private static double _getSquaredDistanceTo(T value, double x, double y, double defaultValue = double.PositiveInfinity)
{
return(value == null
? defaultValue
: Geom.SumSqr(value.X - x, value.Y - y));
}
private void _findAllNearby(Node node, double left, double top, double right, double bottom)
{
if (node.Value != null)
{
if (_getSquaredDistanceTo(node.Value) <= _squaredDistanceE)
{
_values.Add(node.Value);
}
return;
}
if (!node.HasValueBelow)
{
return;
}
var centerX = (left + right) / 2.0D;
var centerY = (top + bottom) / 2.0D;
if (_x < centerX)
{
if (_y < centerY)
{
_findAllNearby(node.LeftTop, left, top, centerX, centerY);
if (_squaredDistanceE >= Geom.Sqr(centerX - _x))
{
_findAllNearby(node.RightTop, centerX, top, right, centerY);
}
if (_squaredDistanceE >= Geom.Sqr(centerY - _y))
{
_findAllNearby(node.LeftBottom, left, centerY, centerX, bottom);
}
if (_squaredDistanceE >= Geom.SumSqr(centerX - _x, centerY - _y))
{
_findAllNearby(node.RightBottom, centerX, centerY, right, bottom);
}
}
else
{
_findAllNearby(node.LeftBottom, left, centerY, centerX, bottom);
if (_squaredDistanceE >= Geom.Sqr(centerX - _x))
{
_findAllNearby(node.RightBottom, centerX, centerY, right, bottom);
}
if (_squaredDistanceE > Geom.Sqr(_y - centerY))
{
_findAllNearby(node.LeftTop, left, top, centerX, centerY);
}
if (_squaredDistanceE >= Geom.SumSqr(centerX - _x, _y - centerY))
{
_findAllNearby(node.RightTop, centerX, top, right, centerY);
}
}
}
else
{
if (_y < centerY)
{
_findAllNearby(node.RightTop, centerX, top, right, centerY);
if (_squaredDistanceE > Geom.Sqr(_x - centerX))
{
_findAllNearby(node.LeftTop, left, top, centerX, centerY);
}
if (_squaredDistanceE >= Geom.Sqr(centerY - _y))
{
_findAllNearby(node.RightBottom, centerX, centerY, right, bottom);
}
if (_squaredDistanceE >= Geom.SumSqr(_x - centerX, centerY - _y))
{
_findAllNearby(node.LeftBottom, left, centerY, centerX, bottom);
}
}
else
{
_findAllNearby(node.RightBottom, centerX, centerY, right, bottom);
if (_squaredDistanceE > Geom.Sqr(_x - centerX))
{
_findAllNearby(node.LeftBottom, left, centerY, centerX, bottom);
}
if (_squaredDistanceE > Geom.Sqr(_y - centerY))
{
_findAllNearby(node.RightTop, centerX, top, right, centerY);
}
if (_squaredDistanceE > Geom.SumSqr(_x - centerX, _y - centerY))
{
_findAllNearby(node.LeftTop, left, top, centerX, centerY);
}
}
}
}
private double _getSquaredDistanceTo(T value, double defaultValue = double.PositiveInfinity)
{
return(value == null || value.Id == _id
? defaultValue
: Geom.SumSqr(value.X - _x, value.Y - _y));
}
private T _findNearest(Node node, double left, double top, double right, double bottom)
{
if (node.Value != null)
{
if (_getSquaredDistanceTo(node.Value, _squaredDistance) <= _squaredDistanceE)
{
return(node.Value);
}
return(null);
}
if (!node.HasValueBelow)
{
return(null);
}
var centerX = (left + right) / 2.0D;
var centerY = (top + bottom) / 2.0D;
if (_x < centerX)
{
if (_y < centerY)
{
var nearestValue = _findNearest(node.LeftTop, left, top, centerX, centerY);
var nearestSquaredDistance = _getSquaredDistanceTo(nearestValue, _squaredDistance);
if (nearestSquaredDistance + _epsilon >= Geom.Sqr(centerX - _x))
{
var otherValue = _findNearest(node.RightTop, centerX, top, right, centerY);
var otherSquaredDistance = _getSquaredDistanceTo(otherValue, _squaredDistance);
if (otherSquaredDistance < nearestSquaredDistance)
{
nearestValue = otherValue;
nearestSquaredDistance = otherSquaredDistance;
}
}
if (nearestSquaredDistance + _epsilon >= Geom.Sqr(centerY - _y))
{
var otherValue = _findNearest(node.LeftBottom, left, centerY, centerX, bottom);
var otherSquaredDistance = _getSquaredDistanceTo(otherValue, _squaredDistance);
if (otherSquaredDistance < nearestSquaredDistance)
{
nearestValue = otherValue;
nearestSquaredDistance = otherSquaredDistance;
}
}
if (nearestSquaredDistance + _epsilon >= Geom.SumSqr(centerX - _x, centerY - _y))
{
var otherValue = _findNearest(node.RightBottom, centerX, centerY, right, bottom);
var otherSquaredDistance = _getSquaredDistanceTo(otherValue, _squaredDistance);
if (otherSquaredDistance < nearestSquaredDistance)
{
nearestValue = otherValue;
}
}
return(nearestValue);
}
else
{
var nearestValue = _findNearest(node.LeftBottom, left, centerY, centerX, bottom);
var nearestSquaredDistance = _getSquaredDistanceTo(nearestValue, _squaredDistance);
if (nearestSquaredDistance + _epsilon >= Geom.Sqr(centerX - _x))
{
var otherValue = _findNearest(node.RightBottom, centerX, centerY, right, bottom);
var otherSquaredDistance = _getSquaredDistanceTo(otherValue, _x, _y, _squaredDistance);
if (otherSquaredDistance < nearestSquaredDistance)
{
nearestValue = otherValue;
nearestSquaredDistance = otherSquaredDistance;
}
}
if (nearestSquaredDistance + _epsilon > Geom.Sqr(_y - centerY))
{
var otherValue = _findNearest(node.LeftTop, left, top, centerX, centerY);
var otherSquaredDistance = _getSquaredDistanceTo(otherValue, _squaredDistance);
if (otherSquaredDistance < nearestSquaredDistance)
{
nearestValue = otherValue;
nearestSquaredDistance = otherSquaredDistance;
}
}
if (nearestSquaredDistance + _epsilon >= Geom.SumSqr(centerX - _x, _y - centerY))
{
var otherValue = _findNearest(node.RightTop, centerX, top, right, centerY);
var otherSquaredDistance = _getSquaredDistanceTo(otherValue, _squaredDistance);
if (otherSquaredDistance < nearestSquaredDistance)
{
nearestValue = otherValue;
}
}
return(nearestValue);
}
}
else
{
if (_y < centerY)
{
var nearestValue = _findNearest(node.RightTop, centerX, top, right, centerY);
var nearestSquaredDistance = _getSquaredDistanceTo(nearestValue, _squaredDistance);
if (nearestSquaredDistance + _epsilon > Geom.Sqr(_x - centerX))
{
var otherValue = _findNearest(node.LeftTop, left, top, centerX, centerY);
var otherSquaredDistance = _getSquaredDistanceTo(otherValue, _squaredDistance);
if (otherSquaredDistance < nearestSquaredDistance)
{
nearestValue = otherValue;
nearestSquaredDistance = otherSquaredDistance;
}
}
if (nearestSquaredDistance + _epsilon >= Geom.Sqr(centerY - _y))
{
var otherValue = _findNearest(node.RightBottom, centerX, centerY, right, bottom);
var otherSquaredDistance = _getSquaredDistanceTo(otherValue, _squaredDistance);
if (otherSquaredDistance < nearestSquaredDistance)
{
nearestValue = otherValue;
nearestSquaredDistance = otherSquaredDistance;
}
}
if (nearestSquaredDistance + _epsilon >= Geom.SumSqr(_x - centerX, centerY - _y))
{
var otherValue = _findNearest(node.LeftBottom, left, centerY, centerX, bottom);
var otherSquaredDistance = _getSquaredDistanceTo(otherValue, _squaredDistance);
if (otherSquaredDistance < nearestSquaredDistance)
{
nearestValue = otherValue;
}
}
return(nearestValue);
}
else
{
var nearestValue = _findNearest(node.RightBottom, centerX, centerY, right, bottom);
var nearestSquaredDistance = _getSquaredDistanceTo(nearestValue, _squaredDistance);
if (nearestSquaredDistance + _epsilon > Geom.Sqr(_x - centerX))
{
var otherValue = _findNearest(node.LeftBottom, left, centerY, centerX, bottom);
var otherSquaredDistance = _getSquaredDistanceTo(otherValue, _squaredDistance);
if (otherSquaredDistance < nearestSquaredDistance)
{
nearestValue = otherValue;
nearestSquaredDistance = otherSquaredDistance;
}
}
if (nearestSquaredDistance + _epsilon > Geom.Sqr(_y - centerY))
{
var otherValue = _findNearest(node.RightTop, centerX, top, right, centerY);
var otherSquaredDistance = _getSquaredDistanceTo(otherValue, _squaredDistance);
if (otherSquaredDistance < nearestSquaredDistance)
{
nearestValue = otherValue;
nearestSquaredDistance = otherSquaredDistance;
}
}
if (nearestSquaredDistance + _epsilon > Geom.SumSqr(_x - centerX, _y - centerY))
{
var otherValue = _findNearest(node.LeftTop, left, top, centerX, centerY);
var otherSquaredDistance = _getSquaredDistanceTo(otherValue, _squaredDistance);
if (otherSquaredDistance < nearestSquaredDistance)
{
nearestValue = otherValue;
}
}
return(nearestValue);
}
}
}