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-() [1/2] Vector2d operator- ( const Vector2d &  v ) const 减法运算符 将两个二维向量相减。 参数 [in] v 要相减的向量 返回 相减结果的向量