| '''OpenGL extension SGIX.ycrcba |
| |
| This module customises the behaviour of the |
| OpenGL.raw.GL.SGIX.ycrcba to provide a more |
| Python-friendly API |
| |
| Overview (from the spec) |
| |
| This extension provides a method for OpenGL to read and store |
| images that are defined in standard YCRCB and YCRCBA video color |
| spaces. As with the CYMK extension, conversion to RGBA takes place |
| immediately following the unpack pixel store, and preceding the |
| pack pixel store operations, and is only available on transfers to |
| and from memory. The algorithms that convert between YCRCB and |
| RGBA are "black-box" in nature, and left undefined by the |
| extension, however it is recommended that conversion comply with |
| the CCIR standard. This extension specifies the format of a pixel |
| rectangle independent of component subsampling. Component |
| subsampling is specified using a separate extension. |
| |
| Two new formats are added, YCRCB_SGIX and YCRCBA_SGIX. |
| |
| YCRCB_SGIX is defined as a 3 component format representing the Cb, |
| Y, and Cr values per pixel. YCRCBA_SGIX is defined as a 4 component |
| format representing Cb, Y, Cr, and A values per pixel. |
| |
| As with the CMYK extension, this extension doesn't preclude the |
| possibility of other higher quality conversion methods. |
| |
| |
| The official definition of this extension is available here: |
| http://www.opengl.org/registry/specs/SGIX/ycrcba.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.SGIX.ycrcba import * |
| from OpenGL.raw.GL.SGIX.ycrcba import _EXTENSION_NAME |
|
|
| def glInitYcrcbaSGIX(): |
| '''Return boolean indicating whether this extension is available''' |
| from OpenGL import extensions |
| return extensions.hasGLExtension( _EXTENSION_NAME ) |
|
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|
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| |
