anchor.diff:  
   ;;------------------------------------------------------------
   
  -(defgeneric draw-tex (tex &optional scale flip-uvs-vertically))
  -(defgeneric draw-tex-tl (sampler &optional flip-uvs-vertically))
  -(defgeneric draw-tex-bl (sampler &optional flip-uvs-vertically))
  -(defgeneric draw-tex-tr (sampler &optional flip-uvs-vertically))
  -(defgeneric draw-tex-br (sampler &optional flip-uvs-vertically))
  -(defgeneric draw-tex-at (sampler &optional pos centered flip-uvs-vertically))
  +(defgeneric draw-tex (tex &key scale flip-uvs-vertically))
  +(defgeneric draw-tex-tl (sampler &key flip-uvs-vertically))
  +(defgeneric draw-tex-bl (sampler &key flip-uvs-vertically))
  +(defgeneric draw-tex-tr (sampler &key flip-uvs-vertically))
  +(defgeneric draw-tex-br (sampler &key flip-uvs-vertically))
  +(defgeneric draw-tex-at (sampler &key pos centered flip-uvs-vertically))
   
   ;;------------------------------------------------------------
   
  
positive.code: 
  ;;------------------------------------------------------------
  
  (defun draw-tex-top-left (sampler/tex &optional (flip-uvs-vertically t))
    (draw-tex-tl sampler/tex flip-uvs-vertically))
  
  (defmethod draw-tex-tl ((sampler sampler) &optional (flip-uvs-vertically t))
    (if (eq (sampler-type sampler) :sampler-cube)
        (%draw-cube-face sampler (v! -0.5 0.5) 1.5707 0.5)
        (%draw-sampler sampler (v! -0.5 0.5) 0s0 0.5 flip-uvs-vertically)))
  
  ;;------------------------------------------------------------
  
  (defun draw-tex-bottom-left (sampler/tex &optional (flip-uvs-vertically t))
    (draw-tex-bl sampler/tex flip-uvs-vertically))
  
  (defmethod draw-tex-bl ((sampler sampler) &optional (flip-uvs-vertically t))
    (if (eq (sampler-type sampler) :sampler-cube)
        (%draw-cube-face sampler (v! -0.5 -0.5) 1.5707 0.5)
        (%draw-sampler sampler (v! -0.5 -0.5) 0s0 0.5 flip-uvs-vertically)))
  
  ;;------------------------------------------------------------
  
  (defun draw-tex-top-right (sampler/tex &optional (flip-uvs-vertically t))
    (draw-tex-tr sampler/tex flip-uvs-vertically))
  
  (defmethod draw-tex-tr ((sampler sampler) &optional (flip-uvs-vertically t))
    (if (eq (sampler-type sampler) :sampler-cube)
        (%draw-cube-face sampler (v! 0.5 0.5) 1.5707 0.5)
        (%draw-sampler sampler (v! 0.5 0.5) 0s0 0.5 flip-uvs-vertically)))
  
  ;;------------------------------------------------------------
  
  (defun draw-tex-bottom-right (sampler/tex &optional (flip-uvs-vertically t))
    (draw-tex-br sampler/tex flip-uvs-vertically))
  
  (defmethod draw-tex-br ((sampler sampler) &optional (flip-uvs-vertically t))
    (if (eq (sampler-type sampler) :sampler-cube)
        (%draw-cube-face sampler (v! 0.5 -0.5) 1.5707 0.5)
        (%draw-sampler sampler (v! 0.5 -0.5) 0s0 0.5 flip-uvs-vertically)))
  
negative.code:   (texture tex tc))
  
  (def-g-> draw-texture-at-pipeline ()
    #'(draw-texture-at-vert g-pt)
    #'(draw-texture-at-frag :vec2))
  
  (defmethod draw-tex-at ((sampler sampler)
                          &key
                            (pos (v! 0 0))
                            (centered t)
                            (flip-uvs-vertically nil))
    (let* ((size (v! (texture-base-dimensions (sampler-texture sampler))))
           (vp-size (viewport-resolution (current-viewport)))
           (ratio (v2:/ size vp-size))
  