How can I use a texture's alpha values for blending?

OpenGL OpenGL: Advanced Coding
1

I am drawing some textures on screen, and I want to use their alpha value. They were loaded as a texture with an alpha (I’ve visually tested this to be true with glAlphaFunc).

How can I do it? I’ve tried glBlendFunc with various modes, but it seems to be ignoring the texture alpha. Either it draws it all black or all opaque.

Why it is that glAlphaFunc is working but glBlendFunc isn’t? I enabled GL_BLEND also of course.

Does anyone know urls to tutorials showing you how to do alpha blending with textures. There is one on nehe, but that uses multiple textures, and I don’t want to do that, I have the alpha value inside the texture as an alpha channel, its neater, and probably faster. At least glAlphaFunc recognises it, so why can’t glBlendFunc?

2

What parameters did you pass to the function glBlendFunc? Between which values do the alpha components of your texture vary?

[This message has been edited by softland_gh (edited 12-24-2000).]