/// <summary>
///
/// </summary>
/// <returns></returns>
public bool MoveNext()
{
if (currNode == null)
{
currNode = nextNode;
currSegIndex = currNode.SegmentIndex;
ReadNextNode();
return(true);
}
// check for trying to read too far
if (nextNode == null)
{
return(false);
}
if (nextNode.SegmentIndex == currNode.SegmentIndex)
{
currNode = nextNode;
currSegIndex = currNode.SegmentIndex;
ReadNextNode();
return(true);
}
if (nextNode.SegmentIndex > currNode.SegmentIndex)
{
}
return(false);
}
/// <summary>
/// Create a new "split edge" with the section of points between
/// (and including) the two intersections.
/// The label for the new edge is the same as the label for the parent edge.
/// </summary>
/// <param name="ei0"></param>
/// <param name="ei1"></param>
/// <returns></returns>
SegmentString CreateSplitEdge(SegmentNode ei0, SegmentNode ei1)
{
int npts = ei1.SegmentIndex - ei0.SegmentIndex + 2;
ICoordinate lastSegStartPt = edge.GetCoordinate(ei1.SegmentIndex);
// if the last intersection point is not equal to the its segment start pt, add it to the points list as well.
// (This check is needed because the distance metric is not totally reliable!)
// The check for point equality is 2D only - Z values are ignored
bool useIntPt1 = ei1.IsInterior || !ei1.Coordinate.Equals2D(lastSegStartPt);
if (!useIntPt1)
{
npts--;
}
ICoordinate[] pts = new ICoordinate[npts];
int ipt = 0;
pts[ipt++] = new Coordinate(ei0.Coordinate);
for (int i = ei0.SegmentIndex + 1; i <= ei1.SegmentIndex; i++)
{
pts[ipt++] = edge.GetCoordinate(i);
}
if (useIntPt1)
{
pts[ipt] = ei1.Coordinate;
}
return(new SegmentString(pts, edge.Data));
}
/// <summary>
///
/// </summary>
/// <param name="outstream"></param>
public void Write(StreamWriter outstream)
{
outstream.Write("Intersections:");
foreach (object obj in this)
{
SegmentNode ei = (SegmentNode)obj;
ei.Write(outstream);
}
}
/// <summary>
///
/// </summary>
private void ReadNextNode()
{
if (nodeIt.MoveNext())
{
nextNode = (SegmentNode)nodeIt.Current;
}
else
{
nextNode = null;
}
}
/// <summary>
/// Adds an intersection into the list, if it isn't already there.
/// The input segmentIndex and dist are expected to be normalized.
/// </summary>
/// <param name="intPt"></param>
/// <param name="segmentIndex"></param>
/// <returns>The SegmentIntersection found or added.</returns>
public SegmentNode Add(ICoordinate intPt, int segmentIndex)
{
SegmentNode eiNew = new SegmentNode(edge, intPt, segmentIndex, edge.GetSegmentOctant(segmentIndex));
SegmentNode ei = (SegmentNode) nodeMap[eiNew];
if(ei != null)
{
// debugging sanity check
Assert.IsTrue(ei.Coordinate.Equals2D(intPt), "Found equal nodes with different coordinates");
return ei;
}
// node does not exist, so create it
nodeMap.Add(eiNew, eiNew);
return eiNew;
}
/// <summary>
/// Adds an intersection into the list, if it isn't already there.
/// The input segmentIndex and dist are expected to be normalized.
/// </summary>
/// <param name="intPt"></param>
/// <param name="segmentIndex"></param>
/// <returns>The SegmentIntersection found or added.</returns>
public SegmentNode Add(ICoordinate intPt, int segmentIndex)
{
SegmentNode eiNew = new SegmentNode(edge, intPt, segmentIndex, edge.GetSegmentOctant(segmentIndex));
SegmentNode ei = (SegmentNode)nodeMap[eiNew];
if (ei != null)
{
// debugging sanity check
Assert.IsTrue(ei.Coordinate.Equals2D(intPt), "Found equal nodes with different coordinates");
return(ei);
}
// node does not exist, so create it
nodeMap.Add(eiNew, eiNew);
return(eiNew);
}
/// <summary>
/// </summary>
/// <param name="obj"></param>
/// <returns>
/// -1 this SegmentNode is located before the argument location, or
/// 0 this SegmentNode is at the argument location, or
/// 1 this SegmentNode is located after the argument location.
/// </returns>
public int CompareTo(object obj)
{
SegmentNode other = (SegmentNode)obj;
if (SegmentIndex < other.SegmentIndex)
{
return(-1);
}
if (SegmentIndex > other.SegmentIndex)
{
return(1);
}
if (Coordinate.Equals2D(other.Coordinate))
{
return(0);
}
return(SegmentPointComparator.Compare(segmentOctant, Coordinate, other.Coordinate));
}
/// <summary>
/// Creates new edges for all the edges that the intersections in this
/// list split the parent edge into.
/// Adds the edges to the provided argument list
/// (this is so a single list can be used to accumulate all split edges
/// for a set of <see cref="SegmentString" />s).
/// </summary>
/// <param name="edgeList"></param>
public void AddSplitEdges(IList edgeList)
{
// ensure that the list has entries for the first and last point of the edge
AddEndPoints();
AddCollapsedNodes();
IEnumerator ie = GetEnumerator();
ie.MoveNext();
// there should always be at least two entries in the list, since the endpoints are nodes
SegmentNode eiPrev = (SegmentNode)ie.Current;
while (ie.MoveNext())
{
SegmentNode ei = (SegmentNode)ie.Current;
SegmentString newEdge = CreateSplitEdge(eiPrev, ei);
edgeList.Add(newEdge);
eiPrev = ei;
}
}
/// <summary>
///
/// </summary>
/// <param name="ei0"></param>
/// <param name="ei1"></param>
/// <param name="collapsedVertexIndex"></param>
/// <returns></returns>
private bool FindCollapseIndex(SegmentNode ei0, SegmentNode ei1, int[] collapsedVertexIndex)
{
// only looking for equal nodes
if (!ei0.Coordinate.Equals2D(ei1.Coordinate))
{
return(false);
}
int numVerticesBetween = ei1.SegmentIndex - ei0.SegmentIndex;
if (!ei1.IsInterior)
{
numVerticesBetween--;
}
// if there is a single vertex between the two equal nodes, this is a collapse
if (numVerticesBetween == 1)
{
collapsedVertexIndex[0] = ei0.SegmentIndex + 1;
return(true);
}
return(false);
}
/// <summary>
///
/// </summary>
/// <param name="intPt"></param>
/// <param name="segmentIndex"></param>
public void AddIntersection(ICoordinate intPt, int segmentIndex)
{
int normalizedSegmentIndex = segmentIndex;
// normalize the intersection point location
int nextSegIndex = normalizedSegmentIndex + 1;
if (nextSegIndex < pts.Length)
{
ICoordinate nextPt = pts[nextSegIndex];
// Normalize segment index if intPt falls on vertex
// The check for point equality is 2D only - Z values are ignored
if (intPt.Equals2D(nextPt))
{
normalizedSegmentIndex = nextSegIndex;
}
}
// Add the intersection point to edge intersection list.
SegmentNode ei = nodeList.Add(intPt, normalizedSegmentIndex);
}
/// <summary>
/// Adds nodes for any collapsed edge pairs caused by inserted nodes
/// Collapsed edge pairs occur when the same coordinate is inserted as a node
/// both before and after an existing edge vertex.
/// To provide the correct fully noded semantics,
/// the vertex must be added as a node as well.
/// </summary>
/// <param name="collapsedVertexIndexes"></param>
private void FindCollapsesFromInsertedNodes(IList collapsedVertexIndexes)
{
int[] collapsedVertexIndex = new int[1];
IEnumerator ie = GetEnumerator();
ie.MoveNext();
// there should always be at least two entries in the list, since the endpoints are nodes
SegmentNode eiPrev = (SegmentNode)ie.Current;
while (ie.MoveNext())
{
SegmentNode ei = (SegmentNode)ie.Current;
bool isCollapsed = FindCollapseIndex(eiPrev, ei, collapsedVertexIndex);
if (isCollapsed)
{
collapsedVertexIndexes.Add(collapsedVertexIndex[0]);
}
eiPrev = ei;
}
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public bool MoveNext()
{
if (currNode == null)
{
currNode = nextNode;
currSegIndex = currNode.SegmentIndex;
ReadNextNode();
return true;
}
// check for trying to read too far
if (nextNode == null)
return false;
if (nextNode.SegmentIndex == currNode.SegmentIndex)
{
currNode = nextNode;
currSegIndex = currNode.SegmentIndex;
ReadNextNode();
return true;
}
if (nextNode.SegmentIndex > currNode.SegmentIndex)
{
}
return false;
}
/// <summary>
///
/// </summary>
private void ReadNextNode()
{
if (nodeIt.MoveNext())
nextNode = (SegmentNode) nodeIt.Current;
else nextNode = null;
}
/// <summary>
/// Create a new "split edge" with the section of points between
/// (and including) the two intersections.
/// The label for the new edge is the same as the label for the parent edge.
/// </summary>
/// <param name="ei0"></param>
/// <param name="ei1"></param>
/// <returns></returns>
SegmentString CreateSplitEdge(SegmentNode ei0, SegmentNode ei1)
{
int npts = ei1.SegmentIndex - ei0.SegmentIndex + 2;
ICoordinate lastSegStartPt = edge.GetCoordinate(ei1.SegmentIndex);
// if the last intersection point is not equal to the its segment start pt, add it to the points list as well.
// (This check is needed because the distance metric is not totally reliable!)
// The check for point equality is 2D only - Z values are ignored
bool useIntPt1 = ei1.IsInterior || !ei1.Coordinate.Equals2D(lastSegStartPt);
if(!useIntPt1)
npts--;
ICoordinate[] pts = new ICoordinate[npts];
int ipt = 0;
pts[ipt++] = new Coordinate(ei0.Coordinate);
for (int i = ei0.SegmentIndex + 1; i <= ei1.SegmentIndex; i++)
pts[ipt++] = edge.GetCoordinate(i);
if (useIntPt1)
pts[ipt] = ei1.Coordinate;
return new SegmentString(pts, edge.Data);
}
/// <summary>
///
/// </summary>
/// <param name="ei0"></param>
/// <param name="ei1"></param>
/// <param name="collapsedVertexIndex"></param>
/// <returns></returns>
private bool FindCollapseIndex(SegmentNode ei0, SegmentNode ei1, int[] collapsedVertexIndex)
{
// only looking for equal nodes
if (!ei0.Coordinate.Equals2D(ei1.Coordinate))
return false;
int numVerticesBetween = ei1.SegmentIndex - ei0.SegmentIndex;
if (!ei1.IsInterior)
numVerticesBetween--;
// if there is a single vertex between the two equal nodes, this is a collapse
if (numVerticesBetween == 1)
{
collapsedVertexIndex[0] = ei0.SegmentIndex + 1;
return true;
}
return false;
}