public List <EPMTriangle> ExtractTriangles_PointsInCircle(Vector2d origin, double radius, int pointCount = 1, List <EPMTriangle> waitingProcessList = null)
{
List <EPMTriangle> extractList = new List <EPMTriangle>();
if (waitingProcessList == null)
{
waitingProcessList = g_triangleList;
}
for (int i = 0; i < waitingProcessList.Count; i++)
{
EPMTriangle t = waitingProcessList[i];
List <EPMPoint> plist = t.g_pointList;
int count = 0;
for (int j = 0; j < plist.Count; j++)
{
Vector2d v2 = plist[j].pos2d - origin;
double distance = v2.Length();
if (distance <= radius)
{
count++;
if (count >= pointCount)
{
extractList.Add(t);
break;
}
}
}
}
return(extractList);
}
//if 2 points are shared, they must share one edge
public bool GetShareEdge(EPMTriangle t2, out int point1Index, out int point2Index)
{
point1Index = point2Index = -1;
if (t2.g_sortedIndexList[0] == g_sortedIndexList[0] || t2.g_sortedIndexList[0] == g_sortedIndexList[1] || t2.g_sortedIndexList[0] == g_sortedIndexList[2])
{
point1Index = t2.g_sortedIndexList[0];
}
if (t2.g_sortedIndexList[1] == g_sortedIndexList[0] || t2.g_sortedIndexList[1] == g_sortedIndexList[1] || t2.g_sortedIndexList[1] == g_sortedIndexList[2])
{
if (point1Index == -1)
{
point1Index = t2.g_sortedIndexList[1];
}
else
{
point2Index = t2.g_sortedIndexList[1];
}
}
if (t2.g_sortedIndexList[2] == g_sortedIndexList[0] || t2.g_sortedIndexList[2] == g_sortedIndexList[1] || t2.g_sortedIndexList[2] == g_sortedIndexList[2])
{
point2Index = t2.g_sortedIndexList[2];
}
return(point2Index != -1);
}
private void AddTriangleByPointIndex(int index, EPMTriangle t)
{
if (m_pointIndexToTriangleList[index] == null)
{
m_pointIndexToTriangleList[index] = new List <EPMTriangle>();
}
m_pointIndexToTriangleList[index].Add(t);
}
public override void StartGenerating()
{
g_triangleList = EPMDelaunayAlgorithm.DoDelaunay(m_vertexList, g_startPoint, g_endPoint);
m_pointIndexToTriangleList = new List <EPMTriangle> [m_vertexList.Count];
for (int i = 0; i < g_triangleList.Count; i++)
{
EPMTriangle t = g_triangleList[i];
t.TryDetermineType();
AddTriangleByPointIndex(t[0].g_indexInList, t);
AddTriangleByPointIndex(t[1].g_indexInList, t);
AddTriangleByPointIndex(t[2].g_indexInList, t);
}
CalculateTriangleNeighbor();
}
//For each triangle, find its neighbors, note that there are 2 types of neighbors, sharedEdge neighbors and sharedPoint neighbors. the TidyNeighbor() function would do the classification.
private void CalculateTriangleNeighbor()
{
for (int i = 0; i < g_triangleList.Count; i++)
{
EPMTriangle t = g_triangleList[i];
List <EPMPoint> vertices = t.g_pointList;
for (int j = 0; j < vertices.Count; j++)
{
List <EPMTriangle> shared = m_pointIndexToTriangleList[vertices[j].g_indexInList];
for (int k = 0; k < shared.Count; k++)
{
t.g_sharePointNeighbors.Add(shared[k]);
}
}
t.TidyNeighbors();
}
}
//It is not accurate, but it can extract most triangles and it is simple&fast
public List <EPMTriangle> ExtractTriangles_IntersectLine(Vector2d lineStart, Vector2d lineEnd, List <EPMTriangle> waitingProcessList = null)
{
List <EPMTriangle> extractList = new List <EPMTriangle>();
if (waitingProcessList == null)
{
waitingProcessList = g_triangleList;
}
Vector2d dir = lineEnd - lineStart;
double lineLength = dir.Length();
dir.Normalize();
Vector2d normal = new Vector2d(-dir.y, dir.x);
for (int i = 0; i < waitingProcessList.Count; i++)
{
EPMTriangle t = waitingProcessList[i];
List <EPMPoint> plist = t.g_pointList;
int side = 0;
for (int j = 0; j < plist.Count; j++)
{
Vector2d v2 = plist[j].pos2d - lineStart;
double dot = v2 * dir;
if (dot < 0 || dot > lineLength)
{
continue;
}
double distance = v2 * normal;
if (side == 0)
{
side = distance > 0 ? 1 : -1;
}
else if (side * distance < 0)
{
extractList.Add(t);
break;
}
}
}
return(extractList);
}
public List <EPMTriangle> ExtractTriangles_PointsInLineWithDistance(Vector2d lineStart, Vector2d lineEnd, double halfWidth, int pointCount = 1, List <EPMTriangle> waitingProcessList = null)
{
List <EPMTriangle> extractList = new List <EPMTriangle>();
if (waitingProcessList == null)
{
waitingProcessList = g_triangleList;
}
Vector2d dir = lineEnd - lineStart;
double lineLength = dir.Length();
dir.Normalize();
Vector2d normal = new Vector2d(-dir.y, dir.x);
for (int i = 0; i < waitingProcessList.Count; i++)
{
EPMTriangle t = waitingProcessList[i];
List <EPMPoint> plist = t.g_pointList;
int count = 0;
for (int j = 0; j < plist.Count; j++)
{
Vector2d v2 = plist[j].pos2d - lineStart;
double dot = v2 * dir;
double distance = v2 * normal;
if (dot >= 0 && dot <= lineLength && System.Math.Abs(distance) <= halfWidth)
{
count++;
if (count >= pointCount)
{
extractList.Add(t);
break;
}
}
}
}
return(extractList);
}