Box2d Box2d Box2d Box2d Box2d Box2d Box2d Box2d Box2d Box2d center contains contains contains contains deflate deflate deflate deflate deflate empty get get get height inflate inflate inflate inflate inflate intersectWith intersectWith isEmpty isEmptyMinus isEqualTo isIntersect isNormalized isNull kIdentity leftBottom leftTop normalize offset offset offset operator & operator &= operator!= operator* operator* operator*= operator*= operator+ operator+ operator+= operator+= operator- operator- operator-= operator-= operator/ operator/= operator== operator| operator|= rightBottom rightTop scaleBy set set set set set set size swapTopBottom unionWith unionWith unionWith unionWith width xmax xmin ymax ymin

unionWith() [1/4] Box2d & Box2d::unionWith ( const Box2d &  r1, const Box2d &  r2  ) 设置为两个矩形框的并集（两者都是规范化矩形） 设置本矩形框为给定的两个矩形框的并集。 如果其中一个为空矩形，则直接设置为另一个矩形框。 参数 r1 第一个矩形框，必须规范化，否则视为空矩形 r2 第二个矩形框，必须规范化，否则视为空矩形 返回 本矩形的引用，并集，规范化矩形 函数调用图: 这是这个函数的调用关系图: