; przem-apply-sepia-v3 - Script-fu dodający prawdziwą sepie do zdjęcia
; author: PRP
; licencja: Public Domain
; Gdańsk - 07-02-2025
; ver. 1.2502010-4 for GIMP 3

(define (przem-apply-sepia-v3 image drawable value-slider-sepia gradient-reverse gradient-shape)
  
  (let* (
       (image-width (car (gimp-image-get-width image)))
       (image-height (car (gimp-image-get-height image)))
       (center-x (/ image-width 2))
       (center-y (* image-height 0.5)) ; either is OK
       (sepia-layer (car (gimp-layer-new image image-width image-height RGBA-IMAGE "Sepia Layer" 100 LAYER-MODE-NORMAL)))
       (is-nocolorful (car (gimp-drawable-is-gray drawable))) ; czy obraz jest w odcieniach szarości
       )
  
  (gimp-image-undo-group-start image)
  ;(gimp-image-undo-disable image)



  ; jeśli obraz jest szary to konwertuje go na RGB - tak na sztukę
  (if (= is-nocolorful TRUE)
    (gimp-image-convert-rgb image)
  )
  
  ; Konwersja obrazu do skali szarości
  ;(gimp-desaturate drawable)
  (gimp-drawable-desaturate drawable DESATURATE-LIGHTNESS)
  
  ; Dodanie koloru sepii
  ;(gimp-context-set-foreground '(112 66 20)) ; Kolor sepii
  
  (gimp-image-insert-layer image sepia-layer 0 -1)
 

  (gimp-context-push)
  (gimp-context-set-foreground (list 112 66 20)) ; ciemniejsza
  (gimp-context-set-background (list 210 180 140)) ; jasniejsza
  ;(plug-in-checkerboard #:run-mode    RUN-NONINTERACTIVE
  ;                        #:image       image
  ;                        #:drawables   (vector drawable)
  ;                        #:psychobilly 0
  ;                        #:check-size  8)
  (plug-in-checkerboard RUN-NONINTERACTIVE image (vector sepia-layer) 0 8)
  
  (gimp-context-pop)

  (gimp-context-push)

  (gimp-selection-all image)
  ; tak było w v. 2.10
  ;(gimp-edit-blend sepia-layer FG-BG-RGB-MODE NORMAL-MODE GRADIENT-LINEAR 100 0 REPEAT-NONE FALSE TRUE 3 0 TRUE 0 0 image-width image-height)
  (if (= gradient-shape TRUE)
    (begin
      (gimp-context-set-gradient-reverse gradient-reverse)
      (gimp-drawable-edit-gradient-fill sepia-layer
				      GRADIENT-LINEAR 0
				      FALSE 1 0
				      TRUE
				      0 0 image-width image-height)
	)
	(begin
      (gimp-context-set-gradient-reverse gradient-reverse)
      (gimp-drawable-edit-gradient-fill sepia-layer
				      GRADIENT-SHAPEBURST-DIMPLED  0
				      FALSE 1 0
				      TRUE
				      0 0 image-width image-height)
	) )
	
  (gimp-context-pop)


  ; Zmiana krycia warstwy
  (gimp-layer-set-opacity sepia-layer value-slider-sepia)
  
  (gimp-image-merge-down image sepia-layer CLIP-TO-IMAGE)
  
  (gimp-image-undo-group-end image)
  ;(gimp-image-undo-enable image)
  
  (gimp-displays-flush)
) )

(script-fu-register "przem-apply-sepia-v3"
  _"Apply a sepia effect to the image"
  _"Tworzy obraz sepii"
  "Przemyslaw R. Pietraszczyk"
  "Public Domain"
  "2025-02-07"
  "RGB* GRAY*"
  SF-IMAGE "Image" 0
  SF-DRAWABLE "Drawable" 0
  SF-ADJUSTMENT "Sepia intensity" '(50 0 100 1 10 0 0)  ; Suwak poziomy
  SF-TOGGLE     "Gradient reverse" FALSE
  SF-TOGGLE     "Shape" TRUE


) 
 
(script-fu-menu-register "przem-apply-sepia-v3"
                         "<Image>/Filters/PIETRASZCZYK/")