Area = a2 / Screen = 4x4
  1x1   1x2   2x2   3x3   Now
AREA_a1 AREA_a2 AREA_a3 AREA_a4
AREA_b1 AREA_b2 AREA_b3 AREA_b4
AREA_c1 AREA_c2 AREA_c3 AREA_c4