; Simon Budig

(define (script-fu-lcd-downscale img drw y-scale)
  (let* ((drawable-width 0)
	 (drawable-height 0)
	 (old-fg (car (gimp-palette-get-foreground)))
	 (red-layer drw)
	 (green-layer #f)
	 (blue-layer #f)
	)
    (gimp-undo-push-group-start img)
    (gimp-selection-all img)
    (if (not (= RGB (car (gimp-image-base-type img))))
        (gimp-convert-rgb img)
    )
    (set! red-layer (car (gimp-image-flatten img)))
    (set! drawable-width (car (gimp-image-width img)))
    (set! drawable-height (car (gimp-image-height img)))
    (if (= TRUE y-scale)
        (begin
	  (set! drawable-height (/ drawable-height 3))
	  (gimp-image-scale img drawable-width drawable-height)
	)
    )
    (plug-in-video 1 img red-layer 2 0 1)
    (set! green-layer (car (gimp-layer-copy red-layer 1)))
    (gimp-image-add-layer img green-layer -1)
    (gimp-layer-set-mode green-layer LIGHTEN-ONLY)
    (set! blue-layer (car (gimp-layer-copy red-layer 1)))
    (gimp-image-add-layer img blue-layer -1)
    (gimp-layer-set-mode blue-layer LIGHTEN-ONLY)
    (gimp-palette-set-foreground '(255 0 0))
    (gimp-bucket-fill red-layer FG-BUCKET-FILL MULTIPLY-MODE 100 0 0 1 1)
    (gimp-palette-set-foreground '(0 255 0))
    (gimp-bucket-fill green-layer FG-BUCKET-FILL MULTIPLY-MODE 100 0 0 1 1)
    (gimp-palette-set-foreground '(0 0 255))
    (gimp-bucket-fill blue-layer FG-BUCKET-FILL MULTIPLY-MODE 100 0 0 1 1)
    (gimp-layer-set-offsets red-layer 0 0)
    (gimp-layer-set-offsets green-layer -1 0)
    (gimp-layer-set-offsets blue-layer -2 0)
    (set! red-layer (car (gimp-image-flatten img)))
    (set! green-layer (car (gimp-layer-copy red-layer 1)))
    (gimp-image-add-layer img green-layer -1)
    (gimp-layer-set-mode green-layer LIGHTEN-ONLY)
    (set! blue-layer (car (gimp-layer-copy red-layer 1)))
    (gimp-image-add-layer img blue-layer -1)
    (gimp-layer-set-mode blue-layer LIGHTEN-ONLY)
    (gimp-layer-set-offsets red-layer 0 0)
    (gimp-layer-set-offsets green-layer 1 0)
    (gimp-layer-set-offsets blue-layer 2 0)
    (set! red-layer (car (gimp-image-flatten img)))
    (gimp-image-scale img (/ drawable-width 3) drawable-height)
    (gimp-selection-none img)
    (gimp-palette-set-foreground old-fg)
    (gimp-undo-push-group-end img)
    
    (gimp-displays-flush)))

(script-fu-register
 "script-fu-lcd-downscale"
 _"<Image>/Script-Fu/Alchemy/LCD Downscale..."
 "Scale Layer down, optimized for LCD's with subpixel ordering RGB"
 "Simon Budig <simon@gimp.org>"
 "Simon Budig"
 "2000"
 ""
 SF-IMAGE "Image" 0
 SF-DRAWABLE "Drawable to apply" 0
 SF-TOGGLE _"Scale Y-direction" TRUE
)