   stamp one texture on another and light both?
  I'm using multitexturing to stamp a texture of a letter on top of a background texture. It works great using GL_DECAL, letting the background texture show through the 0 alpha portions of the stamp texture.Now that I'm adding lighting, GL_DECAL (as expected) isn't affected by any lighting. I learned all about texture combiners, but no longer think they can solve this.What's the best way to overlay one texture on another and light both? Do I need to just draw two textured polygons?   
  I think the best way would be to just forget all of these obscure depreciated texture options and write a fragment shader :)Otherwise, this from the opengl FAQ might be of use: Quote:21.030 Why doesn't lighting work when I turn on texture mapping?    There are many well-meaning texture map demos available on the Web that set the texture environment to GL_DECAL or GL_REPLACE. These environment modes effectively replace the primitive color with the texture color. Because lighting values are calculated before texture mapping (lighting is a per vertex operation, while texture mapping is a per fragment operation), the texture color replaces the colors calculated by lighting. The result is that lighting appears to stop working when texture mapping is enabled.    The default texture environment is GL_MODULATE, which multiplies the texture color by the primitive (or lighting) color. Most applications that use both OpenGL lighting and texture mapping use the GL_MODULATE texture environment.    Look for the following line in your code:   glTexEnv (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL); /* or GL_REPLACE */You should change GL_DECAL to GL_MODULATE, or simply delete the line entirely (since GL_MODULATE is the default).I'm not sure if this applies to your specific multitexturing situation though.   ;  Any reason why you aren't using shaders?   ;  yes, I'm applying updates to a game made with an older version of OpenGL, don't want to update the entire application.   ;  You could try to seperate the lighting out into its own pass that you then do last over the object textured with the letter on the background texture.So it would be draw the parts with multi-texturing with lighting off.Then set the depth buffer test to equal z ( glDepthFunc(GL_EQUAL) I think ), set texturing to off, lighting on, and blending on (with the correct blend mode, glBlendFunc(GL_ZERO, GL_SRC_COLOR) I think).Of course it means redrawing the geometry that uses the GL_DECAL multi texturing, but it should work I think[edit] actually I think the blending should be glBlendFunc(GL_ZERO, GL_SRC_COLOR) now [/edit]   