;
; lineart5.scm - convert an image into sort of line art
;
;
;;; --------------------------------------------------------------------
;;; version 0.1  by Jeff Trefftzs <trefftzs@tcsn.net>
;;;     - Initial relase
;;; version 0.2 Raymond Ostertag <r.ostertag@caramail.com>
;;;     - ported to Gimp 2.0, 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.

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

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

; Define the function:

(define (script-fu-lineart5 inImage inLayer)
  (let*
      (
       (edgelayer1 (copylayer inLayer "Edge Layer 1"))
       (edgelayer2 (copylayer inLayer "Edge Layer 2"))
       (satlayer (copylayer inLayer "Saturation Layer"))
       (colorlayer (copylayer inLayer "Color Layer"))
       )
    (gimp-image-undo-group-start inImage)

    ;; Real work goes in here
  
    (gimp-image-add-layer inImage edgelayer1 -1)
    (gimp-image-add-layer inImage edgelayer2 -1)
    (gimp-drawable-set-visible edgelayer1 TRUE)
    (gimp-drawable-set-visible edgelayer2 TRUE)

    (gimp-image-set-active-layer inImage edgelayer2)
    (gimp-layer-set-mode edgelayer2 15)	; Divide mode
    (plug-in-gauss-iir 1 inImage edgelayer2 5 TRUE TRUE) ; Blur 5 pix radius
    (set! linelayer (car(gimp-image-merge-down inImage edgelayer2 0)))
    (gimp-desaturate linelayer)		; desaturate it
    (gimp-threshold linelayer 250 255)
    (gimp-drawable-set-name linelayer "Edges, mostly")

    (set! copy3 (car (gimp-layer-copy linelayer TRUE)))
    (gimp-image-add-layer inImage copy3 -1);
    (plug-in-gauss-iir 1 inImage copy3 32 TRUE TRUE) ; Blur 32 pix radius
    (gimp-layer-set-mode copy3 4)	; Set to SCREEN-MODE mode
    (gimp-drawable-set-name copy3 "Blurred Edges used as SCREEN")
    
    (gimp-image-add-layer inImage satlayer -1) ; the saturation layer
    (gimp-layer-set-mode satlayer 12)	; saturation

    (gimp-image-add-layer inImage colorlayer -1)
    (gimp-layer-set-mode colorlayer 13)	; color


    )
  (gimp-image-set-active-layer inImage inLayer)
  (gimp-image-undo-group-end inImage)
  (gimp-displays-flush)
)

(script-fu-register
 "script-fu-lineart5"
 _"<Image>/Script-Fu/Line-Art/Jeff's Better Line Art..."
 "Builds a multiple layer image.  From the top: two copies of the original, one set to saturation mode, one set to color mode; then a layer of edges, and, at the bottom, the original itself.  This version uses  Jeff's synthetic edge detector."
 "Jeff Trefftzs"
 "Copyright 2001, Jeff Trefftzs"
 "March 11
, 2001"
 "RGB* GRAY* INDEXED*"
 SF-IMAGE "The Image" 0
 SF-DRAWABLE "The Layer" 0
)