//private float height = .050f;
private LineStrip FindLargestLoop(Segment start)
{
//height += 0.050f;
Vector3 normal = new Vector3 (0, 0, 1);
Segment next = start;
List<Segment> seen = new List<Segment>();
while (!seen.Contains(next))
{
//GL.Disable(EnableCap.Lighting);
//GL.LineWidth(3);
//GL.Begin(PrimitiveType.Lines);
//GL.Color3(Color.Blue);
//GL.Vertex3(next.a.vector.X, next.a.vector.Y, height);
//GL.Color3(Color.LightGreen);
//height += .010f;
//GL.Vertex3(next.b.vector.X, next.b.vector.Y, height);
//GL.End();
//GL.LineWidth(1);
//GL.Enable(EnableCap.Lighting);
seen.Add(next);
Segment best = null;
float largestAngle = 0;
foreach (Segment s in next.b.used_as_a)
{
float angle = Angle(-s.Normal, next.Normal, normal);
if (angle > largestAngle)
{
largestAngle = angle;
best = s;
}
}
if (best == null)
{
// No loops
return null;
}
// Destructive: remove references to this element so it's not searched again.
// Note: only need to remove forward links (from used_as_a). The links from
// used_as_b could be cleared too, but it's not necessary for the algorithm.
next.b.used_as_a.Clear();
//next.b.used_as_b.Clear();
next = best;
}
// Remove all up to the first matched index
int index = seen.IndexOf(next);
seen.RemoveRange(0, index);
LineStrip loop = new LineStrip();
foreach (Segment seg in seen)
{
loop.Append(seg.a.vector);
}
return loop;
}
public void AddSegment(Vector3 a, Vector3 b)
{
var va = FindVectorWrapper(a);
var vb = FindVectorWrapper(b);
var s = new Segment(){a = va, b = vb};
segments.Add(s);
va.used_as_a.Add(s);
vb.used_as_b.Add(s);
}