partition method

dynamic partition(int i, int j, num? value, double left, double top, double right, double bottom,)

Implementation

partition(int i, int j, num? value, double left, double top, double right,
    double bottom) {
  if (i >= j - 1) {
    var node = _children![i];
    node.left = left;
    node.top = top;
    node.right = right;
    node.bottom = bottom;
    return;
  }

  num? valueOffset = _sums[i],
      valueTarget = (value! / 2) + valueOffset,
      k = i + 1,
      hi = j - 1;

  while (k! < hi!) {
    int mid = (k + hi).toInt() >> 1;
    if (_sums[mid] < valueTarget)
      k = mid + 1;
    else
      hi = mid;
  }

  if ((valueTarget - _sums[k - 1 as int]) < (_sums[k as int] - valueTarget) &&
      i + 1 < k) --k;

  var valueLeft = _sums[k] - valueOffset, valueRight = value - valueLeft;

  if ((right - left) > (bottom - top)) {
    var xk = (left * valueRight + right * valueLeft) / value;
    partition(i, k, valueLeft, left, top, xk, bottom);
    partition(k, j, valueRight, xk, top, right, bottom);
  } else {
    var yk = (top * valueRight + bottom * valueLeft) / value;
    partition(i, k, valueLeft, left, top, right, yk);
    partition(k, j, valueRight, left, yk, right, bottom);
  }
}