/// <summary>
/// Adds an <see cref="Edge" /> to the subgraph.
/// The associated <see cref="DirectedEdge" />s and <see cref="Node" />s are also added.
/// </summary>
/// <param name="e">The <see cref="Edge" /> to add.</param>
public void Add(Edge e)
{
if (edges.Contains(e))
return;
edges.Add(e);
dirEdges.Add(e.GetDirEdge(0));
dirEdges.Add(e.GetDirEdge(1));
nodeMap.Add(e.GetDirEdge(0).FromNode);
nodeMap.Add(e.GetDirEdge(1).FromNode);
}
/// <summary>
/// Returns the zero-based index of the given Edge, after sorting in ascending order
/// by angle with the positive x-axis.
/// </summary>
/// <param name="edge"></param>
/// <returns></returns>
public int GetIndex(Edge edge)
{
return deStar.GetIndex(edge);
}
/// <summary>
/// Adds the Edge and its DirectedEdges with this PlanarGraph.
/// Assumes that the Edge has already been created with its associated DirectEdges.
/// Only subclasses can add Edges, to ensure the edges added are of the right class.
/// </summary>
/// <param name="edge"></param>
protected void Add(Edge edge)
{
_edges.Add(edge);
Add(edge.GetDirEdge(0));
Add(edge.GetDirEdge(1));
}
/// <summary>
/// Removes an Edge and its associated DirectedEdges from their from-Nodes and
/// from this PlanarGraph. Note: This method does not remove the Nodes associated
/// with the Edge, even if the removal of the Edge reduces the degree of a
/// Node to zero.
/// </summary>
/// <param name="edge"></param>
public void Remove(Edge edge)
{
Remove(edge.GetDirEdge(0));
Remove(edge.GetDirEdge(1));
_edges.Remove(edge);
edge.Remove();
}
/// <summary>
/// Returns the zero-based index of the given Edge, after sorting in ascending order
/// by angle with the positive x-axis.
/// </summary>
/// <param name="edge"></param>
/// <returns></returns>
public int GetIndex(Edge edge)
{
SortEdges();
for (int i = 0; i < _outEdges.Count; i++)
{
DirectedEdge de = _outEdges[i];
if (de.Edge == edge)
return i;
}
return -1;
}
/// <summary>
/// Tests whether an <see cref="Edge" /> is contained in this subgraph.
/// </summary>
/// <param name="e">The <see cref="Edge" /> to test.</param>
/// <returns><c>true</c> if the <see cref="Edge" /> is contained in this subgraph.</returns>
public bool Contains(Edge e)
{
return edges.Contains(e);
}