/// <summary>
/// 顺时针顶点
/// </summary>
/// <param name="p1"></param>
/// <param name="p2"></param>
/// <param name="p3"></param>
public Triangle2D(Double2 p1, Double2 p2, Double2 p3)
{
this.p1 = p1;
this.p2 = p2;
this.p3 = p3;
Double2 min = Double2.Min(p1, Double2.Min(p2, p3));
Double2 max = Double2.Max(p1, Double2.Max(p2, p3));
this.SetAABB(min, max);
}
/// <summary>
/// 初始化数据
/// </summary>
/// <param name="points"></param>
private void Init(Double2[] points)
{
if (points == null || points.Length < 3)
{
return;
}
this.pointArr = new Double2[points.Length];
this.normalAttr = new Double2[points.Length];
this.distancArr = new double[points.Length + 1];
Double2 min = points[0];
Double2 max = points[0];
int i;
for (i = 0; i < points.Length; i++)
{
this.pointArr[i] = points[i];
if (i > 0)
{
min = Double2.Min(min, points[i]);
max = Double2.Max(max, points[i]);
totalDistance += MathUtil.GetNearDistance(points[i - 1], points[i]);
this.distancArr[i] = totalDistance;
}
else
{
min = points[i];
max = points[i];
this.distancArr[i] = 0;
totalDistance = 0;
}
//
Double2 dir;
if (i < points.Length - 1)
{
dir = (points[i + 1] - points[i]).normalized;
}
else
{
dir = (points[0] - points[i]).normalized;
}
this.normalAttr[i] = Double2.Perpendicular(dir);
}
totalDistance += MathUtil.GetNearDistance(points[points.Length - 1], points[0]);
this.distancArr[i] = totalDistance;
this.SetAABB(min, max);
}
/// <summary>
/// 获取凸包
/// </summary>
/// <param name="listpt"></param>
/// <returns></returns>
public static List <Double2> GenerateConvexPolygon(Double2[] listpt)
{
if (listpt == null || listpt.Length == 0)
{
return(null);
}
// 先生成aabb。
Double2 min = Double2.positiveInfinity;
Double2 max = Double2.negativeInfinity;
foreach (Double2 pos in listpt)
{
min = Double2.Min(min, pos);
max = Double2.Max(max, pos);
}
// 收集条边上的点，按顺时针收集。lb放置在bottom边上，rb 放置在right边上，ru顶点放置up边上, lu顶点放置在left边上
Double2[][] edgePointArray = new Double2[4][];
for (int i = 0; i < 4; i++)
{
edgePointArray[i] = new Double2[2];
if (i < 2)
{
edgePointArray[i][0] = Double2.positiveInfinity;
edgePointArray[i][1] = Double2.negativeInfinity;
}
else
{
edgePointArray[i][0] = Double2.negativeInfinity;
edgePointArray[i][1] = Double2.positiveInfinity;
}
}
// 不在边上的顶点
List <Double2> listOutEdgePoint = new List <Double2>();
// 进行收集了。
foreach (Double2 pos in listpt)
{
bool isInedge = false;
// 第一条边 bottom edge
if (pos.y == min.y)
{
edgePointArray[0][0] = Double2.Min(pos, edgePointArray[0][0]);
edgePointArray[0][1] = Double2.Max(pos, edgePointArray[0][1]);
isInedge = true;
}
if (pos.x == max.x) // right edge
{
edgePointArray[1][0] = Double2.Min(pos, edgePointArray[1][0]);
edgePointArray[1][1] = Double2.Max(pos, edgePointArray[1][1]);
isInedge = true;
}
if (pos.y == max.y) // up edge
{
edgePointArray[2][0] = Double2.Max(pos, edgePointArray[2][0]);
edgePointArray[2][1] = Double2.Min(pos, edgePointArray[2][1]);
isInedge = true;
}
if (pos.x == min.x) // left edge
{
edgePointArray[3][0] = Double2.Max(pos, edgePointArray[3][0]);
edgePointArray[3][1] = Double2.Min(pos, edgePointArray[3][1]);
isInedge = true;
}
if (isInedge == false)
{
listOutEdgePoint.Add(pos);
}
}
// 边上的顶点按顺时针排序了。
//
List <Double2> listPoly = new List <Double2>();
Double2 startPoint;
Double2 endPoint = Double2.negativeInfinity;
for (int i = 0; i < 4; i++)
{
startPoint = edgePointArray[i][0];
if (startPoint != endPoint)
{
listPoly.Add(startPoint);
}
endPoint = edgePointArray[i][1];
if (startPoint != endPoint)
{
listPoly.Add(endPoint);
}
if (endPoint != edgePointArray[(i + 1) % 4][0])
{
List <Double2> llinkPoint = SearchOutPoint(i, endPoint, edgePointArray[(i + 1) % 4][0], listOutEdgePoint);
if (llinkPoint != null && llinkPoint.Count > 0)
{
listPoly.AddRange(llinkPoint);
}
}
}
for (int i = 0; i < 4; i++)
{
edgePointArray[i] = null;
}
edgePointArray = null;
if (listPoly.Count > 1)
{
if (listPoly[0] == listPoly[listPoly.Count - 1])
{
listPoly.RemoveAt(listPoly.Count - 1);
}
}
return(listPoly);
}
