/// <summary>
/// Find the closest object to the specified point within the specified distance
/// </summary>
/// <param name="pt"></param>
/// <param name="distanceSquared"></param>
/// <returns></returns>
public T NearestTo(Vector pt, ref double distanceSquared, T ignore)
{
T result = default(T);
if (_SplitDimension != CoordinateAxis.Undefined)
{
double value = _Tree.PositionInDimension(_SplitDimension, pt);
//Check starting cell:
double t = (value - _Origin) / _CellSize;
int startIndex = (int)Math.Floor(t);
if (startIndex < 0)
{
startIndex = 0;
}
else if (startIndex >= _Branches.Length)
{
startIndex = _Branches.Length - 1;
}
DDTreeNode <T> node = _Branches[startIndex];
if (node != null)
{
result = node.NearestTo(pt, ref distanceSquared, ignore);
}
//Check surrounding cells within max distance:
int offsetIndex = 1;
double cellSizeSquared = _CellSize * _CellSize;
double t0 = t - startIndex;
double t1 = -t0;
t0 -= 1;
bool increase = true;
bool decrease = true;
while (increase || decrease)
{
if (increase)
{
double pInd = offsetIndex + t1;
int i = startIndex + offsetIndex;
if (pInd * pInd * cellSizeSquared >= distanceSquared || i >= _Branches.Length)
{
increase = false;
}
else
{
node = _Branches[i];
if (node != null)
{
T result2 = default(T);
result2 = node.NearestTo(pt, ref distanceSquared, ignore);
if (result2 != null)
{
result = result2;
}
}
}
}
if (decrease)
{
double pInd = offsetIndex + t0;
int i = startIndex - offsetIndex;
if (pInd * pInd * cellSizeSquared >= distanceSquared || i < 0)
{
decrease = false;
}
else
{
node = _Branches[i];
if (node != null)
{
T result2 = default(T);
result2 = node.NearestTo(pt, ref distanceSquared, ignore);
if (result2 != null)
{
result = result2;
}
}
}
}
offsetIndex++;
}
}
else
{
foreach (T item in _Children)
{
if (_Tree.CanReturn(item) && !object.ReferenceEquals(item, ignore))
{
double distSquaredTo = _Tree.DistanceSquaredBetween(pt, item);
if (distSquaredTo < distanceSquared)
{
distanceSquared = distSquaredTo;
result = item;
}
}
}
}
return(result);
}
/// <summary>
/// Find the closest item in the tree to the specified point within the specified maximum distance
/// </summary>
/// <param name="pt">The point to search from</param>
/// <param name="maxDistance">The maximum distance</param>
/// <param name="ignore">Optional. A value in the tree which is to be ignored.</param>
/// <returns></returns>
public T NearestTo(Vector pt, double maxDistance, T ignore = default(T))
{
double distanceSquared = maxDistance * maxDistance;
return(_RootNode.NearestTo(pt, ref distanceSquared, ignore));
}