Function place

external/.d3.js:13415–13437

(b, a, c)

}

function place(b, a, c) {
  var dx = b.x - a.x, x, a2,
      dy = b.y - a.y, y, b2,
      d2 = dx * dx + dy * dy;
  if (d2) {
    a2 = a.r + c.r, a2 *= a2;
    b2 = b.r + c.r, b2 *= b2;
    if (a2 > b2) {
      x = (d2 + b2 - a2) / (2 * d2);
      y = Math.sqrt(Math.max(0, b2 / d2 - x * x));
      c.x = b.x - x * dx - y * dy;
      c.y = b.y - x * dy + y * dx;
    } else {
      x = (d2 + a2 - b2) / (2 * d2);
      y = Math.sqrt(Math.max(0, a2 / d2 - x * x));
      c.x = a.x + x * dx - y * dy;
      c.y = a.y + x * dy + y * dx;
    }
  } else {
    c.x = a.x + c.r;
    c.y = a.y;
  }
}

function intersects(a, b) {
  var dr = a.r + b.r - 1e-6, dx = b.x - a.x, dy = b.y - a.y;