;;;
;;; invert.scm - lasm's color invert effect Version 1.0
;;;
;;;
;;;  lasm <lasm@rocketmail.com>
;;;  http://www.godsimmediatecontact.com
;;;  http://www.godsdirectcontact.org
;;;
;;;
;;; Welcome to the Grandmother's Color Invert
;;; invert.scm - lasm's famous color invert script 
;;; Dedication - to my mother (1917-2002) in loving memory
;;;
;;; --------------------------------------------------------------------
;;; version 1.0  by Lasm 2002/02/20 <lasm@rocketmail.com>
;;;     - Initial relase
;;; version 1.0a by Raymond Ostertag 2004/09
;;;     - Changed menu entry
;;; --------------------------------------------------------------------
;;; 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.
;;; 
;;; You should have received a copy of the GNU General Public License
;;; along with this program; if not, write to the Free Software
;;; Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;
;;; Grandmother's Color Invert::
;;; Requires: 
;;; This effect is fully reversible.
;;; Another quality script brought to you by  the Grandmother Coffee House production.
;;; Created in the Special Palindrome Day of the century 20022002
;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(define (script-fu-invert img inLayer)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;
;;;  Helper function to create a new layer
;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(define (copylayer layer layername)
  (set! new (car(gimp-layer-copy layer 1))) ; Add an alpha channel
  (gimp-layer-set-name new layername)
  new
  )

  (let*
      (
       (width (car (gimp-drawable-width inLayer)))
       (height (car (gimp-drawable-height inLayer)))
       (invert-layer (copylayer inLayer "Invert Layer"))
       (old-fg (car (gimp-palette-get-foreground)))
       (old-bg (car (gimp-palette-get-background)))       
       )
	      
  (gimp-undo-push-group-start img)

;; Real work goes in here

   (gimp-image-add-layer img invert-layer -1)
   (gimp-invert inLayer)
   (gimp-layer-set-mode invert-layer HUE-MODE)               ; Hue Layer Mode

   (gimp-layer-set-name (car (gimp-image-merge-down img invert-layer EXPAND-AS-NECESSARY)) 
                     "GM Color Invert")

  (gimp-undo-push-group-end img)
  (gimp-displays-flush)

  (gimp-palette-set-background old-bg)
  (gimp-palette-set-foreground old-fg)

  )
)


(script-fu-register
 "script-fu-invert"
 _"<Image>/Script-Fu/Alchemy/Color Invert"
 "Lasm's color invert effect. This works on any RGB image and the effect is reversible."
 "lasm"
 "Copyright 2002, lasm"
 "February 20, 2002"
 "RGB*"
 SF-IMAGE "The Image" 0
 SF-DRAWABLE "The Layer" 0
)