/// <summary>
/// Collect all the points from the DirectedEdges of this ring into a contiguous list.
/// </summary>
/// <param name="start"></param>
protected void ComputePoints(DirectedEdge start)
{
startDe = start;
DirectedEdge de = start;
bool isFirstEdge = true;
do
{
if (de == null)
{
throw new TopologyException("found null Directed Edge");
}
if (de.EdgeRing == this)
{
throw new TopologyException("Directed Edge visited twice during ring-building at " + de.Coordinate);
}
_edges.Add(de);
Label label = de.Label;
Assert.IsTrue(label.IsArea());
MergeLabel(label);
AddPoints(de.Edge, de.IsForward, isFirstEdge);
isFirstEdge = false;
SetEdgeRing(de, this);
de = GetNext(de);
}while (de != startDe);
}
/// <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<EdgeEnd> 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 = edges[lastEdgeIndex].Label;
Location startLoc = startLabel.GetLocation(geomIndex, Positions.Left);
Assert.IsTrue(startLoc != Location.Null, "Found unlabelled area edge");
Location currLoc = startLoc;
foreach (EdgeEnd e in Edges)
{
Label label = e.Label;
// we assume that we are only checking a area
Assert.IsTrue(label.IsArea(geomIndex), "Found non-area edge");
Location leftLoc = label.GetLocation(geomIndex, Positions.Left);
Location 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, Geometries.Position.On), label.GetLocation(1, Geometries.Position.On), Dimension.Curve);
if (label.IsArea())
{
im.SetAtLeastIfValid(label.GetLocation(0, Geometries.Position.Left), label.GetLocation(1, Geometries.Position.Left), Dimension.Surface);
im.SetAtLeastIfValid(label.GetLocation(0, Geometries.Position.Right), label.GetLocation(1, Geometries.Position.Right), Dimension.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), Dimension.Curve);
if (label.IsArea())
{
im.SetAtLeastIfValid(label.GetLocation(0, Positions.Left), label.GetLocation(1, Positions.Left), Dimension.Surface);
im.SetAtLeastIfValid(label.GetLocation(0, Positions.Right), label.GetLocation(1, Positions.Right), Dimension.Surface);
}
}
/// <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);
}
}
}
}
