/// <summary>
/// Determines the line segments bounding the selected reference
/// element (cf. <see cref="RefElement"/>) in reference coordinates
/// </summary>
/// <returns></returns>
private LineSegment[] GetReferenceLineSegments()
{
Stack <RefElement> simplexHierarchy = new Stack <RefElement>();
RefElement currentSimplex = RefElement;
int spatialDimension = RefElement.SpatialDimension;
int n = 0;
while (currentSimplex.GetType() != lineSimplex.GetType())
{
// If n > 2, the edge of the edge of a simplex is not a line.
// This is hardly likely in 2d/3d.
if (n > 2)
{
throw new ApplicationException("Something went terribly wrong.");
}
simplexHierarchy.Push(currentSimplex);
currentSimplex = currentSimplex.FaceRefElement;
n++;
}
MultidimensionalArray vertexCoordinates = MultidimensionalArray.Create(2, 1);
vertexCoordinates[0, 0] = -1.0;
vertexCoordinates[1, 0] = 1.0;
while (simplexHierarchy.Count > 0)
{
currentSimplex = simplexHierarchy.Pop();
int noOfVertices = vertexCoordinates.GetLength(0);
int D = currentSimplex.SpatialDimension;
MultidimensionalArray volumeCoordinates = MultidimensionalArray.Create(
noOfVertices * currentSimplex.NoOfFaces, currentSimplex.SpatialDimension);
for (int e = 0; e < currentSimplex.NoOfFaces; e++)
{
MultidimensionalArray coordinates = MultidimensionalArray.Create(noOfVertices, D);
currentSimplex.TransformFaceCoordinates(e, vertexCoordinates, coordinates);
for (int i = 0; i < noOfVertices; i++)
{
for (int d = 0; d < D; d++)
{
volumeCoordinates[e * noOfVertices + i, d] = coordinates[i, d];
}
}
}
vertexCoordinates = volumeCoordinates;
}
Debug.Assert(
vertexCoordinates.GetLength(0) % 2 == 0,
"Even number of vertices expected");
int initialNumberOfLineSegments = vertexCoordinates.GetLength(0) / 2;
List <LineSegment> lineSegments = new List <LineSegment>(initialNumberOfLineSegments);
for (int i = 0; i < initialNumberOfLineSegments; i++)
{
var p0 = vertexCoordinates.GetRow(2 * i + 0);
int iP0 = this.RefElement.Vertices.FindRow(p0, 1.0e-8);
var p1 = vertexCoordinates.GetRow(2 * i + 1);
int iP1 = this.RefElement.Vertices.FindRow(p1, 1.0e-8);
LineSegment newSegment = new LineSegment(spatialDimension, this.RefElement,
p0, p1, iP0, iP1,
RootFindingAlgorithm);
if (!lineSegments.Contains(newSegment))
{
lineSegments.Add(newSegment);
//tracker.Subscribe(newSegment);
}
}
foreach (LineSegment segment in lineSegments)
{
LevelSet levelSetField = levelSetData.LevelSet as LevelSet;
if (levelSetField != null)
{
segment.ProjectBasisPolynomials(levelSetField.Basis);
}
}
return(lineSegments.ToArray());
}
