// 传入的多边形的点需要封闭,即首尾点要相同
        public static List<List<VertexBase>> Cut(List<VertexBase> listS, List<VertexBase> listC)
        {
            //如果是浮点数,使用这个处理保证相等比较正确
            PrepareVertex(listS);
            PrepareVertex(listC);

            int cutStartIdx = 0;//实际切割由这个idx起始即可

            // 阶段1: 这个循环中的切割用于判断方向
            // 如果这步中没有发现交点,则进入不相交多边形的处理
            for (; cutStartIdx < listS.Count; cutStartIdx++)
            {
                //用实体多边形的一条边去切切割多边形
                var s1 = listS[cutStartIdx % listS.Count];
                var s2 = listS[(cutStartIdx + 1) % listS.Count];

                Tuple<CrossInOut, int, bool> ret;
                if (s1.X == s2.X)
                    ret = CutByLineVerticalForCrossDi(s1, s2, listC, false);
                else
                    ret = CutByLineForCrossDi(s1, s2, listC, false);
                //如果没有交点,继续下一条边。
                if (!ret.Item3) continue;

                var interDirect1 = ret.Item1;//交点对于切割多边形的进出性
                var cutLineIdx = ret.Item2;//交点所在的切割多边形的边的起点的索引,用于在使用切割多边形边去切实体多边形时,确定那条边

                WindowLog.Default.Log("得到S多边形边{0}{1}切割C多边形{2}{3}产生的交点,对于S进出性为{4}", s1.Name, s2.Name,
                    listC[cutLineIdx % listC.Count].Name,
                    listC[(cutLineIdx + 1) % listC.Count].Name,
                    interDirect1 == CrossInOut.In ? "进" : "出");

                //用切割多边形的一条边(cutLineIdx->cutLineIdx+1)去切实体多边形
                var ret2 = CutByLineForCrossDi(listC[cutLineIdx % listC.Count],
                                               listC[(cutLineIdx + 1) % listC.Count],
                                               listS, true, cutStartIdx);
                var interDirect2 = ret2.Item1;

                WindowLog.Default.Log("得到C多边形边{0}{1}切割S多边形{2}{3}产生的交点,对于C进出性为{4}",
                  listC[cutLineIdx % listC.Count].Name,
                  listC[(cutLineIdx + 1) % listC.Count].Name,
                  s1.Name, s2.Name,
                  interDirect2 == CrossInOut.In ? "进" : "出");

                if (interDirect1 == interDirect2) //进出性相同表示多边形不同向,反转其中一个多边形
                {
                    WindowLog.Default.Log("交点进出性相同,把C多边形反向");
                    //文档中是把S进行了反向,但这里不行,如果反向S,则记录的第一个交点(主要是记录这个交点的进出性)就不再是第一个交点了
                    //所以实际实现中需要将C反向,而且反向后第一条边,仍然需要是确定第一点那条线段
                    var listCReverse = new List<VertexBase>();
                    var reverseStartIdx = cutLineIdx + 1;
                    for (int i = 0; i < listC.Count; i++)
                    {
                        listCReverse.Add(listC[(reverseStartIdx - i + listC.Count) % listC.Count]);
                    }

                    listC = listCReverse;

                    WindowLog.Default.ReversePolygon();
                    WindowLog.Default.Log("反向后多边形点序列为:{0}", string.Join("->", listC.Select(r => r.Name)));
                }

                WindowLog.Default.Log("使用S多边形边{0}{1}与C多边形{2}{3}交点为第一个点,对于S进出性为{4}", s1.Name, s2.Name,
                        listC[cutLineIdx % listC.Count].Name,
                        listC[(cutLineIdx + 1) % listC.Count].Name,
                        interDirect1 == CrossInOut.In ? "进" : "出");

                _firstInterDi = ret.Item1;
                break;
            }

            if (cutStartIdx == listS.Count)//没有交点
            {
                WindowLog.Default.Log("没有交点,进入无交点情况处理");

                var ret = ProcessNoCross(listS, listC);
                return ret == null ? new List<List<VertexBase>>() : new List<List<VertexBase>> { ret };
            }

            // 阶段2: 链接多边形,即设置Next
            LinkNode(listS.Cast<Vertex>().ToList());
            LinkNode(listC.Cast<Vertex>().ToList());
            var listI = new List<Intersection>();
            var linkC = new LinkedList<VertexBase>(listC);

            //循环中用S中每条边切割C(准确说是C的链表,每次切割后交点插入C的列表再进行下次切割),把交点插入S和C形成多边形链表
            for (; cutStartIdx < listS.Count; cutStartIdx++)
            {
                var s1 = listS[cutStartIdx % listS.Count] as Vertex;
                var s2 = listS[(cutStartIdx + 1) % listS.Count] as Vertex;

                WindowLog.Default.Log("---------------使用S多边形边{0}{1}切割C多边形---------------", s1.Name, s2.Name);

                var inters = CutByLine(s1, s2, linkC);
                //var inters = ret;

                if (inters.Count == 0) continue;

                listI.AddRange(inters);
                //把交点排序,准备插入S的边中
                if (s1.X < s2.X)
                    inters.Sort((p1, p2) => p1.X.CompareTo(p2.X));
                else
                    inters.Sort((p1, p2) => -(p1.X.CompareTo(p2.X)));

                //将交点插入S的边中
                s1.Next = inters[0];
                for (int j = 0; j < inters.Count - 1; j++)
                {
                    inters[j].NextS = inters[j + 1];
                }
                inters[inters.Count - 1].NextS = s2;

                #region log
                var sLinkSb = new StringBuilder();
                var v = listS[0];
                while (v != null)
                {
                    sLinkSb.Append(v.Name);
                    VertexBase next = null;
                    if (v is Intersection)
                    {
                        var curr = v as Intersection;
                        next = curr.NextS;
                    }
                    else if (v is Vertex)
                    {
                        var curr = v as Vertex;
                        next = curr.Next;
                    }

                    if (next.Equals(listS[0]))
                    {
                        break;
                    }
                    v = next;
                    sLinkSb.Append("->");
                }
                WindowLog.Default.Log("------S链表:" + sLinkSb);
                #endregion
            }

            // 设置交点的进出性
            // 不能简单的把listI中的交点按偶奇的顺序标记进出性,因为listI中的顺序可能和S链表中交点出现的顺序不一样
            // 需要安装S链表中交点的顺序标记
            var secondDi = _firstInterDi == CrossInOut.In ? CrossInOut.Out : CrossInOut.In;
            var nextS = (listS[0] as Vertex).Next;
            int order = 1;
            while (!nextS.Equals(listS[0]))
            {
                if (nextS is Intersection)
                {
                    (nextS as Intersection).CrossDi = order %2 ==1 ? _firstInterDi:secondDi;
                    ++order;
                    nextS = (nextS as Intersection).NextS;
                }
                else
                {
                    nextS = (nextS as Vertex).Next;
                }
            }

            #region log

            foreach (var inters in listI)
            {
                WindowLog.Default.Log("交点{0},NextS:{1},NextC:{2},S对于C进出性:{3}",
                    inters.Name, inters.NextS.Name, inters.NextC.Name, inters.CrossDi == CrossInOut.In ? "进" : "出");
                WindowLog.Default.AddLabel(inters.Name, inters.ToPoint());
            }

            #endregion


            //阶段3:按规则连接交点得到结果
            var result = Compose(listI);

            return result;
        }
Beispiel #2
0
        // 传入的多边形的点需要封闭,即首尾点要相同
        public static List <List <VertexBase> > Cut(List <VertexBase> listS, List <VertexBase> listC)
        {
            //如果是浮点数,使用这个处理保证相等比较正确
            PrepareVertex(listS);
            PrepareVertex(listC);

            int cutStartIdx = 0;//实际切割由这个idx起始即可

            // 阶段1: 这个循环中的切割用于判断方向
            // 如果这步中没有发现交点,则进入不相交多边形的处理
            for (; cutStartIdx < listS.Count; cutStartIdx++)
            {
                //用实体多边形的一条边去切切割多边形
                var s1 = listS[cutStartIdx % listS.Count];
                var s2 = listS[(cutStartIdx + 1) % listS.Count];

                Tuple <CrossInOut, int, bool> ret;
                if (s1.X == s2.X)
                {
                    ret = CutByLineVerticalForCrossDi(s1, s2, listC, false);
                }
                else
                {
                    ret = CutByLineForCrossDi(s1, s2, listC, false);
                }
                //如果没有交点,继续下一条边。
                if (!ret.Item3)
                {
                    continue;
                }

                var interDirect1 = ret.Item1; //交点对于切割多边形的进出性
                var cutLineIdx   = ret.Item2; //交点所在的切割多边形的边的起点的索引,用于在使用切割多边形边去切实体多边形时,确定那条边

                WindowLog.Default.Log("得到S多边形边{0}{1}切割C多边形{2}{3}产生的交点,对于S进出性为{4}", s1.Name, s2.Name,
                                      listC[cutLineIdx % listC.Count].Name,
                                      listC[(cutLineIdx + 1) % listC.Count].Name,
                                      interDirect1 == CrossInOut.In ? "进" : "出");

                //用切割多边形的一条边(cutLineIdx->cutLineIdx+1)去切实体多边形
                var ret2 = CutByLineForCrossDi(listC[cutLineIdx % listC.Count],
                                               listC[(cutLineIdx + 1) % listC.Count],
                                               listS, true, cutStartIdx);
                var interDirect2 = ret2.Item1;

                WindowLog.Default.Log("得到C多边形边{0}{1}切割S多边形{2}{3}产生的交点,对于C进出性为{4}",
                                      listC[cutLineIdx % listC.Count].Name,
                                      listC[(cutLineIdx + 1) % listC.Count].Name,
                                      s1.Name, s2.Name,
                                      interDirect2 == CrossInOut.In ? "进" : "出");

                if (interDirect1 == interDirect2) //进出性相同表示多边形不同向,反转其中一个多边形
                {
                    WindowLog.Default.Log("交点进出性相同,把C多边形反向");
                    //文档中是把S进行了反向,但这里不行,如果反向S,则记录的第一个交点(主要是记录这个交点的进出性)就不再是第一个交点了
                    //所以实际实现中需要将C反向,而且反向后第一条边,仍然需要是确定第一点那条线段
                    var listCReverse    = new List <VertexBase>();
                    var reverseStartIdx = cutLineIdx + 1;
                    for (int i = 0; i < listC.Count; i++)
                    {
                        listCReverse.Add(listC[(reverseStartIdx - i + listC.Count) % listC.Count]);
                    }

                    listC = listCReverse;

                    WindowLog.Default.ReversePolygon();
                    WindowLog.Default.Log("反向后多边形点序列为:{0}", string.Join("->", listC.Select(r => r.Name)));
                }

                WindowLog.Default.Log("使用S多边形边{0}{1}与C多边形{2}{3}交点为第一个点,对于S进出性为{4}", s1.Name, s2.Name,
                                      listC[cutLineIdx % listC.Count].Name,
                                      listC[(cutLineIdx + 1) % listC.Count].Name,
                                      interDirect1 == CrossInOut.In ? "进" : "出");

                _firstInterDi = ret.Item1;
                break;
            }

            if (cutStartIdx == listS.Count)//没有交点
            {
                WindowLog.Default.Log("没有交点,进入无交点情况处理");

                var ret = ProcessNoCross(listS, listC);
                return(ret == null ? new List <List <VertexBase> >() : new List <List <VertexBase> > {
                    ret
                });
            }

            // 阶段2: 链接多边形,即设置Next
            LinkNode(listS.Cast <Vertex>().ToList());
            LinkNode(listC.Cast <Vertex>().ToList());
            var listI = new List <Intersection>();
            var linkC = new LinkedList <VertexBase>(listC);

            //循环中用S中每条边切割C(准确说是C的链表,每次切割后交点插入C的列表再进行下次切割),把交点插入S和C形成多边形链表
            for (; cutStartIdx < listS.Count; cutStartIdx++)
            {
                var s1 = listS[cutStartIdx % listS.Count] as Vertex;
                var s2 = listS[(cutStartIdx + 1) % listS.Count] as Vertex;

                WindowLog.Default.Log("---------------使用S多边形边{0}{1}切割C多边形---------------", s1.Name, s2.Name);

                var inters = CutByLine(s1, s2, linkC);
                //var inters = ret;

                if (inters.Count == 0)
                {
                    continue;
                }

                listI.AddRange(inters);
                //把交点排序,准备插入S的边中
                if (s1.X < s2.X)
                {
                    inters.Sort((p1, p2) => p1.X.CompareTo(p2.X));
                }
                else
                {
                    inters.Sort((p1, p2) => - (p1.X.CompareTo(p2.X)));
                }

                //将交点插入S的边中
                s1.Next = inters[0];
                for (int j = 0; j < inters.Count - 1; j++)
                {
                    inters[j].NextS = inters[j + 1];
                }
                inters[inters.Count - 1].NextS = s2;

                #region log
                var sLinkSb = new StringBuilder();
                var v       = listS[0];
                while (v != null)
                {
                    sLinkSb.Append(v.Name);
                    VertexBase next = null;
                    if (v is Intersection)
                    {
                        var curr = v as Intersection;
                        next = curr.NextS;
                    }
                    else if (v is Vertex)
                    {
                        var curr = v as Vertex;
                        next = curr.Next;
                    }

                    if (next.Equals(listS[0]))
                    {
                        break;
                    }
                    v = next;
                    sLinkSb.Append("->");
                }
                WindowLog.Default.Log("------S链表:" + sLinkSb);
                #endregion
            }

            // 设置交点的进出性
            // 不能简单的把listI中的交点按偶奇的顺序标记进出性,因为listI中的顺序可能和S链表中交点出现的顺序不一样
            // 需要安装S链表中交点的顺序标记
            var secondDi = _firstInterDi == CrossInOut.In ? CrossInOut.Out : CrossInOut.In;
            var nextS    = (listS[0] as Vertex).Next;
            int order    = 1;
            while (!nextS.Equals(listS[0]))
            {
                if (nextS is Intersection)
                {
                    (nextS as Intersection).CrossDi = order % 2 == 1 ? _firstInterDi:secondDi;
                    ++order;
                    nextS = (nextS as Intersection).NextS;
                }
                else
                {
                    nextS = (nextS as Vertex).Next;
                }
            }

            #region log

            foreach (var inters in listI)
            {
                WindowLog.Default.Log("交点{0},NextS:{1},NextC:{2},S对于C进出性:{3}",
                                      inters.Name, inters.NextS.Name, inters.NextC.Name, inters.CrossDi == CrossInOut.In ? "进" : "出");
                WindowLog.Default.AddLabel(inters.Name, inters.ToPoint());
            }

            #endregion


            //阶段3:按规则连接交点得到结果
            var result = Compose(listI);

            return(result);
        }