emit method

int emit(double dt, double time)

Returns the number of particles to emit over a step of length dt that starts at system time time.

Implementation

int emit(double dt, double time) {
  var count = 0;
  if (rate > 0.0) {
    _accumulator += rate * dt;
    final whole = _accumulator.floor();
    _accumulator -= whole;
    count += whole;
  }
  if (bursts.isNotEmpty) {
    final end = time + dt;
    for (final burst in bursts) {
      if (burst.interval > 0.0) {
        // Occurrence k is at burst.time + k * interval; count those in the
        // half-open window [time, end) directly rather than iterating cycles.
        final inverse = 1.0 / burst.interval;
        var first = ((time - burst.time) * inverse).ceil();
        if (first < 0) first = 0;
        var last = ((end - burst.time) * inverse).ceil() - 1;
        final cycles = burst.cycles;
        if (cycles != null && last > cycles - 1) last = cycles - 1;
        if (last >= first) count += (last - first + 1) * burst.count;
      } else if (burst.time >= time && burst.time < end) {
        count += burst.count;
      }
    }
  }
  return count;
}