/// <summary>
/// Initializes a new instance of the BufferOp class.
/// </summary>
/// <param name="g0"></param>
public BufferOp(Geometry g0) : base(g0)
{
_graph = new PlanarGraph(new OverlayNodeFactory());
_geomFact = new GeometryFactory( g0.PrecisionModel, g0.GetSRID() );
}
} // public PolygonBuilder( GeometryFactory geometryFactory, CGAlgorithms cga )
#endregion
#region Properties
#endregion
#region Methods
/// <summary>
/// Add a complete graph.
/// The graph is assumed to contain one or more polygons,
/// possibly with holes.
/// </summary>
/// <param name="graph"></param>
public void Add( PlanarGraph graph )
{
ArrayList nodes = new ArrayList();
foreach( DictionaryEntry entry in graph.Nodes.NodeList )
{
Node node = (Node) entry.Value;
nodes.Add( node );
}
Add( graph.EdgeEnds, nodes );
} // public void Add( PlanarGraph graph )
public OverlayOp( Geometry g0, Geometry g1 ) : base( g0, g1 )
{
_graph = new PlanarGraph( new OverlayNodeFactory() );
_geomFact = new GeometryFactory( g0.PrecisionModel, g0.GetSRID() );
} // public OverlayOp( Geometry g0, Geometry g1 ) : base( g0, g1 )
public bool IsInteriorsConnected()
{
// node the edges, in case holes touch the shell
ArrayList splitEdges = new ArrayList();
_geomGraph.ComputeSplitEdges(splitEdges);
// polygonize the edges
PlanarGraph graph = new PlanarGraph(new OverlayNodeFactory());
graph.AddEdges(splitEdges);
SetAllEdgesInResult(graph);
graph.LinkAllDirectedEdges();
ArrayList edgeRings = buildEdgeRings(graph.EdgeEnds);
/**
* Mark all the edges for the edgeRings corresponding to the shells
* of the input polygons. Note only ONE ring gets marked for each shell.
*/
VisitShellInteriors(_geomGraph.Geometry, graph);
/**
* If there are any unvisited shell edges
* (i.e. a ring which is not a hole and which has the interior
* of the parent area on the RHS)
* this means that one or more holes must have split the interior of the
* polygon into at least two pieces. The polygon is thus invalid.
*/
return ! HasUnvisitedShellEdge(edgeRings);
}
private void VisitInteriorRing(ILineString iring, PlanarGraph graph)
{
LineString ring = (LineString)iring;
Coordinates pts = ring.GetCoordinates();
Edge e = graph.FindEdgeInSameDirection(pts[0], pts[1]);
DirectedEdge de = (DirectedEdge) graph.FindEdgeEnd(e);
DirectedEdge intDe = null;
if (de.Label.GetLocation(0, Position.Right) == Location.Interior)
{
intDe = de;
}
else if (de.Sym.Label.GetLocation(0, Position.Right) == Location.Interior)
{
intDe = de.Sym;
}
//Assert.isTrue(intDe != null, "unable to find dirEdge with Interior on RHS");
VisitLinkedDirectedEdges(intDe);
}
/// <summary>
/// Mark all the edges for the edgeRings corresponding to the shells
/// of the input polygons. Note only ONE ring gets marked for each shell.
/// </summary>
/// <param name="g"></param>
/// <param name="graph"></param>
private void VisitShellInteriors(Geometry g, PlanarGraph graph)
{
if (g is Polygon)
{
Polygon p = (Polygon) g;
this.VisitInteriorRing(p.GetExteriorRing(), graph);
}
if (g is MultiPolygon)
{
MultiPolygon mp = (MultiPolygon) g;
for (int i = 0; i < mp.GetNumGeometries(); i++)
{
Polygon p = (Polygon) mp.GetGeometryN(i);
this.VisitInteriorRing(p.GetExteriorRing(), graph);
}
}
}
private void SetAllEdgesInResult(PlanarGraph graph)
{
foreach( object obj in graph.EdgeEnds)
{
DirectedEdge de = (DirectedEdge) obj;
de.InResult=true;
}
}
