/// <summary>
/// Calculate and apply any internal forces due to deformation
/// to the particles connected to this spring
/// </summary>
public void ApplyForces()
{
if (StartParticle != null && EndParticle != null)
{
Vector dir = EndParticle.Position - StartParticle.Position;
double length = dir.Magnitude();
dir /= length;
double extension = length - RestLength;
double T = extension * Stiffness;
if ((Compression && extension < 0) ||
(Tension && extension > 0))
{
// Apply force:
Vector force = dir * T;
StartParticle.ApplyForce(force);
EndParticle.ApplyForce(-force);
}
}
}
