Edge Routing

FlowGraph supports multiple edge routing algorithms to control how edges are drawn between nodes.

Edge Types

Set the edge type when creating an edge:

var edge = new Edge
{
    Source = node1.Id,
    Target = node2.Id,
    SourcePort = "out",
    TargetPort = "in",
    Type = EdgeType.Bezier  // Default
};

Available Types

Type	Description
EdgeType.Bezier	Smooth curved path (default)
EdgeType.Straight	Direct line
EdgeType.Step	Right-angle path
EdgeType.SmoothStep	Rounded right-angle path

Automatic Routing

Enable automatic edge routing to avoid node overlaps:

canvas.Settings.EnableEdgeRouting = true;
canvas.Settings.DefaultEdgeRouter = EdgeRouterType.Orthogonal;

Router Types

Router	Description
EdgeRouterType.Direct	Straight lines (no routing)
EdgeRouterType.Orthogonal	Right-angle paths with A* pathfinding
EdgeRouterType.SmartBezier	Bezier curves that avoid obstacles

Manual Routing

Trigger routing manually:

// Route all edges
canvas.Routing.RouteAllEdges();

// Route a specific edge
canvas.Routing.RouteEdge(edgeId);

Edge Markers

Add arrow markers to edges:

var edge = new Edge
{
    Source = node1.Id,
    Target = node2.Id,
    SourcePort = "out",
    TargetPort = "in",
    MarkerEnd = EdgeMarker.Arrow,      // Open arrow
    // or
    MarkerEnd = EdgeMarker.ArrowClosed // Filled arrow
};

Edge Labels

Add labels to edges:

// Simple label (centered on edge)
var edge = new Edge
{
    Source = node1.Id,
    Target = node2.Id,
    SourcePort = "out",
    TargetPort = "in",
    Label = "Connection"
};

Advanced Label Positioning

Use LabelInfo for precise control over label placement:

using FlowGraph.Core.Models;

// Label at the start of the edge (near source)
var edgeWithStartLabel = new Edge(new EdgeDefinition
{
    Id = "e1",
    Source = node1.Id,
    Target = node2.Id,
    SourcePort = "out",
    TargetPort = "in",
    LabelInfo = new LabelInfo("Yes", LabelAnchor.Start, offsetY: -10)
});

// Label at the end of the edge (near target)
var edgeWithEndLabel = new Edge(new EdgeDefinition
{
    Id = "e2",
    Source = node1.Id,
    Target = node2.Id,
    SourcePort = "out",
    TargetPort = "in",
    LabelInfo = new LabelInfo("No", LabelAnchor.End, offsetX: 5)
});

// Using the fluent builder method
var edge = existingEdge.Definition.WithLabelInfo("Label", LabelAnchor.Center, offsetX: 0, offsetY: -15);

Label Anchor Positions

Anchor	Position	Description
LabelAnchor.Start	~25%	Near the source node
LabelAnchor.Center	~50%	At the midpoint (default)
LabelAnchor.End	~75%	Near the target node

LabelInfo Properties

Property	Type	Description
Text	string	The label text content
Anchor	LabelAnchor	Position along the edge path
OffsetX	double	Horizontal offset in pixels (positive = right)
OffsetY	double	Vertical offset in pixels (positive = down)

Note: When both Label and LabelInfo are set, LabelInfo takes precedence. Use edge.Definition.EffectiveLabel to get the resolved label text.

Edge Reconnection

Users can drag edge endpoints to reconnect them to different ports. This is enabled by default.

// Disable reconnection
canvas.Settings.EnableEdgeReconnection = false;