-1.00   -1  -1.00   -1
-0.75   -1  -0.50   -1
-0.50   -1  -0.50    0
-0.50    0   0.00    0
 0.00    0   0.00    0
 0.25    0   0.00    0
 0.00    1   0.25    0
 0.50    1   0.00    1
 1.00    1   1.00    1
