I had a strange problem where a polygon I created would show up, but nothing would collide with it. I was looking at some other code, which used the old Box2D methods:
b2PolygonDef aShape;
aShape.vertexCount = 4;
aShape.density = 5.0f;
aShape.vertices[0].Set(-80.f/PTM_RATIO,-5.0f/PTM_RATIO);
...I glanced at the new API and it seemd to take care of +/- so I tried:
b2PolygonShape shapeDef;
shapeDef.SetAsBox(-80.f/PTM_RATIO,-5.0f/PTM_RATIO);The shape showed up but other objects just went right through it.
The answer of course is to drop the minuses:
b2PolygonShape shapeDef;
shapeDef.SetAsBox(80.f/PTM_RATIO,5.0f/PTM_RATIO);I hope this was obvious to everyone else. :-)