public void Refresh()
{
Ratchet.Collections.Quadtree <AgregatedParticle> particles = CreateGrid();
Parallel.ForEach <Particle>(_Swarm, (Particle particle) =>
{
float x = particle._x;
float y = particle._y;
float fx = 0;
float fy = 0;
foreach (Ratchet.Collections.Quadtree <AgregatedParticle> .Node neighboor in particles.GetNode((int)x - 15, (int)y - 15, 32, 32))
{
if (neighboor.Element != null)
{
// Quick interaction it is not meant to be accurate just pretty :)
float nx = neighboor.Element._x;
float ny = neighboor.Element._y;
int weight = neighboor.Element._weigth;
float dx = (x - nx) * (x - nx);
float dy = (y - ny) * (y - ny);
// Dirty hack to not count self interaction
if ((dx < float.Epsilon && dy < float.Epsilon))
{
continue;
}
float d2 = (x - nx) * (x - nx) + (y - ny) * (y - ny);
float d = (float)System.Math.Sqrt((double)d2);
// Only look at particles in a small radius
if (d > 30f)
{
continue;
}
float dirx = (float)(nx - x) / d;
float diry = (float)(ny - y) / d;
// Again a hack to avoid some instabilities
if (d2 < 1.0f)
{
d2 = 1.0f;
}
float f = (0.02f * (float)weight) / d2;
fx += dirx * f;
fy += diry * f;
}
}
particle._fx += fx;
particle._fy += fy;
particle._x += particle._fx;
particle._y += particle._fy;
});
}
public Ratchet.Collections.Quadtree <AgregatedParticle> CreateGrid()
{
Ratchet.Collections.Quadtree <AgregatedParticle> grid = new Ratchet.Collections.Quadtree <AgregatedParticle>();
for (int n = 0; n < _Swarm.Length; n++)
{
var node = grid.GetNode((long)_Swarm[n]._x, (long)_Swarm[n]._y, 1, 1);
AgregatedParticle agregatedParticles = node.Element;
if (agregatedParticles == null)
{
agregatedParticles = new AgregatedParticle(node.X + (float)node.Size / 2.0f, node.Y + (float)node.Size / 2.0f);
node.Element = agregatedParticles;
}
else
{
agregatedParticles._weigth++;
}
}
return(grid);
}
private void ParticlesView_Paint(object sender, PaintEventArgs e)
{
System.Drawing.Pen pen = new System.Drawing.Pen(Color.FromArgb(64, 255, 255, 255));
particles.Draw(bitmap, _DrawTree);
if (_DrawTree)
{
var g = System.Drawing.Graphics.FromImage(bitmap);
Ratchet.Collections.Quadtree <Particles.AgregatedParticle> tree = particles.CreateGrid();
foreach (var node in tree.Query(0, 0, (ulong)bitmap.Width, (ulong)bitmap.Height))
{
if (node.Size > 1)
{
g.DrawRectangle(pen, node.X, node.Y, node.Size, node.Size);
}
}
}
e.Graphics.DrawImage(bitmap, new Rectangle(0, 0, Width, Height));
}
