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glextensions - GL_EXT_cmyka.wiki

Contents

  • Dependencies
  • Overview
  • New Procedures and Functions
  • New Tokens
  • Errors
  • New Implementation Dependent State

Dependencies

GL_EXT_abgr affects the definition of this extension

GL_EXT_texture3D affects the definition of this extension

GL_EXT_subtexture affects the definition of this extension

GL_EXT_histogram affects the definition of this extension

GL_EXT_convolution affects the definition of this extension

GL_SGI_color_table affects the definition of this extension

GL_SGIS_texture4D affects the definition of this extension

Overview

This extension provides a simple method for OpenGL to read and store images whose pixels have CMYK or CMYKA formats. The algorithms used to convert to RGBA from CMYKA and to convert back from RGBA to CMYKA are of the "black-box" nature, meaning that the application has little control over how the conversion is done. Also, this black-box mechanism is available only for transfers to or from memory, not for internal copies of pixel data (such as invoked by CopyPixels, CopyTexImage1D, etc.) However, the defined mechanism nicely handles 5-component CMYKA images, and it is very easy to use.

A more configurable and potentially higher quality color conversion can be implemented using the color tables, the color matrix, and possibly 3D and 4D texture lookup. Such a color conversion also applies to copied pixel data.

New Procedures and Functions

None

New Tokens

Accepted by the

<format>

parameter of DrawPixels, ReadPixels, TexImage1D, TexImage2D, TexImage3DEXT, TexImage4DSGIS, TexSubImage1DEXT, TexSubImage2DEXT, TexSubImage3DEXT, TexSubImage4DSGIS, GetTexImage, ColorTableSGI, GetColorTableSGI, ConvolutionFilter1DEXT, ConvolutionFilter2DEXT, ConvolutionFilter3DEXT, GetConvolutionFilterEXT, SeparableFilter2DEXT, SeparableFilter3DEXT, GetSeparableFilterEXT, GetHistogramEXT, and GetMinmaxEXT:

|CMYK_EXT | 0x800C| |:------------------|:-----------| |CMYKA_EXT | 0x800D|

Accepted by the

<target>

parameter of Hint, and by the

<pname>

parameter of GetBooleanv, GetIntegerv, GetFloatv, and GetDoublev:

|PACK_CMYK_HINT_EXT | 0x800E| |:------------------------|:-------| |UNPACK_CMYK_HINT_EXT | 0x800F|

Errors

None

New Implementation Dependent State

None