Mathematica code:

F[A_, B_, s_, L_, K_, t_] := ((1 - K) A + s*(1 - Abs[2 L - 1])*K*B)

ListAnimate[
 Table[
  ParametricPlot[
   Evaluate[
    {F[Cos[t], Cos[t (1/0.7654 - 1)], 1, L, .7654, t],
     F[Sin[t], Sin[t (1/0.7654 - 1)], -1, L, .7654, t]}],
   {t, 0, 389.5},
  Axes -> False, ImageSize -> 500, PlotRange -> 1.01],
{L, 0, 1, .02}]]