/// <summary>
/// Return a square envelope containing the argument envelope,
/// whose extent is a power of two and which is based at a power of 2.
/// </summary>
/// <param name="itemInterval"></param>
public void ComputeKey(Interval itemInterval)
{
_level = ComputeLevel(itemInterval);
_interval = new Interval();
//_interval = Interval.Create();
ComputeInterval(_level, itemInterval);
// MD - would be nice to have a non-iterative form of this algorithm
while (!_interval.Contains(itemInterval))
{
_level += 1;
ComputeInterval(_level, itemInterval);
}
}
/// <summary>
///
/// </summary>
/// <param name="interval"></param>
/// <returns></returns>
public static int ComputeLevel(Interval interval)
{
double dx = interval.Width;
int level = DoubleBits.GetExponent(dx) + 1;
return level;
}
/// <summary>
///
/// </summary>
/// <param name="interval"></param>
public Key(Interval interval)
{
ComputeKey(interval);
}
/// <summary>
///
/// </summary>
/// <param name="level"></param>
/// <param name="itemInterval"></param>
private void ComputeInterval(int level, Interval itemInterval)
{
var size = DoubleBits.PowerOf2(level);
_pt = Math.Floor(itemInterval.Min / size) * size;
_interval.Init(_pt, _pt + size);
//_interval = Interval.Create(_pt, _pt + size);
}
/// <summary>
/// Creates a new interval instance, setting <see cref="Min"/>=<paramref name="interval.Min"/> and <see cref="Max"/>=<paramref name="interval.Max"/>.
/// </summary>
/// <param name="interval"></param>
public Interval(Interval interval)
{
Init(interval.Min, interval.Max);
}
/// <summary>
/// Function to test if this <see cref="Interval"/> contains <paramref name="interval"/>.
/// </summary>
/// <remarks>This is more rigid than <see cref="Overlaps(Interval)"/></remarks>
/// <param name="interval">The interval to test</param>
/// <returns><c>true</c> if this interval contains <paramref name="interval"/></returns>
public bool Contains(Interval interval)
{
return Contains(interval.Min, interval.Max);
}
/// <summary>
/// Function to test if this <see cref="Interval"/> overlaps <paramref name="interval"/>.
/// </summary>
/// <param name="interval">The interval to test</param>
/// <returns><c>true</c> if this interval overlaps <paramref name="interval"/></returns>
public bool Overlaps(Interval interval)
{
return Overlaps(interval.Min, interval.Max);
}
/// <summary>
/// Method to expand this interval to contain <paramref name="interval"/>.
/// </summary>
/// <param name="interval">The interval to contain.</param>
public void ExpandToInclude(Interval interval)
{
if (interval.Max > Max)
Max = interval.Max;
if (interval.Min < Min)
Min = interval.Min;
}
/// <summary> /// /// </summary> /// <param name="interval"></param> /// <returns></returns> protected abstract bool IsSearchMatch(Interval interval);
/// <summary>
///
/// </summary>
/// <param name="interval"></param>
public Key(Interval interval)
{
ComputeKey(interval);
}
