I am working on a 2d game and I want to make the box around my bitmap charaters transparent. I found the following in the FAQs, but I am having trouble understanding it since I am very new to OpenGL. Could anyone explain to me how to do this?
15.080 How can I make part of my texture maps transparent or translucent?
It depends on the effect you're trying to achieve. If you want blending to occur after the texture has been applied, then use the OpenGL blending feature. Try this:
glBlendFunc (GL_ONE, GL_ONE);
You might want to use the alpha values that result from texture mapping in the blend function. If so, (GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA) is always a good function to start with. However, if you want blending to occur when the primitive is texture mapped (i.e., you want parts of the texture map to allow the underlying color of the primitive to show through), then don't use OpenGL blending. Instead, you'd use glTexEnv(), and set the texture environment mode to GL_BLEND. In this case, you'd want to leave the texture environment color to its default value of (0,0,0,0).