/// <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 void ComputeEdgeEnds(Edge edge, IList<EdgeEnd> l)
{
EdgeIntersectionList eiList = edge.EdgeIntersectionList;
// ensure that the list has entries for the first and last point of the edge
eiList.AddEndpoints();
IEnumerator<EdgeIntersection> it = eiList.GetEnumerator();
EdgeIntersection eiPrev;
EdgeIntersection eiCurr = null;
// no intersections, so there is nothing to do
if (! it.MoveNext()) return;
EdgeIntersection eiNext = it.Current;
do
{
eiPrev = eiCurr;
eiCurr = eiNext;
eiNext = null;
if (it.MoveNext())
eiNext = it.Current;
if (eiCurr != null)
{
CreateEdgeEndForPrev(edge, l, eiCurr, eiPrev);
CreateEdgeEndForNext(edge, l, eiCurr, eiNext);
}
}
while (eiCurr != null);
}
/// <summary>
/// Insert an edge unless it is already in the list.
/// </summary>
/// <param name="e"></param>
public void Add(Edge e)
{
_edges.Add(e);
var oca = new OrientedCoordinateArray(e.Coordinates);
_ocaMap.Add(oca, e);
//_index.Insert(e.Envelope, e);
}
/// <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 void CreateEdgeEndForNext(Edge edge, IList<EdgeEnd> 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>
/// 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 void CreateEdgeEndForPrev(Edge edge, IList<EdgeEnd> 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>
///
/// </summary>
/// <param name="edge"></param>
/// <param name="isForward"></param>
/// <param name="isFirstEdge"></param>
protected void AddPoints(Edge edge, bool isForward, bool isFirstEdge)
{
Coordinate[] edgePts = edge.Coordinates;
if (isForward)
{
int startIndex = 1;
if (isFirstEdge)
startIndex = 0;
for (int i = startIndex; i < edgePts.Length; i++)
_pts.Add(edgePts[i]);
}
else
{
// is backward
int startIndex = edgePts.Length - 2;
if (isFirstEdge)
startIndex = edgePts.Length - 1;
for (int i = startIndex; i >= 0; i--)
_pts.Add(edgePts[i]);
}
}
/// <summary>
/// Label an isolated edge of a graph with its relationship to the target point.
/// If the target has dim 2 or 1, the edge can either be in the interior or the exterior.
/// If the target has dim 0, the edge must be in the exterior.
/// </summary>
/// <param name="e"></param>
/// <param name="targetIndex"></param>
/// <param name="target"></param>
private void LabelIsolatedEdge(Edge e, int targetIndex, IGeometry target)
{
// this won't work for GeometryCollections with both dim 2 and 1 geoms
if (target.Dimension > 0)
{
// since edge is not in boundary, may not need the full generality of PointLocator?
// Possibly should use ptInArea locator instead? We probably know here
// that the edge does not touch the bdy of the target Geometry
Location loc = _ptLocator.Locate(e.Coordinate, target);
e.Label.SetAllLocations(targetIndex, loc);
}
else e.Label.SetAllLocations(targetIndex, Location.Exterior);
}
/// <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)
{
Location loc = _ptLocator.Locate(e.Coordinate, _op.GetArgGeometry(targetIndex));
e.Label.SetLocation(targetIndex, loc);
}
private readonly Edge edge; // the parent edge
/// <summary>
///
/// </summary>
/// <param name="edge"></param>
public EdgeIntersectionList(Edge edge)
{
this.edge = edge;
}
/// <summary>
///
/// </summary>
/// <param name="e"></param>
protected 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 EdgeEnd FindEdgeEnd(Edge e)
{
foreach (EdgeEnd ee in edgeEndList )
if (ee.Edge == e) return ee;
return null;
}
/// <summary>
///
/// </summary>
/// <param name="e"></param>
protected void InsertEdge(Edge e)
{
_edges.Add(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 int FindEdgeIndex(Edge e)
{
for (var i = 0; i < _edges.Count; i++)
if ((_edges[i]).Equals(e))
return i;
return -1;
}
/// <summary>
/// Remove the selected Edge element from the list if present.
/// </summary>
/// <param name="e">Edge element to remove from list</param>
public void Remove(Edge e)
{
_edges.Remove(e);
}
/// <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 Edge FindEqualEdge(Edge e)
{
var oca = new OrientedCoordinateArray(e.Coordinates);
// will return null if no edge matches
Edge matchEdge;
_ocaMap.TryGetValue(oca, out matchEdge);
return matchEdge;
}
private void ComputeNodedEdges(IList<ISegmentString> bufferSegStrList, IPrecisionModel precisionModel)
{
var noder = GetNoder(precisionModel);
noder.ComputeNodes(bufferSegStrList);
var nodedSegStrings = noder.GetNodedSubstrings();
// DEBUGGING ONLY
//BufferDebug.saveEdges(nodedEdges, "run" + BufferDebug.runCount + "_nodedEdges");
foreach (var segStr in nodedSegStrings)
{
/**
* Discard edges which have zero length,
* since they carry no information and cause problems with topology building
*/
var pts = segStr.Coordinates;
if (pts.Length == 2 && pts[0].Equals2D(pts[1]))
continue;
var oldLabel = (Label)segStr.Context;
var edge = new Edge(segStr.Coordinates, new Label(oldLabel));
InsertUniqueEdge(edge);
}
//saveEdges(edgeList.getEdges(), "run" + runCount + "_collapsedEdges");
}
/// <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>
protected void InsertUniqueEdge(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);
}
}