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

kYAxis() static const Vector2d Vector2d::kYAxis ( ) static Y轴单位矢量(0,1) 函数调用图: