In my Game, a Scene is composed by several layers. Each layer has different camera transformations.

This way I can have a layer at z=3 (GUI), z=2 (Monsters), z=1 (scrolling background), and this 3 layers compose my whole Scene.

My render loop looks something like:

renderLayer()

   applyTransformations()

   renderVisibleEntities()

   renderChildLayers()

end

If I call DrawDebugData() in the render loop, the whole b2world debug data will be rendered once for each layer in my scene, this generates a mess, because the "debug boxes" get duplicated, some of them get the camera transformations applied and some of them don't, etc.

What I would like to do, would be to make DrawDebugData to draw only certain debug boxes. In that way, I could call something like

b2world->DrawDebugDataForLayer(int layer_id)

and call that on each layer like :

renderLayer()

   applyTransformations()

   renderVisibleEntities()

   //Only render my corresponding layer debug data
   b2world->DrawDebugDataForLayer(layer_id)

   renderChildLayers()

end

Is there a way to subclass b2World so I could add this functionality ( specific to my game ) ?

If not, what would be the best way to achieve this (Cocos2d uses a similar scene graph approach and box2d, but I'm not sure if debugDraw works in Cocos2d... )

Thanks