(if (provided? 'snd-motif)
    (with-let (sublet *motif*)
      ;; set up our user-interface
      (let* ((app (car (main-widgets)))
	     
	     (shell (let* ((xdismiss (XmStringCreate "Go away" XmFONTLIST_DEFAULT_TAG))
			   (xhelp (XmStringCreate "Help" XmFONTLIST_DEFAULT_TAG))
			   (titlestr (XmStringCreate "FM Forever!" XmFONTLIST_DEFAULT_TAG))
			   (dialog (XmCreateTemplateDialog (cadr (main-widgets)) "FM Forever!"
							   (list XmNcancelLabelString   xdismiss
								 XmNhelpLabelString     xhelp
								 XmNautoUnmanage        #f
								 XmNdialogTitle         titlestr
								 XmNresizePolicy        XmRESIZE_GROW
								 XmNnoResize            #f
								 XmNtransient           #f))))
		      (XtAddCallback dialog 
				     XmNhelpCallback (lambda (w context info)
						       (snd-print "This dialog lets you experiment with simple FM")))
		      (XmStringFree xhelp)
		      (XmStringFree xdismiss)
		      (XmStringFree titlestr)
		      dialog))
	     
	     (dpy (XtDisplay shell))
	     (screen (DefaultScreenOfDisplay dpy))
	     ;; (cmap (DefaultColormap dpy (DefaultScreen dpy)))
	     (black (BlackPixelOfScreen screen))
	     (white (WhitePixelOfScreen screen)))
	
	(define (set-flabel label value)
	  (let ((s1 (XmStringCreate (format #f "~,3F" value) XmFONTLIST_DEFAULT_TAG)))
	    (XtVaSetValues label (list XmNlabelString s1))
	    (XmStringFree s1)))
	
	(define (set-ilabel label value)
	  (let ((s1 (XmStringCreate (format #f "~D" value) XmFONTLIST_DEFAULT_TAG)))
	    (XtVaSetValues label (list XmNlabelString s1))
	    (XmStringFree s1)))
	
	(let* ((light-blue *position-color*)
	       (form (XtCreateManagedWidget "form" xmFormWidgetClass shell 
					    (list XmNbackground white
						  XmNforeground black
						  XmNresizePolicy XmRESIZE_GROW)))
	       ;; toggle named "play"
	       (play-button (XtCreateManagedWidget "play" xmToggleButtonWidgetClass form
						   (list XmNleftAttachment   XmATTACH_FORM
							 XmNbottomAttachment XmATTACH_NONE
							 XmNtopAttachment    XmATTACH_FORM
							 XmNrightAttachment  XmATTACH_NONE
							 XmNbackground       white)))
	       ;; carrier freq
	       (carrier (XtCreateManagedWidget "carrier freq:" xmLabelWidgetClass form
					       (list XmNleftAttachment   XmATTACH_FORM
						     XmNbottomAttachment XmATTACH_NONE
						     XmNtopAttachment    XmATTACH_WIDGET
						     XmNtopWidget        play-button
						     XmNrightAttachment  XmATTACH_NONE
						     XmNrecomputeSize    #f
						     XmNbackground       white)))
	       (freq-label (XtCreateManagedWidget "label" xmLabelWidgetClass form
						  (list XmNleftAttachment   XmATTACH_WIDGET
							XmNleftWidget       carrier
							XmNbottomAttachment XmATTACH_NONE
							XmNtopAttachment    XmATTACH_OPPOSITE_WIDGET
							XmNtopWidget        carrier
							XmNrightAttachment  XmATTACH_NONE
							XmNbackground       white)))
	       (freq-scale (XtCreateManagedWidget "carrier freq" xmScaleWidgetClass form
						  (list XmNleftAttachment   XmATTACH_WIDGET
							XmNleftWidget       freq-label
							XmNbottomAttachment XmATTACH_NONE
							XmNtopAttachment    XmATTACH_OPPOSITE_WIDGET
							XmNtopWidget        freq-label
							XmNrightAttachment  XmATTACH_FORM
							XmNshowValue        #f
							XmNorientation      XmHORIZONTAL
							XmNbackground       light-blue)))
	       ;; amp
	       (amp (XtCreateManagedWidget "amp:" xmLabelWidgetClass form
					   (list XmNleftAttachment   XmATTACH_FORM
						 XmNbottomAttachment XmATTACH_NONE
						 XmNtopAttachment    XmATTACH_WIDGET
						 XmNtopWidget        carrier
						 XmNrightAttachment  XmATTACH_NONE
						 XmNrecomputeSize    #f
						 XmNbackground       white)))
	       (amp-label (XtCreateManagedWidget "label" xmLabelWidgetClass form
						 (list XmNleftAttachment   XmATTACH_WIDGET
						       XmNleftWidget       amp
						       XmNbottomAttachment XmATTACH_NONE
						       XmNtopAttachment    XmATTACH_OPPOSITE_WIDGET
						       XmNtopWidget        amp
						       XmNrightAttachment  XmATTACH_NONE
						       XmNbackground       white)))
	       (amp-scale (XtCreateManagedWidget "amp" xmScaleWidgetClass form
						 (list XmNleftAttachment   XmATTACH_WIDGET
						       XmNleftWidget       amp-label
						       XmNbottomAttachment XmATTACH_NONE
						       XmNtopAttachment    XmATTACH_OPPOSITE_WIDGET
						       XmNtopWidget        amp-label
						       XmNrightAttachment  XmATTACH_FORM
						       XmNshowValue        #f
						       XmNorientation      XmHORIZONTAL
						       XmNbackground       light-blue)))
	       ;; fm index
	       (fm-index (XtCreateManagedWidget "fm index:" xmLabelWidgetClass form
						(list XmNleftAttachment   XmATTACH_FORM
						      XmNbottomAttachment XmATTACH_NONE
						      XmNtopAttachment    XmATTACH_WIDGET
						      XmNtopWidget        amp-scale
						      XmNrightAttachment  XmATTACH_NONE
						      XmNrecomputeSize    #f
						      XmNbackground       white)))
	       (fm-label (XtCreateManagedWidget "label" xmLabelWidgetClass form
						(list XmNleftAttachment   XmATTACH_WIDGET
						      XmNleftWidget       fm-index
						      XmNbottomAttachment XmATTACH_NONE
						      XmNtopAttachment    XmATTACH_OPPOSITE_WIDGET
						      XmNtopWidget        fm-index
						      XmNrightAttachment  XmATTACH_NONE
						      XmNbackground       white)))
	       (fm-scale (XtCreateManagedWidget "fm index" xmScaleWidgetClass form
						(list XmNleftAttachment   XmATTACH_WIDGET
						      XmNleftWidget       fm-label
						      XmNbottomAttachment XmATTACH_NONE
						      XmNtopAttachment    XmATTACH_OPPOSITE_WIDGET
						      XmNtopWidget        fm-label
						      XmNrightAttachment  XmATTACH_FORM
						      XmNshowValue        #f
						      XmNorientation      XmHORIZONTAL
						      XmNbackground       light-blue)))
	       ;; c/m ratio
	       (cm-ratio (XtCreateManagedWidget "c/m ratio:" xmLabelWidgetClass form
						(list XmNleftAttachment   XmATTACH_FORM
						      XmNbottomAttachment XmATTACH_NONE
						      XmNtopAttachment    XmATTACH_WIDGET
						      XmNtopWidget        fm-scale
						      XmNrightAttachment  XmATTACH_NONE
						      XmNrecomputeSize    #f
						      XmNbackground       white)))
	       (cm-label (XtCreateManagedWidget "label" xmLabelWidgetClass form
						(list XmNleftAttachment   XmATTACH_WIDGET
						      XmNleftWidget       cm-ratio
						      XmNbottomAttachment XmATTACH_NONE
						      XmNtopAttachment    XmATTACH_OPPOSITE_WIDGET
						      XmNtopWidget        cm-ratio
						      XmNrightAttachment  XmATTACH_NONE
						      XmNbackground       white)))
	       (cm-scale (XtCreateManagedWidget "cm ratio" xmScaleWidgetClass form
						(list XmNleftAttachment   XmATTACH_WIDGET
						      XmNleftWidget       cm-label
						      XmNbottomAttachment XmATTACH_NONE
						      XmNtopAttachment    XmATTACH_OPPOSITE_WIDGET
						      XmNtopWidget        cm-label
						      XmNrightAttachment  XmATTACH_FORM
						      XmNshowValue        #f
						      XmNorientation      XmHORIZONTAL
						      XmNbackground       light-blue)))
	       (frequency 220.0)
	       (low-frequency 40.0)
	       (high-frequency 2000.0)
	       (amplitude 0.5)
	       (index 1.0)
	       (high-index 3.0)
	       (ratio 1)
	       (high-ratio 10)
	       (playing 0.0)
	       (carosc (make-oscil 0.0))
	       (modosc (make-oscil 0.0)))
	  
	  (define (freq-callback w c i)
	    (set! frequency (+ low-frequency (* (.value i) (/ (- high-frequency low-frequency) 100.0))))
	    (set-flabel freq-label frequency))
	  
	  (define (amp-callback w c i)
	    (set! amplitude (/ (.value i) 100.0))
	    (set-flabel amp-label amplitude))
	  
	  (define (fm-callback w c i)
	    (set! index (* (.value i) (/ high-index 100.0)))
	    (set-flabel fm-label index))
	  
	  (define (ratio-callback w c i)
	    (set! ratio (floor (* (.value i) (/ high-ratio 100.0))))
	    (set-ilabel cm-label ratio))
	  
	  ;; add scale-change (drag and value-changed) callbacks
	  (XtAddCallback freq-scale XmNdragCallback freq-callback)
	  (XtAddCallback freq-scale XmNvalueChangedCallback freq-callback)
	  
	  (XtAddCallback amp-scale XmNdragCallback amp-callback)
	  (XtAddCallback amp-scale XmNvalueChangedCallback amp-callback)
	  
	  (XtAddCallback fm-scale XmNdragCallback fm-callback)
	  (XtAddCallback fm-scale XmNvalueChangedCallback fm-callback)
	  
	  (XtAddCallback cm-scale XmNdragCallback ratio-callback)
	  (XtAddCallback cm-scale XmNvalueChangedCallback ratio-callback)
	  
	  (XtAddCallback play-button XmNvalueChangedCallback (lambda (w c i) (set! playing (if (.set i) 1.0 0.0))))
	  
	  ;; set initial values
	  (set-flabel freq-label frequency)
	  (set-flabel amp-label amplitude)
	  (set-flabel fm-label index)
	  (set-ilabel cm-label ratio)
	  
	  (XmScaleSetValue freq-scale (floor (* 100 (/ (- frequency low-frequency) (- high-frequency low-frequency)))))
	  (XmScaleSetValue amp-scale (floor (* 100 amplitude)))
	  (XmScaleSetValue fm-scale (floor (* 100 (/ index high-index))))
	  (XmScaleSetValue cm-scale (floor (* ratio (/ 100 high-ratio))))
	  
	  (XtManageChild shell)
	  (XtRealizeWidget shell)
	  
	  ;; send fm data to dac
	  (let* ((bufsize 256)
		 (srate 22050)
		 (work-proc #f)
		 ;(data (make-float-vector bufsize 0.0))
		 (port (mus-audio-open-output mus-audio-default srate 1 mus-lshort (* bufsize 2))))
	    (if (< port 0) 
		(format #t "can't open DAC!"))
	    
	    (XmAddWMProtocolCallback (cadr (main-widgets)) ; shell
				     (XmInternAtom dpy "WM_DELETE_WINDOW" #f)
				     (lambda (w c i)
				       (XtRemoveWorkProc work-proc) ; odd that there's no XtAppRemoveWorkProc
				       (mus-audio-close port))
				     #f)
	    (XtAddCallback shell
			   XmNcancelCallback (lambda (w context info)
					       (XtRemoveWorkProc work-proc)
					       (mus-audio-close port)
					       (XtUnmanageChild shell)))
	    (set! work-proc (XtAppAddWorkProc app 
					      (lambda (ignored-arg)
						(let ((data (make-float-vector bufsize 0.0)))
						  (do ((i 0 (+ 1 i)))
						      ((= i bufsize))
						    (float-vector-set! data i (* amplitude playing
										 (oscil carosc 
											(+ (hz->radians frequency)
											   (* index 
											      (oscil modosc 
												     (hz->radians (* ratio frequency)))))))))
						  (mus-audio-write port data bufsize)
						  #f)))))))))