d3-dag/src/arquint/column/simpleCenter.js

Layout algorithms for visualizing directed acylic graphs.

export default function() {
  // keeps order of nodes in a layer but spreads nodes in a layer over the middle columns
  function columnIndexAssignmentCenter(layers) {
    const maxNodesPerLayer = Math.max(...layers.map((layer) => layer.length));
    layers.forEach((layer) => {
      const nodesInLayer = layer.length;
      const startColumnIndex = Math.floor(
        (maxNodesPerLayer - nodesInLayer) / 2
      );
      layer.forEach(
        (node, nodeIndex) => (node.columnIndex = startColumnIndex + nodeIndex)
      );
    });
  }

  return columnIndexAssignmentCenter;
}