private static void SwapPoints(ref PointZ a, ref PointZ b)
{
PointZ tmp = a;
a = b;
b = tmp;
}
public Triangle(PointZ a, PointZ b, PointZ c)
{
vertexes = new PointZ[3];
vertexes[0] = a;
vertexes[1] = b;
vertexes[2] = c;
edges.Add(new Edge(a, b));
edges.Add(new Edge(a, c));
edges.Add(new Edge(b, c));
}
public static List <PointZ> JarvisHull(PointZ[] points)
{
var Shell = new List <PointZ>();
//Ищем отправную точку
Int32 asStart = 0;
for (int i = 1; i < points.Length; i++)
{
if (Math.Abs(points[i].Y - points[asStart].Y) < 0.000001)
{
if (points[i].X < points[asStart].X)
{
asStart = i;
}
else
{
;
}
}
else if (points[i].Y < points[asStart].Y)
{
asStart = i;
}
}
var startpoint = new PointZ(points[asStart].X, points[asStart].Y);
Shell.Add(points[asStart]);
PointZ current = points[asStart];
SwapPoints(ref points[points.Length - 1], ref points[asStart]);
Int32 k = 0;
//Алгоритм выборки точек
do
{
for (int i = k; i < points.Length; i++)
{
if (PseudoscolarMult(current, points[i], points[k]) < 0)
{
SwapPoints(ref points[k], ref points[i]);
}
}
current = points[k];
Shell.Add(points[k]);
k++;
}while (!IsEqualPoints(current, startpoint));
//Shell.Add(startpoint);
return(new HashSet <PointZ>(Shell).ToList());
}
public PointZ getSecondPoint(PointZ point) => a == point ? b : a;
public bool Contains(PointZ point) => (a == point) || (b == point);
public Edge(PointZ p1, PointZ p2)
{
a = p1;
b = p2;
}
public bool Contains(PointZ point) => vertexes.Contains(point);
private static bool IsEqualPoints(PointZ current, PointZ startpoint)
{
return(current.X == startpoint.X && current.Y == startpoint.Y);
}
private static double PseudoscolarMult(PointZ k, PointZ a, PointZ b)
{
return((a.X - k.X) * (b.Y - k.Y) - (b.X - k.X) * (a.Y - k.Y));
}
