How do you determine when an object is drawn on-screen in OpenGL?

Posted by Harry on Stack Overflow See other posts from Stack Overflow or by Harry
Published on 2010-03-09T07:43:44Z Indexed on 2010/03/09 7:51 UTC
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Filed under:

opengl

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3d

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text-rendering

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picking

I'm extremely new to OpenGL. I'm writing a program that displays flying text on screen. I need to know when certain text string appears (drawn) onto the screen and are visible to the user. The program needs to identify which text strings are displayed.

At first, I started to think that I could use OpenGL's picking mechanism, but so far I've only seen examples where the selection area is focused on some sort of user interaction. I want to know what objects are displayed on the entire window area. This leads me to think I'm on the wrong track... Am I missing something?

Any suggestions are welcome.

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