/// <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="ring"></param>
private void CheckClosedRing(ILinearRing ring)
{
if (!ring.IsClosed)
{
_validErr = new TopologyValidationError(TopologyValidationErrorType.RingNotClosed, ring.Coordinates[0]);
}
}
/// <summary>
///
/// </summary>
/// <param name="graph"></param>
private void CheckTooFewPoints(GeometryGraph graph)
{
if (graph.HasTooFewPoints)
{
_validErr = new TopologyValidationError(TopologyValidationErrorType.TooFewPoints, graph.InvalidPoint);
return;
}
}
/// <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="coords"></param>
private void CheckInvalidCoordinates(IEnumerable <Coordinate> coords)
{
foreach (Coordinate c in coords)
{
if (!IsValidCoordinate(c))
{
_validErr = new TopologyValidationError(TopologyValidationErrorType.InvalidCoordinate, c);
return;
}
}
}
/// <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>
///
/// </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>
/// 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);
}
/// <summary>
/// Check that a ring does not self-intersect, except at its endpoints.
/// Algorithm is to count the number of times each node along edge occurs.
/// If any occur more than once, that must be a self-intersection.
/// </summary>
private void CheckNoSelfIntersectingRing(EdgeIntersectionList eiList)
{
var nodeSet = new HashSet <Coordinate>();
bool isFirst = true;
foreach (EdgeIntersection ei in eiList)
{
if (isFirst)
{
isFirst = false;
continue;
}
if (nodeSet.Contains(ei.Coordinate))
{
_validErr = new TopologyValidationError(TopologyValidationErrorType.RingSelfIntersection, ei.Coordinate);
return;
}
nodeSet.Add(ei.Coordinate);
}
}
/// <summary>
///
/// </summary>
/// <param name="g"></param>
private void CheckValid(IGeometry g)
{
_validErr = null;
if (g.IsEmpty)
{
return;
}
CheckValidCoordinates(g);
if (g is ILineString)
{
CheckValidLineString(g);
}
ILinearRing r = g as ILinearRing;
if (r != null)
{
CheckValidRing(r);
}
IPolygon p = g as IPolygon;
if (p != null)
{
CheckValidPolygon(p);
}
IMultiPolygon mp = g as IMultiPolygon;
if (mp != null)
{
CheckValidMultipolygon(mp);
}
else
{
IGeometryCollection gc = g as IGeometryCollection;
if (gc != null)
{
CheckValidCollection(gc);
}
}
}
/// <summary>
///
/// </summary>
/// <param name="g"></param>
private void CheckValid(IGeometry g)
{
_validErr = null;
if (g.IsEmpty) return;
CheckValidCoordinates(g);
if (g is ILineString)
CheckValidLineString(g);
ILinearRing r = g as ILinearRing;
if (r != null) CheckValidRing(r);
IPolygon p = g as IPolygon;
if (p != null) CheckValidPolygon(p);
IMultiPolygon mp = g as IMultiPolygon;
if (mp != null) CheckValidMultipolygon(mp);
else
{
IGeometryCollection gc = g as IGeometryCollection;
if (gc != null) CheckValidCollection(gc);
}
}
/// <summary>
///
/// </summary>
/// <param name="graph"></param>
private void CheckTooFewPoints(GeometryGraph graph)
{
if (graph.HasTooFewPoints)
{
_validErr = new TopologyValidationError(TopologyValidationErrorType.TooFewPoints, graph.InvalidPoint);
return;
}
}
/// <summary>
///
/// </summary>
/// <param name="ring"></param>
private void CheckClosedRing(ILinearRing ring)
{
if (!ring.IsClosed)
_validErr = new TopologyValidationError(TopologyValidationErrorType.RingNotClosed, ring.Coordinates[0]);
}
/// <summary>
/// Check that a ring does not self-intersect, except at its endpoints.
/// Algorithm is to count the number of times each node along edge occurs.
/// If any occur more than once, that must be a self-intersection.
/// </summary>
private void CheckNoSelfIntersectingRing(EdgeIntersectionList eiList)
{
ISet nodeSet = new ListSet();
bool isFirst = true;
foreach (EdgeIntersection ei in eiList)
{
if (isFirst)
{
isFirst = false;
continue;
}
if (nodeSet.Contains(ei.Coordinate))
{
_validErr = new TopologyValidationError(TopologyValidationErrorType.RingSelfIntersection, ei.Coordinate);
return;
}
nodeSet.Add(ei.Coordinate);
}
}
/// <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>
/// 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>
/// 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>
/// 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);
}
/// <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="coords"></param>
private void CheckInvalidCoordinates(IEnumerable<Coordinate> coords)
{
foreach (Coordinate c in coords)
{
if (!IsValidCoordinate(c))
{
_validErr = new TopologyValidationError(TopologyValidationErrorType.InvalidCoordinate, c);
return;
}
}
}