/// <summary>
/// Creates stub edges for all the intersections in this
/// Edge (if any) and inserts them into the graph.
/// </summary>
/// <param name="edge"></param>
/// <param name="l"></param>
public virtual void ComputeEdgeEnds(Edge edge, IList l)
{
EdgeIntersectionList eiList = edge.EdgeIntersectionList;
// ensure that the list has entries for the first and last point of the edge
eiList.AddEndpoints();
IEnumerator it = eiList.GetEnumerator();
EdgeIntersection eiCurr = null;
// no intersections, so there is nothing to do
if (!it.MoveNext()) return;
EdgeIntersection eiNext = (EdgeIntersection)it.Current;
do
{
EdgeIntersection eiPrev = eiCurr;
eiCurr = eiNext;
eiNext = null;
if (it.MoveNext())
eiNext = (EdgeIntersection)it.Current;
if (eiCurr != null)
{
CreateEdgeEndForPrev(edge, l, eiCurr, eiPrev);
CreateEdgeEndForNext(edge, l, eiCurr, eiNext);
}
}
while (eiCurr != null);
}
private DirectedEdge _sym; // the symmetric edge
#endregion
#region Constructors
/// <summary>
/// Creates a new instance of a directed edge
/// </summary>
/// <param name="inEdge">The edge to use in order to create a directed edge</param>
/// <param name="inIsForward">A boolean that forces whether or not this edge is counted as forward</param>
public DirectedEdge(Edge inEdge, bool inIsForward)
: base(inEdge)
{
_isForward = inIsForward;
if (_isForward)
base.Init(inEdge.GetCoordinate(0), inEdge.GetCoordinate(1));
else
{
int n = inEdge.NumPoints - 1;
base.Init(inEdge.GetCoordinate(n), inEdge.GetCoordinate(n - 1));
}
ComputeDirectedLabel();
}
/// <summary>
///
/// </summary>
/// <param name="edge"></param>
/// <param name="isForward"></param>
/// <param name="isFirstEdge"></param>
protected virtual void AddPoints(Edge edge, bool isForward, bool isFirstEdge)
{
IList<Coordinate> edgePts = edge.Coordinates;
if (isForward)
{
int startIndex = 1;
if (isFirstEdge)
startIndex = 0;
for (int i = startIndex; i < edgePts.Count; i++)
_pts.Add(edgePts[i]);
}
else
{
// is backward
int startIndex = edgePts.Count - 2;
if (isFirstEdge)
startIndex = edgePts.Count - 1;
for (int i = startIndex; i >= 0; i--)
_pts.Add(edgePts[i]);
}
}
/// <summary>
///
/// </summary>
/// <param name="edge"></param>
public EdgeIntersectionList(Edge edge)
{
_edge = edge;
}
/// <summary>
/// Adds a new EdgeEnd to the planar graph
/// </summary>
/// <param name="e"></param>
protected virtual void InsertEdge(Edge e)
{
_edges.Add(e);
}
/// <summary>
/// Returns the EdgeEnd which has edge e as its base edge
/// (MD 18 Feb 2002 - this should return a pair of edges).
/// </summary>
/// <param name="e"></param>
/// <returns> The edge, if found <c>null</c> if the edge was not found.</returns>
public virtual EdgeEnd FindEdgeEnd(Edge e)
{
for (IEnumerator i = EdgeEnds.GetEnumerator(); i.MoveNext(); )
{
EdgeEnd ee = (EdgeEnd)i.Current;
if (ee.Edge == e)
return ee;
}
return null;
}
/// <summary>
/// Add an Edge computed externally. The label on the Edge is assumed
/// to be correct.
/// </summary>
/// <param name="e"></param>
public virtual void AddEdge(Edge e)
{
InsertEdge(e);
IList<Coordinate> coord = e.Coordinates;
// insert the endpoint as a node, to mark that it is on the boundary
InsertPoint(_argIndex, coord[0], LocationType.Boundary);
InsertPoint(_argIndex, coord[coord.Count - 1], LocationType.Boundary);
}
/// <summary>
/// Label an isolated node with its relationship to the target point.
/// </summary>
/// <param name="e"></param>
/// <param name="targetIndex"></param>
private void LabelIsolatedLine(Edge e, int targetIndex)
{
LocationType loc = _ptLocator.Locate(e.Coordinate, _op.GetArgGeometry(targetIndex));
e.Label.SetLocation(targetIndex, loc);
}
/// <summary>
/// Insert an edge unless it is already in the list.
/// </summary>
/// <param name="e"></param>
public virtual void Add(Edge e)
{
_edges.Add(e);
_index.Insert(e.Envelope, e);
}
/// <summary>
/// Remove the selected Edge element from the list if present.
/// </summary>
/// <param name="e">Edge element to remove from list</param>
public virtual void Remove(Edge e)
{
_edges.Remove(e);
}
/// <summary>
/// If the edge e is already in the list, return its index.
/// </summary>
/// <param name="e"></param>
/// <returns>
/// Index, if e is already in the list,
/// -1 otherwise.
/// </returns>
public virtual int FindEdgeIndex(Edge e)
{
for (int i = 0; i < _edges.Count; i++)
if (_edges[i].Equals(e))
return i;
return -1;
}
// <FIX> fast lookup for edges
/// <summary>
/// If there is an edge equal to e already in the list, return it.
/// Otherwise return null.
/// </summary>
/// <param name="e"></param>
/// <returns>
/// equal edge, if there is one already in the list,
/// null otherwise.
/// </returns>
public virtual Edge FindEqualEdge(Edge e)
{
ICollection testEdges = _index.Query(e.Envelope);
for (IEnumerator i = testEdges.GetEnumerator(); i.MoveNext(); )
{
Edge testEdge = (Edge)i.Current;
if (testEdge.Equals(e))
return testEdge;
}
return null;
}
/// <summary>
/// Inserted edges are checked to see if an identical edge already exists.
/// If so, the edge is not inserted, but its label is merged
/// with the existing edge.
/// </summary>
/// <param name="e"></param>
protected void InsertEdge(Edge e)
{
//<FIX> MD 8 Oct 03 speed up identical edge lookup
// fast lookup
Edge existingEdge = _edgeList.FindEqualEdge(e);
// If an identical edge already exists, simply update its label
if (existingEdge != null)
{
Label existingLabel = existingEdge.Label;
Label labelToMerge = e.Label;
// check if new edge is in reverse direction to existing edge
// if so, must flip the label before merging it
if (!existingEdge.IsPointwiseEqual(e))
{
labelToMerge = new Label(e.Label);
labelToMerge.Flip();
}
existingLabel.Merge(labelToMerge);
// compute new depth delta of sum of edges
int mergeDelta = DepthDelta(labelToMerge);
int existingDelta = existingEdge.DepthDelta;
int newDelta = existingDelta + mergeDelta;
existingEdge.DepthDelta = newDelta;
}
else
{ // no matching existing edge was found
// add this new edge to the list of edges in this graph
//e.setName(name + edges.size());
_edgeList.Add(e);
e.DepthDelta = DepthDelta(e.Label);
}
}
/// <summary>
///
/// </summary>
/// <param name="bufferSegStrList"></param>
/// <param name="precisionModel"></param>
private void ComputeNodedEdges(IList bufferSegStrList, PrecisionModel precisionModel)
{
INoder noder = GetNoder(precisionModel);
noder.ComputeNodes(bufferSegStrList);
IList nodedSegStrings = noder.GetNodedSubstrings();
foreach (object obj in nodedSegStrings)
{
SegmentString segStr = (SegmentString)obj;
Label oldLabel = (Label)segStr.Data;
Edge edge = new Edge(segStr.Coordinates, new Label(oldLabel));
InsertEdge(edge);
}
}
/// <summary>
/// The left and right topological location arguments assume that the ring is oriented CW.
/// If the ring is in the opposite orientation,
/// the left and right locations must be interchanged.
/// </summary>
/// <param name="lr"></param>
/// <param name="cwLeft"></param>
/// <param name="cwRight"></param>
private void AddPolygonRing(IBasicGeometry lr, LocationType cwLeft, LocationType cwRight)
{
IList<Coordinate> coord = CoordinateArrays.RemoveRepeatedPoints(lr.Coordinates);
if (coord.Count < 4)
{
_hasTooFewPoints = true;
_invalidPoint = coord[0];
return;
}
LocationType left = cwLeft;
LocationType right = cwRight;
if (CgAlgorithms.IsCounterClockwise(coord))
{
left = cwRight;
right = cwLeft;
}
Edge e = new Edge(coord, new Label(_argIndex, LocationType.Boundary, left, right));
_lineEdgeMap.Add(lr, e);
InsertEdge(e);
// insert the endpoint as a node, to mark that it is on the boundary
InsertPoint(_argIndex, coord[0], LocationType.Boundary);
}
/// <summary>
/// Create a StubEdge for the edge after the intersection eiCurr.
/// The next intersection is provided
/// in case it is the endpoint for the stub edge.
/// Otherwise, the next point from the parent edge will be the endpoint.
/// eiCurr will always be an EdgeIntersection, but eiNext may be null.
/// </summary>
/// <param name="edge"></param>
/// <param name="l"></param>
/// <param name="eiCurr"></param>
/// <param name="eiNext"></param>
public virtual void CreateEdgeEndForNext(Edge edge, IList l, EdgeIntersection eiCurr, EdgeIntersection eiNext)
{
int iNext = eiCurr.SegmentIndex + 1;
// if there is no next edge there is nothing to do
if (iNext >= edge.NumPoints && eiNext == null)
return;
Coordinate pNext = edge.GetCoordinate(iNext);
// if the next intersection is in the same segment as the current, use it as the endpoint
if (eiNext != null && eiNext.SegmentIndex == eiCurr.SegmentIndex)
pNext = eiNext.Coordinate;
EdgeEnd e = new EdgeEnd(edge, eiCurr.Coordinate, pNext, new Label(edge.Label));
l.Add(e);
}
/// <summary>
///
/// </summary>
/// <param name="line"></param>
private void AddLineString(IBasicGeometry line)
{
IList<Coordinate> coord = CoordinateArrays.RemoveRepeatedPoints(line.Coordinates);
if (coord.Count < 2)
{
_hasTooFewPoints = true;
_invalidPoint = coord[0];
return;
}
// add the edge for the LineString
// line edges do not have locations for their left and right sides
Edge e = new Edge(coord, new Label(_argIndex, LocationType.Interior));
_lineEdgeMap.Add(line, e);
InsertEdge(e);
/*
* Add the boundary points of the LineString, if any.
* Even if the LineString is closed, add both points as if they were endpoints.
* This allows for the case that the node already exists and is a boundary point.
*/
Assert.IsTrue(coord.Count >= 2, "found LineString with single point");
InsertBoundaryPoint(_argIndex, coord[0]);
InsertBoundaryPoint(_argIndex, coord[coord.Count - 1]);
}
/// <summary>
/// Create a EdgeStub for the edge before the intersection eiCurr.
/// The previous intersection is provided
/// in case it is the endpoint for the stub edge.
/// Otherwise, the previous point from the parent edge will be the endpoint.
/// eiCurr will always be an EdgeIntersection, but eiPrev may be null.
/// </summary>
/// <param name="edge"></param>
/// <param name="l"></param>
/// <param name="eiCurr"></param>
/// <param name="eiPrev"></param>
public virtual void CreateEdgeEndForPrev(Edge edge, IList l, EdgeIntersection eiCurr, EdgeIntersection eiPrev)
{
int iPrev = eiCurr.SegmentIndex;
if (eiCurr.Distance == 0.0)
{
// if at the start of the edge there is no previous edge
if (iPrev == 0)
return;
iPrev--;
}
Coordinate pPrev = edge.GetCoordinate(iPrev);
// if prev intersection is past the previous vertex, use it instead
if (eiPrev != null && eiPrev.SegmentIndex >= iPrev)
pPrev = eiPrev.Coordinate;
Label label = new Label(edge.Label);
// since edgeStub is oriented opposite to it's parent edge, have to flip sides for edge label
label.Flip();
EdgeEnd e = new EdgeEnd(edge, eiCurr.Coordinate, pPrev, label);
l.Add(e);
}
/// <summary>
/// Insert an edge from one of the noded input graphs.
/// Checks edges that are inserted to see if an
/// identical edge already exists.
/// If so, the edge is not inserted, but its label is merged
/// with the existing edge.
/// </summary>
/// <param name="e"></param>
protected virtual void InsertUniqueEdge(Edge e)
{
int foundIndex = _edgeList.FindEdgeIndex(e);
// If an identical edge already exists, simply update its label
if (foundIndex >= 0)
{
Edge existingEdge = _edgeList[foundIndex];
Label existingLabel = existingEdge.Label;
Label labelToMerge = e.Label;
// check if new edge is in reverse direction to existing edge
// if so, must flip the label before merging it
if (!existingEdge.IsPointwiseEqual(e))
{
labelToMerge = new Label(e.Label);
labelToMerge.Flip();
}
Depth depth = existingEdge.Depth;
// if this is the first duplicate found for this edge, initialize the depths
if (depth.IsNull())
depth.Add(existingLabel);
depth.Add(labelToMerge);
existingLabel.Merge(labelToMerge);
}
else
{
// no matching existing edge was found
// add this new edge to the list of edges in this graph
_edgeList.Add(e);
}
}
