anchor.diff:                              (world->view :mat4)
                               (point-size :float)
                               (proj :mat4)
  +                            (point-color :vec4)
                               ,@(uniform-args-for kind)
                               ,@uniforms)
            (flet (,func)
              (,(vert-transform-for kind)
  -             #',(first func) vert world->view proj point-size
  +             #',(first func) vert world->view proj point-size point-color
                ,@(mapcar #'first (uniform-args-for kind)))))
          (defpipeline-g ,pline-name ()
            :vertex (,vert-name g-pt)
  -         :fragment (pgraph-dot-frag :vec2))
  +         :fragment (pgraph-dot-frag :vec2 :vec4))
          (defun ,name (position-vec3
                        direction-vec3
                        &key
  
positive.code: ;;------------------------------------------------------------
  
  (defun-g pgraph-dot-frag ((uv :vec2)
                            &uniform
                            (point-color :vec4))
    (let ((sdf-scale 25f0))
      (mix
       (v! 0 0 0 0)
       point-color
       (nineveh.sdf.2d:mask-fill
        (nineveh.sdf.2d:circle (- (* uv 2 sdf-scale) (vec2 sdf-scale))
                               sdf-scale)))))
  
negative.code:                                (world->view :mat4)
                                 (proj :mat4)
                                 (point-size :float)
                                 (point-color :vec4)
                                 ;;
                                 (min :float)
                                 (by :float))
  