/// <summary>
/// Form a Delaunay triangulation by the divide-and-conquer method.
/// </summary>
/// <returns></returns>
/// <remarks>
/// Sorts the vertices, calls a recursive procedure to triangulate them, and
/// removes the bounding box, setting boundary markers as appropriate.
/// </remarks>
public IMesh Triangulate(IList <Vertex> points, Configuration config)
{
this.predicates = config.Predicates();
this.mesh = new Mesh(config);
this.mesh.TransferNodes(points);
Otri hullleft = default(Otri), hullright = default(Otri);
int i, j, n = points.Count;
// Allocate an array of pointers to vertices for sorting.
this.sortarray = new Vertex[n];
i = 0;
foreach (var v in points)
{
sortarray[i++] = v;
}
// Sort the vertices.
VertexSorter.Sort(sortarray);
// Discard duplicate vertices, which can really mess up the algorithm.
i = 0;
for (j = 1; j < n; j++)
{
if ((sortarray[i].x == sortarray[j].x) && (sortarray[i].y == sortarray[j].y))
{
if (Log.Verbose)
{
Log.Instance.Warning(
String.Format("A duplicate vertex appeared and was ignored (ID {0}).", sortarray[j].id),
"Dwyer.Triangulate()");
}
sortarray[j].type = VertexType.UndeadVertex;
mesh.undeads++;
}
else
{
i++;
sortarray[i] = sortarray[j];
}
}
i++;
if (UseDwyer)
{
// Re-sort the array of vertices to accommodate alternating cuts.
VertexSorter.Alternate(sortarray, i);
}
// Form the Delaunay triangulation.
DivconqRecurse(0, i - 1, 0, ref hullleft, ref hullright);
this.mesh.hullsize = RemoveGhosts(ref hullleft);
return(this.mesh);
}
public void IdentifiesTopLeftIndex3()
{
var points = new List <Point>
{
new Point(0, 1),
new Point(-1, 0),
new Point(1, 0),
};
int tl = VertexSorter.GetTopLeftIndex(points);
Assert.AreEqual(0, tl);
}
public void IdentifiesTopLeftPoint4()
{
var points = new List <Point>
{
new Point(1, 1),
new Point(-1, 0),
new Point(1, 0),
};
Point tl = VertexSorter.GetTopLeft(points);
Assert.AreEqual(1, tl.X);
Assert.AreEqual(1, tl.Y);
}
