private static Polygon BuildSubMeshBoundaryGeometry(CMeshData mesh, BoundarySegmentsBuilder bsb, List <CMeshFace> boundaryFaces)
{
// Find connected segments
List <LinkedList <int> > segments = bsb.BuildBoundarySegments(boundaryFaces);
if (segments == null)
{
return(null);
}
LinearRing shell = null;
List <LinearRing> holes = new List <LinearRing>();
// Create mesh boundary with segments
for (int isegment = 0; isegment < segments.Count; isegment++)
{
LinkedList <int> segment = segments[isegment];
CMeshFace first = boundaryFaces[segment.First.Value];
CMeshFace last = boundaryFaces[segment.Last.Value];
if (!NodeEquals(first.FromNode, last.ToNode))
{
Console.Out.WriteLine("Skipping: {0,4} {1,8} {2,8} {3,8}", isegment, segment.Count, first.FromNode, last.ToNode);
continue;
}
Coordinate[] coords = new Coordinate[segment.Count + 1];
int i = 0;
foreach (int iFace in segment)
{
CMeshFace face = boundaryFaces[iFace];
coords[i++] = new Coordinate(face.FromNode.X, face.FromNode.Y);
}
coords[segment.Count] = new Coordinate(last.ToNode.X, last.ToNode.Y);
LinearRing ring = new LinearRing(coords);
if (ring.IsCCW)
{
if (shell != null)
{
throw new Exception("Finding two shells of a connected sub-mesh");
}
shell = ring;
}
else
{
holes.Add(ring);
}
}
Polygon p;
if (holes.Count > 0)
{
p = new Polygon(shell, holes.ToArray());
}
else
{
p = new Polygon(shell);
}
return(p);
}
/// <summary>
/// Build list of <see cref="CMeshBoundary"/>, one for each boundary code, based on the <paramref name="meshFaces"/>
/// <para>
/// The <paramref name="meshFaces"/> need only contain boundary faces. Internal faces are ignored.
/// </para>
/// </summary>
private static List <CMeshBoundary> BuildBoundaryList(CMeshData mesh, List <CMeshFace> meshFaces)
{
// Sort all faces on boundary code, assuming code numbers does not grow very big.
List <List <CMeshFace> > bcs = new List <List <CMeshFace> >();
for (int i = 0; i < meshFaces.Count; i++)
{
CMeshFace meshFace = meshFaces[i];
if (meshFace.IsBoundaryFace())
{
while (meshFace.Code + 1 > bcs.Count)
{
List <CMeshFace> boundaryFaces = new List <CMeshFace>();
bcs.Add(boundaryFaces);
}
bcs[meshFace.Code].Add(meshFace);
}
}
List <CMeshBoundary> boundaries = new List <CMeshBoundary>();
BoundarySegmentsBuilder bsb = new BoundarySegmentsBuilder(mesh);
// For each boundary code, find segments
for (int ic = 0; ic < bcs.Count; ic++)
{
int code = ic;
List <CMeshFace> faces = bcs[ic];
List <LinkedList <int> > segments = bsb.BuildBoundarySegments(faces);
if (segments == null)
{
continue;
}
// Create mesh boundary with segments
CMeshBoundary meshBoundary = new CMeshBoundary()
{
Code = code
};
foreach (LinkedList <int> segment in segments)
{
if (segment == null)
{
continue;
}
List <CMeshFace> segmentFaces = new List <CMeshFace>(segment.Count);
foreach (int currentFace in segment)
{
segmentFaces.Add(faces[currentFace]);
}
meshBoundary.Segments.Add(segmentFaces);
}
boundaries.Add(meshBoundary);
}
//// Sort on boundary codes - well, they are created in code-order
//boundaries.Sort((mb1, mb2) => mb1.Code.CompareTo(mb2.Code));
return(boundaries);
}