public void Test_Div()
{
var pt = new ArborPoint(3, 4);
Assert.AreEqual(3.0f, pt.X);
Assert.AreEqual(4.0f, pt.Y);
pt = pt.Div(5);
Assert.AreEqual(3d / 5d, pt.X);
Assert.AreEqual(4d / 5d, pt.Y);
}
private void UpdateGraphBounds()
{
ArborPoint lt = new ArborPoint(-1.0f, -1.0f);
ArborPoint rb = new ArborPoint(+1.0f, +1.0f);
for (int i = 0, nodesCount = fNodes.Count; i < nodesCount; i++)
{
ArborPoint pt = fNodes[i].Pt;
if (pt.IsExploded())
{
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 -= 1.2f;
lt.Y -= 1.2f;
rb.X += 1.2f;
rb.Y += 1.2f;
ArborPoint sz = rb.Sub(lt);
ArborPoint cent = lt.Add(sz.Div(2.0f));
ArborPoint d = new ArborPoint(Math.Max(sz.X, 4.0f), Math.Max(sz.Y, 4.0f)).Div(2.0f);
fGraphBounds = new PSBounds(cent.Sub(d), cent.Add(d));
fBHTree = new BarnesHutTree(fGraphBounds.LeftTop, fGraphBounds.RightBottom, Theta);
}
private void UpdateVelocityAndPosition(double dt)
{
int nodesCount = fNodes.Count;
if (nodesCount == 0)
{
fEnergyMax = 0.0f;
fEnergyMean = 0.0f;
fEnergySum = 0.0f;
return;
}
double eMax = 0.0f;
double eSum = 0.0f;
// calc center drift
ArborPoint rr = ArborPoint.Zero;
for (int i = 0; i < nodesCount; i++)
{
ArborNode node = fNodes[i];
rr = rr.Sub(node.Pt);
}
ArborPoint drift = rr.Div(nodesCount);
// main updates loop
for (int i = 0; i < nodesCount; i++)
{
ArborNode node = fNodes[i];
// apply center drift
node.ApplyForce(drift);
// apply center gravity
if (fGravity)
{
ArborPoint q = node.Pt.Mul(-1.0f);
node.ApplyForce(q.Mul(fRepulsion / 100.0f));
}
// update velocities
if (node.Fixed)
{
node.V = ArborPoint.Zero;
}
else
{
node.V = node.V.Add(node.F.Mul(dt));
node.V = node.V.Mul(1.0f - fFriction);
double r = node.V.MagnitudeSquare();
if (r > 1000000.0f)
{
node.V = node.V.Div(r);
}
}
node.F = ArborPoint.Zero;
// update positions
node.Pt = node.Pt.Add(node.V.Mul(dt));
// update energy
double energy = node.V.MagnitudeSquare();
eSum += energy;
eMax = Math.Max(energy, eMax);
}
fEnergyMax = eMax;
fEnergyMean = eSum / nodesCount;
fEnergySum = eSum;
}
internal void ApplyForce(ArborPoint a)
{
F = F.Add(a.Div(Mass));
}
