; create animation layers for rotating plane
; found at link: http://gimpchat.com/viewtopic.php?f=23&t=594
; author: Tin Tran
; date: 2014

(define (script-fu-rotate-plane image layer
								frames-per-layer
								rotation-type
         )
	(define (get-visibles image)
    (let loop ((layers (vector->list (cadr (gimp-image-get-layers image))))
               (visibles '()) )
      (if (null? layers)
        visibles
        (loop (cdr layers) 
              (if (zero? (car (gimp-drawable-get-visible (car layers))))
                visibles
                (cons (car layers) visibles) ) ) ) ) )
	(let* 
		(
		(visibles (get-visibles image))
		(current-layer -1)
		(copied-layer -1)
		(horizontal-rotation 0)
		(vertical-rotation 0)
		(new-name "")
		(frame 0)
		(original-layers visibles)
		)
	
	(gimp-image-undo-group-start image)                   ;undo-group in one step
	
	(while (not (null? visibles))
		(set! current-layer (car visibles))
		(gimp-layer-add-alpha current-layer)
		(set! frame 0)
		(while (< frame frames-per-layer)
			(set! copied-layer (car (gimp-layer-copy current-layer TRUE)))
			(gimp-image-insert-layer image copied-layer (car (gimp-item-get-parent current-layer)) 0) ; Add it
			
			(if (= rotation-type 0);;Horizontal rotation
				(begin
					(set! horizontal-rotation (round (+ -90 (* (/ 180.0 frames-per-layer) frame))))
					(set! vertical-rotation 0.0)
				)
			)
			(if (= rotation-type 1);;Vertical rotation
				(begin
					(set! horizontal-rotation 0.0)
					(set! vertical-rotation (round (+ -90 (* (/ 180.0 frames-per-layer) frame))))
				)
			)
			(if (= rotation-type 2);;Both rotations (horizontal and vertical)
				(begin
					(set! horizontal-rotation (round (+ -90 (* (/ 180.0 frames-per-layer) frame))))
					(set! vertical-rotation (round (+ -90 (* (/ 180.0 frames-per-layer) frame))))
				)
			)
			(set! new-name (string-append (car (gimp-item-get-name current-layer)) "_"
											(number->string horizontal-rotation) "_"
											(number->string vertical-rotation) " (replace)"))
			(gimp-item-set-name copied-layer new-name)
			(plug-in-map-object 1 image copied-layer 
										0 ;0-plane 1-sphere 2-box 3-cylinder
										.5 ;viewpoint-x
										.5 ;viewpoint-y
										2 ;viewpoint-z
										.5 ; position-x
										.5 ; position-y
										0  ; position-z
										1.0  ;first axis x
										0  ;first axis y
										0  ;first axis z
										0  ;second axis x
										1.0  ;second axis y
										0  ;second axis z
										0  ;rotate -x
										horizontal-rotation ;rotate y
										vertical-rotation ;rotate z
										0 ; 0-point-light 1-directional 2-none
										'(255 255 255) ;light color
										-0.50 ;light position x
										-0.50 ;light position y
										2.00  ;light position z
										0 ;light direction x
										0 ;light direction y
										0 ;light direction z
										.30  ;ambient-intensity
										1.00 ;diffuse-intensity
										.50  ;diffuse-reflectivity
										.50  ;specular-reflectivity
										27.00 ; highlight
										TRUE ;antialiasing
										FALSE ;tiled
										FALSE ;newimage
										TRUE ;transparent background
										0 ; radius
										0 ;x-scale
										0 ;y-scale
										0 ;z-scale
										0 ;cylinder-length
										-1 ;box front drarwable
										-1 ;box back drawable
										-1 ;box top drawable
										-1 ;box bottom drawable
										-1 ;box left drawable
										-1 ;box right drawable
										-1 ;cyl-top-drawable
										-1 ;cyl-bottom-drawable
			)						
			(set! frame (+ frame 1))					
		) ;end inner-while
			;(gimp-item-set-visible current-layer FALSE) ;maybe deletet layer instead.
			
		(set! visibles (cdr visibles))
	) ;end while
	(map (lambda (x) (gimp-image-remove-layer image x)) original-layers)
	
	(gimp-image-undo-group-end image)        ;undo-group in one step
	(gimp-displays-flush)
	) ;end of let
)     ;end of define
	  
(script-fu-register
  "script-fu-rotate-plane"         ;function name
  "<Image>/Script-Fu/Create New/Rotate Plane Animation..."    ;menu register
  "Create animation layers for rotating plane animation"       ;description
  "Tin Tran"                          ;author name
  "copyright info and description"         ;copyright info or description
  "2014"                          ;date
  "RGB*, GRAY*"                        ;mode
  SF-IMAGE      "Image" 0                   
  SF-DRAWABLE   "Layer" 0
  SF-ADJUSTMENT "Frames per layer" '(12 1 20 1 10 0 1)
  SF-OPTION     "Rotation Type" '("Horizontal" "Vertical" "Both")
)