public void PlotTriple(Site s1, Site s2, Site s3) {
if (Debug) {
Console.WriteLine("triple {0} {1} {2}", s1, s2, s3);
}
var triangle = new Triangle(s1, s2, s3) { New = true };
Triangles.Add(triangle);
}
public void PlotVertex(Site s) {
if (Debug) {
Console.WriteLine("vertex {0},{1}", s.X, s.Y);
Log.InfoFormat("vertex {0},{1}", s.X, s.Y);
}
s.New = true;
Vertices.Add(s);
}
public static int CompareByYThenX(Site s1, ICoord s2)
{
if (s1.Y < s2.Y) return -1;
if (s1.Y > s2.Y) return 1;
if (s1.X < s2.X) return -1;
if (s1.X > s2.X) return 1;
return 0;
}
public void PlotSite(Site site) {
site.New = true;
Sites.Add(site);
if (Debug) {
Console.WriteLine("site {0}", site);
Log.InfoFormat("site {0}", site);
}
if (site.Y > SweepLine) {
SweepLine = site.Y;
}
}
public static bool RightOf(HalfEdge he, Site p) {
var e = he.Edge;
var topSite = e.Region[Side.Right];
var rightOfSite = (p.X > topSite.X);
if (rightOfSite && (he.Side == Side.Left)) {
return true;
}
if (!rightOfSite && (he.Side == Side.Right)) {
return false;
}
bool above;
if (Math.Abs(e.A - 1) < Tolerance) {
var dyp = p.Y - topSite.Y;
var dxp = p.X - topSite.X;
var fast = false;
if ((!rightOfSite && (e.B < 0)) || (rightOfSite && (e.B >= 0))) {
above = fast = (dyp >= e.B*dxp);
} else {
above = ((p.X + p.Y*e.B) > e.C);
if (e.B < 0) {
above = !above;
}
if (!above) {
fast = true;
}
}
if (!fast) {
var dxs = topSite.X - e.Region[Side.Left].X;
above = (e.B*(dxp*dxp - dyp*dyp)) < (dxs*dyp*(1 + 2*dxp/dxs + e.B*e.B));
if (e.B < 0) {
above = !above;
}
}
} else { // e.b == 1
var y1 = e.C - e.A*p.X;
var t1 = p.Y - y1;
var t2 = p.X - topSite.X;
var t3 = y1 - topSite.Y;
above = (t1*t1) > (t2*t2 + t3*t3);
}
return he.Side == Side.Left ? above : !above;
}
public static Edge Bisect(Site s1, Site s2) {
var newEdge = new Edge(s1, s2);
var dx = s2.X - s1.X;
var dy = s2.Y - s1.Y;
var adx = dx > 0 ? dx : -dx;
var ady = dy > 0 ? dy : -dy;
newEdge.C = s1.X * dx + s1.Y * dy + (dx * dx + dy * dy) * 0.5f;
if (adx > ady) {
newEdge.A = 1;
newEdge.B = dy / dx;
newEdge.C /= dx;
} else {
newEdge.B = 1;
newEdge.A = dx / dy;
newEdge.C /= dy;
}
return newEdge;
}
public static Site Intersect(HalfEdge el1, HalfEdge el2) {
var e1 = el1.Edge;
var e2 = el2.Edge;
if (e1 == null || e2 == null) {
return null;
}
if (e1.Region[Side.Right] == e2.Region[Side.Right]) {
return null;
}
var d = (e1.A*e2.B) - (e1.B*e2.A);
if (Math.Abs(d) < Tolerance) {
return null;
}
var xint = (e1.C*e2.B - e2.C*e1.B)/d;
var yint = (e2.C*e1.A - e1.C*e2.A)/d;
var e1Region = e1.Region[Side.Right];
var e2Region = e2.Region[Side.Right];
HalfEdge el;
Edge e;
if ((e1Region.Y < e2Region.Y) || Math.Abs(e1Region.Y - e2Region.Y) < Tolerance && e1Region.X < e2Region.X) {
el = el1;
e = e1;
} else {
el = el2;
e = e2;
}
var rightOfSite = (xint >= e.Region[Side.Right].X);
if ((rightOfSite && (el.Side == Side.Left)) || (!rightOfSite && (el.Side == Side.Right))) {
return null;
}
var vertex = new Site(xint, yint);
//vertex.AddEdge(e1);
//vertex.AddEdge(e2);
return vertex;
}
public Triangle(Site s1, Site s2, Site s3) {
V1 = s1;
V2 = s2;
V3 = s3;
}
public Segment(Site p1, Site p2) {
P1 = p1;
P2 = p2;
}
private void AddSite(Vector2 p, Color4 color, int index)
{
if (_sitesIndexedByLocation.ContainsKey(p)) return;
var weight = MathF.Rand(0, 1.0f) * 100;
var site = new Site(p, index, weight, color);
_sites.Push(site);
_sitesIndexedByLocation[p] = site;
}
private void ClipLine(Edge e) {
var dy = Height;
var dx = Width;
var d = (dx > dy) ? dx : dy;
var pxMin = -(d - dx) / 2;
var pxMax = Width + (d - dx) / 2;
var pyMin = -(d - dy) / 2;
var pyMax = Height + (d - dy) / 2;
Site s1, s2;
float x1, x2, y1, y2;
Side side;
if (Math.Abs(e.A - 1) < Geometry.Tolerance && e.B >= 0) {
side = Side.Right;
s1 = e.Endpoint[Side.Right];
s2 = e.Endpoint[Side.Left];
} else {
side = Side.Left;
s1 = e.Endpoint[Side.Left];
s2 = e.Endpoint[Side.Right];
}
if (s1 != null && s2 != null) {
if ((s1.Y < pyMin && s2.Y > pyMax) || (s1.Y > pyMax && s2.Y < pyMin)) {
return;
}
}
if (Math.Abs(e.A - 1) < Geometry.Tolerance) {
y1 = pyMin;
if (s1 != null && s1.Y > pyMin) {
y1 = s1.Y;
}
if (y1 > pyMax) {
return;
}
x1 = e.C - e.B * y1;
y2 = pyMax;
if (s2 != null && s2.Y < pyMax) {
y2 = s2.Y;
}
if (y2 < pyMin) {
return;
}
x2 = e.C - e.B * y2;
if (((x1 > pxMax) && (x2 > pxMax)) || ((x1 < pxMin) && (x2 < pxMin))) {
return;
}
if (x1 > pxMax) {
x1 = pxMax;
y1 = (e.C - x1) / e.B;
}
if (x1 < pxMin) {
x1 = pxMin;
y1 = (e.C - x1) / e.B;
}
if (x2 > pxMax) {
x2 = pxMax;
y2 = (e.C - x2) / e.B;
}
if (x2 < pxMin) {
x2 = pxMin;
y2 = (e.C - x2) / e.B;
}
} else {
x1 = pxMin;
if (s1 != null && s1.X > pxMin) {
x1 = s1.X;
}
if (x1 > pxMax) {
return;
}
y1 = e.C - e.A * x1;
x2 = pxMax;
if (s2 != null && s2.X < pxMax) {
x2 = s2.X;
}
if (x2 < pxMin) {
return;
}
y2 = e.C - e.A * x2;
if (((y1 > pyMax) && (y2 > pyMax)) || ((y1 < pyMin) && (y2 < pyMin))) {
return;
}
if (y1 > pyMax) {
y1 = pyMax;
x1 = (e.C - y1) / e.A;
}
if (y1 < pyMin) {
y1 = pyMin;
x1 = (e.C - y1) / e.A;
}
if (y2 > pyMax) {
y2 = pyMax;
x2 = (e.C - y2) / e.A;
}
if (y2 < pyMin) {
y2 = pyMin;
x2 = (e.C - y2) / e.A;
}
}
var p1 = new PointF(x1, y1);
var p2 = new PointF(x2, y2);
var clipped = CohenSutherland.ClipSegment(new RectangleF(0,0, Width, Height), p1, p2 );
if (clipped != null) {
var site1 = new Site(clipped.Item1);
var site2 = new Site(clipped.Item2);
var s = new Segment(site1, site2) {
New = true
};
Segments.Add(s);
/*if (s1 == null) {
e.Endpoint[side] = site1;
}
if (s2 == null) {
e.Endpoint[Side.Other(side)] = site2;
}*/
}
}
public static float Distance(Site s, Site t) {
var dx = s.X - t.X;
var dy = s.Y - t.Y;
return (float) Math.Sqrt(dx*dx + dy*dy);
}
public static void EndPoint(Edge edge, Side side, Site site, VoronoiGraph c) {
edge.Endpoint[side] = site;
var opSide = side == Side.Left ? Side.Right : Side.Left;
if (edge.Endpoint[opSide] == null) {
return;
}
c.PlotEndpoint(edge);
}