OpenGL.GL.NV.gpu_program4

OpenGL extension NV.gpu_program4

This module customises the behaviour of the OpenGL.raw.GL.NV.gpu_program4 to provide a more Python-friendly API

Overview (from the spec)

This specification documents the common instruction set and basic functionality provided by NVIDIA's 4th generation of assembly instruction sets supporting programmable graphics pipeline stages.

The instruction set builds upon the basic framework provided by the ARB_vertex_program and ARB_fragment_program extensions to expose considerably more capable hardware. In addition to new capabilities for vertex and fragment programs, this extension provides a new program type (geometry programs) further described in the NV_geometry_program4 specification.

NV_gpu_program4 provides a unified instruction set -- all instruction set features are available for all program types, except for a small number of features that make sense only for a specific program type. It provides fully capable signed and unsigned integer data types, along with a set of arithmetic, logical, and data type conversion instructions capable of operating on integers. It also provides a uniform set of structured branching constructs (if tests, loops, and subroutines) that fully support run-time condition testing.

This extension provides several new texture mapping capabilities. Shadow cube maps are supported, where cube map faces can encode depth values. Texture lookup instructions can include an immediate texel offset, which can assist in advanced filtering. New instructions are provided to fetch a single texel by address in a texture map (TXF) and query the size of a specified texture level (TXQ).

By and large, vertex and fragment programs written to ARB_vertex_program and ARB_fragment_program can be ported directly by simply changing the program header from "!!ARBvp1.0" or "!!ARBfp1.0" to "!!NVvp4.0" or "!!NVfp4.0", and then modifying the code to take advantage of the expanded feature set. There are a small number of areas where this extension is not a functional superset of previous vertex program extensions, which are documented in this specification.

The official definition of this extension is available here: http://www.opengl.org/registry/specs/NV/gpu_program4.txt