Provided by: opengl-4-man-doc_1.0~svn33624-1_all bug

NAME

       glCompressedTexSubImage2D, glCompressedTextureSubImage2D - specify a two-dimensional
       texture subimage in a compressed format

C SPECIFICATION

       void glCompressedTexSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset,
                                      GLsizei width, GLsizei height, GLenum format,
                                      GLsizei imageSize, const GLvoid * data);

       void glCompressedTextureSubImage2D(GLuint texture, GLint level, GLint xoffset,
                                          GLint yoffset, GLsizei width, GLsizei height,
                                          GLenum format, GLsizei imageSize, const void *data);

PARAMETERS

       target
           Specifies the target to which the texture is bound for glCompressedTexSubImage2D
           function. Must be GL_TEXTURE_1D_ARRAY, 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.

       texture
           Specifies the texture object name for glCompressedTextureSubImage2D function.

       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.

       yoffset
           Specifies a texel offset in the y direction within the texture array.

       width
           Specifies the width of the texture subimage.

       height
           Specifies the height 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.

       glCompressedTexSubImage2D and glCompressedTextureSubImage2D redefine a contiguous
       subregion of an existing two-dimensional texture image. The texels referenced by data
       replace the portion of the existing texture array with x indices xoffset and xoffset +
       width - 1, and the y indices yoffset and yoffset + height - 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 glTexImage2D()) 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 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_ENUM is generated by glCompressedTexSubImage2D if target is
       GL_TEXTURE_RECTANGLE or GL_PROXY_TEXTURE_RECTANGLE.

       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 by glCompressedTextureSubImage2D if texture is not the
       name of an existing texture object.

       GL_INVALID_OPERATION is generated by glCompressedTextureSubImage2D if the effective target
       is GL_TEXTURE_RECTANGLE.

       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

VERSION SUPPORT

       ┌──────────────────────────────┬───────────────────────────────────────────────────────────────────────┐
       │                              │                OpenGL Version                                         │
       ├──────────────────────────────┼─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┤
       │Function2.02.13.03.13.23.34.04.14.24.34.44.5 │
       │/                             │     │     │     │     │     │     │     │     │     │     │     │     │
       │Feature                       │     │     │     │     │     │     │     │     │     │     │     │     │
       │Name                          │     │     │     │     │     │     │     │     │     │     │     │     │
       ├──────────────────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
       │glCompressedTexSubImage2D     │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │
       ├──────────────────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
       │glCompressedTextureSubImage2D │  -  │  -  │  -  │  -  │  -  │  -  │  -  │  -  │  -  │  -  │  -  │  ✔  │
       └──────────────────────────────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┘

SEE ALSO

       glActiveTexture(), glCompressedTexImage1D(), glCompressedTexImage2D(),
       glCompressedTexImage3D(), glCompressedTexSubImage1D(), glCompressedTexSubImage3D(),
       glCopyTexImage1D(), glCopyTexImage2D(), glCopyTexSubImage1D(), glCopyTexSubImage2D(),
       glCopyTexSubImage3D(), glPixelStore(), glTexImage2D(), glTexImage3D(), glTexSubImage1D(),
       glTexSubImage2D(), glTexSubImage3D(), glTexParameter()

COPYRIGHT

       Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2010-2014 Khronos Group. This
       document is licensed under the SGI Free Software B License. For details, see
       http://oss.sgi.com/projects/FreeB/.

COPYRIGHT

       Copyright © 1991-2006 Silicon Graphics, Inc.
       Copyright © 2010-2014 Khronos Group

[FIXME: source]                             01/03/2018                   GLCOMPRESSEDTEXSUBIM(3G)