OpenGL.GL.SGIS.texture_lod

OpenGL extension SGIS.texture_lod

This module customises the behaviour of the OpenGL.raw.GL.SGIS.texture_lod to provide a more Python-friendly API

Overview (from the spec)

This extension imposes two constraints related to the texture level of detail parameter LOD, which is represented by the Greek character lambda in the GL Specification. One constraint clamps LOD to a specified floating point range. The other limits the selection of mipmap image arrays to a subset of the arrays that would otherwise be considered.

Together these constraints allow a large texture to be loaded and used initially at low resolution, and to have its resolution raised gradually as more resolution is desired or available. Image array specification is necessarily integral, rather than continuous. By providing separate, continuous clamping of the LOD parameter, it is possible to avoid "popping" artifacts when higher resolution images are provided.

Note: because the shape of the mipmap array is always determined by the dimensions of the level 0 array, this array must be loaded for mipmapping to be active. If the level 0 array is specified with a null image pointer, however, no actual data transfer will take place. And a sufficiently tuned implementation might not even allocate space for a level 0 array so specified until true image data were presented.

The official definition of this extension is available here: http://www.opengl.org/registry/specs/SGIS/texture_lod.txt