| '''OpenGL extension EXT.pvrtc_sRGB |
| |
| This module customises the behaviour of the |
| OpenGL.raw.GLES2.EXT.pvrtc_sRGB to provide a more |
| Python-friendly API |
| |
| Overview (from the spec) |
| |
| The response from electronic display systems given RGB tristimulus values |
| for each pixel is non-linear. Gamma correction is the process of encoding |
| or decoding images in a manner that will correct for non-linear response |
| profiles of output devices. The displayed results of gamma-corrected pixel |
| data are more consistent and predictable for the author of such pixel data |
| than it would otherwise be with linearly encoded pixel data. |
| |
| This EXT_pvrtc_sRGB extension specifies additional tokens for gamma |
| corrected PVRTC compressed sRGB data. |
| |
| Texture assets are developed and evaluated for use in OpenGL applications |
| using electronic displays with non-linear responses. This extension |
| provides a better measure of consistency between textures developed within |
| an asset toolchain and their final rendered result with an OpenGL |
| application that uses those textures. |
| |
| Conventional OpenGL texture tristimulus values as well as their alpha |
| component are encoded linearly. The textures introduced by this extension |
| are encoded with gamma correction in the tristimulus components but |
| linearly in the alpha component. |
| |
| When gamma corrected texture samples are fetched and operated on by ALU |
| operations in an OpenGL shading program those samples will be converted |
| from gamma corrected space to linear space for logical simplicity and |
| performance of the shader. |
| |
| Texture filtering operations as well as mipmap generation are carried out |
| in linear space. |
| |
| The official definition of this extension is available here: |
| http://www.opengl.org/registry/specs/EXT/pvrtc_sRGB.txt |
| ''' |
| from OpenGL import platform, constant, arrays |
| from OpenGL import extensions, wrapper |
| import ctypes |
| from OpenGL.raw.GLES2 import _types, _glgets |
| from OpenGL.raw.GLES2.EXT.pvrtc_sRGB import * |
| from OpenGL.raw.GLES2.EXT.pvrtc_sRGB import _EXTENSION_NAME |
|
|
| def glInitPvrtcSrgbEXT(): |
| '''Return boolean indicating whether this extension is available''' |
| from OpenGL import extensions |
| return extensions.hasGLExtension( _EXTENSION_NAME ) |
|
|
|
|
| |
