This page documents how the graphics of 0 A.D. may be ported to OpenGL ES.

This is required for an Android port, but might also be of interest to possible ports to iOS and other mobile systems.

To-do list: ​https://gist.github.com/1813907

I think a possibly sensible plan would be to focus on getting just the GUI to work for now (plus the build system and anything else required), and #ifdef out any problematic non-GUI code, so we can have a runnable starting point before porting all the other graphics code. (I was attempting to start with the GUI ​here, getting rid of some of the fixed-function code). That will probably involve more changes to the CShaderProgram API so that it can use glVertexAttribPointer instead of the not-in-GLES2 glColorPointer etc, and the rest is probably just tedious rearrangement of code to use the new APIs.