add angle angle2 angledVector angleTo angleTo2 crossProduct distanceToVector dotProduct get isCodirectionalTo isCodirectionalTo isDegenerate isEqualTo isLeftOf isOppositeTo isOppositeTo isParallelTo isParallelTo isPerpendicularTo isPerpendicularTo isRightOf isUnitVector isZeroVector kIdentity kXAxis kYAxis length lengthSquare negate normalize operator!= operator* operator* operator* operator* operator* operator*= operator*= operator+ operator+= operator- operator- operator-= operator/ operator/ operator/= operator== perpVector projectResolveVector projectScaleToVector resolveVector resolveVector scaleBy scaleBy scaledVector set set setAngleLength setLength subtract transform unitVector Vector2d Vector2d Vector2d x y

operator==() bool Vector2d::operator== ( const Vector2d &  v ) const 判断两个矢量是否相等 这是这个函数的调用关系图: