Rotating an OpenGL view with touch gestures →

I wrote a tutorial over on Odyssey Computing’s site on using a UIScrollView to back the touch gestures for rotating an OpenGL view. This was something that came up in the context of a larger project that involved incorporating a GLKViewController as a component of a larger UIView-based interface. I love using UIScrollViews to provide pan gesture handling for custom (unconventional) interfaces. In this case I map the contentOffset property of the UIScrollView to the degree of rotation of the GLKViewController‘s model. The great thing about using UIScrollView is that you get deceleration that feels right for free (and where applicable, bouncing).