a quick register combiners question

glCombinerOutputNV allows to use GL_TEXTURE0,… as <abOutput>, <cdOutput>…

How should I understand this?


It simply means that you can use the texture registers as output registers of a general combiner stage. In other words, the texture registers are read/write for a combiner stage.

Asgard is right.

This is pretty weird, but this can be useful if you need more than 2 spare registers (I’ve never needed more than 2, though).

If you think that you can write to the texture, you can’t. These are just registers and don’t have the ability to change the texture object itself.

Yes this was the first thing that came to my mind when I saw those parameters, but then I know you can’t write to a texture that way, thus the question. asgard mentioning “registers” cleared it up.