/// <summary>
/// Compared HalfEdges should have Origin = origin and Destination > origin.
/// </summary>
private Func <DCEL_HalfEdge, DCEL_HalfEdge, int> AngleComparisonUpperList_HalfEdge(VecRat2 origin)
{
return(delegate(DCEL_HalfEdge a, DCEL_HalfEdge b)
{
return GeomAid.TurnTest(origin, b.Destination.Position, a.Destination.Position);
});
}
private Comparison <OA_Segment> AngleComparisonUpperList(VecRat2 origin)
{
return(delegate(OA_Segment a, OA_Segment b)
{
return GeomAid.TurnTest(origin, b.Lower.Position, a.Lower.Position);
});
}
private static void FindNewEvent(Segment s1, Segment s2, EventPoint eventPoint, RBTreeMap <EventPoint, LinkedList <Segment> > eventQueue)
{
//If two segments intersect below the sweep line, or on it and
//to the right of the current event point, and the intersection
//is not yet present as an event in Q:
//then insert a new event point in Q for this intersection
VecRat2 pointIntersection = new VecRat2();
SegRat2 segmentIntersection = new SegRat2();
//bool intersectionExists = Segment.ComputeIntersection(s1, s2, out pointIntersection);
//if (intersectionExists)
SegmentIntersectionType result = GeomAid.SegmentIntersection(s1.ToSegRat2(), s2.ToSegRat2(), ref pointIntersection, ref segmentIntersection);
if (result == SegmentIntersectionType.Point)
{
EventPoint newEventPoint = new EventPoint(null);
newEventPoint.Position = pointIntersection;
if (eventPoint.CompareTo(newEventPoint) < 0 && !eventQueue.ContainsKey(newEventPoint))
{
LinkedList <Segment> upperList = new LinkedList <Segment>();
eventQueue.Add(new RBTreeMapNode <EventPoint, LinkedList <Segment> >(newEventPoint, upperList));
}
}
else if (result == SegmentIntersectionType.Segment)
{
throw new NotImplementedException("Didn't think this would ever happen?!");
}
}
private static CycleType GetCycleType(DCEL_HalfEdge cycle)
{
if (GeomAid.TurnTest(cycle.Prev.Origin.Position, cycle.Origin.Position, cycle.Destination.Position) > 0)
{
return(CycleType.Interior);
}
else
{
return(CycleType.Exterior);
}
}
public Rational CycleArea()
{
Rational twiceSignedArea = 0;
VecRat2 origin = Origin.Position;
foreach (DCEL_HalfEdge halfEdge in CycleNext)
{
twiceSignedArea += GeomAid.TriangleTwiceSignedArea(origin, halfEdge.Origin.Position, halfEdge.Destination.Position);
}
return(Rational.Abs(twiceSignedArea) / 2);
}
private void FindNewEventPoint(OA_Segment segment1, OA_Segment segment2, OA_EventPoint eventPoint)
{
VecRat2 pointIntersection = new VecRat2();
SegRat2 segmentIntersection = new SegRat2();
SegmentIntersectionType result = GeomAid.SegmentIntersection(segment1.ToSegRat2(), segment2.ToSegRat2(), ref pointIntersection, ref segmentIntersection);
if (result == SegmentIntersectionType.Point)
{
OA_EventPoint newEventPoint = new OA_EventPoint(pointIntersection);
if (eventPoint.CompareTo(newEventPoint) < 0)
{
//Add the new event point if it isn't already in the event queue
eventQueue.Add(new RBTreeSetNode <OA_EventPoint>(newEventPoint));
}
}
else if (result == SegmentIntersectionType.Segment)
{
throw new NotImplementedException("Didn't think this would ever happen?!");
}
}