Opengl: use a texture only to give alpha channel to a colored object

Question

I'm new at OpenGL and I can't find out how to do this:
I want to render a letter and be able to change it's color, so I have a texture with the letter on a transparent background. I managed to render it using this code:

glEnable(GL_BLEND)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)  

But that renders the letter in black, as it's on the texture. How can I render it with the color setted with glColor4f?

Answer 1

Have you been messing with glTexEnv? If you did, call :

glTexEnv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE)

and that will restore the default behaviour, which is to multiply the texture color with the vertex color.

Answer 2

There are a couple of other possibilities. One would be to put the shape of the letter into the stencil buffer, and then draw a quad in your preferred color. Another would be to draw your text in light grey, and use lighting to have it displayed in the color you want.