/// <summary> Tests whether a <see cref="Geometry"/> is sequenced correctly.
/// <see cref="LineString"/>s are trivially sequenced.
/// <see cref="MultiLineString"/>s are checked for correct sequencing.
/// Otherwise, <code>isSequenced</code> is defined
/// to be <see langword="true"/> for geometries that are not lineal.
///
/// </summary>
/// <param name="geom">the geometry to test
/// </param>
/// <returns> <see langword="true"/> if the geometry is sequenced or is not lineal
/// </returns>
public static bool IsSequenced(Geometry geom)
{
if (!(geom is MultiLineString))
{
return(true);
}
MultiLineString mls = (MultiLineString)geom;
// the nodes in all subgraphs which have been completely scanned
//TODO--PAUL 'java.util.TreeSet' was converted to ListSet
ListSet prevSubgraphNodes = new ListSet();
Coordinate lastNode = null;
IList currNodes = new ArrayList();
for (int i = 0; i < mls.NumGeometries; i++)
{
LineString line = (LineString)mls.GetGeometry(i);
Coordinate startNode = line.GetCoordinate(0);
Coordinate endNode = line.GetCoordinate(line.NumPoints - 1);
// If this linestring is connected to a previous subgraph,
// geom is not sequenced
if (prevSubgraphNodes.Contains(startNode))
{
return(false);
}
if (prevSubgraphNodes.Contains(endNode))
{
return(false);
}
if (lastNode != null)
{
if (!startNode.Equals(lastNode))
{
// start new connected sequence
prevSubgraphNodes.AddAll(currNodes);
currNodes.Clear();
}
}
currNodes.Add(startNode);
currNodes.Add(endNode);
lastNode = endNode;
}
return(true);
}
/// <summary>
/// Gets the <see cref="Coordinate"/> along the
/// given linear <see cref="Geometry"/> which is
/// referenced by this location.
///
/// </summary>
/// <param name="linearGeom">a linear geometry
/// </param>
/// <returns> the <tt>Coordinate</tt> at the location
/// </returns>
public Coordinate GetCoordinate(Geometry linearGeom)
{
LineString lineComp =
(LineString)linearGeom.GetGeometry(componentIndex);
Coordinate p0 = lineComp.GetCoordinate(segmentIndex);
if (segmentIndex >= lineComp.NumPoints - 1)
{
return(p0);
}
Coordinate p1 = lineComp.GetCoordinate(segmentIndex + 1);
return(PointAlongSegmentByFraction(p0, p1, segmentFraction));
}
/// <summary>
/// Converts a LineString to <LineString Text> format, then
/// appends it to the writer.
/// </summary>
/// <param name="lineString"> the LineString to process
/// </param>
/// <param name="writer"> the output writer to append to
/// </param>
private void AppendLineStringText(LineString lineString,
int level, bool doIndent, TextWriter writer)
{
if (lineString.IsEmpty)
{
writer.Write(WktEmpty);
}
else
{
if (doIndent)
{
Indent(level, writer);
}
writer.Write(WktLParan);
for (int i = 0; i < lineString.NumPoints; i++)
{
if (i > 0)
{
writer.Write(WktComma);
if (i % 10 == 0)
{
Indent(level + 2, writer);
}
}
AppendCoordinate(lineString.GetCoordinate(i), writer);
}
writer.Write(WktRParan);
}
}
/// <summary>
/// Gets the length of the segment in the given Geometry containing
/// this location.
/// </summary>
/// <param name="linearGeom">A linear geometry.</param>
/// <returns>The length of the segment.</returns>
public double GetSegmentLength(Geometry linearGeom)
{
LineString lineComp =
(LineString)linearGeom.GetGeometry(componentIndex);
// ensure segment index is valid
int segIndex = segmentIndex;
if (segmentIndex >= lineComp.NumPoints - 1)
{
segIndex = lineComp.NumPoints - 2;
}
Coordinate p0 = lineComp.GetCoordinate(segIndex);
Coordinate p1 = lineComp.GetCoordinate(segIndex + 1);
return(p0.Distance(p1));
}