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;
}
}
/// <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));
//}
}
/// <summary>
/// Compute ideal edge lengths for the given graph component based on the given settings
/// </summary>
/// <param name="settings">settings for calculating ideal edge length</param>
/// <param name="component">a graph component</param>
public static void ComputeDesiredEdgeLengths(IdealEdgeLengthSettings settings, GeometryGraph component)
{
if (component == null)
{
return;
}
foreach (var e in component.Edges)
{
e.SourcePort = null;
e.TargetPort = null;
// use larger of DefaultLength and
// minimum of the diagonal of a square of area equal to the bounding box of the source and that of the target
e.Length = Math.Max(settings.DefaultLength,
Math.Sqrt(2d * Math.Min(e.Source.BoundingBox.Width * e.Source.BoundingBox.Height, e.Target.BoundingBox.Width * e.Target.BoundingBox.Height)));
}
if (settings.ProportionalToSymmetricDifference)
{
SetEdgeLengthsProportionalToSymmetricDifference(component, settings.ProportionalEdgeLengthOffset, settings.ProportionalEdgeLengthAdjustment);
}
}
/// <summary>
/// Compute ideal edge lengths for the given graph component based on the given settings
/// </summary>
/// <param name="settings">settings for calculating ideal edge length</param>
/// <param name="component">a graph component</param>
public static void ComputeDesiredEdgeLengths(IdealEdgeLengthSettings settings, GeometryGraph component)
{
if (component == null)
{
return;
}
foreach (var e in component.Edges)
{
e.SourcePort = null;
e.TargetPort = null;
// use larger of DefaultLength and
// minimum of the diagonal of a square of area equal to the bounding box of the source and that of the target
e.Length = Math.Max(settings.DefaultLength,
Math.Sqrt(2d * Math.Min(e.Source.BoundingBox.Width * e.Source.BoundingBox.Height, e.Target.BoundingBox.Width * e.Target.BoundingBox.Height)));
}
if (settings.ProportionalToSymmetricDifference)
{
SetEdgeLengthsProportionalToSymmetricDifference(component, settings.ProportionalEdgeLengthOffset, settings.ProportionalEdgeLengthAdjustment);
}
}