/// <summary>
/// Given a normalized coordinate in multiple dimensions, calculate its derived key for given level
/// </summary>
private long?DerivedValueFor(long[] normalizedValues, int level)
{
AssertValidLevel(level);
long derivedValue = 0;
long mask = 1L << (_maxLevel - 1);
// The starting curve depends on the dimensions
CurveRule currentCurve = RootCurve();
for (int i = 1; i <= _maxLevel; i++)
{
int bitIndex = _maxLevel - i;
int npoint = 0;
foreach (long val in normalizedValues)
{
npoint = npoint << 1 | ( int )((val & mask) >> bitIndex);
}
int derivedIndex = currentCurve.IndexForNPoint(npoint);
derivedValue = (derivedValue << _nbrDim) | derivedIndex;
mask = mask >> 1;
currentCurve = currentCurve.ChildAt(derivedIndex);
}
if (level < _maxLevel)
{
derivedValue = derivedValue << (_nbrDim * _maxLevel - level);
}
return(derivedValue);
}
