public bool debug = false; // Used for debugging
/**
* Constructor.
* All sites must fall within the initial triangle.
* @param triangle the initial triangle
*/
public DelaunayTriangulation(Simplex triangle) : base(triangle)
{
mostRecent = triangle;
}
/**
* 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;
}
private Graphics g; // Stored graphics context
/**
* Create and initialize the DT.
*/
public DelaunayPanel()
{
initialTriangle = new Simplex(new Pnt[] {
new Pnt(-initialSize, -initialSize),
new Pnt( initialSize, -initialSize),
new Pnt( 0, initialSize)});
dt = new DelaunayTriangulation(initialTriangle);
}
/**
* Main program; used for testing.
*/
public static void main(String[] args) {
Simplex tri = new Simplex(new Pnt[] {new Pnt(-10,10), new Pnt(10,10), new Pnt(0,-10)});
Console.WriteLine("Triangle created: " + tri);
DelaunayTriangulation dt = new DelaunayTriangulation(tri);
Console.WriteLine("DelaunayTriangulation created: " + dt);
dt.delaunayPlace(new Pnt(0,0));
dt.delaunayPlace(new Pnt(1,0));
dt.delaunayPlace(new Pnt(0,1));
Console.WriteLine("After adding 3 points, the DelaunayTriangulation is a " + dt);
dt.printStuff();
}
/* Navigation */
/**
* Report neighbor opposite the given vertex of simplex.
* @param vertex a vertex of simplex
* @param simplex we want the neighbor of this Simplex
* @return the neighbor opposite vertex of simplex; null if none
* @throws IllegalArgumentException if vertex is not in this Simplex
*/
public Simplex neighborOpposite(Object vertex, Simplex simplex)
{
if (!simplex.contains(vertex))
throw new InvalidOperationException("Bad vertex; not in simplex");
for (Iterator it = ((Set)_neighbors.get(simplex)).iterator(); it.hasNext(); )
{
Simplex s = (Simplex)it.next();
for (Iterator otherIt = simplex.iterator(); otherIt.hasNext(); )
{
var v = otherIt.next();
if (v.Equals(vertex)) continue;
if (!s.contains(v))
{
s = null;
break;
}
}
if (s == null)
continue;
return s;
}
return null;
}
/**
* True iff simplices are neighbors.
* Two simplices are neighbors if they are the same dimension and they share
* a facet.
* @param simplex the other Simplex
* @return true iff this Simplex is a neighbor of simplex
*/
public bool isNeighbor(Simplex simplex)
{
HashSet h = new HashSet(this);
h.removeAll(simplex);
return (this.size() == simplex.size()) && (h.size() == 1);
}
/**
* True iff the simplex is in this Triangulation.
* @param simplex the simplex to check
* @return true iff the simplex is in this Triangulation
*/
public bool contains(Simplex simplex)
{
return this._neighbors.containsKey(simplex);
}
private HashMap _neighbors; // Maps Simplex to Set of neighbors
/**
* Constructor.
* @param simplex the initial Simplex.
*/
public Triangulation(Simplex simplex)
{
this._neighbors = new HashMap();
this._neighbors.put(simplex, new HashSet());
}
/**
* Report neighbors of the given simplex.
* @param simplex a Simplex
* @return the Set of neighbors of simplex
*/
public Set neighbors(Simplex simplex)
{
return new HashSet((Set)this._neighbors.get(simplex));
}
/**
* 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);
}
public bool debug = false; // Used for debugging
/**
* Constructor.
* All sites must fall within the initial triangle.
* @param triangle the initial triangle
*/
public DelaunayTriangulation(Simplex triangle) : base(triangle)
{
mostRecent = triangle;
}
