; FU_photo_BlueSkyClouds.scm 
; version 3.2 [gimphelp.org]
; last modified/tested by Paul Sherman
; 02/14/2014 on GIMP-2.8.10
; 15/09/2020 on GIMP-2.10.20
;
; See description on author's site:
; http://www.farcrydesign.com/GIMP/BlueSkyClouds.html
;
; 02/14/2014 - convert to RGB if needed
;==============================================================
;
; Installation:
; This script should be placed in the user or system-wide script folder.
;
;	Windows Vista/7/8)
;	C:\Program Files\GIMP 2\share\gimp\2.0\scripts
;	or
;	C:\Users\YOUR-NAME\.gimp-2.8\scripts
;	
;	Windows XP
;	C:\Program Files\GIMP 2\share\gimp\2.0\scripts
;	or
;	C:\Documents and Settings\yourname\.gimp-2.8\scripts   
;    
;	Linux
;	/home/yourname/.gimp-2.8/scripts  
;	or
;	Linux system-wide
;	/usr/share/gimp/2.0/scripts
;
;==============================================================
;
; 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 3 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, see <http://www.gnu.org/licenses/>.
;
;==============================================================
; Original information 
; 
; Blue Sky & Clouds, V2.0
; AUTHOR: Darla McKay (Darla@FarcryDesign.com), (C) 2007,2008
; This plugin was tested with GIMP 2.4
;
; DESCRIPTION:
; To fix burned out or white skies by adding a blue sky gradient.
; The script is located in menu "<Image> / Script-Fu / Darla / Blue Sky & Clouds"
;
; USAGE NOTES:
; Two colours are selectable, specifying the upper (darker) and lower 
; (lighter) sky.  The gradient is applied based on a level horizon.
; Threshold masking is applied.  Optionally, a layer with rendered clouds
; can be added.
;     See http://www.FarcryDesign.com/GIMP/ for more information.
;==============================================================


(define (FU-BlueSkyClouds 
            InImage 
            InLayer 
            InThreshold 
            InSkyTop 
            InSkyBottom 
            InFeather 
            InClouds 
            InFlatten
        )
     
    (gimp-image-undo-group-start InImage)
    (if (not (= RGB (car (gimp-image-base-type InImage))))
            (gimp-image-convert-rgb InImage)
    )
    
    (let*   (
                (BlueGradientLayer (car (gimp-layer-copy InLayer TRUE)))
                (CloudLayer (car (gimp-layer-copy InLayer TRUE)))
                (ThresholdLayer (car (gimp-layer-copy InLayer TRUE)))
                (CloudMask (car (gimp-layer-create-mask CloudLayer ADD-MASK-WHITE)))
                (BlueGradientMask (car (gimp-layer-create-mask BlueGradientLayer ADD-MASK-WHITE)))
                (TheHeight (car (gimp-image-height InImage)))
                (Old-FG-Color (car (gimp-context-get-foreground)))
                (Old-BG-Color (car (gimp-context-get-background)))
            )
        
        ; add threshold layer
        (gimp-image-insert-layer InImage ThresholdLayer 0 -1)
        (gimp-drawable-threshold ThresholdLayer HISTOGRAM-VALUE (/ InThreshold 255) 1.0)
        (plug-in-gauss TRUE InImage ThresholdLayer InFeather InFeather 0)
        (gimp-item-set-name ThresholdLayer "Threshold Layer")
        (gimp-item-set-visible ThresholdLayer FALSE)
        
        ; add clouds if applicable, interactive solid noise
        (if (not (= InClouds 0)) 
            (begin
                (gimp-image-insert-layer InImage CloudLayer 0 -1)
                (gimp-selection-all InImage)
                (gimp-edit-clear CloudLayer)
                (plug-in-solid-noise FALSE InImage CloudLayer 0 0 7 2 3.6 7.4)
                (gimp-item-set-name CloudLayer "Cloud Layer")
                (gimp-layer-add-mask CloudLayer CloudMask)
                (gimp-selection-all InImage)
                (gimp-edit-copy ThresholdLayer)
                (gimp-floating-sel-anchor (car (gimp-edit-paste CloudMask FALSE)))
                (gimp-selection-none InImage)
                (gimp-layer-set-mode CloudLayer LAYER-MODE-DARKEN-ONLY)
                (gimp-layer-set-opacity CloudLayer 15)
            )
        )
        
        ; add blue gradient layer
        (gimp-image-insert-layer InImage BlueGradientLayer 0 -1)
        (gimp-context-set-foreground InSkyTop)
        (gimp-context-set-background InSkyBottom)
        (gimp-edit-blend BlueGradientLayer BLEND-FG-BG-RGB LAYER-MODE-NORMAL  GRADIENT-LINEAR 100 0 REPEAT-NONE FALSE FALSE 0 0 TRUE 0 0 0 (- TheHeight 1))
        (gimp-item-set-name BlueGradientLayer "Blue Gradient Layer")
        (gimp-layer-add-mask BlueGradientLayer BlueGradientMask)
        (gimp-selection-all InImage)
        (gimp-edit-copy ThresholdLayer)
        (gimp-floating-sel-anchor (car (gimp-edit-paste BlueGradientMask FALSE)))
        (gimp-selection-none InImage)
        (if (not (= InClouds 0)) 
            (begin
                (gimp-layer-set-mode BlueGradientLayer LAYER-MODE-HSL-COLOR)
                (gimp-layer-set-opacity BlueGradientLayer 90)
            )
            (begin
                (gimp-layer-set-mode BlueGradientLayer LAYER-MODE-DARKEN-ONLY)
                (gimp-layer-set-opacity BlueGradientLayer 70)
            )
        )
        
        ; return original color palette, flatten image if needed
        (gimp-context-set-foreground Old-FG-Color)
        (gimp-context-set-background Old-BG-Color)
        (if (= InFlatten TRUE) (gimp-image-flatten InImage))
        (gimp-image-undo-group-end InImage)
        (gimp-displays-flush)
    )
)

(script-fu-register 
    "FU-BlueSkyClouds"
    "<Toolbox>/Script-Fu/Photo/Highlight/Highlight by adding Blue Sky and Clouds"
    "Highlights -> Blue Sky & Clouds \n\
    To fix burned out or white skies by adding a blue sky \n
    gradient and clouds (uses a threshold mask). \n\
    USE LOWER THRESHOLD to fill a larger white/highlight area. \n\
    See http://www.FarcryDesign.com/GIMP for more information.
    \nfile:FU_photo_BlueSkyClouds.scm"
    "Darla McKay (Darla@FarcryDesign.com)"
    "Darla McKay"
    "2007,2008"
    "*"
    SF-IMAGE        "The Image"                 0
    SF-DRAWABLE     "The Layer"                 0
    SF-ADJUSTMENT   "Threshold"                 '(248 0 254 1 0 0 0)
    SF-COLOR        "Sky Top Color"             '(187 219 255)
    SF-COLOR        "Sky Bottom Color"          '(221 234 255)
    SF-ADJUSTMENT   "Edges: Feather Amount"     '(5.0 1.0 10.0 1.0 0 1 0)
    SF-TOGGLE       "Add Rendered Clouds"       TRUE
    SF-TOGGLE       "Flatten Image"	            FALSE
)

; end of script