OpenGL.GL.SGIX.texture_lod_bias

OpenGL extension SGIX.texture_lod_bias

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

Overview (from the spec)

This extension modifies the calculation of texture level of detail parameter LOD, which is represented by the Greek character lambda in the GL Specification. The LOD equation assumes that a 2^n x 2^m x 2^l texture is band limited at 2^(n-1), 2^(m-1), 2^(l-1). Often a texture is oversampled or filtered such that the texture is band limited at lower frequencies in one or more dimensions. The result is that texture-mapped primitives appear excessively blurry. This extension provides biases for n, m, and l in the LOD calculation to to compensate for under or over sampled texture images. Mipmapped textures can be made to appear sharper or blurrier by supplying a negative or positive bias respectively.

Examples of textures which can benefit from this LOD control include video-capture images which are filtered differently horizontally and vertically; a texture which appears blurry because it is mapped with a nonuniform scale, such as a road texture which is repeated hundreds of times in one dimension and only once in the other; and textures which had to be magnified to a power-of-two for mipmapping.

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