Example #1
0
    /**
     * Locate the triangle with point inside it or on its boundary.
     *
     * @param point the point to locate
     * @return the triangle that holds point; null if no such triangle
     */
    public Triangle locate(Pnt point) {
      Triangle triangle = mostRecent;
      if (!this.contains(triangle)) triangle = null;

      // Try a directed walk (this works fine in 2D, but can
      // fail in 3D)
      Set<Triangle> visited = new HashSet<Triangle>();
      while (triangle != null) {
        if (visited.contains(triangle)) { // This should
          // never
          // happen
          ; // System.out.println("Warning: Caught in a locate loop");
          break;
        }
        visited.add(triangle);
        // Corner opposite point
        Pnt corner = point.isOutside(triangle.toArray(new Pnt[0]));
        if (corner == null) return triangle;
        triangle = this.neighborOpposite(corner, triangle);
      }
      // No luck; try brute force
      ; // System.out.println("Warning: Checking all triangles for " + point);
      for (Triangle tri : this) {
        if (point.isOutside(tri.toArray(new Pnt[0])) == null) return tri;
      }
      // No such triangle
      ; // System.out.println("Warning: No triangle holds " + point);
      return null;
    }
Example #2
0
 /**
  * Determine the cavity caused by site.
  *
  * @param site the site causing the cavity
  * @param triangle the triangle containing site
  * @return set of all triangles that have site in their circumcircle
  */
 private Set<Triangle> getCavity(Pnt site, Triangle triangle) {
   Set<Triangle> encroached = new HashSet<Triangle>();
   Queue<Triangle> toBeChecked = new LinkedList<Triangle>();
   Set<Triangle> marked = new HashSet<Triangle>();
   toBeChecked.add(triangle);
   marked.add(triangle);
   while (!toBeChecked.isEmpty()) {
     triangle = toBeChecked.remove();
     if (site.vsCircumcircle(triangle.toArray(new Pnt[0])) == 1)
       continue; // Site outside triangle =>
     // triangle not in
     // cavity
     encroached.add(triangle);
     // Check the neighbors
     for (Triangle neighbor : triGraph.neighbors(triangle)) {
       if (marked.contains(neighbor)) continue;
       marked.add(neighbor);
       toBeChecked.add(neighbor);
     }
   }
   return encroached;
 }