/// <summary>
/// Obtains the geometry for spans along an alternate face attached to this leg.
/// </summary>
/// <param name="legStart">The position for the start of the leg.
/// <param name="legEnd">The position for the end of the leg.</param>
/// <param name="spans">Information for the spans coinciding with this leg.</param>
/// <returns>The sections along this leg</returns>
internal override ILineGeometry[] GetSpanSections(IPosition legStart, IPosition legEnd, SpanInfo[] spans)
{
var result = new ILineGeometry[spans.Length];
Debug.Assert(AlternateFace != null);
// Define the arc that corresponds to the complete leg (the circle should have been
// already defined when we processed the primary face_.
Debug.Assert(Circle != null);
var arc = new CircularArcGeometry(Circle, legStart, legEnd, m_Metrics.IsClockwise);
// Handle case where the leg is a cul-de-sac with no observed spans on the alternate face
if (spans.Length == 1 && spans[0].ObservedDistance == null)
{
result[0] = arc;
return(result);
}
// Get the required arc length (in meters on the ground)
double len = arc.Length.Meters;
// Get the observed arc length (in meters on the ground)
double obs = AlternateFace.GetTotal();
// Get the adjustment factor for stretching-compressing the observed distances.
double factor = len / obs;
// Define start of first arc.
IPosition sPos = legStart;
IPosition ePos = null;
// Haven't got anywhere yet.
double totobs = 0.0;
// Figure out the location of each span
for (int i = 0; i < result.Length; i++, sPos = ePos)
{
if (i == result.Length - 1)
{
ePos = legEnd;
}
else
{
// Add on the unscaled distance
totobs += spans[i].ObservedDistance.Meters;
// Scale to the required length for the overall leg
double elen = totobs * factor;
// Define the end position.
arc.GetPosition(new Length(elen), out ePos);
}
result[i] = new CircularArcGeometry(Circle, sPos, ePos, m_Metrics.IsClockwise);
}
return(result);
}
/// <summary>
/// Gets the position that is a specific distance from the start of this line.
/// </summary>
/// <param name="distance">The distance from the start of the line.</param>
/// <param name="result">The position found</param>
/// <returns>True if the distance is somewhere ON the line. False if the distance
/// was less than zero, or more than the line length (in that case, the position
/// found corresponds to the corresponding terminal point).</returns>
internal override bool GetPosition(ILength distance, out IPosition result)
{
return(CircularArcGeometry.GetPosition(this, distance, out result));
}