/// <summary>
/// Calculates the positions of the split point.
/// </summary>
/// <param name="line">The line being subdivided.</param>
/// <param name="dist">The distance to the split point.</param>
/// <param name="isFromEnd">Is the distance from the end of the line?</param>
/// <returns>The calculated position (null if the distance is longer than the line being subdivided,
/// or supplied information is incomplete)</returns>
internal static IPosition Calculate(LineFeature line, Distance dist, bool isFromEnd)
{
// Can't calculate if there is insufficient data.
if (line == null || dist == null)
{
return(null);
}
// The length must be defined.
if (!dist.IsDefined)
{
return(null);
}
// Return if the observed distance is longer than the total
// length of the line.
double maxlen = line.Length.Meters;
double obsvlen = dist.Meters;
if (obsvlen > maxlen)
{
return(null);
}
// Get the approximate position of the split point.
IPosition start, approx;
LineGeometry g = line.LineGeometry;
if (isFromEnd)
{
start = line.EndPoint;
g.GetPosition(new Length(maxlen - obsvlen), out approx);
}
else
{
start = line.StartPoint;
g.GetPosition(new Length(obsvlen), out approx);
}
// Get the distance to the approximate position on the mapping plane.
ISpatialSystem sys = CadastralMapModel.Current.SpatialSystem;
double planlen = dist.GetPlanarMetric(start, approx, sys);
// Figure out the true position on the line.
IPosition splitpos;
if (isFromEnd)
{
g.GetPosition(new Length(maxlen - planlen), out splitpos);
}
else
{
g.GetPosition(new Length(planlen), out splitpos);
}
return(splitpos);
}
/// <summary>
/// Performs the data processing associated with this face.
/// </summary>
/// <param name="parentLine">The line that is being subdivided</param>
/// <param name="ctx">The context in which the geometry is being calculated.</param>
internal void CalculateGeometry(LineFeature parentLine, EditingContext ctx)
{
// Get adjusted lengths for each section
double[] adjray = GetAdjustedLengths(parentLine, m_Distances);
double edist = 0.0; // Distance to end of section.
PointFeature start = parentLine.StartPoint;
LineGeometry lineGeom = parentLine.LineGeometry;
for (int i = 0; i < adjray.Length; i++)
{
// Calculate the position at the end of the span
edist += adjray[i];
IPosition to;
if (!lineGeom.GetPosition(new Length(edist), out to))
{
throw new Exception("Cannot adjust line section");
}
// Get the point feature at the end of the span
LineFeature line = m_Sections[i];
PointFeature end = line.EndPoint;
// Assign the calculated position so long as we're not at
// the end of the line
if (end != parentLine.EndPoint)
{
end.ApplyPointGeometry(ctx, PointGeometry.Create(to));
}
// The end of the current span is the start of the next one
start = end;
}
}
