How to use

bitIndex

method

in

com.artemis.utils.BitVector

public int size() {
  // the number of bytes that can fit without using "more" memory
  return bitIndex(array.length());
}

public int nextClearBit(int fromIndex) {
  checkIndex(fromIndex);
  int index = wordIndex(fromIndex);
  // special case for first index
  int fromBit = fromIndex - (bitIndex(index));
  int word = getWord(array, index);
  for (int i = fromBit; i < 32; i++) {
    if ((word & (1 << i)) == 0) {
      return (bitIndex(index)) + i;
    }
  }
  // loop through the rest
  while (true) {
    index++;
    word = getWord(array, index);
    if (word != 0xffffffff) {
      return (bitIndex(index)) + Integer.numberOfTrailingZeros(~word);
    }
  }
}

public int length() {
  int last = trimToSize(array);
  if (last == -1) {
    return 0;
  }
  // compute the position of the leftmost bit's index
  int offsets[] = { 16, 8, 4, 2, 1 };
  int bitMasks[] = { 0xffff0000, 0xff00, 0xf0, 0xc, 0x2 };
  int position = bitIndex(last) + 1;
  int word = getWord(array, last);
  for (int i = 0; i < offsets.length; i++) {
    if ((word & bitMasks[i]) != 0) {
      word >>>= offsets[i];
      position += offsets[i];
    }
  }
  return position;
}

public int nextSetBit(int fromIndex) {
  checkIndex(fromIndex);
  int index = wordIndex(fromIndex);
  // check the current word
  int word = getWord(array, index);
  if (word != 0) {
    for (int i = bitOffset(fromIndex); i < 32; i++) {
      if ((word & (1 << i)) != 0) {
        return (bitIndex(index)) + i;
      }
    }
  }
  index++;
  // find the next set word
  trimToSize(array);
  index = nextSetWord(array, index);
  if (index == -1) {
    return -1;
  }
  // return the next set bit
  return (bitIndex(index))
      + Integer.numberOfTrailingZeros(array.get(index));
};

if ((bitIndex(newLength)) - fromIndex != 0) {
  maskOutWord(array, newLength - 1, bitOffset(fromIndex), 32);