; 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.

; Added semi-flatten option to allow transparent areas of image to be "anti-aliased"
; using a chosen background color.  This allows user be able to blend an image
; with a web page background of specified color.

(define (script-fu-anim-settings-sf image drawable req-delay req-mode antiAlias color)
  (define (visible-layers img)
    (let* (
        (all-layers (gimp-image-get-layers img))
        (i (car all-layers))
        (viewable nil)
        (tmp FALSE)
        )
      (set! all-layers (cadr all-layers))
      (while (> i 0)
        (set! tmp (car (gimp-drawable-get-visible (aref all-layers (- i 1)))))
        (if (= tmp TRUE)
          (set! viewable (append viewable (cons (aref all-layers (- i 1)) '())))
          )
        (set! i (- i 1))
        )
      viewable
      )
    )
  (gimp-image-undo-group-start image)
  (let* (
      (layers nil)
      (full-name nil)
      (par-name nil)
      (layer-name nil)
      (mode nil)
      (delay "")
      )
    (set! layers (visible-layers image))
    (while (pair? layers)
      (cond
        ( (or (= req-mode 0) (= req-mode 3))
          (set! mode "")
          )
        ( (= req-mode 1)
          (set! mode "(combine)")
          )
        ( (= req-mode 2)
          (set! mode "(replace)")
          )
        )
      (set! full-name (strbreakup (car (gimp-drawable-get-name (car layers))) "("))
      (set! layer-name (car full-name))
      (set! full-name (cdr full-name))
      (while (pair? full-name) ;; for each parenthetical, see if it is a delay or a mode (it might be a delay)
        (set! par-name (string-trim (car full-name)))
        (cond
          ( (string-ci=? "combine)" par-name)
            (if (= req-mode 0) ;; Keep
              (set! mode "(combine)")
              )
            )
          ( (string-ci=? "replace)" par-name)
            (if (= req-mode 0) ;; Keep
              (set! mode "(replace)")
              )
            )
          ( (char-numeric? (string-ref par-name 0))
            (if (= req-delay 0)
              (set! delay (string-append "(" par-name))
              (set! delay "") ;; clear delay for -1 or for positive request
              )
            )
          )
        (set! full-name (cdr full-name))
        )
      (if (> req-delay 0)
        (set! delay (string-append "(" (number->string req-delay 10) "ms) "))
        )
      (gimp-drawable-set-name (car layers) (string-append layer-name delay mode))
      
    	(if (= antiAlias TRUE)
		(begin
		(gimp-context-set-background color) 
		(plug-in-semiflatten RUN-NONINTERACTIVE image (car layers))
		)
	)
	(set! layers (cdr layers))
      )

    )
  (gimp-image-undo-group-end image)
  (gimp-displays-flush)
  )

(script-fu-register "script-fu-anim-settings-sf"
 "<Image>/Filters/Animation/_Settings with Semi-Flatten..." ;; might like to keep it separate from the standard plugins
 "Sets the Frame delay and mode of GIF animations by renaming visible layers."
 "Saul Goode and Art Wade"
 "Saul Goode and Art Wade"
 "3/11/2006 & 8/28/2008"
 "RGB*"
 SF-IMAGE    "Image"    0
 SF-DRAWABLE "Drawable" 0
 SF-ADJUSTMENT "Delay: (1-10000 mS, 0=Keep, -1=Clear)" '( 100 -1 10000 1 10 0 1 )
 SF-OPTION "Mode:" '( "Keep" "(combine)" "(replace)" "Clear")
 SF-TOGGLE "Semi-Flatten? (Uses color below to blend image to background)" TRUE
 SF-COLOR "Background Color (Only used if Semi-Flatten option is TRUE)" '(255 255 255)
 )