public static List <LineSegmentFr> Voronoi(List <PointFr> points)
{
var triangulation = TriangulateIterative(points);
var ch = new PolygonFr(ConvexHullJarvis(points));
var dictTriEdges = new Dictionary <LineSegmentFr, PointFr>();
var voronoiDiagram = new List <LineSegmentFr>();
foreach (var triangle in triangulation)
{
var circumCenter = triangle.CircumCircle().Center;
foreach (var edge in triangle.Edges(true))
{
if (dictTriEdges.ContainsKey(edge))
{
voronoiDiagram.Add(new LineSegmentFr(circumCenter, dictTriEdges[edge], true));
dictTriEdges.Remove(edge);
}
else
{
dictTriEdges.Add(edge, circumCenter);
}
}
}
voronoiDiagram.AddRange(
dictTriEdges.Where(kvp => ch.Contains2(kvp.Value) && kvp.Key.Center() != kvp.Value)
.Select(kvp => new LineSegmentFr(kvp.Key.Center(), kvp.Value)));
for (var i = voronoiDiagram.Count - 1; i >= 0; i--)
{
var edge = voronoiDiagram[i];
var chIntersections = ch.Intersections(edge);
if (chIntersections.Count > 2)
{
throw new Exception("Błędne obliczenia");
}
if (!ch.Contains2(edge.StartPoint) && !ch.Contains2(edge.EndPoint)) // chIntersections.Count > 1 ||
{
voronoiDiagram.Remove(edge);
continue;
}
if (!ch.Contains2(edge.StartPoint))
{
edge.StartPoint = chIntersections.Except(edge.EndPoints()).Single();
}
else if (!ch.Contains2(edge.EndPoint))
{
edge.EndPoint = chIntersections.Except(edge.EndPoints()).Single();
}
voronoiDiagram[i] = edge;
}
return(voronoiDiagram);
}
public static bool IsInsideConvexPolygon(PointFr point, PolygonFr polygon)
{
var vertices = polygon.Vertices.ToList(); // wierzchołki posortowane przeciwnie do wskazówek zegara względem wnętrza wielokąta
var edges = polygon.Edges().ToList();
if (vertices.Count < 3)
{
throw new ArgumentException("Polygon can't have less than 3 vertices");
}
if (ConvexHullJarvis(vertices).Count != vertices.Count) // Powinno wystarczyć Count
{
throw new ArgumentException("Polygon must be convex");
}
if (vertices.Count == 3)
{
return(!edges.Any(point.IsRightOf));
}
var polyCenter = polygon.Center;
if (polyCenter == null)
{
throw new Exception("Can't calculate center of the Polygon");
}
var mid = (PointFr)polyCenter;
while (edges.Count > 1)
{
var testSegment = new LineSegmentFr(mid, edges[edges.Count / 2].StartPoint);
if (point.IsRightOf(testSegment))
{
edges = edges.Take(edges.Count / 2).ToList();
}
else if (point.IsLeftOf(testSegment))
{
edges = edges.Skip(edges.Count / 2).ToList();
}
else if (testSegment.Contains(point))
{
return(true);
}
else
{
throw new Exception("Invalid calculations performed, it should never happen");
}
}
return(!point.IsRightOf(edges.Single())); // czyli IsLeftOf + Contains, jeżeli jest we wierzchołku to będzie spełniony ostatni warunek z while'a
}
public static bool IsInsidePolygon(PointFr point, PolygonFr polygon)
{
if (polygon.Edges(true).Any(edge => edge.Contains(point)))
{
return(true);
}
var vertices = polygon.Vertices.ToList();
int i, j = vertices.Count - 1;
var contains = false;
for (i = 0; i < vertices.Count; i++)
{
if ((vertices[i].Y < point.Y && vertices[j].Y >= point.Y || vertices[j].Y < point.Y && vertices[i].Y >= point.Y) && (vertices[i].X <= point.X || vertices[j].X <= point.X))
{
contains ^= (vertices[i].X + (point.Y - vertices[i].Y) / (vertices[j].Y - vertices[i].Y) * (vertices[j].X - vertices[i].X) < point.X);
}
j = i;
}
return(contains);
}
public bool Contains(PolygonFr polygon)
{
var ps = polygon.Vertices.ToList();
return(ps.Count != 0 && ps.All(Contains));
}