private static List<EdgeAggregator> InstantiateToAltitude(Triangle triangle, Perpendicular perp, GroundedClause original)
{
List<EdgeAggregator> newGrounded = new List<EdgeAggregator>();
// Acquire the side of the triangle containing the intersection point
// This point may or may not be directly on the triangle side
Segment baseSegment = triangle.GetSegmentWithPointOnOrExtends(perp.intersect);
if (baseSegment == null) return newGrounded;
// The altitude must pass through the intersection point as well as the opposing vertex
Point oppositeVertex = triangle.OtherPoint(baseSegment);
Segment altitude = new Segment(perp.intersect, oppositeVertex);
// The alitude must alig with the intersection
if (!perp.ImpliesRay(altitude)) return newGrounded;
// The opposing side must align with the intersection
if (!perp.OtherSegment(altitude).IsCollinearWith(baseSegment)) return newGrounded;
//
// Create the new Altitude object
//
Altitude newAltitude = new Altitude(triangle, altitude);
// For hypergraph
List<GroundedClause> antecedent = new List<GroundedClause>();
antecedent.Add(triangle);
antecedent.Add(original);
newGrounded.Add(new EdgeAggregator(antecedent, newAltitude, annotation));
//
// Check if this induces a second altitude for a right triangle (although we don't know this is a strengthened triangle)
// The intersection must be on the vertex of the triangle
if (triangle.HasPoint(perp.intersect))
{
Angle possRightAngle = new Angle(triangle.OtherPoint(new Segment(perp.intersect, oppositeVertex)), perp.intersect, oppositeVertex);
if (triangle.HasAngle(possRightAngle))
{
Altitude secondAltitude = new Altitude(triangle, new Segment(perp.intersect, oppositeVertex));
newGrounded.Add(new EdgeAggregator(antecedent, secondAltitude, annotation));
}
}
return newGrounded;
}
private static List<EdgeAggregator> CheckAndGeneratePerpendicular(Perpendicular perp, Parallel parallel, Intersection inter, GroundedClause original)
{
List<EdgeAggregator> newGrounded = new List<EdgeAggregator>();
// The perpendicular intersection must refer to one of the parallel segments
Segment shared = perp.CommonSegment(parallel);
if (shared == null) return newGrounded;
// The other intersection must refer to a segment in the parallel pair
Segment otherShared = inter.CommonSegment(parallel);
if (otherShared == null) return newGrounded;
// The two shared segments must be distinct
if (shared.Equals(otherShared)) return newGrounded;
// Transversals must align
if (!inter.OtherSegment(otherShared).Equals(perp.OtherSegment(shared))) return newGrounded;
// Strengthen the old intersection to be perpendicular
Strengthened strengthenedPerp = new Strengthened(inter, new Perpendicular(inter));
// Construct hyperedge
List<GroundedClause> antecedent = new List<GroundedClause>();
antecedent.Add(original);
antecedent.Add(parallel);
antecedent.Add(inter);
newGrounded.Add(new EdgeAggregator(antecedent, strengthenedPerp, annotation));
return newGrounded;
}