public bool Contains(Particle p)
{
return(PA.GetHashCode() == p.GetHashCode() || PB.GetHashCode() == p.GetHashCode());
}
public bool Contains(Particle p)
{
return (PA.GetHashCode() == p.GetHashCode() || PB.GetHashCode() == p.GetHashCode());
}
private void CalculateElasticity(float deltaTime)
{
float sqDist;
for (int i = 0; i < Particles.Count; i++)
{
Particle pa = Particles[i];
if (Particles.CountNearBy(pa) <= 1)
{
continue;
}
_tempParticles = Particles.GetNearby(pa);
int len2 = _tempParticles.Count;
if (len2 > MaxNeighbors)
{
len2 = MaxNeighbors;
}
for (int j = 0; j < len2; j++)
{
Particle pb = Particles[j];
Vector2.DistanceSquared(ref pa.Position, ref pb.Position, out sqDist);
if (sqDist > RestLengthSquared)
{
continue;
}
if (pa.GetHashCode() == pb.GetHashCode())
{
continue;
}
if (!_springPresenceTable[pa.GetHashCode()].Contains(pb.GetHashCode()))
{
_springs.Add(new Spring2(pa, pb, RestLength));
_springPresenceTable[pa.GetHashCode()].Add(pb.GetHashCode());
}
}
}
for (int i = _springs.Count - 1; i >= 0; i--)
{
Spring2 spring = _springs[i];
spring.Update();
// Stretch
if (spring.CurrentDistance > (spring.RestLength + DeformationFactor))
{
spring.RestLength += deltaTime * Plasticity * (spring.CurrentDistance - spring.RestLength - (YieldRatioStretch * spring.RestLength));
}
// Compress
else if (spring.CurrentDistance < (spring.RestLength - DeformationFactor))
{
spring.RestLength -= deltaTime * Plasticity * (spring.RestLength - (YieldRatioCompress * spring.RestLength) - spring.CurrentDistance);
}
// Remove springs with restLength longer than REST_LENGTH
if (spring.RestLength > RestLength)
{
_springs.RemoveAt(i);
_springPresenceTable[spring.PA.GetHashCode()].Remove(spring.PB.GetHashCode());
}
else
{
if (spring.CurrentDistance == 0)
{
continue;
}
Vector2.Subtract(ref spring.PB.Position, ref spring.PA.Position, out _rij);
_rij /= spring.CurrentDistance;
float D = deltaTime * KSpring * (spring.RestLength - spring.CurrentDistance);
_rij *= (D * 0.5f);
spring.PA.Position = new Vector2(spring.PA.Position.X - _rij.X, spring.PA.Position.Y - _rij.Y);
spring.PB.Position = new Vector2(spring.PB.Position.X + _rij.X, spring.PB.Position.Y + _rij.Y);
}
}
}
