Coding a complicated physics game without the right tools is tedious and slow. Fortunately there is a tool that makes this work easy and fast so you can concentrate on creating a great game.
LevelHelper along with SpriteHelper are excellent tools for creating sprite sheets and generating usable physics code. The author of this tool, Vladu Bogdan, is constantly improving the tools allowing you to easily create levels for your games complete with physics working with your sprite sheets taken from SpriteHelper. The tool allows instant testing of the physics using the built in Scene Tester.
The software only works for the MAC and it is well worth purchasing a MAC just for this tool as it will save weeks and months of work for your development project. The author supports cocos2d-x which can be run on several platforms.
The software can be purchased in the Apple App store, more information can be found at http://www.levelhelper.org/
Ray Wenderlich has excellent tutorials for cocos2d and Vladu has contributed an excellent tutorial series using LevelHelper and SpriteHelper.
The final code for this tutorial series has been converted to cocos2d-x and will be posted soon. Using cocos2d-x and Marmalade SDK it was an easy task to get the finished game onto the Kindle Fire.
Cocos2d to Cocos2d-x
The difference between the Objective-C and C++ code can be viewed here and can be used as an aid to converting between the languages for cocos2d to cocos2d-x conversions.