How can I use the modulate2x for my lightmap objects?
I can't find function to use modulate 2x? Is there an extension for doing this? How does it work?
ARB_texture_env_combine has a scale factor as do many of the other fragment shading models. For your multipass fallback path, you can do a src*dst + dst*src blend.
How do you do this?
I tried to use
glTexEnvf(GL_TEXTURE_ENV, RGB_SCALE_ARB, 2.0);
but it doesn't work. it doesn't compile...
glTexEnvf(GL_TEXTURE_ENV, GL_RGB_SCALE_ARB, 2.0);