; The GIMP -- an image manipulation program
; Copyright (C) 1995 Spencer Kimball and Peter Mattis
; 
; 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.
;
; Copyright (C) 2004 Kevin Payne paynekj@hotmail.com
;
; Version 0.1 14.04.2004 First Go

; A debug routine to place some text into the image
(define (place_comment img adraw xpos ypos text)
      (set! text-float (car (gimp-text-fontname img adraw xpos ypos text 0 1 20 0 "-*-*courier*-*-r-*-*-*-*-*-*-*-*-*-*"))) 
      (gimp-floating-sel-anchor text-float)
)

; this is the main routine
(define (script-fu-grad_kp aimg adraw colour grad_rev)
  (let* (
		 (rval (/ (* 1.0 (car colour)) 255.0))
		 (gval (/ (* 1.0 (car      (cdr colour))) 255.0))
		 (bval (/ (* 1.0 (car (cdr (cdr colour)))) 255.0))
         (old-bg-colour (car (gimp-palette-get-background)))
         (old-fg-colour (car (gimp-palette-get-foreground)))
		 (old-gradient  (car (gimp-gradients-get-gradient)))
	     (height (car (gimp-drawable-height adraw)))
        )

   (gimp-image-undo-group-start aimg)

;  (place_comment img adraw 10 40 "got here")

; Create a duplicate of the original layer and re-name it
   (set! new-layer (car (gimp-layer-copy adraw TRUE)))
   (gimp-image-add-layer aimg new-layer 0)
   (gimp-drawable-set-name new-layer "Filtered layer")

;   (place_comment img adraw 10 40 (number->string rval 10))
;   (place_comment img adraw 10 80 (number->string gval 10))
;   (place_comment img adraw 10 120 (number->string bval 10))

; filter the colours of the new layer
   (plug-in-colors-channel-mixer 1 aimg new-layer FALSE rval 0 0   0 gval 0   0 0 bval)

; create a layer mask
   (set! l-mask (car (gimp-layer-create-mask new-layer 0)))
   (gimp-layer-add-mask new-layer l-mask)

; set the foreground and background colours to their default values of black and white
   (gimp-palette-set-default-colors)

; apply a gradient to the layer mask
   (gimp-gradients-set-gradient "FG to BG (RGB)")
   (gimp-edit-blend l-mask 0 0 0 100.0 0.0 0 grad_rev FALSE 0 0.0 TRUE 0 0 0 height)

; reset the foreground and background colours and the gradient
   (gimp-palette-set-foreground old-fg-colour)
   (gimp-palette-set-background old-bg-colour)
   (gimp-gradients-set-gradient old-gradient)

; flush the image
   (gimp-displays-flush)

   (gimp-image-undo-group-end aimg)
  )
)

(script-fu-register "script-fu-grad_kp"
		    _"<Image>/Script-Fu/Kevin/Grad Filter..."
		    "Add a graduated filter of an image"
		    "Kevin Payne <paynekj@hotmail.com>"
		    "Kevin Payne"
		    "14/04/2004"
		    "RGB*"
		    SF-IMAGE "Input Image" 0
		    SF-DRAWABLE "Input Drawable" 0
		    SF-COLOR _"Filter Colour" '(255 204 153)
		    SF-TOGGLE     _"Gradient Reverse"   TRUE
		    )