question: public WallForce ( float gravConst , float x1 , float y1 , float x2 , float y2 ) { params = new float [ ] { gravConst } ; minValues = new float [ ] { DEFAULT_MIN_GRAV_CONSTANT } ; maxValues = new float [ ] { DEFAULT_MAX_GRAV_CONSTANT } ; this . x1 = x1 ; this . y1 = y1 ; this . x2 = x2 ; this . y2 = y2 ; dx = x2 - x1 ; dy = y2 - y1 ; float r = ( float ) Math . sqrt ( dx * dx + dy * dy ) ; if ( dx != 0.0 ) dx /= r ; if ( dy != 0.0 ) dy /= r ; }
target:  Create a new WallForce.