public List <short> TriangulateAndReturnIndices()
{
EarClipping EarClipper = new EarClipping();
EarClipper.SetPoints(Vertices, null, Normal);
EarClipper.Triangulate();
var Result = EarClipper.Result;
List <short> Indices = new List <short>();
for (short Index = 0; Index < Result.Count; Index++)
{
Vector3m Vertex = Result[Index];
for (short IndexPoint = 0; IndexPoint < Vertices.Count; IndexPoint++)
{
if (Vertex.Equals(Vertices[IndexPoint]))
{
Indices.Add(IndexPoint);
}
}
}
return(Indices);
}
public void Triangulate()
{
if (Normal.Equals(Vector3m.Zero()))
{
throw new Exception("The input is not a valid polygon");
}
if (_holes != null && _holes.Count > 0)
{
ProcessHoles();
}
List <ConnectionEdge> nonConvexPoints = FindNonConvexPoints(_mainPointList);
if (nonConvexPoints.Count == _mainPointList.PointCount)
{
throw new ArgumentException("The triangle input is not valid");
}
while (_mainPointList.PointCount > 2)
{
bool guard = false;
foreach (var cur in _mainPointList.GetPolygonCirculator())
{
if (!IsConvex(cur))
{
continue;
}
if (!IsPointInTriangle(cur.Prev.Origin, cur.Origin, cur.Next.Origin, nonConvexPoints))
{
// cut off ear
guard = true;
Result.Add(cur.Prev.Origin);
Result.Add(cur.Origin);
Result.Add(cur.Next.Origin);
// Check if prev and next are still nonconvex. If not, then remove from non convex list
if (IsConvex(cur.Prev))
{
int index = nonConvexPoints.FindIndex(x => x == cur.Prev);
if (index >= 0)
{
nonConvexPoints.RemoveAt(index);
}
}
if (IsConvex(cur.Next))
{
int index = nonConvexPoints.FindIndex(x => x == cur.Next);
if (index >= 0)
{
nonConvexPoints.RemoveAt(index);
}
}
_mainPointList.Remove(cur);
break;
}
}
if (PointsOnLine(_mainPointList))
{
break;
}
if (!guard)
{
throw new Exception("No progression. The input must be wrong");
}
}
}