/// <summary>
/// Determines whether the specified polyline has valid point occurrences.
/// If a point occurs once, the point connects a chain of segments.
/// If a point occurs twice, and this only occurs for one point, this point is the point that closes the polyline to form a shape.
/// If a point occurs more than twice, the shape is connecting back on itself. This case is best handled as a composite shape.
/// </summary>
/// <param name="polyline">The polyline.</param>
/// <returns><c>true</c> if [is valid point ordering] [the specified polyline]; otherwise, <c>false</c>.</returns>
public static bool IsValidPointOccurrences(PolyLine polyline)
{
PointBoundary points = polyline.PointBoundary();
bool closureCounted = false;
var selectQuery =
from point in points
group point by point into g
select new { Point = g.Key, Count = g.Count() };
foreach (var point in selectQuery)
{
if (point.Count == 2 && !closureCounted)
{
closureCounted = true;
continue;
}
if (point.Count > 1)
{
return(false);
}
}
return(true);
}
/// <summary>
/// Returns the points that define the shape.
/// </summary>
/// <returns>PointBoundary.</returns>
public PointBoundary PointBoundary()
{
return(_polyline.PointBoundary());
}