AnchorPoint

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The anchorPoint of a node is the link point where the related edges link to. In other words, it is the intersection of a node and its related edges. anchorPoints is a 2d array, each element represents the position of one anchor point. The positions of the anchor points in a Shape are shown below, the range of each x and y is [0, 1]:
img

You can select the link points for an edge by sourceAnchor and targetAnchor if there are anchorPoints in the source and target node. Where This sourceAnchor and targetAnchor indicate the index of the array of anchorPoints. mechanism beautifies the graphs when there are multiple edges between two nodes.

The data below shows how to configure the anchorPoints on a node and link points for an edge:

const data = {
  nodes: [
    {
      id: 'node1',
      label: 'node1',
      x: 100,
      y: 200,
      // There are two anchorPoints for this node
      anchorPoints: [
        [0, 1],
        [0.5, 1],
      ],
      type: 'rect',
    },
    {
      id: 'node2',
      label: 'node2',
      x: 300,
      y: 400,
      // There are two anchorPoints for this node
      anchorPoints: [
        [0.5, 0],
        [1, 0.5],
      ],
      type: 'rect',
    },
  ],
  edges: [
    {
      source: 'node1',
      target: 'node2',
      // The source link point of the edge is the 0-th anchorPoint of the source node
      sourceAnchor: 0,
      // The target link point of the edge is the 0-th anchorPoint of the target node
      targetAnchor: 0,
      style: {
        endArrow: true,
      },
    },
    {
      source: 'node2',
      target: 'node1',
      // The source link point of the edge is the 1-st anchorPoint of the source node
      sourceAnchor: 1,
      // The target link point of the edge is the 1-st anchorPoint of the target node
      targetAnchor: 1,
      style: {
        endArrow: true,
      },
    },
  ],
};