add asVector distanceSquare distanceTo get isDegenerate isEqualTo kInvalid kOrigin length negate offset offset operator!= operator* operator* operator* operator* operator*= operator*= operator+ operator+ operator+ operator+= operator+= operator- operator- operator- operator-= operator/ operator/= operator== Point2d Point2d Point2d polarPoint rulerPoint rulerPoint scaleBy scaleBy set set subtract subtract transform x y

scaleBy() [1/2] Point2d& Point2d::scaleBy ( float  sx, float  sy  ) 比例放缩 这是这个函数的调用关系图: