private void QuickHull()
{
Engine.hull.Clear();
int min_x = 0, max_x = 0;
for (int i = 1; i < Engine.points.Count; i++)
{
if (Engine.points[i].X < Engine.points[min_x].X)
{
min_x = i;
}
if (Engine.points[i].X > Engine.points[max_x].X)
{
max_x = i;
}
}
Engine.hull.Add(Engine.points[min_x]);
Engine.hull.Add(Engine.points[max_x]);
Point A = Engine.hull[0];
Point B = Engine.hull[1];
{
myGraphics.gfx.DrawLine(new Pen(Color.Purple), A.X, A.Y, B.X, B.Y);
}
List <Point> S1 = new List <Point>();
List <Point> S2 = new List <Point>();
foreach (Point point in Engine.points)
{
float side = Matematics.FindSide(A, B, point);
if (side == -1)
{
S1.Add(point);
}
side = Matematics.FindSide(B, A, point);
if (side == -1)
{
S2.Add(point);
}
}
foreach (Point point in S1)
{
//point.fillColor = Color.Blue;
point.fillColor = Color.FromArgb(rnd.Next(255), rnd.Next(255), rnd.Next(255));
point.draw(myGraphics.gfx);
}
foreach (Point point in S2)
{
//point.fillColor = Color.Green;
point.fillColor = Color.FromArgb(rnd.Next(255), rnd.Next(255), rnd.Next(255));
point.draw(myGraphics.gfx);
}
FindHull(S1, A, B);
FindHull(S2, B, A);
}
private void FindHull(List <Point> sk, Point P, Point Q)
{
if (sk.Count == 0)
{
return;
}
int farthestPointIndex = 0;
float max_dist = 0;
for (int i = 0; i < sk.Count; i++)
{
float dist = Matematics.lineDist(P, Q, sk[i]);
if (dist > max_dist)
{
max_dist = dist;
farthestPointIndex = i;
}
}
Point C = sk[farthestPointIndex];
int idx = Engine.hull.IndexOf(P);
Engine.hull.Insert(idx, C);
List <Point> S1 = new List <Point>();
List <Point> S2 = new List <Point>();
foreach (Point point in Engine.points)
{
float side = Matematics.FindSide(P, C, point);
if (side == -1)
{
S1.Add(point);
}
side = Matematics.FindSide(C, Q, point);
if (side == -1)
{
S2.Add(point);
}
}
FindHull(S1, P, C);
FindHull(S2, C, Q);
}
private void DivideEtConquer()
{
Engine.hull.Clear();
int min_x = 0, max_x = 0;
for (int i = 1; i < Engine.points.Count; i++)
{
if (Engine.points[i].X < Engine.points[min_x].X)
{
min_x = i;
}
if (Engine.points[i].X > Engine.points[max_x].X)
{
max_x = i;
}
}
Engine.hull.Add(Engine.points[min_x]);
Engine.hull.Add(Engine.points[max_x]);
Point A = Engine.hull[0];
Point B = Engine.hull[1];
List <Point> S1 = new List <Point>();
List <Point> S2 = new List <Point>();
foreach (Point point in Engine.points)
{
float side = Matematics.FindSide(A, B, point);
if (side == -1)
{
S1.Add(point);
}
side = Matematics.FindSide(B, A, point);
if (side == -1)
{
S2.Add(point);
}
}
FindHull(S1, A, B);
FindHull(S2, B, A);
}