/**
* Draw all the Voronoi edges.
*/
public void drawAllVoronoi()
{
// Loop through all the edges of the DT (each is done twice)
for (Iterator it = dt.iterator(); it.hasNext();)
{
Simplex triangle = (Simplex)it.next();
for (Iterator otherIt = dt.neighbors(triangle).iterator(); otherIt.hasNext();)
{
Simplex other = (Simplex)otherIt.next();
Pnt p = Pnt.circumcenter((Pnt[])triangle.toArray(new Pnt[0]));
Pnt q = Pnt.circumcenter((Pnt[])other.toArray(new Pnt[0]));
draw(p, q);
}
}
}
/**
* Locate the triangle with point (a Pnt) inside (or on) it.
* @param point the Pnt to locate
* @return triangle (Simplex<Pnt>) that holds the point; null if no such triangle
*/
public Simplex locate(Pnt point)
{
Simplex triangle = mostRecent;
if (!this.contains(triangle))
{
triangle = null;
}
// Try a directed walk (this works fine in 2D, but can fail in 3D)
Set visited = new HashSet();
while (triangle != null)
{
if (visited.contains(triangle)) // This should never happen
{
Console.WriteLine("Warning: Caught in a locate loop");
break;
}
visited.add(triangle);
// Corner opposite point
Pnt corner = point.isOutside((Pnt[])triangle.toArray(new Pnt[0]));
if (corner == null)
{
return(triangle);
}
triangle = this.neighborOpposite(corner, triangle);
}
// No luck; try brute force
Console.WriteLine("Warning: Checking all triangles for " + point);
for (Iterator it = this.iterator(); it.hasNext();)
{
Simplex tri = (Simplex)it.next();
if (point.isOutside((Pnt[])tri.toArray(new Pnt[0])) == null)
{
return(tri);
}
}
// No such triangle
Console.WriteLine("Warning: No triangle holds " + point);
return(null);
}
/**
* Draw all the empty circles (one for each triangle) of the DT.
*/
public void drawAllCircles()
{
// Loop through all triangles of the DT
for (Iterator it = dt.iterator(); it.hasNext();)
{
Simplex triangle = (Simplex)it.next();
for (Iterator otherIt = initialTriangle.iterator(); otherIt.hasNext();)
{
Pnt p = (Pnt)otherIt.next();
if (triangle.contains(p))
{
triangle = null;
break;
}
}
if (triangle != null)
{
Pnt c = Pnt.circumcenter((Pnt[])triangle.toArray(new Pnt[0]));
double radius = c.subtract((Pnt)triangle.iterator().next()).magnitude();
draw(c, radius, null);
}
}
}
/**
* Place a new point site into the DT.
* @param site the new Pnt
* @return set of all new triangles created
*/
public Set delaunayPlace(Pnt site)
{
Set newTriangles = new HashSet();
Set oldTriangles = new HashSet();
Set doneSet = new HashSet();
LinkedList waitingQ = new LinkedList();
// Locate containing triangle
if (debug)
{
Console.WriteLine("Locate");
}
Simplex triangle = locate(site);
// Give up if no containing triangle or if site is already in DT
var triangle_null = triangle == null;
if (triangle_null || triangle.contains(site))
{
return(newTriangles);
}
// Find Delaunay cavity (those triangles with site in their circumcircles)
if (debug)
{
Console.WriteLine("Cavity");
}
waitingQ.add(triangle);
while (!waitingQ.isEmpty())
{
triangle = (Simplex)waitingQ.removeFirst();
if (site.vsCircumcircle((Pnt[])triangle.toArray(new Pnt[0])) == 1)
{
continue;
}
oldTriangles.add(triangle);
Iterator it = this.neighbors(triangle).iterator();
for (; it.hasNext();)
{
Simplex tri = (Simplex)it.next();
if (doneSet.contains(tri))
{
continue;
}
doneSet.add(tri);
waitingQ.add(tri);
}
}
// Create the new triangles
if (debug)
{
Console.WriteLine("Create");
}
for (Iterator it = Simplex.boundary(oldTriangles).iterator(); it.hasNext();)
{
Set facet = (Set)it.next();
facet.add(site);
newTriangles.add(new Simplex(facet));
}
// Replace old triangles with new triangles
if (debug)
{
Console.WriteLine("Update");
}
this.update(oldTriangles, newTriangles);
// Update mostRecent triangle
if (!newTriangles.isEmpty())
{
mostRecent = (Simplex)newTriangles.iterator().next();
}
return(newTriangles);
}
