/// <summary>
/// Find the nearest <see cref="LinearLocation"/> along the linear
/// <see cref="Geometry"/> to a given <see cref="Coordinate"/>
/// after the specified minimum <see cref="LinearLocation"/>.
/// </summary>
/// <param name="inputPt">the coordinate to locate
/// </param>
/// <param name="minLocation">the minimum location for the point location
/// </param>
/// <returns>The location of the nearest point.</returns>
/// <remarks>
/// If possible the location returned will be strictly greater than the
/// <c>minLocation</c>.
/// If this is not possible, the
/// value returned will equal <c>minLocation</c>.
/// (An example where this is not possible is when
/// minLocation = [end of line] ).
/// </remarks>
public LinearLocation IndexOfAfter(Coordinate inputPt,
LinearLocation minIndex)
{
if (minIndex == null)
{
return(IndexOf(inputPt));
}
// sanity check for minLocation at or past end of line
LinearLocation endLoc = LinearLocation.GetEndLocation(linearGeom);
if (endLoc.CompareTo(minIndex) <= 0)
{
return(endLoc);
}
LinearLocation closestAfter = IndexOfFromStart(inputPt, minIndex);
// Return the minDistanceLocation found.
// This will not be null, since it was initialized to minLocation
Debug.Assert(closestAfter.CompareTo(minIndex) >= 0,
"computed location is before specified minimum location");
return(closestAfter);
}
private LinearLocation GetLocationForward(double length)
{
if (length <= 0.0)
{
return(new LinearLocation());
}
double totalLength = 0.0;
LinearIterator it = new LinearIterator(linearGeom);
while (it.HasNext())
{
if (!it.EndOfLine)
{
Coordinate p0 = it.SegmentStart;
Coordinate p1 = it.SegmentEnd;
double segLen = p1.Distance(p0);
// length falls in this segment
if ((totalLength + segLen) > length)
{
double frac = (length - totalLength) / segLen;
int compIndex = it.ComponentIndex;
int segIndex = it.VertexIndex;
return(new LinearLocation(compIndex, segIndex, frac));
}
totalLength += segLen;
}
it.Next();
}
// length is longer than line - return end location
return(LinearLocation.GetEndLocation(linearGeom));
}