internal InternalKdNode Split(out LeafKdNode rightSibling)
{
Particle.Dim splitDirection =
Dimension(Particle.Dim.Horizontal) > Dimension(Particle.Dim.Vertical)
? Particle.Dim.Horizontal : Particle.Dim.Vertical;
Particle.Dim nonSplitDirection =
splitDirection == Particle.Dim.Horizontal
? Particle.Dim.Vertical : Particle.Dim.Horizontal;
int n = Size(), nLeft = n / 2, nRight = n - nLeft;
Particle[][]
leftParticles = new Particle[][] { new Particle[nLeft], new Particle[nLeft] },
rightParticles = new Particle[][] { new Particle[nRight], new Particle[nRight] };
int lCtr = 0, rCtr = 0;
for (int i = 0; i < n; ++i)
{
Particle p = particles[(int)splitDirection][i];
if (i < nLeft)
{
leftParticles[(int)splitDirection][i] = p;
p.splitLeft = true;
}
else
{
rightParticles[(int)splitDirection][i - nLeft] = p;
p.splitLeft = false;
}
}
for (int i = 0; i < n; ++i)
{
Particle p = particles[(int)nonSplitDirection][i];
if (p.splitLeft)
{
leftParticles[(int)nonSplitDirection][lCtr++] = p;
}
else
{
rightParticles[(int)nonSplitDirection][rCtr++] = p;
}
}
Debug.Assert(lCtr == nLeft);
Debug.Assert(rCtr == nRight);
Disc parentMED = med;
particles = leftParticles;
ComputeMED();
rightSibling = new LeafKdNode(rightParticles);
return(new InternalKdNode(parentMED, this, rightSibling));
}
private double Dimension(Particle.Dim d)
{
return(Max(d) - Min(d));
}
private double Min(Particle.Dim d)
{
return(particles[(int)d][0].pos(d));
}
private double Max(Particle.Dim d)
{
return(particles[(int)d][Size() - 1].pos(d));
}
private Particle[] particlesBy(Particle.Dim d)
{
return((from Particle p in particles
orderby p.pos(d)
select p).ToArray());
}