Blitting and direct video manipulation

Hi There!

Is there a possibility to do some “putpixel(x,y,color)” after opengl has rendered the scene?
that means, accessing the surface direct (like or OpenPTC does)…?
perhaps for some 2d effects in a “over” a 3d-scene? (like blitting some text or pics)

greets’n thanx 4 help


Use glDrawPixels(). This function can draw directly to the frame buffer.

Is this fast? cause I have many pixels to draw. or is it faster to manipulate a texture, load it and put it on a square?

thanx, bastian.

This may or may not help, but here is how they do it with DirectX 7 on the Radeon adapter:…ectedVideo.html