OpenGL Google Maps Like Navigation

I would like to create an application using OpenGL ES (in ObjC) allowing user to navigate into a detailled 2D map (pan, scale, rotate) using Gesture Recognizers.

I have, like Google Maps, a folder containing 128x128 textures for every "chunk" and LOD Level, for example, LOD 0 = 1 texture, LOD 1 = 4 textures, LOD 2 = 16 textures, etc... Depending on the scale/zoom, I can switch LOD to show more details...

How would you implement something like that, technically ?

For example, how to load/unload textures has needed (N开发者_Python百科SOperationQueue ? What will happen if user zoom & dezoom and/or pan very fast ?), how to switch LOD, etc.

I would look at the WWDC 2010 Session#104 presentation and its PhotoScroller demo code. It goes into some detail about using tiles in a UIScrollView and handles zooming, etc.