/// <summary>
/// Compute the change in depth as an edge is crossed from R to L.
/// </summary>
/// <param name="label"></param>
private static int DepthDelta(Label label)
{
Locations lLoc = label.GetLocation(0, Positions.Left);
Locations rLoc = label.GetLocation(0, Positions.Right);
if (lLoc == Locations.Interior && rLoc == Locations.Exterior)
return 1;
else if (lLoc == Locations.Exterior && rLoc == Locations.Interior)
return -1;
return 0;
}
/// <summary>
/// Update incomplete dirEdge labels from the labelling for the node.
/// </summary>
/// <param name="nodeLabel"></param>
public void UpdateLabelling(Label nodeLabel)
{
for (IEnumerator it = GetEnumerator(); it.MoveNext();)
{
DirectedEdge de = (DirectedEdge)it.Current;
Label label = de.Label;
label.SetAllLocationsIfNull(0, nodeLabel.GetLocation(0));
label.SetAllLocationsIfNull(1, nodeLabel.GetLocation(1));
}
}
/// <summary>
/// Converts a Label to a Line label (that is, one with no side Locations).
/// </summary>
/// <param name="label">Label to convert.</param>
/// <returns>Label as Line label.</returns>
public static Label ToLineLabel(Label label)
{
Label lineLabel = new Label(Locations.Null);
for (int i = 0; i < 2; i++)
lineLabel.SetLocation(i, label.GetLocation(i));
return lineLabel;
}
/// <summary>
/// Converts a Label to a Line label (that is, one with no side Locations).
/// </summary>
/// <param name="label">Label to convert.</param>
/// <returns>Label as Line label.</returns>
public static Label ToLineLabel(Label label)
{
Label lineLabel = new Label(Locations.Null);
for (int i = 0; i < 2; i++)
{
lineLabel.SetLocation(i, label.GetLocation(i));
}
return(lineLabel);
}
/// <summary>
///
/// </summary>
/// <param name="geomIndex"></param>
/// <returns></returns>
private bool CheckAreaLabelsConsistent(int geomIndex)
{
// Since edges are stored in CCW order around the node,
// As we move around the ring we move from the right to the left side of the edge
IList edges = Edges;
// if no edges, trivially consistent
if (edges.Count <= 0)
{
return(true);
}
// initialize startLoc to location of last Curve side (if any)
int lastEdgeIndex = edges.Count - 1;
Label startLabel = ((EdgeEnd)edges[lastEdgeIndex]).Label;
Locations startLoc = startLabel.GetLocation(geomIndex, Positions.Left);
Assert.IsTrue(startLoc != Locations.Null, "Found unlabelled area edge");
Locations currLoc = startLoc;
for (IEnumerator it = GetEnumerator(); it.MoveNext();)
{
EdgeEnd e = (EdgeEnd)it.Current;
Label label = e.Label;
// we assume that we are only checking a area
Assert.IsTrue(label.IsArea(geomIndex), "Found non-area edge");
Locations leftLoc = label.GetLocation(geomIndex, Positions.Left);
Locations rightLoc = label.GetLocation(geomIndex, Positions.Right);
// check that edge is really a boundary between inside and outside!
if (leftLoc == rightLoc)
{
return(false);
}
// check side location conflict
if (rightLoc != currLoc)
{
return(false);
}
currLoc = leftLoc;
}
return(true);
}
/// <summary>
/// Updates an IM from the label for an edge.
/// Handles edges from both L and A geometries.
/// </summary>
/// <param name="im"></param>
/// <param name="label"></param>
public static void UpdateIM(Label label, IntersectionMatrix im)
{
im.SetAtLeastIfValid(label.GetLocation(0, Positions.On), label.GetLocation(1, Positions.On), Dimensions.Curve);
if (label.IsArea())
{
im.SetAtLeastIfValid(label.GetLocation(0, Positions.Left), label.GetLocation(1, Positions.Left), Dimensions.Surface);
im.SetAtLeastIfValid(label.GetLocation(0, Positions.Right), label.GetLocation(1, Positions.Right), Dimensions.Surface);
}
}
/// <summary>
/// Updates an IM from the label for an edge.
/// Handles edges from both L and A geometries.
/// </summary>
/// <param name="im"></param>
/// <param name="label"></param>
public static void UpdateIM(Label label, IntersectionMatrix im)
{
im.SetAtLeastIfValid(label.GetLocation(0, Positions.On), label.GetLocation(1, Positions.On), Dimensions.Curve);
if (label.IsArea())
{
im.SetAtLeastIfValid(label.GetLocation(0, Positions.Left), label.GetLocation(1, Positions.Left), Dimensions.Surface);
im.SetAtLeastIfValid(label.GetLocation(0, Positions.Right), label.GetLocation(1, Positions.Right), Dimensions.Surface);
}
}
/// <summary>
/// The location for a given eltIndex for a node will be one
/// of { Null, Interior, Boundary }.
/// A node may be on both the boundary and the interior of a point;
/// in this case, the rule is that the node is considered to be in the boundary.
/// The merged location is the maximum of the two input values.
/// </summary>
/// <param name="label2"></param>
/// <param name="eltIndex"></param>
public Locations ComputeMergedLocation(Label label2, int eltIndex)
{
Locations loc = Locations.Null;
loc = label.GetLocation(eltIndex);
if (!label2.IsNull(eltIndex))
{
Locations nLoc = label2.GetLocation(eltIndex);
if (loc != Locations.Boundary)
{
loc = nLoc;
}
}
return(loc);
}
/// <summary>
/// Merge the RHS label from a DirectedEdge into the label for this EdgeRing.
/// The DirectedEdge label may be null. This is acceptable - it results
/// from a node which is NOT an intersection node between the Geometries
/// (e.g. the end node of a LinearRing). In this case the DirectedEdge label
/// does not contribute any information to the overall labelling, and is simply skipped.
/// </summary>
/// <param name="deLabel"></param>
/// <param name="geomIndex"></param>
protected void MergeLabel(Label deLabel, int geomIndex)
{
Locations loc = deLabel.GetLocation(geomIndex, Positions.Right);
// no information to be had from this label
if (loc == Locations.Null)
{
return;
}
// if there is no current RHS value, set it
if (label.GetLocation(geomIndex) == Locations.Null)
{
label.SetLocation(geomIndex, loc);
return;
}
}
/// <summary>
///
/// </summary>
/// <param name="geomIndex"></param>
/// <param name="coord"></param>
/// <returns></returns>
public bool IsBoundaryNode(int geomIndex, ICoordinate coord)
{
Node node = nodes.Find(coord);
if (node == null)
{
return(false);
}
Label label = node.Label;
if (label != null && label.GetLocation(geomIndex) == Locations.Boundary)
{
return(true);
}
return(false);
}
/// <summary>
///
/// </summary>
/// <param name="lbl"></param>
public void Add(Label lbl)
{
for (int i = 0; i < 2; i++)
{
for (int j = 1; j < 3; j++)
{
Locations loc = lbl.GetLocation(i, (Positions)j);
if (loc == Locations.Exterior || loc == Locations.Interior)
{
// initialize depth if it is null, otherwise add this location value
if (IsNull(i, (Positions)j))
{
depth[i, j] = DepthAtLocation(loc);
}
else
{
depth[i, j] += DepthAtLocation(loc);
}
}
}
}
}
/// <summary>
/// Adds points using the mod-2 rule of SFS. This is used to add the boundary
/// points of dim-1 geometries (Curves/MultiCurves). According to the SFS,
/// an endpoint of a Curve is on the boundary
/// if it is in the boundaries of an odd number of Geometries.
/// </summary>
/// <param name="argIndex"></param>
/// <param name="coord"></param>
private void InsertBoundaryPoint(int argIndex, ICoordinate coord)
{
Node n = nodes.AddNode(coord);
Label lbl = n.Label;
// the new point to insert is on a boundary
int boundaryCount = 1;
// determine the current location for the point (if any)
Locations loc = Locations.Null;
if (lbl != null)
{
loc = lbl.GetLocation(argIndex, Positions.On);
}
if (loc == Locations.Boundary)
{
boundaryCount++;
}
// determine the boundary status of the point according to the Boundary Determination Rule
Locations newLoc = DetermineBoundary(boundaryCount);
lbl.SetLocation(argIndex, newLoc);
}
/// <summary>
/// Compute the labelling for all dirEdges in this star, as well
/// as the overall labelling.
/// </summary>
/// <param name="geom"></param>
public override void ComputeLabelling(GeometryGraph[] geom)
{
base.ComputeLabelling(geom);
// determine the overall labelling for this DirectedEdgeStar
// (i.e. for the node it is based at)
label = new Label(Locations.Null);
IEnumerator it = GetEnumerator();
while (it.MoveNext())
{
EdgeEnd ee = (EdgeEnd)it.Current;
Edge e = ee.Edge;
Label eLabel = e.Label;
for (int i = 0; i < 2; i++)
{
Locations eLoc = eLabel.GetLocation(i);
if (eLoc == Locations.Interior || eLoc == Locations.Boundary)
{
label.SetLocation(i, Locations.Interior);
}
}
}
}
/// <summary>
/// Merge the RHS label from a DirectedEdge into the label for this EdgeRing.
/// The DirectedEdge label may be null. This is acceptable - it results
/// from a node which is NOT an intersection node between the Geometries
/// (e.g. the end node of a LinearRing). In this case the DirectedEdge label
/// does not contribute any information to the overall labelling, and is simply skipped.
/// </summary>
/// <param name="deLabel"></param>
/// <param name="geomIndex"></param>
protected void MergeLabel(Label deLabel, int geomIndex)
{
Locations loc = deLabel.GetLocation(geomIndex, Positions.Right);
// no information to be had from this label
if (loc == Locations.Null)
return;
// if there is no current RHS value, set it
if (label.GetLocation(geomIndex) == Locations.Null)
{
label.SetLocation(geomIndex, loc);
return;
}
}
/// <summary>
///
/// </summary>
/// <param name="geom"></param>
public virtual void ComputeLabelling(GeometryGraph[] geom)
{
ComputeEdgeEndLabels();
// Propagate side labels around the edges in the star
// for each parent Geometry
PropagateSideLabels(0);
PropagateSideLabels(1);
/*
* If there are edges that still have null labels for a point
* this must be because there are no area edges for that point incident on this node.
* In this case, to label the edge for that point we must test whether the
* edge is in the interior of the point.
* To do this it suffices to determine whether the node for the edge is in the interior of an area.
* If so, the edge has location Interior for the point.
* In all other cases (e.g. the node is on a line, on a point, or not on the point at all) the edge
* has the location Exterior for the point.
*
* Note that the edge cannot be on the Boundary of the point, since then
* there would have been a parallel edge from the Geometry at this node also labelled Boundary
* and this edge would have been labelled in the previous step.
*
* This code causes a problem when dimensional collapses are present, since it may try and
* determine the location of a node where a dimensional collapse has occurred.
* The point should be considered to be on the Exterior
* of the polygon, but locate() will return Interior, since it is passed
* the original Geometry, not the collapsed version.
*
* If there are incident edges which are Line edges labelled Boundary,
* then they must be edges resulting from dimensional collapses.
* In this case the other edges can be labelled Exterior for this Geometry.
*
* MD 8/11/01 - NOT True! The collapsed edges may in fact be in the interior of the Geometry,
* which means the other edges should be labelled Interior for this Geometry.
* Not sure how solve this... Possibly labelling needs to be split into several phases:
* area label propagation, symLabel merging, then finally null label resolution.
*/
bool[] hasDimensionalCollapseEdge = { false, false };
for (IEnumerator it = GetEnumerator(); it.MoveNext();)
{
EdgeEnd e = (EdgeEnd)it.Current;
Label label = e.Label;
for (int geomi = 0; geomi < 2; geomi++)
{
if (label.IsLine(geomi) && label.GetLocation(geomi) == Locations.Boundary)
{
hasDimensionalCollapseEdge[geomi] = true;
}
}
}
for (IEnumerator it = GetEnumerator(); it.MoveNext();)
{
EdgeEnd e = (EdgeEnd)it.Current;
Label label = e.Label;
for (int geomi = 0; geomi < 2; geomi++)
{
if (label.IsAnyNull(geomi))
{
Locations loc = Locations.Null;
if (hasDimensionalCollapseEdge[geomi])
{
loc = Locations.Exterior;
}
else
{
ICoordinate p = e.Coordinate;
loc = GetLocation(geomi, p, geom);
}
label.SetAllLocationsIfNull(geomi, loc);
}
}
}
}
/// <summary>
/// Update incomplete dirEdge labels from the labelling for the node.
/// </summary>
/// <param name="nodeLabel"></param>
public void UpdateLabelling(Label nodeLabel)
{
for (IEnumerator it = GetEnumerator(); it.MoveNext(); )
{
DirectedEdge de = (DirectedEdge)it.Current;
Label label = de.Label;
label.SetAllLocationsIfNull(0, nodeLabel.GetLocation(0));
label.SetAllLocationsIfNull(1, nodeLabel.GetLocation(1));
}
}
/// <summary>
///
/// </summary>
/// <param name="label"></param>
/// <param name="opCode"></param>
/// <returns></returns>
public static bool IsResultOfOp(Label label, SpatialFunctions opCode)
{
Locations loc0 = label.GetLocation(0);
Locations loc1 = label.GetLocation(1);
return IsResultOfOp(loc0, loc1, opCode);
}
/// <summary>
///
/// </summary>
/// <param name="geomIndex"></param>
public void PropagateSideLabels(int geomIndex)
{
// Since edges are stored in CCW order around the node,
// As we move around the ring we move from the right to the left side of the edge
Locations startLoc = Locations.Null;
// initialize loc to location of last Curve side (if any)
for (IEnumerator it = GetEnumerator(); it.MoveNext();)
{
EdgeEnd e = (EdgeEnd)it.Current;
Label label = e.Label;
if (label.IsArea(geomIndex) && label.GetLocation(geomIndex, Positions.Left) != Locations.Null)
{
startLoc = label.GetLocation(geomIndex, Positions.Left);
}
}
// no labelled sides found, so no labels to propagate
if (startLoc == Locations.Null)
{
return;
}
Locations currLoc = startLoc;
for (IEnumerator it = GetEnumerator(); it.MoveNext();)
{
EdgeEnd e = (EdgeEnd)it.Current;
Label label = e.Label;
// set null On values to be in current location
if (label.GetLocation(geomIndex, Positions.On) == Locations.Null)
{
label.SetLocation(geomIndex, Positions.On, currLoc);
}
// set side labels (if any)
if (label.IsArea(geomIndex))
{
Locations leftLoc = label.GetLocation(geomIndex, Positions.Left);
Locations rightLoc = label.GetLocation(geomIndex, Positions.Right);
// if there is a right location, that is the next location to propagate
if (rightLoc != Locations.Null)
{
if (rightLoc != currLoc)
{
throw new TopologyException("side location conflict", e.Coordinate);
}
if (leftLoc == Locations.Null)
{
Assert.ShouldNeverReachHere("found single null side (at " + e.Coordinate + ")");
}
currLoc = leftLoc;
}
else
{
/* RHS is null - LHS must be null too.
* This must be an edge from the other point, which has no location
* labelling for this point. This edge must lie wholly inside or outside
* the other point (which is determined by the current location).
* Assign both sides to be the current location.
*/
Assert.IsTrue(label.GetLocation(geomIndex, Positions.Left) == Locations.Null, "found single null side");
label.SetLocation(geomIndex, Positions.Right, currLoc);
label.SetLocation(geomIndex, Positions.Left, currLoc);
}
}
}
}
/// <summary>
///
/// </summary>
/// <param name="lbl"></param>
public void Add(Label lbl)
{
for (int i = 0; i < 2; i++)
{
for (int j = 1; j < 3; j++)
{
Locations loc = lbl.GetLocation(i, (Positions)j);
if (loc == Locations.Exterior || loc == Locations.Interior)
{
// initialize depth if it is null, otherwise add this location value
if (IsNull(i, (Positions)j))
depth[i,j] = DepthAtLocation(loc);
else depth[i,j] += DepthAtLocation(loc);
}
}
}
}
/// <summary>
/// The location for a given eltIndex for a node will be one
/// of { Null, Interior, Boundary }.
/// A node may be on both the boundary and the interior of a point;
/// in this case, the rule is that the node is considered to be in the boundary.
/// The merged location is the maximum of the two input values.
/// </summary>
/// <param name="label2"></param>
/// <param name="eltIndex"></param>
public Locations ComputeMergedLocation(Label label2, int eltIndex)
{
Locations loc = Locations.Null;
loc = label.GetLocation(eltIndex);
if (!label2.IsNull(eltIndex))
{
Locations nLoc = label2.GetLocation(eltIndex);
if (loc != Locations.Boundary)
loc = nLoc;
}
return loc;
}