/// <summary>
/// Constructs a table of the area of intersection between each face and the vertices around it.
/// </summary>
public static double[][] AreaInEachVertex(IPolyhedron surface)
{
var allAreas = new double[surface.Faces.Count][];
foreach (var face in surface.Faces)
{
var vertices = face.Vertices;
var areas = vertices.Select(vertex => PolyhedronUtilities.AreaSharedByVertexAndFace(surface, vertex, face)).ToArray();
allAreas[surface.IndexOf(face)] = areas;
}
return(allAreas);
}
public void BisectionPoint_OfTheEdgeOfACube_ShouldBeEquidistantFromBothEnds
(IPolyhedron polyhedron)
{
// Fixture setup
// Exercise system
var points = polyhedron.Edges.Select(edge => PolyhedronUtilities.BisectionPoint(polyhedron, edge)).ToList();
// Verify outcome
var expected = polyhedron.Edges.Select((edge, i) => (edge.A.Position - points[i]).Norm()).ToList();
var actual = polyhedron.Edges.Select((edge, i) => (edge.B.Position - points[i]).Norm()).ToList();
TestUtilities.WriteExpectedAndActual(expected, actual);
Assert.True(Enumerable.SequenceEqual(expected, actual));
// Teardown
}
public void AreaSharedByVertexAndFace_OnACube_ShouldProduceTheCorrectValues
(IPolyhedron polyhedron)
{
// Fixture setup
var vertices = polyhedron.Vertices;
var faces = polyhedron.Faces;
var expected = Enumerable.Repeat(1.0, 24).Concat(Enumerable.Repeat(0.0, 24)).ToList();
// Exercise system
var actual = vertices.SelectMany(vertex => faces.Select(face => PolyhedronUtilities.AreaSharedByVertexAndFace(polyhedron, vertex, face))).ToList();
// Verify outcome
TestUtilities.WriteExpectedAndActual(expected, actual);
Assert.True(TestUtilities.UnorderedEquals(expected, actual));
// Teardown
}
/// <summary>
/// Constructs a table of the distances from each vertex to the bisectors running across each neighbouring edge.
/// </summary>
public static double[][] HalfEdgeLengths(IPolyhedron surface)
{
var halfLengthsTable = new double[surface.Vertices.Count][];
foreach (var vertex in surface.Vertices)
{
var edges = surface.EdgesOf(vertex);
var lengths = new List <double>();
foreach (var edge in edges)
{
var neighbour = edge.Vertices().First(v => v != vertex);
var bisectionPoint = PolyhedronUtilities.BisectionPoint(surface, edge);
var length = (neighbour.Position - bisectionPoint).Norm();
//TODO: This is planar distance, not geodesic.
lengths.Add(length);
}
halfLengthsTable[surface.IndexOf(vertex)] = lengths.ToArray();
}
return(halfLengthsTable);
}
