;; rotate-anim : Create multiple layers that rotate 180 degrees
;; author: Yoonsuck Choe, copyright 2001 (gnuPL)
;; See comment below for description and usage.

(define (script-fu-rotate-anim inStep Blur)

	(let* ((step inStep) (blur Blur) (img 0)(drawable 2)(n drawable)(sn n) (w 85) (h 85) (s 0.2))
	       	; (w (/ (gimp-drawable-width n) 2)) 
	       	; (h (/ (gimp-drawable-height n) 2)) 
	        ; (s (/ (* 3.141592 step) 180.0))) 

		;; convert to RGB if image is INDEXED
		(if (= 1 (car (gimp-drawable-is-indexed drawable)))
			 (gimp-convert-rgb img))

		;; copy current layer, add the layer, and rotate HUE by step
		;; degrees
		(set! w (+ (/ (car (gimp-drawable-width n)) 2.0) 0))
		(set! h (+ (/ (car (gimp-drawable-height n)) 2.0) 0))
		(set! s (/ (* 3.141592 inStep) 180.0))
		(while (< n (/ (/ 360 step) 2)) 
			(gimp-layer-copy sn TRUE) 
			;; new copied layer is now n+1
			(set! n (+ n 1)) 
			(gimp-image-add-layer img n -1) 
			;; Strangely, value shift 0.0 makes image darker
			(gimp-transform-2d n blur w h 1.0 1.0 (* s n) w h)
		)

	)
)

(script-fu-register
	"script-fu-rotate-anim"
	"<Toolbox>/Xtns/Script-Fu/Misc/Rotate Animation - Simple"
	"Create multiple layers that rotate 180 degrees (for animations).\nStart with a fresh new image loaded at gimp startup.\nAt each step, a new layer is created and the bottom layer is copied and rotated. Parameters: step = degrees rotated per layer, blur = blur when rotating (gives better result)."
       "Yoonsuck Choe"
       "copyright 2001 (gnuPL), Yoonsuck Choe "
       "Dec 8, 2001"
       ""
       SF-VALUE "Step:"       "10"
       SF-VALUE "Blur"       "1"
)