Force-directed layout

The force-directed layout positions nodes with a physics simulation — edges pull connected nodes together, all nodes push apart — until the graph settles into a balanced, organic shape. kymo uses it for mindmaps, where a central idea branches out radially.

It's a pure-Rust cose-bilkent (Compound Spring Embedder) implementation, vendored as the kymo-manatee crate — the same algorithm mermaid.js uses for mindmaps, so the result reads the same.

How it works

1. Each node gets a size (from its label); edges become springs.
2. The simulation iterates: spring forces shorten edges, repulsion spreads nodes, and compound (nested) nodes keep their children grouped.
3. When the energy settles, kymo shifts the result into positive coordinates and sizes the canvas to fit.

mindmap
  root((kymo))
    Layouts
      Dagre
      Grid
      Force
    Diagrams
      Flowchart
      Mindmap

Trade-offs

• Best for trees and loosely-connected graphs where an organic, radial shape reads better than strict ranks — mindmaps above all.
• Not strictly deterministic across unrelated inputs the way ranked layouts are, but the simulation is seeded so a given source is stable.
• Not for process flows or DAGs — those want the predictable ranks of Dagre.

→ Related: Mindmap.