; This program is free software; you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation; either version 2 of the License, or
; (at your option) any later version.  
; 
; This program is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
; GNU General Public License for more details.
; 
;; This plugin takes the current image active layer,
;;  and creates an animation with the specified number
;;  of frames. Each frame has the hue of the previous 
;;  frame rotated by a uniform amount. The new frames
;;  are created in a new image, to give a complete 
;;  360 degree hue rotation.
;;
;; Tested on version 1.2.1, should work on higher versions. 
;;
;; Certainly needs improvements and additional features still.
;;
;; If anyone is interested, contact me at ashrb2k@yahoo.co.in
;;
;; Ashish Bhambhani, India, June 2003.
;;

(define (script-fu-huecycling-anim Img Lyr Num)
   
 	(set! Lyr (car (gimp-image-get-active-layer Img)))
	(gimp-selection-all Img)
	(gimp-edit-copy Lyr)
	(gimp-selection-none Img)
	(set! Img (car (gimp-image-new (car (gimp-drawable-width Lyr)) (car (gimp-drawable-height Lyr)) (car (gimp-image-base-type Img)))))
	(set! Lyr (car (gimp-layer-new Img (car (gimp-drawable-width Lyr)) (car (gimp-drawable-height Lyr)) (car (gimp-image-base-type Img)) "Frame # 0" 100 0)))
	(gimp-image-add-layer Img Lyr 0)
	(gimp-display-new Img)
	(set! Fl (car (gimp-edit-paste Lyr 0)))
	(gimp-floating-sel-anchor Fl)
	(gimp-image-undo-disable Img)
	(set! fnum 1)
	(while (< fnum Num)
	 	(set! L (car (gimp-layer-copy Lyr FALSE)))
		(gimp-layer-set-name L (string-append "Frame " (number->string fnum 10 3 0)))
		(set! offset (/ (* 360 fnum) Num))
		(if (> offset 180) (set! offset (- (- 360 offset))))
		(gimp-hue-saturation L 0 offset 0 0)
		(gimp-image-add-layer Img L 0)
		(set! fnum (+ 1 fnum))
	)
  
	(gimp-image-undo-enable Img)
)

(script-fu-register "script-fu-huecycling-anim" 
		    "<Image>/Script-Fu/Animators/Hue-cycling..."
		    "Creates an animation that rotates the hue of an image"
		    "Ashish Bhambhani (ashrb2k@yahoo.co.in)"
		    "Ashish Bhambhani"
		    "2003 June"
		    "RGB*"
		    SF-IMAGE "Image" 0
		    SF-DRAWABLE "Drawable" 0
		    SF-VALUE  "Number of frames (atleast 2)" "10")