/// <summary>
/// Applies this force to a simulation.
/// </summary>
/// <param name="sim">the Simulation to apply the force to</param>
public void Apply(Simulation sim)
{
foreach (var edge in sim.Springs)
{
var s = edge.p1;
var t = edge.p2;
dx = s.x - t.x;
dy = s.y - t.y;
dn = Math.Sqrt(dx * dx + dy * dy);
dd = dn < 1.0 ? 1.0 : dn;
k = edge.tension * (dn - edge.restLength);
k += edge.damping * (dx * (s.vx - t.vx) + dy * (s.vy - t.vy)) / dd;
k /= dd;
Random rnd = new Random();
if (dn == 0)
{
dx = 0.01 * (0.5 - rnd.NextDouble());
dy = 0.01 * (0.5 - rnd.NextDouble());
}
fx = -k * dx;
fy = -k * dy;
s.fx += fx; s.fy += fy;
t.fx -= fx; t.fy -= fy;
}
}
/// <summary>
/// Applies this force to a simulation.
/// </summary>
/// <param name="sim">the Simulation to apply the force to</param>
public void Apply(Simulation sim)
{
if (_dc == 0) return;
foreach (var particle in sim.Particles)
{
var p = particle;
p.fx -= _dc * p.vx;
p.fy -= _dc * p.vy;
}
}
/// <summary>
/// Applies this force to a simulation.
/// </summary>
/// <param name="sim">the Simulation to apply the force to</param>
public void Apply(Simulation sim)
{
if (_gx == 0 && _gy == 0) return;
foreach (var n in sim.Particles)
{
n.fx += _gx * n.mass;
n.fy += _gy * n.mass;
}
}
public Graph(IDictionary<string, string> initParams)
{
InitializeComponent();
sim = new Simulation();
particles = new Dictionary<string, Particle>();
Loaded += new RoutedEventHandler(Graph_Loaded);
string xml;
if (initParams.TryGetValue("xml", out xml))
LoadXML(initParams["xml"]);
}
private void bounds(Simulation graph)
{
double dx, dy;
_x1 = _y1 = double.MaxValue;
_x2 = _y2 = double.MinValue;
// get bounding box
foreach(var p in graph.Particles) {
if (p.x < _x1) _x1 = p.x;
if (p.y < _y1) _y1 = p.y;
if (p.x > _x2) _x2 = p.x;
if (p.y > _y2) _y2 = p.y;
}
// square the box
dx = _x2 - _x1;
dy = _y2 - _y1;
if (dx > dy) {
_y2 = _y1 + dx;
} else {
_x2 = _x1 + dy;
}
}
/// <summary>
/// Applies this force to a simulation.
/// </summary>
/// <param name="sim">the Simulation to apply the force to</param>
public void Apply(Simulation sim)
{
if (_g == 0) return;
// clear the quadtree
clear(_root); _root = QuadTreeNode.Particle();
// get the tree bounds
bounds(sim);
// populate the tree
foreach (var particle in sim.Particles) {
insert(particle, _root, _x1, _y1, _x2, _y2);
}
// traverse tree to compute mass
accumulate(_root);
// calculate forces on each Particle
foreach (var particle in sim.Particles) {
forces(particle, _root, _x1, _y1, _x2, _y2);
}
}