D3D9函数(持续添加)

1：

HRESULT  D3DXComputeBoundingBox(  __in   const D3DXVECTOR3 *pFirstPosition,  __in   DWORD NumVertices,  __in   DWORD dwStride,  __out  D3DXVECTOR3 *pMin,  __out  D3DXVECTOR3 *pMax);

HRESULT  D3DXComputeBoundingSphere(  __in   const D3DXVECTOR3 *pFirstPosition,  __in   DWORD NumVertices,  __in   DWORD dwStride,  __out  D3DXVECTOR3 *pCenter,  __out  FLOAT *pRadius);

根据顶点数据，计算包围体的最小值和最大值，可以用于碰撞检测