;
;  burn-in-anim.scm V2.1  -  script-fu for the GIMP 1.1 and higher
;
;  Copyright (C) 9/2000  Roland Berger
;  roland@fuchur.leute.server.de
;  http://fuchur.leute.server.de
;
;  Let text appear and fade out with a "burn-in" like SFX.
;  Works on an image with a text and a background layer
;
;  Copying Policy:  GNU Public License http://www.gnu.org
;

(define (script-fu-burn-in-anim org-img
				org-layer
				glow-color
				fadeout
				bl-width
				corona-width
				after-glow
				show-glow
				optimize
				speed)

  (let* (
	 ;--- main variable: "bl-x" runs from 0 to layer-width
	 (bl-x 0)
	 (frame-nr 0)
	 (old-fg (car (gimp-palette-get-foreground)))
	 (old-bg (car (gimp-palette-get-background))))

    (if (< speed 1)
	(set! speed (* -1 speed)) )

    ;--- check image and work on a copy
    (if (= (car (gimp-image-get-layers org-img)) 2)
    
        ;--- main program structure starts here, begin of "if-1"
	(begin
	  (set! img (car (gimp-image-duplicate org-img)))
	  (gimp-image-undo-disable img) 
	  (if (> (car (gimp-drawable-type org-layer)) 1 )
	      (gimp-convert-rgb img))
	  (set! source-layer    (aref (cadr (gimp-image-get-layers img)) 0 ))
	  (set! bg-source-layer (aref (cadr (gimp-image-get-layers img)) 1 ))
	  (set! source-layer-width (car (gimp-drawable-width  source-layer)))

          ;--- hide layers, cause we want to "merge visible layers" later
	  (gimp-layer-set-visible source-layer FALSE)
	  (gimp-layer-set-visible bg-source-layer     FALSE)

          ;--- process image horizontal with pixel-speed
	  (while (< bl-x (+ source-layer-width bl-width))
		 (set! bl-layer (car (gimp-layer-copy source-layer TRUE)))
		 (set! bl-layer-name (string-append "fr-nr"
						    (number->string frame-nr 10) ) )

		 (gimp-image-add-layer img bl-layer -2)
		 (gimp-layer-set-name bl-layer bl-layer-name)
		 (gimp-layer-set-visible bl-layer TRUE)
		 (gimp-layer-set-preserve-trans bl-layer TRUE)
		 (gimp-layer-add-alpha bl-layer)

                 ;--- add an alpha mask for blending and select it
		 (gimp-selection-layer-alpha bl-layer)
		 (set! bl-mask (car (gimp-layer-create-mask bl-layer BLACK-MASK)))
		 (gimp-image-add-layer-mask img bl-layer bl-mask)

                 ;--- handle layer geometry
		 (set! bl-layer-width source-layer-width)
		 (set! bl-height      (car (gimp-drawable-height bl-layer)))
		 (set! bl-x-off (- bl-x     bl-width))
		 (set! bl-x-off (+ bl-x-off (car  (gimp-drawable-offsets bl-layer))))
		 (set! bl-y-off             (cadr (gimp-drawable-offsets bl-layer)))

                 ;--- select a rectangular area to blend
		 (gimp-rect-select img bl-x-off bl-y-off bl-width bl-height REPLACE 0 0)
                 ;--- select at least 1 pixel!
		 (gimp-rect-select img bl-x-off bl-y-off (+ bl-width 1) bl-height ADD 0 0)

		 (if (= fadeout FALSE)
		     (begin
		       (set! nofadeout-bl-x-off (car (gimp-drawable-offsets bl-layer)))
		       (set! nofadeout-bl-width (+ nofadeout-bl-x-off bl-x))
		       (set! nofadeout-bl-width (max nofadeout-bl-width 1))
		       (gimp-rect-select img nofadeout-bl-x-off bl-y-off
					 nofadeout-bl-width bl-height
					 REPLACE 0 0)))

                 ;--- alpha blending text to trans (fadeout)
		 (gimp-palette-set-foreground '(255 255 255))
		 (gimp-palette-set-background '(  0   0   0))
		 (if (= fadeout TRUE)
		     (begin
                       ; blend with 20% offset to get less transparency in the front
		       (gimp-blend bl-mask FG-BG-RGB NORMAL-MODE
				   GRADIENT-LINEAR 100 20 REPEAT-NONE FALSE
				   FALSE 0 0 TRUE
				   (+ bl-x-off bl-width) 0 bl-x-off 0)))

		 (if (= fadeout FALSE)
		     (begin
		       (gimp-palette-set-foreground '(255 255 255))
		       (gimp-bucket-fill bl-mask FG-BUCKET-FILL NORMAL-MODE
					 100 255 0 0 0)))

		 (gimp-image-remove-layer-mask img bl-layer APPLY)

                 ;--- add bright glow in front
		 (if (= show-glow TRUE)
		     (begin
                       ;--- add some brightness to whole text
		       (if (= fadeout TRUE)
			   (gimp-brightness-contrast bl-layer 100 0)))

                     ;--- blend glow color inside the letters
		     (gimp-palette-set-foreground glow-color)
		     (gimp-blend bl-layer FG-TRANS NORMAL-MODE
				 GRADIENT-LINEAR 100 0 REPEAT-NONE FALSE
				 FALSE 0 0 TRUE
				 (+ bl-x-off bl-width) 0
				 (- (+ bl-x-off bl-width) after-glow) 0)

                     ;--- add corona effect
		     (gimp-selection-layer-alpha bl-layer)
		     (gimp-selection-sharpen img)
		     (gimp-selection-grow img corona-width)
		     (gimp-layer-set-preserve-trans bl-layer FALSE)
		     (gimp-selection-feather img corona-width)
		     (gimp-palette-set-foreground glow-color)
		     (gimp-blend bl-layer FG-TRANS NORMAL-MODE
				 GRADIENT-LINEAR 100 0 REPEAT-NONE FALSE
				 FALSE 0 0 TRUE
				 (- (+ bl-x-off bl-width) corona-width) 0
				 (- (+ bl-x-off bl-width) after-glow) 0)))

          ;--- merge with bg layer
	  (set! bg-layer (car (gimp-layer-copy bg-source-layer FALSE)))
	  (gimp-image-add-layer img bg-layer -1)
	  (gimp-image-lower-layer img bg-layer)
	  (set! bg-layer-name (string-append "bg-"
					     (number->string frame-nr 10)))
	  (gimp-layer-set-name bg-layer bg-layer-name)
	  (gimp-layer-set-visible bg-layer TRUE)
	  (set! blended-layer (car (gimp-image-merge-visible-layers img CLIP-TO-IMAGE)))
          ;(set! blended-layer bl-layer)
	  (gimp-layer-set-visible blended-layer FALSE)

          ;--- end of "while" loop
	  (set! frame-nr (+ frame-nr 1))
	  (set! bl-x     (+ bl-x speed)))

        ;--- finalize the job
	(gimp-selection-none img)
	(gimp-image-remove-layer img    source-layer)
	(gimp-image-remove-layer img bg-source-layer)

	(gimp-image-set-filename img "burn-in")

	(if (= optimize TRUE)
	    (begin
	      (gimp-convert-indexed img 1 WEB-PALETTE 250 FALSE TRUE "")
	      (set! img-out (car (plug-in-animationoptimize 0 img bl-layer)))))

	(gimp-layer-set-visible (aref (cadr (gimp-image-get-layers img)) 0)
				TRUE)
	(gimp-image-undo-enable img)
	(gimp-image-clean-all img)
	(set! img-display (car (gimp-display-new img)))
	(gimp-palette-set-foreground old-fg)
	(gimp-palette-set-background old-bg)

	(gimp-displays-flush))

    ;--- false form of "if-1"
    (gimp-message _"Burn-In: Need two layers in total!"
		  "A foreground text layer with transparency"
		  "and a background layer.")))


(script-fu-register "script-fu-burn-in-anim"
		    "<Image>/Script-Fu/Animators/B_urn-In..."
		    "Burn-in like effect on a fg (text) layer and a bg layer; V2.1"
		    "Roland Berger roland@fuchur.leute.server.de"
		    "Roland Berger"
		    "January 2001"
		    "RGBA GRAYA INDEXEDA"
		    SF-IMAGE "The Image"              0
		    SF-DRAWABLE "Layer to animate"    0
		    SF-COLOR  _"Glow Color"           '(255 255 255)
		    SF-TOGGLE _"Fadeout"              FALSE
		    SF-VALUE  _"Fadeout Width"        "100"
		    SF-VALUE  _"Corona Width"         "7"
		    SF-VALUE  _"After Glow"           "50"
		    SF-TOGGLE _"Add Glowing"          TRUE
		    SF-TOGGLE _"Prepare for GIF"      FALSE
		    SF-VALUE  _"Speed (pixels/frame)" "50")
