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Thread: OpenGL for 2D

  1. #1
    Junior Member Newbie
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    Jul 2006
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    OpenGL for 2D

    I'm doing a 2D graphics project for a class. Is
    it reasonable to use OpenGL? I've got it working
    OK for drawing, but I need an inverse transform
    (viewport to worldspace). This is indeterminate
    in a 3D-2D projection, is there some way around
    it?

    Thanks-

  2. #2
    Senior Member Frequent Contributor
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    Re: OpenGL for 2D

    Yes there is, use glOrtho projection, with it you can set the projection to match the window coordinates, or use some custom coordinate grid.

  3. #3
    Super Moderator OpenGL Guru imported_dorbie's Avatar
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    Re: OpenGL for 2D

    Exactly, you have complete control over the projection matrix and the viewport.

    If you draw primitives on an x y plane where z is constant this can work even with a glFrustum call made to set up the projection.

    If you go drawing 3D stuff and expect to infer the position from a 2D screen then the solution is not actually indeterminate, is a 3D solution i.e. a point in teh screen defines a world space vector from the eye and a rectangle on the screen is a frustum.

    Doing basic 2D is very straightforward, you have all the tools for this in OpenGL.

  4. #4
    Junior Member Newbie
    Join Date
    Jul 2005
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    Re: OpenGL for 2D

    OpenGL is really good for 2D vector graphic. You can see the results that i have achieved with my engine here: http://www.youtube.com/watch?v=7fdSlw3F92U .
    Then, if you are interested, you can learn more here: http://www.amanithvg.com

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