| '''OpenGL extension MESA.ycbcr_texture |
| |
| This module customises the behaviour of the |
| OpenGL.raw.GL.MESA.ycbcr_texture to provide a more |
| Python-friendly API |
| |
| Overview (from the spec) |
| |
| This extension supports texture images stored in the YCbCr format. |
| There is no support for converting YCbCr images to RGB or vice versa |
| during pixel transfer. The texture's YCbCr colors are converted to |
| RGB during texture sampling, after-which, all the usual per-fragment |
| operations take place. Only 2D texture images are supported (not |
| glDrawPixels, glReadPixels, etc). |
| |
| A YCbCr pixel (texel) is a 16-bit unsigned short with two components. |
| The first component is luminance (Y). For pixels in even-numbered |
| image columns, the second component is Cb. For pixels in odd-numbered |
| image columns, the second component is Cr. If one were to convert the |
| data to RGB one would need to examine two pixels from columns N and N+1 |
| (where N is even) to deduce the RGB color. |
| |
| The official definition of this extension is available here: |
| http://www.opengl.org/registry/specs/MESA/ycbcr_texture.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.MESA.ycbcr_texture import * |
| from OpenGL.raw.GL.MESA.ycbcr_texture import _EXTENSION_NAME |
|
|
| def glInitYcbcrTextureMESA(): |
| '''Return boolean indicating whether this extension is available''' |
| from OpenGL import extensions |
| return extensions.hasGLExtension( _EXTENSION_NAME ) |
|
|
|
|
| |
