(define (script-fu-hoh image layer)
  (let* ((duplicate-layer (car (gimp-layer-copy layer 0)))
         (layer-height    (car (gimp-drawable-height duplicate-layer)))
         (layer-width     (car (gimp-drawable-width  duplicate-layer))))
    (gimp-image-add-layer image duplicate-layer 0)
    (gimp-item-transform-flip-simple duplicate-layer 0 1 0)
    (gimp-layer-resize duplicate-layer
                       (/ layer-width 2)
                       layer-height
                       (/ layer-width -2)
                       0)))

(define (script-fu-sis image layer)
  (let* ((duplicate-layer (car (gimp-layer-copy layer 0)))
         (layer-height    (car (gimp-drawable-height duplicate-layer)))
         (layer-width     (car (gimp-drawable-width  duplicate-layer))))
    (gimp-image-add-layer image duplicate-layer 0)
    (gimp-item-transform-flip-simple duplicate-layer 0 1 0)
    (gimp-layer-resize duplicate-layer
                       (/ layer-width 2)
                       layer-height
                       0
                       0)))


(script-fu-register
 "script-fu-hoh"
 "HoH"
 "Horizontal mirroring"
 "Hayley Patton"
 "(c) 2019"
 "Janurary 20, 2019"
 ""
 SF-IMAGE    "Image" 0
 SF-DRAWABLE "Drawable" 0)

(script-fu-register
 "script-fu-sis"
 "SiS"
 "Horizontal mirroring"
 "Hayley Patton"
 "(c) 2019"
 "Janurary 20, 2019"
 ""
 SF-IMAGE    "Image" 0
 SF-DRAWABLE "Drawable" 0)

(script-fu-menu-register "script-fu-hoh" "<Image>/Script-Fu/HohSis")
(script-fu-menu-register "script-fu-sis" "<Image>/Script-Fu/HohSis")