public ArborPoint toScreen(ArborPoint pt)
{
if (fViewBounds == null)
{
return(ArborPoint.Null);
}
ArborPoint vd = fViewBounds.RightBottom.sub(fViewBounds.LeftTop);
double sx = margins[3] + pt.sub(fViewBounds.LeftTop).div(vd.X).X *(this.fScreenWidth - (margins[1] + margins[3]));
double sy = margins[0] + pt.sub(fViewBounds.LeftTop).div(vd.Y).Y *(this.fScreenHeight - (margins[0] + margins[2]));
return(new ArborPoint(sx, sy));
}
public ArborNode nearest(int sx, int sy)
{
ArborPoint x = this.fromScreen(sx, sy);
ArborNode resNode = null;
double minDist = +1.0;
foreach (ArborNode node in this.fNodes)
{
ArborPoint z = node.Pt;
if (z.exploded())
{
continue;
}
double dist = z.sub(x).magnitude();
if (dist < minDist)
{
resNode = node;
minDist = dist;
}
}
//minDist = this.toScreen(resNode.Pt).sub(this.toScreen(x)).magnitude();
return(resNode);
}
private void updateGraphBounds()
{
ArborPoint lt = new ArborPoint(-1, -1);
ArborPoint rb = new ArborPoint(1, 1);
foreach (ArborNode node in this.fNodes)
{
ArborPoint pt = node.Pt;
if (pt.exploded())
{
continue;
}
if (pt.X < lt.X)
{
lt.X = pt.X;
}
if (pt.Y < lt.Y)
{
lt.Y = pt.Y;
}
if (pt.X > rb.X)
{
rb.X = pt.X;
}
if (pt.Y > rb.Y)
{
rb.Y = pt.Y;
}
}
lt.X -= 1.2;
lt.Y -= 1.2;
rb.X += 1.2;
rb.Y += 1.2;
ArborPoint sz = rb.sub(lt);
ArborPoint cent = lt.add(sz.div(2));
ArborPoint d = new ArborPoint(Math.Max(sz.X, 4.0), Math.Max(sz.Y, 4.0)).div(2);
this.fGraphBounds = new PSBounds(cent.sub(d), cent.add(d));
}
public BarnesHutTree(ArborPoint origin, ArborPoint h, double dist)
{
this.fDist = dist * dist;
this.fRoot = new Branch(origin, h.sub(origin));
}
private void updateVelocityAndPosition(double dt)
{
int size = fNodes.Count;
if (size == 0)
{
EnergySum = 0;
EnergyMax = 0;
EnergyMean = 0;
return;
}
double eSum = 0;
double eMax = 0;
// calc center drift
ArborPoint rr = new ArborPoint(0, 0);
foreach (ArborNode node in fNodes)
{
rr = rr.sub(node.Pt);
}
ArborPoint drift = rr.div(size);
// main updates loop
foreach (ArborNode node in fNodes)
{
// apply center drift
node.applyForce(drift);
// apply center gravity
if (ParamGravity)
{
ArborPoint q = node.Pt.mul(-1);
node.applyForce(q.mul(ParamRepulsion / 100));
}
// update velocities
if (node.Fixed)
{
node.V = new ArborPoint(0, 0);
}
else
{
node.V = node.V.add(node.F.mul(dt));
node.V = node.V.mul(1 - ParamFriction);
double r = node.V.magnitudeSquare();
if (r > 1000000)
{
node.V = node.V.div(r);
}
}
node.F.X = node.F.Y = 0;
// update positions
node.Pt = node.Pt.add(node.V.mul(dt));
// update energy
double z = node.V.magnitudeSquare();
eSum += z;
eMax = Math.Max(z, eMax);
}
EnergySum = eSum;
EnergyMax = eMax;
EnergyMean = eSum / size;
}