code: function initHannWindow(buffer, size, normCoefs) {
    let linSum = 0;
    let powSum = 0;
    const step = 2 * PI / size;
  
    for (let i = 0; i < size; i++) {
      const phi = i * step;
      const value = 0.5 - 0.5 * cos(phi);
  
      buffer[i] = value;
  
      linSum += value;
      powSum += value * value;
    }
  
    normCoefs.linear = size / linSum;
    normCoefs.power = sqrt(size / powSum);
  }
docs: window creation functions