16 #ifndef BT_SIMPLEX_1TO4_SHAPE    17 #define BT_SIMPLEX_1TO4_SHAPE    54         virtual int     getNumVertices() 
const;
    56         virtual int getNumEdges() 
const;
    60         virtual void getVertex(
int i,
btVector3& vtx) 
const;
    62         virtual int     getNumPlanes() 
const;
    66         virtual int getIndex(
int i) 
const;
    72         virtual const char*     
getName()
const { 
return "btBU_Simplex1to4";}
    76 #endif //BT_SIMPLEX_1TO4_SHAPE 
The btBU_Simplex1to4 implements tetrahedron, triangle, line, vertex collision shapes. In most cases it is better to use btConvexHullShape instead. 
btVector3 can be used to represent 3D points and vectors. 
#define ATTRIBUTE_ALIGNED16(a)
The btPolyhedralConvexAabbCachingShape adds aabb caching to the btPolyhedralConvexShape. 
virtual const char * getName() const
getName is for debugging 
#define BT_DECLARE_ALIGNED_ALLOCATOR()
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...