- // Case D: Diagonal samples have four-way symmetry.
- for (int xy = 1; xy <= R; ++xy) {
- vec4 sample = PREFIX(samples)[xy * (R + 1) + xy];
-
- vec4 local_sum = INPUT(tc - sample.xy) + INPUT(tc + sample.xy);
- sample.y = -sample.y;
- local_sum += INPUT(tc - sample.xy) + INPUT(tc + sample.xy);
-
- sum += sample.z * local_sum;
- }
-
- // Case *: All other samples have eight-way symmetry.
+ // Case D: All other samples have four-way symmetry.
+ // (Actually we have eight-way, but since we are using normalized
+ // coordinates, we can't just flip x and y.)