query capabilities

OpenGL OpenGL: Advanced Coding
1

in GLview I saw that they can query what tex_env_combine functions are possible on the system.
testing the engine on multiple systems so far I saw that a sis640 (nightmare !!) based graphic card claims that it supports tex_env_combine but then had to find out it doesnt support interpolate function

how do they query in GLview what modes for tex_env_combine are allowed ?
do they just test all and check with glerror ?

I looked up ext_tex_env paper on sgi but couldnt find anything how one could get these infos with glGet

sorry for double topic, but seems like its too advanced for beginner forum

2

Two ways I can think of:

  1. set the mode

  2. call glGetError()

  3. set the mode

  4. render something

  5. read back a pixel you know what the color of should be

3

thanks :slight_smile: