1991-2006
Silicon Graphics, Inc.
glCompressedTexSubImage1D
3G
glCompressedTexSubImage1D
specify a one-dimensional texture subimage in a compressed format
C Specification
void glCompressedTexSubImage1D
GLenum target
GLint level
GLint xoffset
GLsizei width
GLenum format
GLsizei imageSize
const GLvoid * data
Parameters
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.
Description
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
xoffset
+
width
-
1
,
inclusive. This region may not include any texels
outside the range of the texture array as it was originally specified. It
is not an error to specify a subtexture with width of 0, but such a
specification has no effect.
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.
Errors
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.
Associated Gets
glGetCompressedTexImage
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
See Also
glActiveTexture,
glCompressedTexImage1D,
glCompressedTexImage2D,
glCompressedTexImage3D,
glCompressedTexSubImage2D,
glCompressedTexSubImage3D,
glCopyTexImage1D,
glCopyTexImage2D,
glCopyTexSubImage1D,
glCopyTexSubImage2D,
glCopyTexSubImage3D,
glPixelStore,
glTexImage2D,
glTexImage3D,
glTexSubImage1D,
glTexSubImage2D,
glTexSubImage3D,
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/.