; Cross Processing is a script for The GIMP
;
; Description: creates cross-processing-like effects on a RGB image.
;
; Last changed: 30.11.2007
;
; Copyright (C) 2005 Marco Alici <maalici@tin.it)
;
;
; Edit for use with gimp 2.4 
; (c) 2007 Bert Zulauf zulauf@uni-wuppertal.de
;
; --------------------------------------------------------------------
; 
; 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.

(define (script-crossprocessing img draw red green blue)
 ; new in gimp 2.4 vartiables must be deklared first
 (let* (
	; local variables
	; array with 6 elements
	(points (cons-array 6 'byte))
	; array with 8 elements 	
	(points2 (cons-array 8 'byte))
        )
  (gimp-image-undo-group-start img)
  (gimp-image-flatten img)
 (set! draw   (car (gimp-image-get-active-drawable img)))
  ; x and y coordinates first point
  (aset points 0 0)
  (aset points 1 0)
  ; x and y coordinates second point
  (aset points 2 128)
  (aset points 3 red)
  ; x and y coordinates third point
  (aset points 4 255)
  (aset points 5 255)
  ; drawing of the red channel 
  (gimp-curves-spline draw 1 6 points)
  ; x and y coordinates first point
  (aset points 0 0)
  (aset points 1 0)
  ; x and y coordinates second point
  (aset points 2 128)
  (aset points 3 148)
  ; x and y coordinates third point
  (aset points 4 255)
  (aset points 5 green)
  ; drawinf of the green channel
  (gimp-curves-spline draw 2 6 points)
  ; x and y coordinates first point  
  (aset points 0 0)
  (aset points 1 0)
  ; x and y coordinates second point
  (aset points 2 128)
  (aset points 3 148)
  ; x and y coordinates third point
  (aset points 4 255)
  (aset points 5 blue)
  ; drawing of the blue channel 
  (gimp-curves-spline draw 3 6 points)
  
  ; adjustment of contrast
  (aset points2 0 0)
  (aset points2 1 0)
  (aset points2 2 64)
  (aset points2 3 54)
  (aset points2 4 192)
  (aset points2 5 202)
  (aset points2 6 255)
  (aset points2 7 255)
  (gimp-curves-spline draw 0 8 points2)
  

  (gimp-image-undo-group-end img)
  (gimp-displays-flush)
 )
)
(script-fu-register 
  "script-crossprocessing"
  "<Image>/Colors/Map/Cross Processing"
  "creates cross-processing-like effects on a RGB image (for gimp2.4)"
  "Bert Zulauf <zulauf@uni-wuppertal.de>"
  "Bert Zulauf"
  "30/10/2007"
  "RGB*"
  SF-IMAGE      "Image"         0
  SF-DRAWABLE   "Drawable"      0
  SF-ADJUSTMENT "red"         '(64 1 255 1 10 0 0)
  SF-ADJUSTMENT "green"         '(224 1 255 1 10 0 0)
  SF-ADJUSTMENT "blue"           '(148 1 255 1 10 0 0)
  )