/// <summary>
/// Initializes a new instance of MapAround.Geometry.Tesselations.Triangle.
/// </summary>
/// <param name="cell1">First cell</param>
/// <param name="cell2">Second cell</param>
/// <param name="cell3">Third sell</param>
internal Triangle(VoronoiCell cell1, VoronoiCell cell2, VoronoiCell cell3)
{
_cell1 = cell1;
_cell2 = cell2;
_cell3 = cell3;
}
/// <summary>
/// Builds a Voronoi tessellation.
/// </summary>
/// <param name="points">Enumerator of points for tesselation building</param>
/// <param name="buildTraingles">A value indicating whether the constructed Delaunay triangulation</param>
/// <returns>A Voronoi tessellation for cpecified points</returns>
public VoronoiTesselation Build(IEnumerable <ICoordinate> points, bool buildTraingles)
{
List <ICoordinate> sourcePoints = new List <ICoordinate>();
foreach (ICoordinate point in points)
{
sourcePoints.Add(point);
}
if (sourcePoints.Count < 3)
{
throw new ArgumentException("Voronoi tesselation building for this number of point is not supported", "points");
}
_buildTriangles = buildTraingles;
if (_buildTriangles)
{
_triangles = new List <Triangle>();
}
// sort list
sortPoints(sourcePoints);
// remove coincident points
for (int i = sourcePoints.Count - 1; i > 0; i--)
{
if (sourcePoints[i].ExactEquals(sourcePoints[i - 1]))
{
sourcePoints.RemoveAt(i);
}
}
// need to count the number of points with the same (maximum) coordinates as they must be handled in a special way
int lastMaxYIndex = 0;
while (lastMaxYIndex < sourcePoints.Count - 1 && sourcePoints[lastMaxYIndex].Y == sourcePoints[lastMaxYIndex + 1].Y)
{
lastMaxYIndex++;
}
if (lastMaxYIndex > 0)
{
sourcePoints.Sort(0, lastMaxYIndex + 1, new StartPointsComparer());
}
List <VoronoiCell> cells = new List <VoronoiCell>();
foreach (ICoordinate point in sourcePoints)
{
VoronoiCell cell = new VoronoiCell();
cell.DataPoint = point;
cells.Add(cell);
}
build(cells, lastMaxYIndex);
VoronoiTesselation result = new VoronoiTesselation(cells, _triangles);
_triangles = null;
return(result);
}
