【cocos sreator】判定多边形和多边形相交

核心代码：

cc.Intersection.polygonPolygon(points2, points)

拖拽物品拖到多个目标位置判定，取最近的：

    getTargetItem(collider2: cc.PolygonCollider, touchPos: cc.Vec2, targetRoot: cc.Node) {
        let length = 99999;
        let target = null;
        //collider2 拖拽物 需要添加cc.PolygonCollider作为判定范围
        //targetRoot子节点为拖拽目标节点，需要添加cc.PolygonCollider作为判定范围

        targetRoot.children.forEach(element => {
            let collider = element.getComponent(cc.PolygonCollider);
            let points = [];
            collider.points.forEach(point => {
                let ws = collider.node.convertToWorldSpaceAR(cc.v2(this.node.position));
                points.push(cc.v2(ws))//转换到世界坐标
            });
            let points2 = []
            collider2.points.forEach(point => {
                let ws = collider2.node.convertToWorldSpaceAR(cc.v2(this.node.position));
                points2.push(cc.v2(ws))//转换到世界坐标
            });
            let isIn = cc.Intersection.polygonPolygon(points2, points)
            if (isIn) {//拖拽到了目标物品内
                const pos = targetRoot.convertToNodeSpaceAR(cc.v2(touchPos));
                let dis = pos.sub(cc.v2(element.position)).mag();
                if (dis <= length) {//取出拖拽位置距离目标物体最近的
                    target = element
                    length = dis
                }
            }
        })
        return target;
    }