1. GMSprAddToForceSum (ForceSum.c:119) 
        void GMSprAddToForceSum(GMSprForceStruct *Force,
                                                    GMSprForceStruct *AddedForce)
  2. GMSprCreateForceSum (ForceSum.c:62) 
        GMSprForceStruct *GMSprCreateForceSum()
  3. GMSprDestroyForceSum (ForceSum.c:92) 
        void GMSprDestroyForceSum(GMSprForceStruct *ForceSum)