/// <summary>
/// Gets the force.
/// </summary>
/// <param name="s">The s.</param>
public override void GetForce(Spring s)
{
ForceItem item1 = s.Item1;
ForceItem item2 = s.Item2;
float length = (s.Length < 0 ? parms[SpringLength] : s.Length);
float x1 = item1.Location[0], y1 = item1.Location[1];
float x2 = item2.Location[0], y2 = item2.Location[1];
float dx = x2 - x1, dy = y2 - y1;
float r = (float)Math.Sqrt(dx * dx + dy * dy);
if (r == 0.0)
{
dx = ((float)rnd.NextDouble() - 0.5f) / 50.0f;
dy = ((float)rnd.NextDouble() - 0.5f) / 50.0f;
r = (float)Math.Sqrt(dx * dx + dy * dy);
}
float d = r - length;
float coeff = (s.Coeff < 0 ? parms[SpringCoeff] : s.Coeff) * d / r;
item1.Force[0] += coeff * dx;
item1.Force[1] += coeff * dy;
item2.Force[0] += -coeff * dx;
item2.Force[1] += -coeff * dy;
}
/// <summary>
/// Updates the force calculation on the given Spring. The ForceItems
/// attached to Spring will have their force values updated appropriately.
/// </summary>
/// <param name="spring">spring the Spring on which to compute updated forces</param>
public virtual void GetForce(Spring spring)
{
throw new NotImplementedException("This class does not support this operation");
}