public bool IsPointInsideCircumcircle(DelaunayPoint point)
{
var d_squared = (point.X - Circumcenter.X) * (point.X - Circumcenter.X) +
(point.Y - Circumcenter.Y) * (point.Y - Circumcenter.Y);
return(d_squared < RadiusSquared);
}
private bool IsCounterClockwise(DelaunayPoint point1, DelaunayPoint point2, DelaunayPoint point3)
{
var result = (point2.X - point1.X) * (point3.Y - point1.Y) -
(point3.X - point1.X) * (point2.Y - point1.Y);
return(result > 0);
}
private void UpdateCircumcircle()
{
// https://codefound.wordpress.com/2013/02/21/how-to-compute-a-circumcircle/#more-58
// https://en.wikipedia.org/wiki/Circumscribed_circle
var p0 = Vertices[0];
var p1 = Vertices[1];
var p2 = Vertices[2];
var dA = p0.X * p0.X + p0.Y * p0.Y;
var dB = p1.X * p1.X + p1.Y * p1.Y;
var dC = p2.X * p2.X + p2.Y * p2.Y;
var aux1 = (dA * (p2.Y - p1.Y) + dB * (p0.Y - p2.Y) + dC * (p1.Y - p0.Y));
var aux2 = -(dA * (p2.X - p1.X) + dB * (p0.X - p2.X) + dC * (p1.X - p0.X));
var div = (2 * (p0.X * (p2.Y - p1.Y) + p1.X * (p0.Y - p2.Y) + p2.X * (p1.Y - p0.Y)));
if (div == 0)
{
throw new System.Exception();
}
var center = new DelaunayPoint(aux1 / div, aux2 / div);
Circumcenter = center;
RadiusSquared = (center.X - p0.X) * (center.X - p0.X) + (center.Y - p0.Y) * (center.Y - p0.Y);
}
public Triangle(DelaunayPoint point1, DelaunayPoint point2, DelaunayPoint point3)
{
if (!IsCounterClockwise(point1, point2, point3))
{
Vertices[0] = point1;
Vertices[1] = point3;
Vertices[2] = point2;
}
else
{
Vertices[0] = point1;
Vertices[1] = point2;
Vertices[2] = point3;
}
Vertices[0].AdjacentTriangles.Add(this);
Vertices[1].AdjacentTriangles.Add(this);
Vertices[2].AdjacentTriangles.Add(this);
UpdateCircumcircle();
}
public Edge(DelaunayPoint point1, DelaunayPoint point2)
{
Point1 = point1;
Point2 = point2;
}
//private Triangle GenerateSupraTriangle()
//{
// // 1 -> maxX
// // / \
// // 2---3
// // |
// // v maxY
// var margin = 500;
// var point1 = new DelaunayPoint(0.5 * MaxX, -2 * MaxX - margin);
// var point2 = new DelaunayPoint(-2 * MaxY - margin, 2 * MaxY + margin);
// var point3 = new DelaunayPoint(2 * MaxX + MaxY + margin, 2 * MaxY + margin);
// return new Triangle(point1, point2, point3);
//}
private ISet <Triangle> FindBadTriangles(DelaunayPoint point, HashSet <Triangle> triangles)
{
var badTriangles = triangles.Where(o => o.IsPointInsideCircumcircle(point));
return(new HashSet <Triangle>(badTriangles));
}
//-----------------------
private void openFileToolStripMenuItem_Click(object sender, EventArgs e)
{
openFileDialog1.InitialDirectory = AppDomain.CurrentDomain.BaseDirectory;
if (openFileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
pictureBox1.Load(openFileDialog1.FileName);
bmp = (Bitmap)pictureBox1.Image.Clone();
width = bmp.Width;
height = bmp.Height;
Polys1.init(ref bmp);
MakePoints Makepoints1 = new MakePoints(ref bmp);
Makepoints1.doit();
var point0 = new DelaunayPoint(0, 0);
var point1 = new DelaunayPoint(0, height - 1);
var point2 = new DelaunayPoint(width - 1, height - 1);
var point3 = new DelaunayPoint(width - 1, 0);
var points = new List <DelaunayPoint>()
{
point0, point1, point2, point3
};
var tri1 = new Triangle(point0, point1, point2);
var tri2 = new Triangle(point0, point2, point3);
var border = new List <Triangle>()
{
tri1, tri2
};
DelaunayTriangulator delaunay = new DelaunayTriangulator();
foreach (Point pnt in Makepoints1.PointsLst)
{
bmp.SetPixel(pnt.X, pnt.Y, Color.Black);
points.Add(new DelaunayPoint(pnt.X + 0.2, pnt.Y + 0.1));
}
IEnumerable <Triangle> tmp = delaunay.BowyerWatson(points, border);
Graphics grp = pictureBox1.CreateGraphics();
List <Point> pntlist = new List <Point>();
List <string> strlist = new List <string>();
foreach (var triangle in tmp)
{
string key = triangle.Vertices[0].Key();
if (!strlist.Contains(key))
{
strlist.Add(key);
pntlist.Add(triangle.Vertices[0].GetPoint());
}
key = triangle.Vertices[1].Key();
if (!strlist.Contains(key))
{
strlist.Add(key);
pntlist.Add(triangle.Vertices[1].GetPoint());
}
key = triangle.Vertices[2].Key();
if (!strlist.Contains(key))
{
strlist.Add(key);
pntlist.Add(triangle.Vertices[2].GetPoint());
}
}
Polys1.PointsLst.Clear();
Polys1.PointsLst_cpy.Clear();
Polys1.Items.Clear();
foreach (Point pnt in pntlist)
{
Polys1.PointsLst.Add(pnt);
Polys1.PointsLst_cpy.Add(pnt);
}
foreach (var triangle in tmp)
{
string key1 = triangle.Vertices[0].Key();
string key2 = triangle.Vertices[1].Key();
string key3 = triangle.Vertices[2].Key();
strlist.IndexOf(key1);
Poly pol = new Poly(strlist.IndexOf(key1),
strlist.IndexOf(key2),
strlist.IndexOf(key3), Polys1.PointsLst);
if (pol.IsCounterClockwise)
{
int kk = pol.p2;
pol.p2 = pol.p1;
pol.p1 = kk;
}
Polys1.Items.Add(pol);
}
binImg = new byte[width * 3 * height];
refreshtriagles(false);
BuStart.Enabled = true;
BuEnd.Enabled = true;
}
}
