public Node()
{
NodeId = Guid.NewGuid ();
links = new List<Spring> ();
Location = new Point ();
Charge = 1;
Mass = 0.1;
Velocity = new Vector3D ();
NetForce = new Vector3D ();
}
// compute one step
public void Compute( Action<Node> callback )
{
totalKE = 0.0;
foreach (var a in Nodes) {
// calculate repulsive forces
a.NetForce = new Vector3D ();
foreach (var b in Nodes) {
if (!b.Equals (a)) {
a.NetForce += (a.Location - b.Location).UnitVector * Repulsion (a, b);
// Console.WriteLine ("repulsion {0}", Repulsion (a, b));
}
}
// calculate spring forces
foreach (var s in a.Links) {
a.NetForce += (a.Location - s.Other (a).Location).UnitVector * SpringAttraction (a, s);
// Console.WriteLine ("attraction {0}", SpringAttraction (a, s));
}
}
// move and calculate KE
foreach (var x in Nodes) {
Vector3D vel = new Vector3D(){
X = x.NetForce.X * ComputeTimeStep * Damping,
Y = x.NetForce.Y * ComputeTimeStep * Damping,
Z = x.NetForce.Z * ComputeTimeStep * Damping
};
x.Location += new Point(){
X = vel.X * ComputeTimeStep,
Y = vel.Y * ComputeTimeStep,
Z = vel.Z * ComputeTimeStep
};
if ( x.Location.X < minX ) minX = x.Location.X;
if ( x.Location.Y < minY ) minY = x.Location.Y;
if ( x.Location.X > maxX ) maxX = x.Location.X;
if ( x.Location.Y > maxY ) maxY = x.Location.Y;
totalKE += x.Mass * Math.Pow( vel.Length , 2 );
if ( callback != null ){
callback( x );
}
}
}
