/// <summary>
/// Obtains the position ratio for a position that is coincident with a line.
/// </summary>
/// <param name="line">The line the position is coincident with</param>
/// <param name="posn">The position on the line</param>
/// <returns>The position ratio of the position, expressed in the numeric range
/// expected by this editing operation.</returns>
/// <exception cref="ArgumentException">If the position does not appear to coincide
/// with the supplied line.</exception>
static internal uint GetPositionRatio(LineFeature line, IPosition posn)
{
// Get the distance to the supplied position (confirming that it does fall on the line)
LineGeometry g = line.LineGeometry;
double lineLen = g.Length.Meters;
double posnLen = g.GetLength(posn).Meters;
if (posnLen < 0.0)
{
throw new ArgumentException("Position does not appear to coincide with line.");
}
// Express the position as a position ratio in the range [0,1 billion]
double prat = posnLen / lineLen;
uint result = (uint)(prat * (double)MAX_POSITION_RATIO);
Debug.Assert(result <= MAX_POSITION_RATIO);
return(result);
}
