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'''OpenGL extension EXT.cmyka |
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This module customises the behaviour of the |
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OpenGL.raw.GL.EXT.cmyka to provide a more |
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Python-friendly API |
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Overview (from the spec) |
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This extension provides a simple method for OpenGL to read and store |
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images whose pixels have CMYK or CMYKA formats. The algorithms used to |
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convert to RGBA from CMYKA and to convert back from RGBA to CMYKA are of |
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the "black-box" nature, meaning that the application has little control |
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over how the conversion is done. Also, this black-box mechanism is |
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available only for transfers to or from memory, not for internal copies |
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of pixel data (such as invoked by CopyPixels, CopyTexImage1D, etc.) |
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However, the defined mechanism nicely handles 5-component CMYKA images, |
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and it is very easy to use. |
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A more configurable and potentially higher quality color conversion can |
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be implemented using the color tables, the color matrix, and possibly 3D |
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and 4D texture lookup. Such a color conversion also applies to copied |
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pixel data. |
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The official definition of this extension is available here: |
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http://www.opengl.org/registry/specs/EXT/cmyka.txt |
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''' |
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from OpenGL import platform, constant, arrays |
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from OpenGL import extensions, wrapper |
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import ctypes |
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from OpenGL.raw.GL import _types, _glgets |
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from OpenGL.raw.GL.EXT.cmyka import * |
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from OpenGL.raw.GL.EXT.cmyka import _EXTENSION_NAME |
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def glInitCmykaEXT(): |
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'''Return boolean indicating whether this extension is available''' |
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from OpenGL import extensions |
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return extensions.hasGLExtension( _EXTENSION_NAME ) |
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from OpenGL import images as _i |
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_i.COMPONENT_COUNTS[ GL_CMYK_EXT ] = 4 |
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_i.COMPONENT_COUNTS[ GL_CMYKA_EXT ] = 5 |
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