/// <summary>
///
/// </summary>
/// <param name="g0"></param>
public GeometryGraphOperation(IGeometry g0)
{
ComputationPrecision = new PrecisionModel(g0.PrecisionModel);
Arg = new GeometryGraph[1];
Arg[0] = new GeometryGraph(0, g0);
}
/// <summary>
///
/// </summary>
/// <param name="g0"></param>
/// <param name="g1"></param>
public GeometryGraphOperation(IGeometry g0, IGeometry g1)
{
// use the most precise model for the result
ComputationPrecision = g0.PrecisionModel.CompareTo(g1.PrecisionModel) >= 0 ? new PrecisionModel(g0.PrecisionModel) : new PrecisionModel(g1.PrecisionModel);
Arg = new GeometryGraph[2];
Arg[0] = new GeometryGraph(0, g0);
Arg[1] = new GeometryGraph(1, g1);
}
/// <summary>
///
/// </summary>
/// <param name="geomGraph"></param>
public virtual void Build(GeometryGraph geomGraph)
{
// compute nodes for intersections between previously noded edges
ComputeIntersectionNodes(geomGraph, 0);
/*
* Copy the labelling for the nodes in the parent Geometry. These override
* any labels determined by intersections.
*/
CopyNodesAndLabels(geomGraph, 0);
/*
* Build EdgeEnds for all intersections.
*/
EdgeEndBuilder eeBuilder = new EdgeEndBuilder();
IList eeList = eeBuilder.ComputeEdgeEnds(geomGraph.GetEdgeEnumerator());
InsertEdgeEnds(eeList);
}
/// <summary>
/// This routine checks to see if a shell is properly contained in a hole.
/// It assumes that the edges of the shell and hole do not
/// properly intersect.
/// </summary>
/// <param name="shell"></param>
/// <param name="hole"></param>
/// <param name="graph"></param>
/// <returns>
/// <c>null</c> if the shell is properly contained, or
/// a Coordinate which is not inside the hole if it is not.
/// </returns>
private static Coordinate CheckShellInsideHole(LinearRing shell, LinearRing hole, GeometryGraph graph)
{
IList<Coordinate> shellPts = shell.Coordinates;
IList<Coordinate> holePts = hole.Coordinates;
// TODO: improve performance of this - by sorting pointlists?
Coordinate shellPt = FindPointNotNode(shellPts, hole, graph);
// if point is on shell but not hole, check that the shell is inside the hole
if (shellPt != null)
{
bool insideHole = CgAlgorithms.IsPointInRing(shellPt, holePts);
if (!insideHole) return shellPt;
}
Coordinate holePt = FindPointNotNode(holePts, shell, graph);
// if point is on hole but not shell, check that the hole is outside the shell
if (holePt != null)
{
bool insideShell = CgAlgorithms.IsPointInRing(holePt, shellPts);
return insideShell ? holePt : null;
}
throw new ShellHoleIdentityException();
}
/// <summary>
///
/// </summary>
/// <param name="graph"></param>
private void CheckConnectedInteriors(GeometryGraph graph)
{
ConnectedInteriorTester cit = new ConnectedInteriorTester(graph);
if (!cit.IsInteriorsConnected())
_validErr = new TopologyValidationError(TopologyValidationErrorType.DisconnectedInteriors, cit.Coordinate);
}
/// <summary>
///
/// </summary>
/// <param name="geom"></param>
/// <returns></returns>
private static bool IsSimpleLinearGeometry(IGeometry geom)
{
if (geom.IsEmpty)
return true;
GeometryGraph graph = new GeometryGraph(0, geom);
LineIntersector li = new RobustLineIntersector();
SegmentIntersector si = graph.ComputeSelfNodes(li, true);
// if no self-intersection, must be simple
if (!si.HasIntersection) return true;
if (si.HasProperIntersection) return false;
if (HasNonEndpointIntersection(graph)) return false;
if (HasClosedEndpointIntersection(graph)) return false;
return true;
}
/// <summary>
/// Insert nodes for all intersections on the edges of a Geometry.
/// Label the created nodes the same as the edge label if they do not already have a label.
/// This allows nodes created by either self-intersections or
/// mutual intersections to be labelled.
/// Endpoint nodes will already be labelled from when they were inserted.
/// Precondition: edge intersections have been computed.
/// </summary>
/// <param name="geomGraph"></param>
/// <param name="argIndex"></param>
public virtual void ComputeIntersectionNodes(GeometryGraph geomGraph, int argIndex)
{
for (IEnumerator edgeIt = geomGraph.GetEdgeEnumerator(); edgeIt.MoveNext(); )
{
Edge e = (Edge)edgeIt.Current;
LocationType eLoc = e.Label.GetLocation(argIndex);
for (IEnumerator eiIt = e.EdgeIntersectionList.GetEnumerator(); eiIt.MoveNext(); )
{
EdgeIntersection ei = (EdgeIntersection)eiIt.Current;
RelateNode n = (RelateNode)_nodes.AddNode(ei.Coordinate);
if (eLoc == LocationType.Boundary)
n.SetLabelBoundary(argIndex);
else if (n.Label.IsNull(argIndex))
n.SetLabel(argIndex, LocationType.Interior);
}
}
}
/// <summary>
///
/// </summary>
/// <param name="geomGraph"></param>
public ConsistentAreaTester(GeometryGraph geomGraph)
{
_geomGraph = geomGraph;
}
/// <summary>
/// Find a point from the list of testCoords
/// that is NOT a node in the edge for the list of searchCoords.
/// </summary>
/// <param name="testCoords"></param>
/// <param name="searchRing"></param>
/// <param name="graph"></param>
/// <returns>The point found, or <c>null</c> if none found.</returns>
public static Coordinate FindPointNotNode(IList<Coordinate> testCoords, ILinearRing searchRing, GeometryGraph graph)
{
// find edge corresponding to searchRing.
Edge searchEdge = graph.FindEdge(searchRing);
// find a point in the testCoords which is not a node of the searchRing
EdgeIntersectionList eiList = searchEdge.EdgeIntersectionList;
// somewhat inefficient - is there a better way? (Use a node map, for instance?)
foreach (Coordinate pt in testCoords)
if (!eiList.IsIntersection(pt))
return pt;
return null;
}
/// <summary>
///
/// </summary>
/// <param name="graph"></param>
private void CheckConsistentArea(GeometryGraph graph)
{
ConsistentAreaTester cat = new ConsistentAreaTester(graph);
bool isValidArea = cat.IsNodeConsistentArea;
if (!isValidArea)
{
_validErr = new TopologyValidationError(TopologyValidationErrorType.SelfIntersection, cat.InvalidPoint);
return;
}
if (cat.HasDuplicateRings)
{
_validErr = new TopologyValidationError(TopologyValidationErrorType.DuplicateRings, cat.InvalidPoint);
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.
*
* Notice 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) == LocationType.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))
{
LocationType loc;
if (hasDimensionalCollapseEdge[geomi])
loc = LocationType.Exterior;
else
{
Coordinate p = e.Coordinate;
loc = GetLocation(geomi, p, geom);
}
label.SetAllLocationsIfNull(geomi, loc);
}
}
}
}
/// <summary>
///
/// </summary>
/// <param name="g"></param>
private void CheckValidMultipolygon(IMultiPolygon g)
{
foreach (Polygon p in g.Geometries)
{
CheckInvalidCoordinates(p);
if (_validErr != null) return;
CheckClosedRings(p);
if (_validErr != null) return;
}
GeometryGraph graph = new GeometryGraph(0, g);
CheckTooFewPoints(graph);
if (_validErr != null) return;
CheckConsistentArea(graph);
if (_validErr != null) return;
if (!IsSelfTouchingRingFormingHoleValid)
{
CheckNoSelfIntersectingRings(graph);
if (_validErr != null) return;
}
foreach (Polygon p in g.Geometries)
{
CheckHolesInShell(p, graph);
if (_validErr != null) return;
}
foreach (Polygon p in g.Geometries)
{
CheckHolesNotNested(p, graph);
if (_validErr != null) return;
}
CheckShellsNotNested(g, graph);
if (_validErr != null) return;
CheckConnectedInteriors(graph);
}
/// <summary>
///
/// </summary>
/// <param name="graph"></param>
private void CheckTooFewPoints(GeometryGraph graph)
{
if (graph.HasTooFewPoints)
{
_validErr = new TopologyValidationError(TopologyValidationErrorType.TooFewPoints, graph.InvalidPoint);
return;
}
}
/// <summary>
/// Checks the validity of a polygon and sets the validErr flag.
/// </summary>
/// <param name="g"></param>
private void CheckValidPolygon(IPolygon g)
{
CheckClosedRings(g);
if (_validErr != null) return;
GeometryGraph graph = new GeometryGraph(0, g);
CheckConsistentArea(graph);
if (_validErr != null) return;
if (!IsSelfTouchingRingFormingHoleValid)
{
CheckNoSelfIntersectingRings(graph);
if (_validErr != null) return;
}
CheckHolesInShell(g, graph);
if (_validErr != null) return;
CheckHolesNotNested(g, graph);
if (_validErr != null) return;
CheckConnectedInteriors(graph);
}
/// <summary>
/// Checks validity of a LinearRing.
/// </summary>
/// <param name="g"></param>
private void CheckValidRing(ILinearRing g)
{
CheckClosedRing(g);
if (_validErr != null) return;
GeometryGraph graph = new GeometryGraph(0, g);
LineIntersector li = new RobustLineIntersector();
graph.ComputeSelfNodes(li, true);
CheckNoSelfIntersectingRings(graph);
}
/// <summary>
/// Checks validity of a LineString.
/// Almost anything goes for lineStrings!
/// </summary>
/// <param name="g"></param>
private void CheckValidLineString(IGeometry g)
{
GeometryGraph graph = new GeometryGraph(0, g);
CheckTooFewPoints(graph);
}
/// <summary>
///
/// </summary>
/// <param name="graph"></param>
public QuadtreeNestedRingTester(GeometryGraph graph)
{
_graph = graph;
}
/// <summary>
/// Check that there is no ring which self-intersects (except of course at its endpoints).
/// This is required by OGC topology rules (but not by other models
/// such as ESRI SDE, which allow inverted shells and exverted holes).
/// </summary>
/// <param name="graph"></param>
private void CheckNoSelfIntersectingRings(GeometryGraph graph)
{
for (IEnumerator i = graph.GetEdgeEnumerator(); i.MoveNext(); )
{
Edge e = (Edge)i.Current;
CheckNoSelfIntersectingRing(e.EdgeIntersectionList);
if (_validErr != null) return;
}
}
/// <summary>
///
/// </summary>
/// <param name="arg"></param>
public RelateComputer(GeometryGraph[] arg)
{
_arg = arg;
}
/// <summary>
///
/// </summary>
/// <param name="g"></param>
/// <param name="li"></param>
/// <param name="includeProper"></param>
/// <returns></returns>
public virtual SegmentIntersector ComputeEdgeIntersections(GeometryGraph g, LineIntersector li, bool includeProper)
{
SegmentIntersector si = new SegmentIntersector(li, includeProper, true);
si.SetBoundaryNodes(BoundaryNodes, g.BoundaryNodes);
EdgeSetIntersector esi = CreateEdgeSetIntersector();
esi.ComputeIntersections(Edges, g.Edges, si);
return si;
}
/// <summary>
///
/// </summary>
/// <param name="geomIndex"></param>
/// <param name="p"></param>
/// <param name="geom"></param>
/// <returns></returns>
public virtual LocationType GetLocation(int geomIndex, Coordinate p, GeometryGraph[] geom)
{
// compute location only on demand
if (_ptInAreaLocation[geomIndex] == LocationType.Null)
_ptInAreaLocation[geomIndex] = SimplePointInAreaLocator.Locate(p, geom[geomIndex].Geometry);
return _ptInAreaLocation[geomIndex];
}
/// <summary>
/// For all edges, check if there are any intersections which are NOT at an endpoint.
/// The Geometry is not simple if there are intersections not at endpoints.
/// </summary>
/// <param name="graph"></param>
private static bool HasNonEndpointIntersection(GeometryGraph graph)
{
for (IEnumerator i = graph.GetEdgeEnumerator(); i.MoveNext(); )
{
Edge e = (Edge)i.Current;
int maxSegmentIndex = e.MaximumSegmentIndex;
for (IEnumerator eiIt = e.EdgeIntersectionList.GetEnumerator(); eiIt.MoveNext(); )
{
EdgeIntersection ei = (EdgeIntersection)eiIt.Current;
if (!ei.IsEndPoint(maxSegmentIndex))
return true;
}
}
return false;
}
/// <summary>
/// Tests that each hole is inside the polygon shell.
/// This routine assumes that the holes have previously been tested
/// to ensure that all vertices lie on the shell or inside it.
/// A simple test of a single point in the hole can be used,
/// provide the point is chosen such that it does not lie on the
/// boundary of the shell.
/// </summary>
/// <param name="p">The polygon to be tested for hole inclusion.</param>
/// <param name="graph">A GeometryGraph incorporating the polygon.</param>
private void CheckHolesInShell(IPolygon p, GeometryGraph graph)
{
ILinearRing shell = p.Shell;
IPointInRing pir = new McPointInRing(shell);
for (int i = 0; i < p.NumHoles; i++)
{
LinearRing hole = (LinearRing)p.GetInteriorRingN(i);
Coordinate holePt = FindPointNotNode(hole.Coordinates, shell, graph);
/*
* If no non-node hole vertex can be found, the hole must
* split the polygon into disconnected interiors.
* This will be caught by a subsequent check.
*/
if (holePt == null)
return;
bool outside = !pir.IsInside(holePt);
if (outside)
{
_validErr = new TopologyValidationError(TopologyValidationErrorType.HoleOutsideShell, holePt);
return;
}
}
}
/// <summary>
///
/// </summary>
/// <param name="graph"></param>
public SweeplineNestedRingTester(GeometryGraph graph)
{
_graph = graph;
}
/// <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(LocationType.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++)
{
LocationType eLoc = eLabel.GetLocation(i);
if (eLoc == LocationType.Interior || eLoc == LocationType.Boundary)
_label.SetLocation(i, LocationType.Interior);
}
}
}
/// <summary>
/// Tests that no hole is nested inside another hole.
/// This routine assumes that the holes are disjoint.
/// To ensure this, holes have previously been tested
/// to ensure that:
/// They do not partially overlap
/// (checked by <c>checkRelateConsistency</c>).
/// They are not identical
/// (checked by <c>checkRelateConsistency</c>).
/// </summary>
private void CheckHolesNotNested(IPolygon p, GeometryGraph graph)
{
QuadtreeNestedRingTester nestedTester = new QuadtreeNestedRingTester(graph);
foreach (LinearRing innerHole in p.Holes)
nestedTester.Add(innerHole);
bool isNonNested = nestedTester.IsNonNested();
if (!isNonNested)
_validErr = new TopologyValidationError(TopologyValidationErrorType.NestedHoles, nestedTester.NestedPoint);
}
/// <summary>
/// Test that no edge intersection is the
/// endpoint of a closed line. To check this we compute the
/// degree of each endpoint. The degree of endpoints of closed lines
/// must be exactly 2.
/// </summary>
/// <param name="graph"></param>
private static bool HasClosedEndpointIntersection(GeometryGraph graph)
{
IDictionary endPoints = new SortedList();
for (IEnumerator i = graph.GetEdgeEnumerator(); i.MoveNext(); )
{
Edge e = (Edge)i.Current;
bool isClosed = e.IsClosed;
Coordinate p0 = e.GetCoordinate(0);
AddEndpoint(endPoints, p0, isClosed);
Coordinate p1 = e.GetCoordinate(e.NumPoints - 1);
AddEndpoint(endPoints, p1, isClosed);
}
for (IEnumerator i = endPoints.Values.GetEnumerator(); i.MoveNext(); )
{
EndpointInfo eiInfo = (EndpointInfo)i.Current;
if (eiInfo.IsClosed && eiInfo.Degree != 2)
return true;
}
return false;
}
/// <summary>
/// Tests that no element polygon is wholly in the interior of another element polygon.
/// Preconditions:
/// Shells do not partially overlap.
/// Shells do not touch along an edge.
/// No duplicate rings exists.
/// This routine relies on the fact that while polygon shells may touch at one or
/// more vertices, they cannot touch at ALL vertices.
/// </summary>
private void CheckShellsNotNested(IGeometry mp, GeometryGraph graph)
{
for (int i = 0; i < mp.NumGeometries; i++)
{
Polygon p = (Polygon)mp.GetGeometryN(i);
LinearRing shell = (LinearRing)p.ExteriorRing;
for (int j = 0; j < mp.NumGeometries; j++)
{
if (i == j)
continue;
Polygon p2 = (Polygon)mp.GetGeometryN(j);
CheckShellNotNested(shell, p2, graph);
if (_validErr != null) return;
}
}
}
/// <summary>
///
/// </summary>
/// <param name="geomGraph"></param>
public ConnectedInteriorTester(GeometryGraph geomGraph)
{
_geomGraph = geomGraph;
}
/// <summary>
/// Check if a shell is incorrectly nested within a polygon. This is the case
/// if the shell is inside the polygon shell, but not inside a polygon hole.
/// (If the shell is inside a polygon hole, the nesting is valid.)
/// The algorithm used relies on the fact that the rings must be properly contained.
/// E.g. they cannot partially overlap (this has been previously checked by
/// <c>CheckRelateConsistency</c>).
/// </summary>
private void CheckShellNotNested(LinearRing shell, Polygon p, GeometryGraph graph)
{
IList<Coordinate> shellPts = shell.Coordinates;
// test if shell is inside polygon shell
LinearRing polyShell = (LinearRing)p.ExteriorRing;
IList<Coordinate> polyPts = polyShell.Coordinates;
Coordinate shellPt = FindPointNotNode(shellPts, polyShell, graph);
// if no point could be found, we can assume that the shell is outside the polygon
if (shellPt == null) return;
bool insidePolyShell = CgAlgorithms.IsPointInRing(shellPt, polyPts);
if (!insidePolyShell) return;
// if no holes, this is an error!
if (p.NumHoles <= 0)
{
_validErr = new TopologyValidationError(TopologyValidationErrorType.NestedShells, shellPt);
return;
}
/*
* Check if the shell is inside one of the holes.
* This is the case if one of the calls to checkShellInsideHole
* returns a null coordinate.
* Otherwise, the shell is not properly contained in a hole, which is an error.
*/
Coordinate badNestedPt = null;
for (int i = 0; i < p.NumHoles; i++)
{
LinearRing hole = (LinearRing)p.GetInteriorRingN(i);
badNestedPt = CheckShellInsideHole(shell, hole, graph);
if (badNestedPt == null) return;
}
_validErr = new TopologyValidationError(TopologyValidationErrorType.NestedShells, badNestedPt);
}
