer object's data store.
glCompressedTexImage2D
is available only if the GL version is 1.3 or greater.
Non-power-of-two textures are supported if the GL version is 2.0 or greater, or if the implementation exports the GL_ARB_texture_non_power_of_two
extension.
GL_INVALID_ENUM
is generated if internalformat
is one of the generic compressed internal formats: GL_COMPRESSED_ALPHA
, GL_COMPRESSED_LUMINANCE
, GL_COMPRESSED_LUMINANCE_ALPHA
, GL_COMPRESSED_INTENSITY
, GL_COMPRESSED_RGB
, or GL_COMPRESSED_RGBA
.
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.
GL_INVALID_OPERATION
is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER
target and the buffer object's data store is currently mapped.
GL_INVALID_OPERATION
is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER
target and the data would be unpacked from the buffer object such that the memory reads required would exceed the data store size.
GL_INVALID_OPERATION
is generated if glCompressedTexImage2D
is executed between the execution of glBegin and the corresponding execution of glEnd.
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 argument GL_TEXTURE_COMPRESSED
glGet with argument GL_PIXEL_UNPACK_BUFFER_BINDING
glGetTexLevelParameter with arguments GL_TEXTURE_INTERNAL_FORMAT
and GL_TEXTURE_COMPRESSED_IMAGE_SIZE
glIsEnabled with argument GL_TEXTURE_2D
or GL_TEXTURE_CUBE_MAP
glActiveTexture, glColorTable, glCompressedTexImage1D, glCompressedTexImage3D, glCompressedTexSubImage1D, glCompressedTexSubImage2D, glCompressedTexSubImage3D, glConvolutionFilter1D, glCopyPixels, glCopyTexImage1D, glCopyTexSubImage1D, glCopyTexSubImage2D, glCopyTexSubImage3D, glDrawPixels, glMatrixMode, glPixelStore, glPixelTransfer, glTexEnv, glTexGen, glTexImage2D, glTexImage3D, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D, 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/.