/// <summary>
/// Creates a VerticalSeparationConstraint for each edge in the given set to structural constraints,
/// to require these edges to be downward pointing. Also checks for cycles, and edges involved
/// in a cycle receive no VerticalSeparationConstraint, but can optionally receive a circle constraint.
/// </summary>
/// <param name="edges"></param>
/// <param name="settings"></param>
/// <param name="horizontalSolver"></param>
/// <param name="verticalSolver"></param>
internal static void GenerateEdgeConstraints(
IEnumerable <Edge> edges,
IdealEdgeLengthSettings settings,
AxisSolver horizontalSolver,
AxisSolver verticalSolver)
{
if (settings.EdgeDirectionConstraints == Directions.None)
{
return;
}
EdgeConstraintGenerator g = new EdgeConstraintGenerator(edges, settings, horizontalSolver, verticalSolver);
g.GenerateSeparationConstraints();
}
/// <summary>
/// Creates a VerticalSeparationConstraint for each edge in the given set to structural constraints,
/// to require these edges to be downward pointing. Also checks for cycles, and edges involved
/// in a cycle receive no VerticalSeparationConstraint, but can optionally receive a circle constraint.
/// </summary>
/// <param name="edges"></param>
/// <param name="settings"></param>
/// <param name="horizontalSolver"></param>
/// <param name="verticalSolver"></param>
internal static void GenerateEdgeConstraints(
IEnumerable <Edge> edges,
IdealEdgeLengthSettings settings,
AxisSolver horizontalSolver,
AxisSolver verticalSolver)
{
if (settings.EdgeDirectionConstraints == Directions.None)
{
return;
}
EdgeConstraintGenerator g = new EdgeConstraintGenerator(edges, settings, horizontalSolver, verticalSolver);
g.GenerateSeparationConstraints();
// we have in the past used Circular constraints to better show cycles... it's a little experimental though
// so it's not currently enabled
//foreach (var c in g.CyclicComponents) {
// constraints.Add(new ProcrustesCircleConstraint(c));
//}
}
internal EdgeConstraintGenerator(
IEnumerable <Edge> edges,
IdealEdgeLengthSettings settings,
AxisSolver horizontalSolver,
AxisSolver verticalSolver)
{
// filter out self edges
this.edges = edges.Where(e => e.Source != e.Target);
this.settings = settings;
this.horizontalSolver = horizontalSolver;
this.verticalSolver = verticalSolver;
foreach (var e in this.edges)
{
TNode u = CreateTNode(e.Source), v = CreateTNode(e.Target);
u.outNeighbours.Add(v);
v.inNeighbours.Add(u);
}
foreach (var v in nodeMap.Values)
{
if (v.stackNode == null)
{
DFS(v);
}
}
while (stack.Count > 0)
{
component = new List <TNode>();
RDFS(stack.Last.Value);
if (component.Count > 1)
{
var cyclicComponent = new Set <Node>();
foreach (var v in component)
{
cyclicComponent.Insert(v.v);
}
cyclicComponents.Add(cyclicComponent);
}
}
switch (settings.EdgeDirectionConstraints)
{
case Directions.South:
this.addConstraint = this.AddSConstraint;
break;
case Directions.North:
this.addConstraint = this.AddNConstraint;
break;
case Directions.West:
this.addConstraint = this.AddWConstraint;
break;
case Directions.East:
this.addConstraint = this.AddEConstraint;
break;
}
}
