This was the tutorial that got me to understand ContactListener, so thanks for that!
However, I have a problem...I can't seem to get my preSolve (or postSolve) methods to be called.
I'm using GLES2, and all the rest of my physics stuff is working perfectly, including stuff in beginContact and endContact.
I know there used to be a bug in GLES1 regarding preSolve, but I also know that was fixed. Is there anything special I need to to with GLES2 to get preSolve "working"? An updated library, or something?
Or, should I not be setting the contact listener on the actual physicsworld? Should I set contactlisteners on the actual objects? (Bearing in mind that the rest of my physics is working great....).