| '''OpenGL extension NV.fragment_program |
| |
| This module customises the behaviour of the |
| OpenGL.raw.GL.NV.fragment_program to provide a more |
| Python-friendly API |
| |
| Overview (from the spec) |
| |
| OpenGL mandates a certain set of configurable per-fragment computations |
| defining texture lookup, texture environment, color sum, and fog |
| operations. Each of these areas provide a useful but limited set of fixed |
| operations. For example, unextended OpenGL 1.2.1 provides only four |
| texture environment modes, color sum, and three fog modes. Many OpenGL |
| extensions have either improved existing functionality or introduced new |
| configurable fragment operations. While these extensions have enabled new |
| and interesting rendering effects, the set of effects is limited by the |
| set of special modes introduced by the extension. This lack of |
| flexibility is in contrast to the high-level of programmability of |
| general-purpose CPUs and other (frequently software-based) shading |
| languages. The purpose of this extension is to expose to the OpenGL |
| application writer an unprecedented degree of programmability in the |
| computation of final fragment colors and depth values. |
| |
| This extension provides a mechanism for defining fragment program |
| instruction sequences for application-defined fragment programs. When in |
| fragment program mode, a program is executed each time a fragment is |
| produced by rasterization. The inputs for the program are the attributes |
| (position, colors, texture coordinates) associated with the fragment and a |
| set of constant registers. A fragment program can perform mathematical |
| computations and texture lookups using arbitrary texture coordinates. The |
| results of a fragment program are new color and depth values for the |
| fragment. |
| |
| This extension defines a programming model including a 4-component vector |
| instruction set, 16- and 32-bit floating-point data types, and a |
| relatively large set of temporary registers. The programming model also |
| includes a condition code vector which can be used to mask register writes |
| at run-time or kill fragments altogether. The syntax, program |
| instructions, and general semantics are similar to those in the |
| NV_vertex_program and NV_vertex_program2 extensions, which provide for the |
| execution of an arbitrary program each time the GL receives a vertex. |
| |
| The fragment program execution environment is designed for efficient |
| hardware implementation and to support a wide variety of programs. By |
| design, the entire set of existing fragment programs defined by existing |
| OpenGL per-fragment computation extensions can be implemented using the |
| extension's programming model. |
| |
| The fragment program execution environment accesses textures via |
| arbitrarily computed texture coordinates. As such, there is no necessary |
| correspondence between the texture coordinates and texture maps previously |
| lumped into a single "texture unit". This extension separates the notion |
| of "texture coordinate sets" and "texture image units" (texture maps and |
| associated parameters), allowing implementations with a different number |
| of each. The initial implementation of this extension will support 8 |
| texture coordinate sets and 16 texture image units. |
| |
| The official definition of this extension is available here: |
| http://www.opengl.org/registry/specs/NV/fragment_program.txt |
| ''' |
| from OpenGL import platform, constant, arrays |
| from OpenGL import extensions, wrapper |
| import ctypes |
| from OpenGL.raw.GL import _types, _glgets |
| from OpenGL.raw.GL.NV.fragment_program import * |
| from OpenGL.raw.GL.NV.fragment_program import _EXTENSION_NAME |
|
|
| def glInitFragmentProgramNV(): |
| '''Return boolean indicating whether this extension is available''' |
| from OpenGL import extensions |
| return extensions.hasGLExtension( _EXTENSION_NAME ) |
|
|
| glProgramNamedParameter4fNV=wrapper.wrapper(glProgramNamedParameter4fNV).setInputArraySize( |
| 'name', 1 |
| ) |
| glProgramNamedParameter4fvNV=wrapper.wrapper(glProgramNamedParameter4fvNV).setInputArraySize( |
| 'name', 1 |
| ).setInputArraySize( |
| 'v', 4 |
| ) |
| glProgramNamedParameter4dNV=wrapper.wrapper(glProgramNamedParameter4dNV).setInputArraySize( |
| 'name', 1 |
| ) |
| glProgramNamedParameter4dvNV=wrapper.wrapper(glProgramNamedParameter4dvNV).setInputArraySize( |
| 'name', 1 |
| ).setInputArraySize( |
| 'v', 4 |
| ) |
| glGetProgramNamedParameterfvNV=wrapper.wrapper(glGetProgramNamedParameterfvNV).setInputArraySize( |
| 'name', 1 |
| ).setOutput( |
| 'params',size=(4,),orPassIn=True |
| ) |
| glGetProgramNamedParameterdvNV=wrapper.wrapper(glGetProgramNamedParameterdvNV).setInputArraySize( |
| 'name', 1 |
| ).setOutput( |
| 'params',size=(4,),orPassIn=True |
| ) |
| |
