Class VirtualHalfEdge2D

  extended by org.jcae.mesh.amibe.ds.AbstractHalfEdge
      extended by org.jcae.mesh.amibe.ds.VirtualHalfEdge
          extended by org.jcae.mesh.amibe.patch.VirtualHalfEdge2D

public class VirtualHalfEdge2D
extends VirtualHalfEdge

A handle to abstract edge objects for initial 2D mesh. This class implements some features which are only relevant to the initial 2D mesh. In particular, boundary edges have not yet been rebuilt, so we cannot check whether the OUTER attribute is set but need to test if vertices are equal to the infinite point instead.

Field Summary
Fields inherited from class org.jcae.mesh.amibe.ds.VirtualHalfEdge
attributes, localNumber, tri
Fields inherited from class org.jcae.mesh.amibe.ds.AbstractHalfEdge
Constructor Summary
VirtualHalfEdge2D(Triangle t, int o)
          Create an object to handle data about a triangle.
Method Summary
 int checkSmallerAndSwap(Mesh2D mesh)
 int forceBoundaryEdge(Mesh2D mesh, Vertex2D end)
          Tries to rebuild a boundary edge by swapping edges.
 boolean isDelaunay(Mesh2D mesh, Vertex2D apex2)
          Checks whether an edge is Delaunay.
 int split3(Mesh2D mesh, Vertex2D v, java.util.Set<Triangle> modifiedTriangles, boolean force)
          Splits a triangle into three new triangles by inserting a vertex.
Methods inherited from class org.jcae.mesh.amibe.ds.VirtualHalfEdge
apex, area, bind, bind, canCollapse, checkNewRingNormals, checkSwap3D, checkSwap3D, clearAttributes, collapse, computeNormal3D, computeNormal3DT, copyOTri, destination, fanIterator, getLocalNumber, getTempVector, getTri, glue, hasAttributes, hasSymmetricEdge, isMutable, next, next, nextOrigin, nextOrigin, nextOriginLoop, nextOTri, origin, prev, prev, prevOTri, pullAttributes, pushAttributes, setApex, setAttributes, setDestination, setOrigin, split, swap, sym, sym, symOTri, toString
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail


public VirtualHalfEdge2D()


public VirtualHalfEdge2D(Triangle t,
                         int o)
Create an object to handle data about a triangle.

t - geometrical triangle.
o - a number between 0 and 2 determining an edge.
Method Detail


public final int split3(Mesh2D mesh,
                        Vertex2D v,
                        java.util.Set<Triangle> modifiedTriangles,
                        boolean force)
Splits a triangle into three new triangles by inserting a vertex. Two new triangles have to be created, the last one is updated. For efficiency reasons, no checks are performed to ensure that the vertex being inserted is contained by this triangle. Once triangles are created, edges are swapped if they are not Delaunay. If edges are not swapped after vertex is inserted, the quality of newly created triangles has decreased, and the vertex is eventually not inserted unless the force argument is set to true. Origin and destination points must not be at infinite, which is the case when current triangle is returned by getSurroundingTriangle(). If apex is Mesh.outerVertex, then getSurroundingTriangle() ensures that v.onLeft(o,d) > 0.

v - vertex being inserted.
modifiedTriangles - if not null, this set of triangles is updated by adding all triangles modified during this operation.
force - if false, the vertex is inserted only if some edges were swapped after its insertion. If true, the vertex is unconditionnally inserted.
number of edges swapped during insertion. If it is 0, vertex has not been inserted.


public int checkSmallerAndSwap(Mesh2D mesh)


public final int forceBoundaryEdge(Mesh2D mesh,
                                   Vertex2D end)
Tries to rebuild a boundary edge by swapping edges. This routine is applied to an oriented triangle, its origin is an end point of the boundary edge to rebuild. The other end point is passed as an argument. Current oriented triangle has been set up by calling routine so that it is the leftmost edge standing to the right of the boundary edge. A traversal between end points is performed, and intersected edges are swapped if possible. At exit, current oriented triangle has end as its origin, and is the rightmost edge standing to the left of the inverted edge. This algorithm can then be called iteratively back and forth, and it is known that it is guaranteed to finish.

end - end point of the boundary edge.
the number of intersected edges.


public final boolean isDelaunay(Mesh2D mesh,
                                Vertex2D apex2)
Checks whether an edge is Delaunay.

apex2 - apex of the symmetric edge
true if edge is Delaunay, false otherwise.