/// <summary>
/// BufferSubgraphs are compared on the x-value of their rightmost Coordinate.
/// This defines a partial ordering on the graphs such that:
/// g1 >= g2 - Ring(g2) does not contain Ring(g1)
/// where Polygon(g) is the buffer polygon that is built from g.
/// This relationship is used to sort the BufferSubgraphs so that shells are guaranteed to
/// be built before holes.
/// </summary>
public int CompareTo(Object o)
{
BufferSubgraph graph = (BufferSubgraph)o;
if (RightMostCoordinate.X < graph.RightMostCoordinate.X)
{
return(-1);
}
if (RightMostCoordinate.X > graph.RightMostCoordinate.X)
{
return(1);
}
return(0);
}
private static IEnumerable<BufferSubgraph> CreateSubgraphs(PlanarGraph graph)
{
var subgraphList = new List<BufferSubgraph>();
foreach (Node node in graph.Nodes)
{
if (!node.IsVisited)
{
var subgraph = new BufferSubgraph();
subgraph.Create(node);
subgraphList.Add(subgraph);
}
}
/*
* Sort the subgraphs in descending order of their rightmost coordinate.
* This ensures that when the Polygons for the subgraphs are built,
* subgraphs for shells will have been built before the subgraphs for
* any holes they contain.
*/
subgraphList.Sort();
subgraphList.Reverse();
return subgraphList;
}
