Esempio n. 1
0
  /** checks the combinatorial validity of the triangulation. */
  public boolean isValid() {
    boolean result = true;
    System.out.print("Checking combinatorial validity...");
    for (TriangulationDSVertex_2<X> p : this.vertices) {
      if (p == null) {
        result = false;
        System.out.println("\n vertex with null point");
      }
      if (p != null && p.getFace() == null) {
        result = false;
        System.out.println("\n vertex with null associated triangle");
      }
      if (p != null && !hasFace(p.getFace())) {
        result = false;
        System.out.println("\n vertex with non-existing associated triangle");
      }
    }
    for (TriangulationDSFace_2<X> c : this.faces) {
      if (c == null) {
        result = false;
        System.out.println("null face");
      }
      if (c != null && (c.vertex(0) == null || c.vertex(1) == null || c.vertex(2) == null)) {
        result = false;
        System.out.println("\n face with null vertex");
      }
      if (c != null
          && (!hasVertex(c.vertex(0)) || !hasVertex(c.vertex(1)) || !hasVertex(c.vertex(2)))) {
        result = false;
        System.out.println("\n face with non-existing vertex");
      }

      // check for the coherence of the 3 neighbors of a given face
      if (c != null) {
        for (int i = 0; i < 3; i++) {
          TriangulationDSFace_2<X> adjacentFace = c.neighbor(i);
          if (adjacentFace != null && adjacentFace.neighbors.contains(c) == false) {
            System.out.println("\n adjacent face error");
            result = false;
          }
        }
      }
    }
    if (result == true) System.out.println(" ok");
    else System.out.println("errors in combinatorial validity");

    return result;
  }
Esempio n. 2
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  /**
   * checks whether an edge is shared by two faces f1 and f2: the function check whether the
   * corresponding vertices appear both in f1 and f2, in the correct order. LCA: a' tester
   */
  public boolean areEqual(
      TriangulationDSFace_2<X> face1, int i1, TriangulationDSFace_2<X> face2, int i2) {
    HalfedgeHandle<X> edge1 = new HalfedgeHandle<X>(face1, i1);
    HalfedgeHandle<X> edge2 = new HalfedgeHandle<X>(face2, i2);

    TriangulationDSVertex_2<X> v1 = edge1.getVertex(0); // first vertex of edge1
    TriangulationDSVertex_2<X> v2 = edge1.getVertex(1); // second vertex of edge1

    boolean contained = edge2.hasVertex(v1);
    if (contained == false) return false;
    contained = edge2.hasVertex(v2);
    if (contained == false) return false;

    if (v1.equals(edge2.getVertex(0))) return false;

    return true;
  }
Esempio n. 3
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  /** Inserts point p in face c. Face c is split into 3 triangles. */
  public TriangulationDSVertex_2<X> insertInTriangle(X p, TriangulationDSFace_2<X> t) {
    if (t == null) throw new Error("Trying to star a null cell");
    TriangulationDSFace_2<X> f1 = t.neighbor(1);
    TriangulationDSFace_2<X> f2 = t.neighbor(2);
    TriangulationDSFace_2<X> f0 = t.neighbor(0);
    TriangulationDSVertex_2<X> v0 = t.vertex(0);
    TriangulationDSVertex_2<X> v1 = t.vertex(1);
    TriangulationDSVertex_2<X> v2 = t.vertex(2);

    // create new vertex
    TriangulationDSVertex_2<X> v = new TriangulationDSVertex_2<X>(p);
    vertices.add(v);

    // create and set two new faces
    TriangulationDSFace_2<X> newFace2 = createFace(v0, v1, v, t, null, f2);
    TriangulationDSFace_2<X> newFace1 = createFace(v0, v, v2, t, f1, newFace2);
    newFace2.setNeighbor(1, newFace1);

    // set new vertex and neighbors of old triangle
    t.setVertex(0, v);
    t.setNeighbor(1, newFace1);
    t.setNeighbor(2, newFace2);

    // set the faces incident to v and v0
    v.setFace(t);
    v0.setFace(newFace1);

    // restore the marks of the initial triangle edges
    for (int i = 0; i < 3; i++) t.unmark(i);
    if (t.neighbor(0) != null) {
      HalfedgeHandle<X> e = new HalfedgeHandle<X>(t, 0);
      e.setMark(e.getOpposite().isMarked());
    }
    if (newFace1.neighbor(1) != null) {
      HalfedgeHandle<X> e = new HalfedgeHandle<X>(newFace1, 1);
      e.setMark(e.getOpposite().isMarked());
    }
    if (newFace2.neighbor(2) != null) {
      HalfedgeHandle<X> e = new HalfedgeHandle<X>(newFace2, 2);
      e.setMark(e.getOpposite().isMarked());
    }

    // return the new vertex
    return v;
  }
Esempio n. 4
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  /** creates a triangle with vertices p1, p2, p3. */
  public TriangulationDSFace_2<X> makeTriangle(X p1, X p2, X p3) {
    TriangulationDSVertex_2<X> v1 = new TriangulationDSVertex_2<X>(p1);
    TriangulationDSVertex_2<X> v2 = new TriangulationDSVertex_2<X>(p2);
    TriangulationDSVertex_2<X> v3 = new TriangulationDSVertex_2<X>(p3);

    TriangulationDSFace_2<X> c = createFace(v1, v2, v3, null, null, null);
    v1.setFace(c);
    v2.setFace(c);
    v3.setFace(c);

    this.vertices.add(v1);
    this.vertices.add(v2);
    this.vertices.add(v3);

    return c;
  }
Esempio n. 5
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  /**
   * Create a new triangulation from the face-vertex incidence relations It takes linear space and
   * linear time.
   */
  public TriangulationDS_2(X[] points, int[][] neighbors) {

    if (points == null || neighbors == null || points[0] == null)
      throw new Error("error: null vertices or null faces");
    System.out.print("Creating triangulated 3D mesh... ");

    this.faces = new ArrayList<TriangulationDSFace_2<X>>();
    this.vertices = new ArrayList<TriangulationDSVertex_2<X>>();

    for (int i = 0; i < points.length; i++) {
      if (points[i] == null) throw new Error("null vertex error");
      TriangulationDSVertex_2<X> v = new TriangulationDSVertex_2<X>(points[i]);
      this.vertices.add(v);
    }

    // first pair (the key) represents the edges of the triangulation
    // second pair (the associated value) represents the two neighboring faces (sharing an edge)
    HashMap<Pair<Integer>, Pair<Integer>> edges = new HashMap<Pair<Integer>, Pair<Integer>>();
    for (int i = 0; i < neighbors.length; i++) {
      int i0 = neighbors[i][0], i1 = neighbors[i][1], i2 = neighbors[i][2];
      createFace(this.vertices.get(i0), vertices.get(i1), vertices.get(i2), null, null, null);

      for (int j = 0; j < 3; j++) {
        int index1 = neighbors[i][(j + 1) % 3];
        int index2 = neighbors[i][(j + 2) % 3];
        Pair<Integer> edge;
        if (index1 <= index2) edge = new Pair<Integer>(index1, index2);
        else edge = new Pair<Integer>(index2, index1);

        if (edges.containsKey(edge) == false) {
          Pair<Integer> face;
          if (index1 <= index2) face = new Pair<Integer>(i, -1);
          else face = new Pair<Integer>(-1, i);
          edges.put(edge, face);
        } else {
          Pair<Integer> face = edges.get(edge);
          if (face.getFirst() == -1) face.setFirst(i);
          else face.setSecond(i);
        }
      }
    }

    // System.out.println("setting neighboring faces");
    for (int i = 0; i < neighbors.length; i++) {
      TriangulationDSFace_2<X> currentFace = this.faces.get(i);
      for (int j = 0; j < 3; j++) {

        // setting vertex adjacent face
        TriangulationDSVertex_2<X> v = this.vertices.get(neighbors[i][j]);
        v.setFace(this.faces.get(i));

        int index1 = neighbors[i][(j + 1) % 3];
        int index2 = neighbors[i][(j + 2) % 3];
        Pair<Integer> edge;
        if (index1 <= index2) edge = new Pair<Integer>(index1, index2);
        else edge = new Pair<Integer>(index2, index1);

        if (edges.containsKey(edge) == false) throw new Error("error: edge not found");
        else {
          Pair<Integer> face = edges.get(edge);
          if (face.getFirst() == -1 && face.getSecond() == -1)
            throw new Error("error: wrong adjacent faces");
          if (face.getFirst() == -1 || face.getSecond() == -1) ; // boundary edge
          else {
            int neighborFace;
            if (index1 <= index2) neighborFace = face.getSecond();
            else neighborFace = face.getFirst();
            if (neighborFace < 0 || neighborFace >= this.faces.size())
              throw new Error("error neighbor face index");
            currentFace.setNeighbor(j, this.faces.get(neighborFace));
          }
        }
      }
    }
    System.out.println("done");
  }