public static void BuildCircle(int x, int y, int r, int R)
{
Particle mid = new Particle();
mid.Position = new Vector(x, y);
mid.Radius = R;
World.AddParticle(mid);
Particle prev = null;
Particle first = null;
Vector rv = new Vector(r, 0);
int k = (int)((2 * 3.14 * r) / (mid.Radius * 3));
k += 1;
for (int i = 0; i < k; i++)
{
Particle p = new Particle();
p.Radius = R;
p.Mass = 1;
if (first == null)
{
first = p;
}
p.Position = new Vector(x + rv.X, y + rv.Y);
Vector n = rv.Orthogonal();
n.Normalize();
n *= (p.Radius * 3);
rv += n;
rv.Normalize();
rv *= r;
World.AddParticle(p);
ParticleConnection cm = new ParticleConnection(mid, p);
//cm.RestLength = r - r / 8;
cm.SpringConstant = 200;
//cm.DampingConstant = 100;
World.Connections.Add(cm);
if (prev != null)
{
ParticleConnection c = new ParticleConnection(prev, p);
c.RestLength /= 1.1;
c.SpringConstant = 300;
c.DampingConstant = 40;
World.Connections.Add(c);
}
prev = p;
}
ParticleConnection cc = new ParticleConnection(prev, first);
cc.SpringConstant = 300;
cc.DampingConstant = 40;
cc.RestLength /= 1.1;
//cc.RestLength = (prev.Position - first.Position).Length;
World.Connections.Add(cc);
}
public static bool TryCollision(Particle p, Line line)
{
Vector L = p.Position - line.Point1;
Vector u = line.Point2 - line.Point1; u.Normalize();
double d = Math.Abs(L.OrthogonalDistance(u));
if (d > p.Radius)
{
return(false);
}
Vector v = p.Velocity;
Vector x = (v * u) * u;
Vector n = u.Orthogonal(); n.Normalize();
if (Vector.Direction(line.Point1, line.Point2, p.Position) < 0)
{
n = -n;
}
Vector y = (v * n) * n;
double e = Math.Min(p.Restitution, line.Restitution);
p.Velocity -= (2 * y) * e;
Vector G = p.Mass * new Vector(0, -World.Gravity);
//p.Force += G;
//Vector F = (G * u) * u;
Vector N = (G * n) * n;
//p.Force += N;
//? czy jest ok ?
if ((n ^ p.Velocity) > 0)
{
u = -u;
}
Vector T = 10000.9 * (N * u) * u;
//p.Force += T;
p.Position += (p.Radius - d) * -n;
return(true);
}
public static bool TryCollision(Particle p, Segment s)
{
Vector L = p.Position - s.Point1;
Vector u = s.Point2 - s.Point1; u.Normalize();
double d = Math.Abs(L.OrthogonalDistance(u));
if (d > p.Radius)
{
return(false);
}
Vector v = p.Velocity;
Vector x = (v * u) * u;
Vector n = u.Orthogonal(); n.Normalize();
if (Vector.Direction(s.Point1, s.Point2, p.Position) < 0)
{
n = -n;
}
Vector s1 = s.Point1 + n;
Vector s2 = s.Point2 + n;
Vector p1 = p.Position - s.Point1;
Vector p2 = p.Position - s.Point2;
Vector mid = s.Middle();
if ((mid - p.Position).Length > s.Length / 2) //nie ma zderzenia z odcinkiem
{
return(false);
}
//if ((s.Point1 - p.Position).Length > p.Radius && (s.Point2 - p.Position).Length > p.Radius)
// return false;
Vector y = (v * n) * n;
double e = Math.Min(p.Restitution, s.Restitution);
p.Velocity -= (2 * y) * e;
Vector G = p.Mass * new Vector(0, -World.Gravity);
//p.Force += G;
//Vector F = (G * u) * u;
Vector N = (G * n) * n;
//p.Force += N;
if ((n ^ p.Velocity) > 0)
{
u = -u;
}
Vector T = 10000.9 * (N * u) * u;
//p.Force += T;
p.Position += (p.Radius - d) * -n;
return(true);
}