/// <summary>
/// Determines whether the sections in this list can be trimmed using the
/// <see cref="TrimLineOperation"/>
/// </summary>
/// <returns>True if either end dangles, and we would be left with something
/// after the trim.</returns>
internal bool CanTrim()
{
// Can't trim if we don't have at least two sections
if (m_Sections.Count < 2)
{
return(false);
}
// Get the sections at the ends.
IDivider s = this.FirstDivider;
IDivider e = this.LastDivider;
Debug.Assert(s != e);
// Return if neither end is dangling
bool sDangle = Topology.IsDangle(s, s.From);
bool eDangle = Topology.IsDangle(e, e.To);
if (!(sDangle || eDangle))
{
return(false);
}
// Can't process if both ends are dangling and the common point is coincident
if (sDangle && eDangle && s.To.IsCoincident(e.From))
{
return(false);
}
return(true);
}
/// <summary>
/// Checks if a divider is a dangle, floating, or a bridge.
/// </summary>
/// <param name="d">The divider to check</param>
/// <returns>Bit mask of the check(s) the divider failed.</returns>
static CheckType CheckNeighbours(IDivider d)
{
Debug.Assert(!d.IsOverlap);
// Return if the divider has different polygons on both sides.
if (d.Left != d.Right)
{
return(CheckType.Null);
}
bool sDangle = Topology.IsDangle(d, d.From);
bool eDangle = Topology.IsDangle(d, d.To);
if (sDangle && eDangle)
{
return(CheckType.Floating);
}
if (sDangle || eDangle)
{
return(CheckType.Dangle);
}
return(CheckType.Bridge);
}