;; generate knobs for reaktor

(define (script-fu-reaktor-knob size width active-width
				steps scale-steps
				start-degree start-dent small-dent
				active-color inactive-color bg-color)
  (let* ((img (car (gimp-image-new size (* steps size) RGB)))
	 (animation-layer (car (gimp-layer-new img size (* size steps) RGBA-IMAGE
					       "Animation Layer" 100 NORMAL-MODE)))
;	 (bg-layer (car (gimp-layer-new img size size RGB-IMAGE
;					"Background Layer" 100 NORMAL-MODE)))
;;	 (inactive-layer (car (gimp-layer-new img size size RGB-IMAGE
;;					      "Inactive Layer" 100 NORMAL-MODE)))
;;	 (active-layer (car (gimp-layer-new img size size RGB-IMAGE
;;					    "Active Layer" 100 NORMAL-MODE)))

	 )

    (gimp-context-push) ;; pushes a context to the top of the plug-in's contet stack

    (gimp-image-undo-disable img) ;; disables the image's undo stack
    (gimp-image-add-layer img animation-layer 0) ;; (gimp-image-add-layer image layer position)
    (gimp-edit-clear animation-layer)
    (gimp-context-set-background bg-color)
;    (gimp-layer-set-preserve-trans animation-layer 1)
    (gimp-edit-fill animation-layer BACKGROUND-FILL) ;; fill background of layer

    (let* ((i 0)
	  (radius (/ (- size (+ width 3)) 2))
	  (inactive-channel
	   (make-circle-selection img size radius width
				  scale-steps start-degree start-dent small-dent))
	  (active-channel
	   (make-circle-selection img size radius active-width
				  scale-steps start-degree start-dent small-dent))
	  (inc (/ 1 (- steps 1)))
	  (pos 0))
      (while (< i steps)
	     (make-button img size bg-color inactive-color active-color
			  inactive-channel active-channel
			  i start-degree start-dent pos)
	     (set! i (+ i 1))
	     (set! pos (+ pos inc))))

;;    (gimp-image-add-layer img inactive-layer 0)
    ;(let ((array (cons-array (* 3 2) 'double)))
    ;  (aset array 0 32)
    ;  (aset array 1 32)
    ;  (aset array 2 0)
    ;  (aset array 3 0)
    ;  (aset array 4 64)
    ;  (aset array 5 0)
    ;  (gimp-free-select img 6 array CHANNEL-OP-SUBTRACT TRUE FALSE 0))

    ;; (gimp-edit-bucket-fill drawable fill-mode paint-mode opacity threshold sample-merged x y)
    (gimp-selection-none img)
    (gimp-image-undo-enable img)
   (gimp-image-flatten img)
    (gimp-display-new img)
    (gimp-context-pop)))
    
    ;; (gimp-edit-blend img FG-BG-RGB-MODE NORMAL-MODE
    ;;		     GRADIENT-RADIAL 100 0 REPEAT-NONE FALSE
    ;; FALSE 0 0 TRUE

(define (make-circle-selection img size radius width scale-steps start-degree
			       start-dent small-dent)
  (let ((cx (/ size 2))
	(cy (/ size 2)))
    (gimp-selection-none img)
    (let ((r (+ radius (/ width 2))))
      (gimp-ellipse-select img (- cx r) (- cy r) (* 2 r) (* 2 r)
			   CHANNEL-OP-REPLACE TRUE FALSE 0))
    
    (let ((r (- radius (/ width 2))))
      (gimp-ellipse-select img (- cx r) (- cy r) (* 2 r) (* 2 r)
			   CHANNEL-OP-SUBTRACT TRUE FALSE 0))
    
    ;; start dent
    (subtract-dent img size (deg-to-radian start-degree) (deg-to-radian start-dent))
    
    ;; interval dents
    (let* ((i scale-steps)
	   (step (/ (- 360 start-dent) scale-steps))
	   (offs (+ start-degree (/ start-dent 2) 0)))
      (while (>= i 0)
	     (subtract-dent img size (deg-to-radian offs) (deg-to-radian small-dent))
	     (set! i (- i 1))
	     (set! offs (+ offs step))))
    (car (gimp-selection-save img))))
  
(define (make-button img 
		     size bg-color inactive-color active-color
		     inactive-channel active-channel
		     step start-degree start-dent position)
  (let ((layer (car (gimp-layer-new img size size RGBA-IMAGE
				    "Button Layer" 100 NORMAL-MODE))))
    (gimp-image-add-layer img layer -1)
    (gimp-edit-clear layer)
;    (gimp-layer-set-preserve-trans layer 1)
    (dented-circle img layer inactive-channel size inactive-color 
		   start-degree start-dent 1)
    (if (> position 0)
	(dented-circle img layer active-channel size active-color
		       start-degree start-dent position))
    (gimp-layer-translate layer 0 (* size step))))
;    (gimp-image-merge-visible-layers img CLIP-TO-IMAGE)))
    

(define (dented-circle img layer channel size color 
		       start-degree start-dent length)
  (let ((cx (/ size 2))
	(cy (/ size 2)))

    (gimp-selection-none img)
    (gimp-context-set-foreground color)
    (gimp-selection-load channel)
    
    (let* ((start (- start-degree (/ start-dent 2)))
	   (end (- start (* (- 360 start-dent) length))))
;      (gimp-message (string-append "(intersect-segment nil " (number->string size) " "
;				   (number->string (deg-to-radian start 'f))
;				   " "
;				   (number->string (deg-to-radian end 'f))
;				   ")"))
      (intersect-segment img size
			 (deg-to-radian start)
			 (deg-to-radian end)))
    (gimp-edit-bucket-fill layer FG-BUCKET-FILL NORMAL-MODE 100 0 FALSE 0 0)
    (gimp-selection-none img)
    ))
    

(define (fround x)
  (- x (fmod x 1)))

(define (fwrap x mod)
  (- x (* mod (fround (/ x mod)))))

(define (anglewrap x)
  (let ((res (fwrap x (* 2 *pi*))))
    (if (< res 0)
	(+ res (* 2 *pi*))
	res)))

(define (contains x start end)
  (let ((low (min start end))
	(high (max start end)))
    (and (<= x max)
	 (>= x min))))

(define (intersect-segment img size start end)
  (let* ((array (cons-array 24 'double))
	 (radius (/ size 2))
	 (cx (/ size 2))
	 (cy (/ size 2)))

    (aset array 0 cx)
    (aset array 1 cy)

    (let ((xy (prolungate-segment size start)))
      (aset array 2 (car xy))
      (aset array 3 (cadr xy)))

    (let* ((winkelliste (list (list (* (/ 7 4) *pi*) 1 1)
			      (list (* (/ 5 4) *pi*) 0 1)
			      (list (* (/ 3 4) *pi*) 0 0)
			      (list (* (/ 1 4) *pi*) 1 0)))
	   (i 4))

      (let ((wl winkelliste)
	    (finished '())
	    (e (if (< end start) end 0)))

	(while (and (not (null? wl))
		    (not finished))

	       (let* ((wxy (car wl))
		      (angle (car wxy))
		      (x (cadr wxy))
		      (y (caddr wxy)))

		 (if (and (<= angle start)
			  (>= angle e))
		     
		     (begin (aset array i (* x size))
			    (aset array (+ i 1) (* y size))
;			    (print (list x y))
			    (set! i (+ i 2)))))
	       
	       (set! wl (cdr wl))))

      (if (and (> end start)
	       (> end 0))
	  (let ((wl winkelliste)
		(finished '()))

	    (while (and (not (null? wl))
			(not finished))
		   
		   (let* ((wxy (car wl))
			  (angle (car wxy))
			  (x (cadr wxy))
			  (y (caddr wxy)))
		     (if (>= angle end)
			 (begin (aset array i (* x size))
				(aset array (+ i 1) (* y size))
;				(print (list x y))
				(set! i (+ i 2)))))
		   
		   (set! wl (cdr wl)))))

      (let ((xy (prolungate-segment size end)))
	(aset array i (car xy))
	(aset array (+ i 1) (cadr xy)))
      (set! i (+ i 2))
      (aset array i cx)
      (aset array (+ i 1) cy)
      (set! i (+ i 2))

;      (list i array))))

      (gimp-free-select img i array CHANNEL-OP-INTERSECT TRUE TRUE 1))))
    
(define (subtract-dent img size mid-angle angle-size)
  (let* ((array (cons-array (* 3 2) 'double))
	 (radius (/ size 2))
	 (cx (/ size 2))
	 (cy (/ size 2))
	 (sa (+ mid-angle (/ angle-size 2)))
	 (ea (- mid-angle (/ angle-size 2))))

    (aset array 0 cx)
    (aset array 1 cy)

    (let ((xy (prolungate-segment size sa)))
      (aset array 2 (car xy))
      (aset array 3 (cadr xy)))

    (let ((xy (prolungate-segment size ea)))
      (aset array 4 (car xy))
      (aset array 5 (cadr xy)))

    (gimp-free-select img 6 array CHANNEL-OP-SUBTRACT TRUE TRUE 1)))

(define (prolungate-segment size angle)
  (let ((cx (/ size 2))
	(cy (/ size 2))
	(sx (cos angle))
	(sy (- (sin angle))))
    
    (list (+ cx (* size sx))
	  (+ cy (* size sy)))))

(define (deg-to-radian deg)
  (anglewrap (fmod (* 2 *pi* (/ deg 360.0)) (* 2 *pi*))))

(define (circle-coords angle size)
  (let* ((cx (/ size 2))
	 (cy (/ size 2))
	 (radius (/ size 2))
	 (dx (* radius (cos angle)))
	 (dy (* radius (sin angle))))
    (list (+ cx dx) (+ cy dy))))


(script-fu-register "script-fu-reaktor-knob"
		    "<Toolbox>/Xtns/Script-Fu/My Stuff/Reaktor Knob..."
		    "Create a knob animation for reaktor"
		    "das wesen"
		    "das wesen"
		    "Nov 2005"
		    ""
		    SF-VALUE "Size" "64"	
		    SF-VALUE "Width" "10"
		    SF-VALUE "Inactive Width" "5"
		    
		    SF-VALUE "Number of steps" "4"
		    SF-VALUE "Scale steps" "4"

		    SF-VALUE "Start degree" "270"
		    SF-VALUE "Start dent size (degrees)" "30"
		    SF-VALUE "Small dent size (degrees)" "10"
		    
		    SF-COLOR "Active color" '(255 255 255)
		    SF-COLOR "Inactive color" '(40 40 40)
		    SF-COLOR "Background color" '(0 0 0))
		    
;; (script-fu-reaktor-knob 64 10 5 32 10 270 45 10 '(255 255 255) '(255 0 0) '(0 0 0))