shading 2d textures darker

For my isometric 2d application, I would like to introduce ‘fake’ light, i.e. render some objects of the game darker depending on whether they are close to another light-radiating object or not.

I know I could, say, prepare 5 different pixmaps with different shadings before making textures out of them and then using one of these textures depending on the light. But that appears a bit unconvenient and not very efficient to me. So my question is this: Is there some (fast) method to make a (2d) texture for a 2d application darker or lighter when rendering it or maybe even apply, say, a blue color filter?

Thanks a lot for your thoughts.

See ya, Johannes.

Just use glColor3f before you draw your textured quad.glColor3f(0.1, 0.1, 0.1) for example will make your texture look very dark, whereas glColor3f(0,0,1) will give it a blue color.

Hey, now that was exactly what I wanted to know! Thanks a thousand times!