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);
}