Open GLES, 2D/3D split screen?

Discussion in 'iPhone/iPad Programming' started by BananaDuffle, Apr 27, 2009.

  1. macrumors member

    Joined:
    Mar 29, 2009
    #1
    Hi guys, I've just started iphone development. I've managed to get 2D graphics working in open gl along with rudimentary 3D graphics.

    The effect I'm after is getting 50/50(top/bottom) split screen with 2D graphics in one view and a 3D view in the other... Imagine like a DS game where you get, say, a map on the bottom screen and the game view in the top (for example only, obviously thats not a great use of iphone screen-space).

    Unfortunately my experience with 3D and Open GL is pretty limited so i'm not even sure what techniques or methods I should be googling for to achieve this.

    Thanks.
     
  2. macrumors 6502a

    Joined:
    Sep 3, 2005
    Location:
    Cramlington, UK
    #2
    Hi

    Are you using OpenGL for 2D and 3D? If so you could achieve your split view quite easily by using glViewport() twice, once for each of your views. After defining a view/viewport using glViewport() set up your perspective and viewing transformations as normal for your view type, ie 2D or 3D. A couple of things to be aware of though:

    glClear() clears the whole context and not the viewport so you can't use it to clear your split views independently. If your views have different colour backgrounds then use a coloured quad or something similar.

    According to the docs it's possible that some drawing operations might bleed outside the viewport. I haven't seen this happen but if you do run into this then it's easily fixed, set up a clipping rectangle around your viewport using glScissors().

    ß e n
     
  3. thread starter macrumors member

    Joined:
    Mar 29, 2009
    #3
    Thank you :)
    Yes i'm doing my 2D on OGLES... I wasn't expecting the answer to be so easy, thank you very much.
     

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