How do I get the color to shade ground with?

[zwzsg]

So, the ground of a Spring map is shaded according to which direction it faces and where the sun is.

I'd like to know what the gl.Color I should apply to a Lua textured quad so it's shaded just like the ground is.

Because currently all my Lua drawn textures are fully lit, and it breaks the melting in the map.

I'm sure that with all the Lua coders around, one has already written down the formula to get the shading according to sun position and the face normal, and it would be a waste of time to attempt to figure it myself anew.

[Kloot]

Bind the ground shading texture ($shading) and modulate yours with it.

[zwzsg]

I wish I'd understand what you mean.

Edit: Nevermind, I didn't understand half of what I did, but I've gotten half decent results.