Function collide

external/.d3.js:8867–8954

(radius)

}

function collide(radius) {
  var nodes,
      radii,
      random,
      strength = 1,
      iterations = 1;

  if (typeof radius !== "function") radius = constant$4(radius == null ? 1 : +radius);

  function force() {
    var i, n = nodes.length,
        tree,
        node,
        xi,
        yi,
        ri,
        ri2;

    for (var k = 0; k < iterations; ++k) {
      tree = quadtree(nodes, x$3, y$3).visitAfter(prepare);
      for (i = 0; i < n; ++i) {
        node = nodes[i];
        ri = radii[node.index], ri2 = ri * ri;
        xi = node.x + node.vx;
        yi = node.y + node.vy;
        tree.visit(apply);
      }
    }

    function apply(quad, x0, y0, x1, y1) {
      var data = quad.data, rj = quad.r, r = ri + rj;
      if (data) {
        if (data.index > node.index) {
          var x = xi - data.x - data.vx,
              y = yi - data.y - data.vy,
              l = x * x + y * y;
          if (l < r * r) {
            if (x === 0) x = jiggle(random), l += x * x;
            if (y === 0) y = jiggle(random), l += y * y;
            l = (r - (l = Math.sqrt(l))) / l * strength;
            node.vx += (x *= l) * (r = (rj *= rj) / (ri2 + rj));
            node.vy += (y *= l) * r;
            data.vx -= x * (r = 1 - r);
            data.vy -= y * r;
          }
        }
        return;
      }
      return x0 > xi + r || x1 < xi - r || y0 > yi + r || y1 < yi - r;
    }
  }

  function prepare(quad) {
    if (quad.data) return quad.r = radii[quad.data.index];
    for (var i = quad.r = 0; i < 4; ++i) {
      if (quad[i] && quad[i].r > quad.r) {
        quad.r = quad[i].r;
      }