glCompressedTexImage2D

glCompressedTexImage2D: man2/glCompressedTexImage2D.xml

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.