; gradient-from-image.scm
; by Rob Antonishen
; http://ffaat.pointclark.net

; Version 1.0 (20080131)

; Description
;
; Script to create a gradient from a horizontal image of a gradient
; Will appear in the Gradients Menu
;

; License:
;
; 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.
;
; The GNU Public License is available at
; http://www.gnu.org/copyleft/gpl.html

(define (script-fu-gradient-from-image img inLayer inSegments inSmooth inName)
  (let* 
    (
	  (img (car (gimp-image-duplicate img)))  ;create a duplicate
	  (width (car (gimp-image-width img)))
	  (height (car (gimp-image-height img)))
	  (segments (truncate inSegments))
	  (colors (+ segments (if (= inSmooth TRUE) 1 0)))
	  (theGradient "")
	  (counter 0)
	)
	
	; it begins here
	(gimp-image-undo-group-start img)

	;flatten inage and get drawable (layer)
	(set! inLayer (car (gimp-image-merge-visible-layers img 1)))
	
	; blur then resize to number of colors  by 1
    (gimp-image-scale img colors 1)
	
    ;create new gradient
	(set! theGradient (car (gimp-gradient-new inName)))
	(gimp-context-set-gradient theGradient)
	
	;subdivide
	(gimp-gradient-segment-range-split-uniform theGradient 0 0 segments)

	(while (< counter segments)	
	    (gimp-gradient-segment-set-left-color theGradient counter (car (gimp-image-pick-color img inLayer counter 0 FALSE FALSE 0)) 100)
	    (gimp-gradient-segment-set-right-color theGradient counter (car (gimp-image-pick-color img inLayer (+ counter (if (= inSmooth TRUE) 1 0)) 0 FALSE FALSE 0)) 100)
		(set! counter (+ counter 1))
	)
	
	;done
	(gimp-image-undo-group-end img)
	(gimp-image-delete img)
  )
)

(script-fu-register "script-fu-gradient-from-image"
        		    "<Gradients>/Gradient from _Image..."
                    "Create a gradient from an image of a gradient."
                    "Rob Antonishen"
                    "Rob Antonishen"
                    "Jan 2008"
                    ""
                    SF-IMAGE      "image"      0
                    SF-DRAWABLE   "drawable"   0
                    SF-ADJUSTMENT "Segments in the gradient" (list 25 2 256 1 10 0 SF-SLIDER)
				    SF-TOGGLE     "Smooth Gradient" TRUE
                    SF-STRING     "Gradient Name"  "Gradient From Image"				
)