clipLine cross2Beeline cross2Line cross2LineV crossLineAbc crossLineBeeline isBetweenLine isBetweenLine2 isBetweenLine3 isColinear isColinear2 isConvex isIntersect isIntersectProp isLeft isLeft2 isLeftOn isLeftOn2 isProjectBetweenLine isProjectBetweenRayline ptInArea PtInAreaRet ptToBeeline ptToBeeline2 ptToLine

isLeft() bool mglnrel::isLeft ( const Point2d &  a, const Point2d &  b, const Point2d &  pt  ) static 判断点pt是否在有向直线a->b的左边 (开区间) 参数 [in] a 直线的起点 [in] b 直线的终点 [in] pt 给定的测试点 返回 在直线的左边时返回true，否则返回false 这是这个函数的调用关系图: