private static Tuple<CrossInOut, int, bool> CutByLineVerticalForCrossDi(VertexBase v1, VertexBase v2, List<VertexBase> list, bool withIdx, int line2Idx = 0)
{
bool hasIntersection = false;
bool smallToBig = true;
var crossXsmaller = new List<IntersWithIndex>();
var crossXbigger = new List<IntersWithIndex>();
var minY = v1.Y;
var maxY = v2.Y;
if (v1.Y > v2.Y)
{
minY = v2.Y;
maxY = v1.Y;
smallToBig = false;
}
var x = v1.X;
for (var toCutLineStart = 0; toCutLineStart < list.Count; toCutLineStart++)
{
var c1 = list[toCutLineStart % list.Count];
var c2 = list[(toCutLineStart + 1) % list.Count];
// 重合
if (c1.X == c2.X && c1.X == x) continue;
//不相交
if (c1.X > x && c2.X > x) continue;
if (c1.X < x && c2.X < x) continue;
var y = LineCrossV(x, c1, c2);
if (!hasIntersection)
if ((y > minY && y < maxY) ||
(c2.X == x && y == v2.Y) ||
(y == minY && c1.X != x && c2.X != x) ||
(y == maxY && c1.X != x && c2.X != x)
)
hasIntersection = true;
var inters = new IntersWithIndex(x, y, toCutLineStart);
if (smallToBig)
{
if (y < minY) crossXsmaller.Add(inters);
if ((y > minY && y < maxY) ||
(y == minY && c2.X == x) ||
(y == minY && c1.X != x && c2.X != x) ||
(y == maxY && c2.X == x) ||
(y == maxY && c1.X != x && c2.X != x) ||
(y > maxY)
)
crossXbigger.Add(inters);
}
else
{
if (y > maxY) crossXsmaller.Add(inters);
if ((y > minY && y < maxY) ||
(y == maxY && c2.X == x) ||
(y == maxY && c1.X != x && c2.X != x) ||
(y == minY && c2.X == x) ||
(y == minY && c1.X != x && c2.X != x) ||
(y < minY)
)
crossXbigger.Add(inters);
}
}
if (!hasIntersection) return Tuple.Create(CrossInOut.In, 0, false);
if (smallToBig)
crossXbigger.Sort((p1, p2) => p1.X.CompareTo(p2.X));
else
crossXbigger.Sort((p1, p2) => -(p1.X.CompareTo(p2.X)));
var count = crossXbigger.Count;
CrossInOut crossRet;
int cuttedLineIdx;
if (withIdx)//切割多边形的一条边去切实体多边形的一条边
{
int countSkip = 0;
for (; ; countSkip++)
{
if (crossXbigger[countSkip].Idx == line2Idx)//line2Idx确定了实体多边形的这条边
break;
}
count += countSkip;
crossRet = count % 2 == 0 ? CrossInOut.In : CrossInOut.Out;
cuttedLineIdx = crossXbigger[countSkip].Idx;
}
else//实体多边形的一条边去切切割多边形
{
crossRet = count % 2 == 0 ? CrossInOut.In : CrossInOut.Out;
cuttedLineIdx = crossXbigger[0].Idx;
}
return Tuple.Create(crossRet, cuttedLineIdx, true);
}
/// <summary>
/// 用于获得交点进出性的切割函数
/// </summary>
/// <param name="v1"></param>
/// <param name="v2"></param>
/// <param name="list"></param>
/// <param name="line2Idx"> </param>
/// <returns></returns>
private static Tuple<CrossInOut, int, bool> CutByLineForCrossDi(VertexBase v1, VertexBase v2, List<VertexBase> list, bool withIdx, int line2Idx = 0)
{
bool hasIntersection = false;
bool smallToBig = true;
var crossXsmaller = new List<IntersWithIndex>();
var crossXbigger = new List<IntersWithIndex>();
var slope = (v2.Y - v1.Y) / (v1.X - v2.X);
var minX = v1.X;
var maxX = v2.X;
if (v1.X > v2.X)
{
minX = v2.X;
maxX = v1.X;
smallToBig = false;
}
//错切后的切割多边形
var shearedPolyC = list.Select(r => new Vertex(r.X, r.X * slope + r.Y) { Name = r.Name }).ToList();
//把实体多边形的第一条边（即切线）错切后得到一条水平直线
var y = v1.X * slope + v1.Y;
for (var toCutLineStart = 0; toCutLineStart < list.Count; toCutLineStart++)
{
var c1 = shearedPolyC[toCutLineStart % list.Count];//注意，不要漏了文档中C4->C1这种结尾的线段
var c2 = shearedPolyC[(toCutLineStart + 1) % list.Count];
// 重合
if (c1.Y == c2.Y && c1.Y == y) continue;
//不相交
if (c1.Y > y && c2.Y > y) continue;
if (c1.Y < y && c2.Y < y) continue;
var x = LineCrossH(y, c1, c2);
var npy = y - x * slope;
if (!hasIntersection)
if ((x > minX && x < maxX) ||
(c2.Y == y && x == v2.X) ||
(x == minX && c1.Y != y && c2.Y != y) ||
(x == maxX && c1.Y != y && c2.Y != y)
)
hasIntersection = true;
var inters = new IntersWithIndex(x, npy, toCutLineStart);
if (smallToBig)
{
if (x < minX) crossXsmaller.Add(inters);
if ((x > minX && x < maxX) ||
(x == minX && c2.Y == y) ||
(x == minX && c1.Y != y && c2.Y != y) ||
(x == maxX && c2.Y == y) ||
(x == maxX && c1.Y != y && c2.Y != y) ||
(x > maxX) //这个必不可少，不然影响进出性判断
)
crossXbigger.Add(inters);
}
else
{
if (x > maxX) crossXsmaller.Add(inters);
if ((x > minX && x < maxX) ||
(x == maxX && c2.Y == y) ||
(x == maxX && c1.Y != y && c2.Y != y) ||
(c2.Y == y && x == minX) ||
(x == minX && c1.Y != y && c2.Y != y) ||
(x < minX) //这个必不可少，不然影响进出性判断
)
crossXbigger.Add(inters);
}
}
if (!hasIntersection) return Tuple.Create(CrossInOut.In, 0, false);
if (smallToBig)
crossXbigger.Sort((p1, p2) => p1.X.CompareTo(p2.X));
else
crossXbigger.Sort((p1, p2) => -(p1.X.CompareTo(p2.X)));
var count = crossXbigger.Count;
CrossInOut crossRet;
int cuttedLineIdx;
if (withIdx)//切割多边形的一条边去切实体多边形的一条边
{
int countSkip = 0;
for (; ; countSkip++)
{
if (crossXbigger[countSkip].Idx == line2Idx)//line2Idx确定了实体多边形的这条边
break;
}
count += countSkip;
crossRet = count % 2 == 0 ? CrossInOut.In : CrossInOut.Out;
cuttedLineIdx = crossXbigger[countSkip].Idx;
}
else//实体多边形的一条边去切切割多边形
{
crossRet = count % 2 == 0 ? CrossInOut.In : CrossInOut.Out;
cuttedLineIdx = crossXbigger[0].Idx;
}
return Tuple.Create(crossRet, cuttedLineIdx, true);
}