public ArborPoint GetViewCoords(ArborPoint pt)
{
if (fViewBounds == null)
{
return(ArborPoint.Null);
}
ArborPoint vd = fViewBounds.RightBottom.Sub(fViewBounds.LeftTop);
double x = Margins[3] + (pt.Sub(fViewBounds.LeftTop).Div(vd.X).X *(fViewWidth - (Margins[1] + Margins[3])));
double y = Margins[0] + (pt.Sub(fViewBounds.LeftTop).Div(vd.Y).Y *(fViewHeight - (Margins[0] + Margins[2])));
return(new ArborPoint(x, y));
}
public ArborNode GetNearestNode(int viewX, int viewY)
{
ArborPoint pt = GetModelCoords(viewX, viewY);
ArborNode result = null;
double minDist = +1.0f;
for (int i = 0, nodesCount = fNodes.Count; i < nodesCount; i++)
{
ArborNode node = fNodes[i];
ArborPoint nodePt = node.Pt;
if (nodePt.IsExploded())
{
continue;
}
double dist = nodePt.Sub(pt).Magnitude();
if (dist < minDist)
{
result = node;
minDist = dist;
}
}
return(result);
}
private ArborPoint NewRandomPoint()
{
ArborPoint lt = fGraphBounds.LeftTop;
ArborPoint rb = fGraphBounds.RightBottom;
ArborPoint dt = rb.Sub(lt);
double x = lt.X + (dt.X * ArborSystem.GetRandom());
double y = lt.Y + (dt.Y * ArborSystem.GetRandom());
return(new ArborPoint(x, y));
}
public void Test_Sub()
{
var pt = new ArborPoint(3, 4);
Assert.AreEqual(3.0f, pt.X);
Assert.AreEqual(4.0f, pt.Y);
pt = pt.Sub(new ArborPoint(10, 11));
Assert.AreEqual(-7.0f, pt.X);
Assert.AreEqual(-7.0f, 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);
}
public BarnesHutTree(ArborPoint lt, ArborPoint rb, double dist)
{
fDist = dist;
fRoot = new Branch(lt, rb.Sub(lt));
}
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;
}
