; 210_effects-selection_glass-selection.scm
; last modified/tested by Paul Sherman [gimphelp.org]
; Thursday, 07/02/2020 on GIMP 2.10.20
;==================================================
;
; Installation:
; This script should be placed in the user or system-wide script folder.
;
;	Windows 7/10
;	C:\Program Files\GIMP 2\share\gimp\2.0\scripts
;	or
;	C:\Users\YOUR-NAME\AppData\Roaming\GIMP\2.10\scripts
;	
;    
;	Linux
;	/home/yourname/.config/GIMP/2.10/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 
; 
; Create Glass Effect of Selection
; based upon glass-text.scm by Scott Mosteller
;==============================================================
; Define Function For Glass Translucency Values
;
(define (get-glass-trans-curve parm)
  (let* ((curve-value (make-vector 4 'byte)))
   (aset curve-value 0 0)
   (aset curve-value 1 0)
   (aset curve-value 2 255)
   (aset curve-value 3 parm)
   curve-value     
   )
)
(define (210-glass-selection image
			drawable
			glass-color
			glass-depth
			glass-trans
			shadow-color
			shx
			shy
			shb
			sho
			dsh
			flat)
			(if (= (car (gimp-selection-is-empty image)) TRUE)
			(begin
				(gimp-message "The current image doesn't have a SELECTION.\n\nThis plugin works on a \nSELECTED AREA of the image.")
			)
				(begin; START OF PROCESSING
					   (gimp-image-undo-group-start image)
						(if (not (= RGB (car (gimp-image-base-type image))))
							(gimp-image-convert-rgb image))					   
						(let* (
							(theHeight (car (gimp-image-height image)))
							(theWidth (car (gimp-image-width image))) 
							(theSelection (car (gimp-selection-save image)))
							(glass-layer3 -1)
							(glass-layer4 -1)
							(glass-layer)
							(trns)
							(spvalues (make-vector 4 'byte)))
							(gimp-context-set-foreground glass-color)
							(set! glass-layer4 (car (gimp-layer-new image theWidth theHeight 1 "Copied 2" 100 LAYER-MODE-NORMAL-LEGACY)))
							(gimp-image-insert-layer image glass-layer4 0 -1) 
							(gimp-edit-fill glass-layer4 0)
							(gimp-context-set-foreground '( 255 255 255))
							(set! glass-layer3 (car (gimp-layer-new image theWidth theHeight 1 "Copied 1" 100 LAYER-MODE-NORMAL-LEGACY)))
							(gimp-image-insert-layer image glass-layer3 0 -1) 
							(gimp-selection-feather image 2)
							(gimp-edit-fill glass-layer3 0)
							(gimp-image-resize-to-layers image)
						; Create Glass Area
							(gimp-image-set-active-layer image glass-layer3)
							(gimp-layer-resize-to-image-size glass-layer3)
							(gimp-image-select-item image CHANNEL-OP-REPLACE glass-layer3)   
							(plug-in-gauss 1 image glass-layer3 5 5 1)
							(gimp-item-set-visible glass-layer3 0)
							(gimp-image-set-active-layer image glass-layer4)
							(gimp-layer-resize-to-image-size glass-layer4)
							(gimp-invert glass-layer4)
							(plug-in-bump-map 1 image glass-layer4 glass-layer3 135 45 (+ glass-depth 0) 0 0 0 0 0 0 0)
							(gimp-selection-shrink image glass-depth)
							(gimp-selection-feather image (- glass-depth 1))
							(gimp-curves-spline glass-layer4 4 4 (get-glass-trans-curve glass-trans))
							(set! glass-layer (car (gimp-layer-copy glass-layer4 1)))
							(gimp-image-insert-layer image glass-layer 0 -1)
							(gimp-edit-clear glass-layer4)
							(gimp-selection-none image)
							(gimp-hue-saturation glass-layer4 0 0 0 -100)
							(gimp-invert glass-layer)
						 ;
						 ; Create shadow layer on request
							(if (= dsh TRUE)
							(begin
								(script-fu-drop-shadow image glass-layer4 shx shy shb shadow-color sho TRUE)
							))
						 ;
						 ; Clean up & delete layers as needed
							(gimp-image-remove-layer image glass-layer3)
							(gimp-image-remove-layer image glass-layer4)
							(gimp-selection-none image)
							(gimp-layer-resize-to-image-size glass-layer)
						 ; Flatten on request
							(if (= flat TRUE)
							(begin
								(gimp-image-flatten image)
							))
					);end of LET
					;Finish the undo group for the process
						(gimp-image-undo-group-end image)   
						(gimp-displays-flush)
				); end of BEGIN
			); end of first IF (checking for a selection)
)
(script-fu-register "210-glass-selection"
		"Glass Selection"
		"Makes the current selection into glass"
		"Paul Sherman"
		"Paul Sherman"
		"12/30/2009"
		"*"
		SF-IMAGE "Image" 0
		SF-DRAWABLE "Drawable" 0
		SF-COLOR      _"Glass color"         '(119 171 234)
		SF-ADJUSTMENT _"Glass Depth (1-10)"        '(3 1 10 1 1 0 1)
		SF-ADJUSTMENT _"Glass Opacity (0-255)" '(140 0 255 1 1 0 1)
		SF-COLOR      _"Shadow color"       '(0 0 0)
		SF-ADJUSTMENT _"Shadow Offset X"    '(12 -25 25 1 1 0 1)
		SF-ADJUSTMENT _"Shadow Offset Y"    '(12 -25 25 1 1 0 1)
		SF-ADJUSTMENT _"Shadow Blur"        '(8 0 25 1 1 0 1)
		SF-ADJUSTMENT _"Shadow Opacity"     '(60 0 100 1 1 0 1)
		SF-TOGGLE     _"Include Shadow?"     TRUE
		SF-TOGGLE     "Flatten Image?"      TRUE
        )
(script-fu-menu-register "210-glass-selection" "<Image>/Script-Fu/Effects Selection")