public TruncateGeometryOperation(Geometry src, bool close)
{
Source = src;
// Pass 1: Create truncated versions of old polygons
foreach (Polygon oldPolygon in Source.Polygons)
{
Polygon newPolygon = MakeNewPolygonFromPolygon(oldPolygon);
double n1 = (double)(oldPolygon.Corners.Count);
double n2 = (double)(2 * oldPolygon.Corners.Count);
float ratio = (float)(System.Math.Tan(System.Math.PI / n2) / System.Math.Tan(System.Math.PI / n1));
float t = 0.5f - 0.5f * ratio;
// Pass 1A: Create truncated corners
for (int i = 0; i < oldPolygon.Corners.Count; ++i)
{
Corner oldCorner = oldPolygon.Corners[i];
Corner nextCorner = oldPolygon.Corners[(i + 1) % oldPolygon.Corners.Count];
UpdateTruncatedEdge(newPolygon, oldCorner, nextCorner, t);
}
// Pass 1B: Collect open edges from new polygon to per point dictionary
// Note the order of points in new edge is important in this case.
for (int i = 0; i < newPolygon.Corners.Count; i += 2)
{
Corner newCorner = newPolygon.Corners[i];
Corner previousCorner = newPolygon.Corners[(i + newPolygon.Corners.Count - 1) % newPolygon.Corners.Count];
Point newPoint = newCorner.Point;
Point previousPoint = previousCorner.Point;
Point oldPoint = newPointToOld[newPoint];
Edge newEdge = new Edge(newPoint, previousPoint);
if (oldPointToOpenEdges.ContainsKey(oldPoint) == false)
{
oldPointToOpenEdges[oldPoint] = new List <Edge>();
}
oldPointToOpenEdges[oldPoint].Add(newEdge);
}
}
// Pass 2: Connect open edges
if (close)
{
foreach (Point oldPoint in src.Points)
{
if (oldPointToOpenEdges.ContainsKey(oldPoint) == false)
{
continue;
}
if (oldPointToOpenEdges[oldPoint].Count < 3)
{
continue;
}
Polygon newPolygon = Destination.MakePolygon();
// TODO This polygon has no sources.. inherit average of surrounding polygons?
Edge edge = oldPointToOpenEdges[oldPoint].First();
Edge startEdge = edge;
// TODO MUSTFIX This loop does not terminate for some geometries
// such as tetrahemihexahedron
do
{
bool nextEdgeFound = false;
int edgeIndex = 0;
foreach (Edge nextEdge in oldPointToOpenEdges[oldPoint])
{
++edgeIndex;
if (nextEdge.A == edge.B)
{
Point newPoint = edge.A;
Corner newCorner = newPolygon.MakeCorner(newPoint);
DistributeCornerSources(newCorner, 1.0f, newPoint);
edge = nextEdge;
nextEdgeFound = true;
break;
}
}
/* This can happen */
if (nextEdgeFound == false)
{
break;
}
}while(edge.Equals(startEdge) == false);
if (newPolygon.Corners.Count < 3)
{
Destination.RemovePolygon(newPolygon);
}
}
}
Destination.BuildEdges();
InterpolateAllAttributeMaps();
}
public void RemoveCorner(Corner corner)
{
corner.Point.Corners.Remove(corner);
corners.Remove(corner);
}