From move distance and time, compute peak speed, acceleration and distance split.
t_acc = t_dec = f·t ; t_const = (1-2f)·t v_peak = S / ( t·(1-f) ) a = v_peak / t_acc S_acc = 0.5·v_peak·t_acc ; S_const = v_peak·t_const ; S_dec = S_acc