View Full Version : Open GLES, 2D/3D split screen?

Apr 27, 2009, 12:38 PM
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.


Apr 27, 2009, 04:13 PM

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().

e n

Apr 28, 2009, 11:36 AM
Thank you :)
Yes i'm doing my 2D on OGLES... I wasn't expecting the answer to be so easy, thank you very much.