Function start

d3-3.2.8/d3.js:7718–7729

(elapsed)

        if (delay <= elapsed) return start(elapsed);
        d3_timer_replace(start, delay, time);
        function start(elapsed) {
          if (lock.active > id) return stop();
          lock.active = id;
          transition.event && transition.event.start.call(node, d, i);
          transition.tween.forEach(function(key, value) {
            if (value = value.call(node, d, i)) {
              tweened.push(value);
            }
          });
          if (tick(elapsed)) return 1;
          d3_timer_replace(tick, 0, time);
        }
        function tick(elapsed) {
          if (lock.active !== id) return stop();
          var t = (elapsed - delay) / duration, e = ease(t), n = tweened.length;