glCompressedTexSubImage1D — specify a one-dimensional texture subimage in a compressed format
void glCompressedTexSubImage1D( | GLenum | target, |
GLint | level, | |
GLint | xoffset, | |
GLsizei | width, | |
GLenum | format, | |
GLsizei | imageSize, | |
const GLvoid * | data) ; |
target
Specifies the target texture.
Must be GL_TEXTURE_1D
.
level
Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
xoffset
Specifies a texel offset in the x direction within the texture array.
width
Specifies the width of the texture subimage.
format
Specifies the format of the compressed image data stored at address data
.
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 allows elements of an image array to be read by shaders.
glCompressedTexSubImage1D
redefines a contiguous subregion of an existing one-dimensional
texture image. The texels referenced by data
replace the portion of the
existing texture array with x indices xoffset
and
internalformat
must be a known compressed image format (such as GL_RGTC
)
or an extension-specified compressed-texture format.
The format
of the compressed texture
image is selected by the GL implementation that compressed it (see
glTexImage1D), and should be queried at the time the texture was
compressed with 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.
GL_INVALID_ENUM
is generated if internalformat
is not one of the generic
compressed internal formats:
GL_COMPRESSED_RED
,
GL_COMPRESSED_RG
,
GL_COMPRESSED_RGB
,
GL_COMPRESSED_RGBA
.
GL_COMPRESSED_SRGB
, or
GL_COMPRESSED_SRGB_ALPHA
.
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.
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
glActiveTexture, glCompressedTexImage1D, glCompressedTexImage2D, glCompressedTexImage3D, glCompressedTexSubImage2D, glCompressedTexSubImage3D, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glCopyTexSubImage3D, glPixelStore, 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 http://oss.sgi.com/projects/FreeB/.