I am working on a project that requires on-the-fly changing of the intensity (brightness/darkness) of textures.
The textures are loaded and stored in RGB format. I do not want them to be transparent at all (they’re drawn over a background which shouldn’t be visible).
updating the texture itself is one of the slowest things you can do. You can get around it (to some extent) by using GL_MODULATE texture mode job.
This way your underlying colour (if not using lighting) or material properties (if using lighting) will be modulated with the texture colour. Changing the material properties and/or colours is considerably quicker…