private static bool IsTargetRingNullPoint(
[NotNull] SegmentIntersection thisLinearIntersection,
[CanBeNull] SegmentIntersection previousLinearIntersection,
ISegmentList targetSegments)
{
if (previousLinearIntersection == null)
{
return(false);
}
if (thisLinearIntersection.TargetStartIntersects &&
targetSegments.IsFirstSegmentInPart(thisLinearIntersection.TargetIndex) &&
targetSegments.IsLastSegmentInPart(previousLinearIntersection.TargetIndex) &&
targetSegments.IsClosed)
{
return(true);
}
// The linear intersections can be inverted, i.e. travelling backwards along target:
if (thisLinearIntersection.TargetStartIntersects && // TargetEndIntersects??
targetSegments.IsLastSegmentInPart(thisLinearIntersection.TargetIndex) &&
targetSegments.IsFirstSegmentInPart(previousLinearIntersection.TargetIndex) &&
targetSegments.IsClosed)
{
return(true);
}
return(false);
}
private static void CollectIntersection(
[NotNull] SegmentIntersection intersection,
[NotNull] ISegmentList source,
[NotNull] IDictionary <int, HashSet <double> > allLinearIntersectionFactors,
[NotNull] ICollection <SegmentIntersection> intersectionsForCurrentSourceSegment)
{
// Collect segments for current index in list, unless they are clearly not needed
// (and would need to be filtered by a later linear intersection if added)
bool isLinear = intersection.HasLinearIntersection;
if (isLinear)
{
int partIndex;
int localSegmentIndex =
source.GetLocalSegmentIndex(intersection.SourceIndex, out partIndex);
double linearIntersectionStartFactor =
localSegmentIndex +
intersection.GetLinearIntersectionStartFactor(true);
double linearIntersectionEndFactor =
localSegmentIndex +
intersection.GetLinearIntersectionEndFactor(true);
if (intersection.IsSourceZeroLength2D &&
ContainsIntersection(allLinearIntersectionFactors,
partIndex, linearIntersectionEndFactor))
{
// avoid double linear segments if the source segment is vertical
return;
}
AddIntersectionFactor(linearIntersectionStartFactor, partIndex,
allLinearIntersectionFactors, source);
AddIntersectionFactor(linearIntersectionEndFactor, partIndex,
allLinearIntersectionFactors, source);
}
if (!isLinear && intersection.SourceStartIntersects &&
source.IsFirstSegmentInPart(intersection.SourceIndex) && source.IsClosed)
{
// will be reported again at the end
return;
}
if (!isLinear && intersection.SourceEndIntersects &&
!source.IsLastSegmentInPart(intersection.SourceIndex))
{
// will be reported again at next segment
return;
}
intersectionsForCurrentSourceSegment.Add(intersection);
}
