d3-sankey-diagram/src/sankeyLayout/utils.js

Sankey diagram d3 plugin

export function findFirst (links, p) {
  let jmid = null
  for (let j = 0; j < links.length; ++j) {
    if (p(links[j])) { jmid = j; break }
  }
  return jmid
}

/**
 * Adjust radii of curvature to avoid overlaps, as much as possible.
 * @param links - the list of links, ordered from outside to inside of bend
 * @param rr - "r0" or "r1", the side to work on
 */
export function sweepCurvatureInwards (links, rr) {
  if (links.length === 0) return

  // sweep from inside of curvature towards outside
  let Rmin = 0; let h
  for (let i = links.length - 1; i >= 0; --i) {
    h = links[i].dy / 2
    if (links[i][rr] - h < Rmin) { // inner radius
      links[i][rr] = Math.min(links[i].Rmax, Rmin + h)
    }
    Rmin = links[i][rr] + h
  }

  // sweep from outside of curvature towards centre
  let Rmax = links[0].Rmax + links[0].dy / 2
  for (let i = 0; i < links.length; ++i) {
    h = links[i].dy / 2
    if (links[i][rr] + h > Rmax) { // outer radius
      links[i][rr] = Math.max(h, Rmax - h)
    }
    Rmax = links[i][rr] - h
  }
}