/// <summary>
/// Determines the topological relationship (location) of a single point
/// to a Geometry. It handles both single-element and multi-element Geometries.
/// The algorithm for multi-part Geometries is more complex, since it has
/// to take into account the boundaryDetermination rule.
/// </summary>
/// <param name="p"></param>
/// <param name="geom"></param>
/// <returns>Returns the location of the point relative to the input Geometry.</returns>
public int Locate( Coordinate p, Geometry geom )
{
if ( geom.IsEmpty() ) return Location.Exterior;
if ( geom is LineString )
{
return Locate( p, (LineString) geom );
}
if ( geom is LinearRing )
{
return Locate( p, (LinearRing) geom );
}
else if ( geom is Polygon )
{
return Locate( p, (Polygon) geom );
}
_isIn = false;
_numBoundaries = 0;
ComputeLocation( p, geom );
if ( GeometryGraph.IsInBoundary( _numBoundaries ) )
{
return Location.Boundary;
}
if ( _numBoundaries > 0 || _isIn)
{
return Location.Interior;
}
return Location.Exterior;
} // public int Locate( Coordinate p, Geometry geom )
/// <summary>
/// Locate is the main location function. It handles both single-element
/// and multi-element Geometries. The algorithm for multi-element Geometries
/// is more complex, since it has to take into account the boundaryDetermination rule
/// </summary>
/// <param name="p"></param>
/// <param name="geom"></param>
/// <returns></returns>
public static int Locate(Coordinate p, Geometry geom)
{
if ( geom.IsEmpty() ) return Location.Exterior;
if ( ContainsPoint( p, geom ) )
{
return Location.Interior;
}
return Location.Exterior;
} // public static int Locate(Coordinate p, Geometry geom)
public bool HasRepeatedPoint(Geometry g)
{
if ( g.IsEmpty() ) return false;
if (g is Point) return false;
else if (g is MultiPoint) return false;
// LineString also handles LinearRings
else if (g is LineString)
{
return HasRepeatedPoint(((LineString) g).GetCoordinates() );
}
else if (g is Polygon) return HasRepeatedPoint((Polygon) g);
else if (g is GeometryCollection) return HasRepeatedPoint((GeometryCollection) g);
else throw new NotSupportedException(g.GetType().Name);
}
private void Add(Geometry g)
{
if ( g.IsEmpty() ) return;
// check if this Geometry should obey the Boundary Determination Rule
// all collections except MultiPolygons obey the rule
if ( g is GeometryCollection && !(g is MultiPolygon) )
{
_useBoundaryDeterminationRule = true;
}
if ( g is Polygon )
{
AddPolygon( (Polygon) g );
}
// LineString also handles LinearRings
else if ( g is LineString )
{
AddLineString( (LineString) g );
}
else if ( g is Point )
{
AddPoint( (Point) g );
}
else if ( g is MultiPoint )
{
AddCollection( (MultiPoint) g );
}
else if ( g is MultiLineString )
{
AddCollection( (MultiLineString) g );
}
else if ( g is MultiPolygon )
{
AddCollection( (MultiPolygon) g );
}
else if ( g is GeometryCollection )
{
AddCollection( (GeometryCollection) g );
}
else
{
throw new NotSupportedException(g.GetType().Name);
}
}
} // public bool IsSimple( MultiPoint mp )
/// <summary>
/// Tests to see if geometry is simple.
/// </summary>
/// <param name="geom">Geometry to test.</param>
/// <returns>Returns true if geometry is simple, false otherwise.</returns>
private bool IsSimpleLinearGeometry( Geometry geom )
{
if( geom.IsEmpty() )
{
return true;
}
GeometryGraph graph = new GeometryGraph( 0, geom );
LineIntersector li = new RobustLineIntersector();
SegmentIntersector si = graph.ComputeSelfNodes( li );
// 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;
} // private bool IsSimpleLinearGeometry( Geometry geom )
private void Add(Geometry g)
{
if ( g.IsEmpty() ) return;
if (g is Polygon) AddPolygon((Polygon) g);
// LineString also handles LinearRings
else if (g is LineString) AddLineString((LineString) g);
else if (g is Point) AddPoint((Point) g);
else if (g is MultiPoint) AddCollection((MultiPoint) g);
else if (g is MultiLineString) AddCollection((MultiLineString) g);
else if (g is MultiPolygon) AddCollection((MultiPolygon) g);
else if (g is GeometryCollection) AddCollection((GeometryCollection) g);
else throw new NotSupportedException(g.GetType().Name);
}
private void CheckValid(Geometry g)
{
if (_isChecked)
{
return;
}
_validErr = null;
if ( g.IsEmpty() )
{
return;
}
if (g is Point)
{
return;
}
else if (g is MultiPoint)
{
return;
}
// LineString also handles LinearRings
else if (g is LineString)
{
CheckValid( (LineString) g);
}
else if (g is Polygon)
{
CheckValid( (Polygon) g);
}
else if (g is MultiPolygon)
{
CheckValid( (MultiPolygon) g);
}
else if (g is GeometryCollection)
{
CheckValid( (GeometryCollection) g);
}
else throw new NotSupportedException(g.GetType().Name);
}