alongLineAngleMoveDistancePt alongLineNormalDir alongLineNormalMoveDistancePt Angle Distance Distance FromPolar GetAngle IsEqual IsLess IsNull Length moveAlongLine Negate Normalize operator* operator* operator*= operator+ operator+ operator+= operator- operator- operator-= operator/ operator/= operator= operator== Perpendicular perpendicularPointOnLine ProjectToLine Rotate Scale Set Sqr Vector2d Vector2d Vector2d Vector2d x y

operator+=() Vector2d & operator+= ( const Vector2d &  v ) 加法赋值运算符 将另一个二维向量加到当前向量。 参数 [in] v 要相加的向量 返回 当前向量的引用