/// <summary>
/// Updates the label of a node to BOUNDARY,
/// obeying the mod-2 boundaryDetermination rule.
/// </summary>
/// <param name="argIndex"></param>
public void SetLabelBoundary(int argIndex)
{
if (Label == null)
{
return;
}
// determine the current location for the point (if any)
Location loc = Location.Null;
if (Label != null)
{
loc = Label.GetLocation(argIndex);
}
// flip the loc
Location newLoc;
switch (loc)
{
case Location.Boundary:
newLoc = Location.Interior;
break;
case Location.Interior:
newLoc = Location.Boundary;
break;
default:
newLoc = Location.Boundary;
break;
}
Label.SetLocation(argIndex, newLoc);
}
/// <summary>
/// Converts a Label to a Line label (that is, one with no side Location).
/// </summary>
/// <param name="label">Label to convert.</param>
/// <returns>Label as Line label.</returns>
public static Label ToLineLabel(Label label)
{
Label lineLabel = new Label(Location.Null);
for (int i = 0; i < 2; i++)
{
lineLabel.SetLocation(i, label.GetLocation(i));
}
return(lineLabel);
}
/// <summary>
///
/// </summary>
/// <param name="argIndex"></param>
/// <param name="onLocation"></param>
public void SetLabel(int argIndex, Location onLocation)
{
if (Label == null)
{
Label = new Label(argIndex, onLocation);
}
else
{
Label.SetLocation(argIndex, onLocation);
}
}
/// <summary>
/// To merge labels for two nodes,
/// the merged location for each LabelElement is computed.
/// The location for the corresponding node LabelElement is set to the result,
/// as long as the location is non-null.
/// </summary>
/// <param name="label2"></param>
public void MergeLabel(Label label2)
{
for (int i = 0; i < 2; i++)
{
Location loc = ComputeMergedLocation(label2, i);
Location thisLoc = Label.GetLocation(i);
if (thisLoc == Location.Null)
{
Label.SetLocation(i, loc);
}
}
}
/// <summary>
///
/// </summary>
/// <param name="argIndex"></param>
/// <param name="coord"></param>
/// <param name="onLocation"></param>
private void InsertPoint(int argIndex, Coordinate coord, Location onLocation)
{
Node n = NodeMap.AddNode(coord);
Label lbl = n.Label;
if (lbl == null)
{
n.Label = new Label(argIndex, onLocation);
}
else
{
lbl.SetLocation(argIndex, onLocation);
}
}
/// <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)
{
Location loc = deLabel.GetLocation(geomIndex, Positions.Right);
// no information to be had from this label
if (loc == Location.Null)
{
return;
}
// if there is no current RHS value, set it
if (_label.GetLocation(geomIndex) == Location.Null)
{
_label.SetLocation(geomIndex, loc);
return;
}
}
/// <summary>
/// Adds candidate boundary points using the current <see cref="IBoundaryNodeRule"/>.
/// This is used to add the boundary
/// points of dim-1 geometries (Curves/MultiCurves).
/// </summary>
/// <param name="argIndex"></param>
/// <param name="coord"></param>
private void InsertBoundaryPoint(int argIndex, Coordinate coord)
{
var n = NodeMap.AddNode(coord);
// nodes always have labels
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)
//Location loc = Location.Null;
var loc = lbl.GetLocation(argIndex, Positions.On);
if (loc == Location.Boundary)
{
boundaryCount++;
}
// determine the boundary status of the point according to the Boundary Determination Rule
Location newLoc = DetermineBoundary(_boundaryNodeRule, 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(Location.Null);
IEnumerator <EdgeEnd> it = GetEnumerator();
while (it.MoveNext())
{
EdgeEnd ee = it.Current;
Edge e = ee.Edge;
Label eLabel = e.Label;
for (int i = 0; i < 2; i++)
{
Location eLoc = eLabel.GetLocation(i);
if (eLoc == Location.Interior || eLoc == Location.Boundary)
{
_label.SetLocation(i, Location.Interior);
}
}
}
}
/// <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
Location startLoc = Location.Null;
// initialize loc to location of last Curve side (if any)
foreach (EdgeEnd e in Edges)
{
Label label = e.Label;
if (label.IsArea(geomIndex) && label.GetLocation(geomIndex, Positions.Left) != Location.Null)
{
startLoc = label.GetLocation(geomIndex, Positions.Left);
}
}
// no labelled sides found, so no labels to propagate
if (startLoc == Location.Null)
{
return;
}
Location currLoc = startLoc;
foreach (EdgeEnd e in Edges)
{
Label label = e.Label;
// set null On values to be in current location
if (label.GetLocation(geomIndex, Positions.On) == Location.Null)
{
label.SetLocation(geomIndex, Positions.On, currLoc);
}
// set side labels (if any)
if (label.IsArea(geomIndex))
{
Location leftLoc = label.GetLocation(geomIndex, Positions.Left);
Location rightLoc = label.GetLocation(geomIndex, Positions.Right);
// if there is a right location, that is the next location to propagate
if (rightLoc != Location.Null)
{
if (rightLoc != currLoc)
{
throw new TopologyException("side location conflict", e.Coordinate);
}
if (leftLoc == Location.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) == Location.Null, "found single null side");
label.SetLocation(geomIndex, Positions.Right, currLoc);
label.SetLocation(geomIndex, Positions.Left, currLoc);
}
}
}
}
