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colour buffer

Started by arbuckle911 Oct 27, 2005 at 7:34 AM 3 replies 550+ views

Original Post

Oct 27, 2005 at 7:34 AM

I've looked on the internet for articles on the openGL colour buffer (in the frame buffer) but I haven't really been able to find what I need. I'm looking for colour buffer access because I want to be able to work with post-prosessing effects like motion blur and real-time glow. Could somebody tell me something along the lines of: Use so and so extension Get so and so varibale and each element in that array will be the color of a pixel from left ro right top down and you can edit them by..etc. I really have no idea where to start on ths topic. Thanks.

DadleFish

Oct 27, 2005 at 7:49 AM

Check out chapter 10 in the OpenGL programming guide, which you can see here:

http://fly.cc.fer.hr/~unreal/theredbook/

Specifically you want to take a look into glCopyPixels.

Code-R

Oct 27, 2005 at 8:14 AM

or you can render to a texure, thn in a second pass apply it to a full screen quad and bind the appropriate shader effect.

benjamin bunny

144

benjamin bunny

Oct 27, 2005 at 8:40 AM

Rendering to a texture, as Code-R suggested, is a lot faster than glCopyPixels on most implementations. If you do this, you should make sure you glCopyTexSubImage2D rather than glCopyTexImage2D, since it's faster.

arbuckle911

Author

arbuckle911

Oct 27, 2005 at 11:20 AM

Ok, thanks alot. I've always wanted to learn to render to texture anyway.

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