anchor.diff:             (texture-lod tex
                           (+ (rtg-math.vectors:s~ uv :zw)
                              (* (rtg-math.base-vectors:v2! 1 1)
  -                              (rtg-math.vectors:s~ rcp-frame :xy)))
  +                              (rtg-math.vectors:s~ one-over-resolution :xy)))
                           0.0)
              :xyz))
            (rgb-m
  
positive.code:            (texture-lod tex
                          (+ (rtg-math.vectors:s~ uv :zw)
                             (* (rtg-math.base-vectors:v2! 0 1)
                                (rtg-math.vectors:s~ rcp-frame :xy)))
                          0.0)
             :xyz))
           (rgb-se
  
negative.code:                    (rtg-math.base-vectors:v2! (- fxaa-span-max)
                                                (- fxaa-span-max))
                     (* dir rcp-dir-min)))
               (rtg-math.vectors:s~ one-over-resolution :xy)))
        (let* ((rgb-a
                (* (/ 1.0 2.0)
                   (+
  