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MaxH
12-11-2007, 08:17 PM
Is it possible to draw to a double-buffered, OpenGL, window without doing ANY clearing whatsoever. I want whatever was on my desktop to serve as the background in the OGL window. Was hoping that if I didn't call glClear I'd get this effect. No luck. The window was still cleared to black. I guess what I really need is for each pixel in the window to be 'cleared' to the color of the pixel BENEATH the OpenGL window. The reason for this is that I want to write an OGL application that I superimpose over another application running underneath it. Been playing around with glClear, unsuccessfully, trying to get this effect. Thanks for your suggestions.

ZbuffeR
12-12-2007, 04:20 AM
I am not familiar with the actual win32 code needed, but basically you have to take a screenshot of the desktop, put it on a texture, and draw it as a textured quad in the background.

Do a search in these forums (especially on the windows part), there have been a number of transparent / overlay GL windows successfully completed.