...var fm_shift_x, fm_shift_y, fm_next_x, fm_next_y;
var step_x, step_y;
compute_shifts();
step_x = (fm_shift_x + target_x - fm_next_x) * .07;
if (Math.abs(step_x) < .5)
step_x = fm_shift_x + target_x - fm_next_x;
step_y = (fm_shift_y + target_y - fm_next_y) *...