//
// Returns the exact transversal between the intersections
//
public Segment AcquireTransversal(Intersection thatInter)
{
// The two intersections should not be at the same vertex
if (intersect.Equals(thatInter.intersect))
{
return(null);
}
Segment common = CommonSegment(thatInter);
if (common == null)
{
return(null);
}
// A legitimate transversal must belong to both intersections (is a subsegment of one of the lines)
Segment transversal = new Segment(this.intersect, thatInter.intersect);
Segment thisTransversal = this.GetCollinearSegment(transversal);
Segment thatTransversal = thatInter.GetCollinearSegment(transversal);
if (!thisTransversal.HasSubSegment(transversal))
{
return(null);
}
if (!thatTransversal.HasSubSegment(transversal))
{
return(null);
}
return(transversal);
}
public bool CreatesAValidTransversalWith(Intersection thatInter)
{
Segment transversal = this.AcquireTransversal(thatInter);
if (transversal == null)
{
return(false);
}
// Ensure the non-traversal segments align with the parallel segments
Segment nonTransversalThis = this.OtherSegment(transversal);
Segment nonTransversalThat = thatInter.OtherSegment(transversal);
Segment thisTransversalSegment = this.OtherSegment(nonTransversalThis);
Segment thatTransversalSegment = thatInter.OtherSegment(nonTransversalThat);
// Parallel lines should not coincide
if (nonTransversalThis.IsCollinearWith(nonTransversalThat))
{
return(false);
}
// Avoid:
// | |
// __| ________|
// | |
// | |
// Both intersections (transversal segments) must contain the actual transversal
return(thatTransversalSegment.HasSubSegment(transversal) && thisTransversalSegment.HasSubSegment(transversal));
}
//
// Does the given segment contain a radius of this circle?
//
public bool ContainsRadiusWithin(Segment thatSegment)
{
foreach (Segment radius in radii)
{
if (thatSegment.HasSubSegment(radius)) return true;
}
return false;
}
//
// Does the given segment contain a chord? Return the chord.
//
public Segment ContainsChord(Segment thatSegment)
{
foreach (KeyValuePair<Segment, Segment> pair in secants)
{
// Does the secant contain that segment? If so, is the chord contained in that Segment?
if (pair.Key.HasSubSegment(thatSegment))
{
if (thatSegment.HasSubSegment(pair.Value)) return pair.Value;
}
}
return null;
}