Paletted Textures and Shared Paletted Textures

Paletted Textures and Shared Paletted Textures still needs to be supported. This is particularly true if OpenGL wants to be used as a sophisticated Medical volume rendering platform. Shared paleted textures allows pre filtering of 16bit lighting info and then interpolation. 16 bit encoding fo lighting does not lend itself well to post filtering with dependent textures because it causes 0 degree, 360 degree artifacts. The average of 359 degrees and 1 degree from interpolation first is problematic because the average is 180 degrees and is therefore mapped incorrectly to the look up table. The average for a vector at 359 and 1 degree is 0 degrees which shared paletted texture extension produces correctly. These two extensions need to remain in all driver implementations in Nvidia, ATI, etc.

You can always use fragment programs to emulate this funtionality, if it’s not already present. The code to do that has been posted several times on these forums (notably, the advanced one).