explain glBlendFunc

[Warrior]

hi, i have found documentation that explains how to use glBlendFunc¥¤, but i dont understand
exactly what it does© what falls into the source category and the destination category? whats the difference between using GL_SRC_ALPHA
and GL_SRC_COLOR? stuff like that© if anyone can explain this stuff to me i will be grateful, thanks
-Dave

[Bob]

You should try read the Red Book (http://ask.ii.uib.no/ebt-bin/nph-dweb/dynaweb/SGI_Developer/OpenGL_PG/) . Chapter 6 is about blending and some more stuff.

In short, glBlendFunc controls how the incomming fragment is mixed with the existing fragment. The incomming fragment is the pixel being drawn into the framebuffer, and the existing fragment is the pixel already in the framebuffer. Source is the incomming, and destination is the existing fragment.

Blending is a bit hard in the beginning, but the Red Book should explain what you need to know.