GLCOMPRESSEDTEXSUBIM(3G)

    .SH "NAME" glCompressedTexSubImage2D, glCompressedTextureSubImage2D - specify a two-dimensional texture subimage in a compressed format
    .SH "C SPECIFICATION"

            .HP u void glCompressedTexSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height, GLenum format, GLsizei imageSize, const void * data);
            .HP u void glCompressedTextureSubImage2D(GLuint texture, GLint level, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height, GLenum format, GLsizei imageSize, const void *data);

    .SH "PARAMETERS"

        .PP 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.

          .RE
          .PP texture

                  Specifies the texture object name for glCompressedTextureSubImage2D function.

              .RE
              .PP level

                      Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.

                  .RE
                  .PP xoffset

                          Specifies a texel offset in the x direction within the texture array.

                      .RE
                      .PP yoffset

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

                          .RE
                          .PP width

                                  Specifies the width of the texture subimage.

                              .RE
                              .PP height

                                      Specifies the height of the texture subimage.

                                  .RE
                                  .PP format

                                          Specifies the format of the compressed image data stored at address data.

                                      .RE
                                      .PP imageSize

                                              Specifies the number of unsigned bytes of image data starting at the address specified by data.

                                          .RE
                                          .PP data

                                                  Specifies a pointer to the compressed image data in memory.

                                              .RE

                                          .SH "DESCRIPTION"

                                            .PP Texturing allows elements of an image array to be read by shaders.
                                            .PP 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.
                                            .PP 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().
                                            .PP 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.

                                          .SH "ERRORS"

                                            .PP 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.
                                            .PP GL_INVALID_ENUM is generated by glCompressedTexSubImage2D if target is GL_TEXTURE_RECTANGLE or GL_PROXY_TEXTURE_RECTANGLE.
                                            .PP GL_INVALID_VALUE is generated if imageSize is not consistent with the format, dimensions, and contents of the specified compressed image data.
                                            .PP 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.
                                            .PP 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.
                                            .PP 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.
                                            .PP GL_INVALID_OPERATION is generated by glCompressedTextureSubImage2D if texture is not the name of an existing texture object.
                                            .PP GL_INVALID_OPERATION is generated by glCompressedTextureSubImage2D if the effective target is GL_TEXTURE_RECTANGLE.
                                            .PP 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.

                                            .SH "ASSOCIATED GETS"
                                                .PP glGetCompressedTexImage()
                                                .PP glGet() with argument GL_TEXTURE_COMPRESSED
                                                .PP glGet() with argument GL_PIXEL_UNPACK_BUFFER_BINDING
                                                .PP glGetTexLevelParameter() with arguments GL_TEXTURE_INTERNAL_FORMAT and GL_TEXTURE_COMPRESSED_IMAGE_SIZE

                                            .SH "VERSION SUPPORT"
                                                .TS allbox tab(:); lB cB s s s s s s s s s s s lB cB cB cB cB cB cB cB cB cB cB cB cB. T{ T}:T{ OpenGL Version T} T{ Function / Feature Name T}:T{ 2.0 T}:T{ 2.1 T}:T{ 3.0 T}:T{ 3.1 T}:T{ 3.2 T}:T{ 3.3 T}:T{ 4.0 T}:T{ 4.1 T}:T{ 4.2 T}:T{ 4.3 T}:T{ 4.4 T}:T{ 4.5 T} l c c c c c c c c c c c c l c c c c c c c c c c c c. T{ glCompressedTexSubImage2D T}:T{ ✔ T}:T{ ✔ T}:T{ ✔ T}:T{ ✔ T}:T{ ✔ T}:T{ ✔ T}:T{ ✔ T}:T{ ✔ T}:T{ ✔ T}:T{ ✔ T}:T{ ✔ T}:T{ ✔ T} T{ glCompressedTextureSubImage2D T}:T{ - T}:T{ - T}:T{ - T}:T{ - T}:T{ - T}:T{ - T}:T{ - T}:T{ - T}:T{ - T}:T{ - T}:T{ - T}:T{ ✔ T}

                                            .SH "SEE ALSO"
                                                .PP glActiveTexture(), glCompressedTexImage1D(), glCompressedTexImage2D(), glCompressedTexImage3D(), glCompressedTexSubImage1D(), glCompressedTexSubImage3D(), glCopyTexImage1D(), glCopyTexImage2D(), glCopyTexSubImage1D(), glCopyTexSubImage2D(), glCopyTexSubImage3D(), glPixelStore(), glTexImage2D(), glTexImage3D(), glTexSubImage1D(), glTexSubImage2D(), glTexSubImage3D(), glTexParameter()

                                            .SH "COPYRIGHT"
                                                .PP 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 https://khronos.org/registry/OpenGL-Refpages/LICENSES/LicenseRef-FreeB.txt.

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