ecmascript:

function initialize()
{
   positionArray        = new MFVec3f ();
   orientationArray     = new MFRotation ();
   positionTimeArray    = new MFTime ();
   orientationTimeArray = new MFTime ();

      positionEventsReceived = false;
   orientationEventsReceived = false;
}

function roundoff (value, digits)
{
	resolution = 1;
	for (i = 1; i <= digits; i++ )
	{
		resolution *= 10;
	}
	return Math.round (value*resolution) / resolution; // round to resolution
}
function filterPositions()
{
    // TODO
}

function filterOrientations()
{
    // TODO
}

function set_position (eventValue, timestamp)
{
// Browser.println ('position=' + eventValue);
   // we are counting on an initialization eventValue being sent by ProximitySensor
   positionEventsReceived = true;
   if ( positionArray.length == 0 )
   {
   	positionArray[0]     = eventValue; // initialize
   	positionTimeArray[0] = timestamp;  // initialize
   }
   precedingPositionSampleTime = positionTimeArray[ positionArray.length - 1 ];

   // seconds duration since last valid sample
   if ( (timestamp - precedingPositionSampleTime) > samplingInterval )
   {
	// append values to each array
	positionArray[positionArray.length] = eventValue;
	positionTimeArray[positionTimeArray.length] = timestamp;
   }
   precedingPosition = eventValue;
}

function set_orientation (eventValue, timestamp)
{
   // we are counting on an initialization eventValue being sent by ProximitySensor
   orientationEventsReceived = true;
   if ( orientationArray.length == 0 )
   {
     r = Math.sqrt (eventValue.x*eventValue.x + eventValue.y*eventValue.y + eventValue.z*eventValue.z);
//   Browser.println ('orientation=' + eventValue.toString() + ', r=' + r); // trace
     if (r != 0)
     {
        eventValue.x = eventValue.x / r;
        eventValue.y = eventValue.y / r;
        eventValue.z = eventValue.z / r;
     }
   	 orientationArray[0]     = eventValue; // initialize
   	 orientationTimeArray[0] = timestamp;  // initialize
   }
   precedingOrientationSampleTime = orientationTimeArray[ orientationTimeArray.length - 1 ];

   // append sample values to each array
   if ( (timestamp - precedingOrientationSampleTime) > samplingInterval )
   {
     orientationTimeArray[orientationTimeArray.length] = timestamp;
	 // normalize SFRotation axis if needed
     r = Math.sqrt (eventValue.x*eventValue.x + eventValue.y*eventValue.y + eventValue.z*eventValue.z);
//    Browser.println ('orientation=' + eventValue.toString() + ', r=' + r); // trace
     if (r != 0)
     {
        eventValue.x = eventValue.x / r;
        eventValue.y = eventValue.y / r;
        eventValue.z = eventValue.z / r;
        // auto append to array, no need to allocate
        orientationArray[orientationArray.length] = eventValue;
     }
     else // illegal zero-magnitude axis returned by browser, so just use previous rotation
     {
        // auto append to array, no need to allocate
        orientationArray[orientationArray.length] = precedingOrientation;
     }
   }
   precedingOrientation = eventValue;
}

function start (eventValue, timestamp)
{
	if (eventValue == false) return; // only accept start if eventValue == true
	if (recordingInProgress == true) return; // ignore repeated starts while already running
	recordingInProgress  = true;
    // arrays need to be reinitialized from previous run
	initialize();

    Browser.println ('    <!-- start recording ' + numberOfToursCreated + ' -->');
}

function stop (eventValue, timestamp)
{
	if (eventValue == false) return; // only accept stop  if eventValue == true
	if (recordingInProgress == false)
	{
	   Browser.println ('    <!-- stopped recording without first starting. -->');
       return;
	}

    // ensure legal array lengths in case some events were never sent due to not moving
    if (positionEventsReceived == false)
    {
       Browser.println ('<!-- warning:  no position values received! no action taken. -->');
       return;
    }
    if (orientationEventsReceived == false)
    {
       Browser.println ('<!-- warning:  no orientation values received! no action taken. -->');
       return;
    }
	recordingInProgress = false;

	// preceding last values were at last sampleInterval (either set_position or set_orientation)
	// add one more to each array since they are not sent values by sensor when not changing
       positionArray[   positionArray.length] = precedingPosition;
    orientationArray[orientationArray.length] = precedingOrientation;
       positionTimeArray[   positionTimeArray.length] = timestamp;
    orientationTimeArray[orientationTimeArray.length] = timestamp;

    if (positionArray.length != positionTimeArray.length)
    {
       Browser.println ('<!-- internal error:  positionArray.length (' + positionArray.length + ') != positionTimeArray.length (' + positionTimeArray.length + ') -->');
    }
    if (orientationArray.length != orientationTimeArray.length)
    {
       Browser.println ('<!-- internal error:  orientationArray.length (' + orientationArray.length + ') != orientationTimeArray.length (' + orientationTimeArray.length + ') -->');
    }

   filterPositions();
   filterOrientations();

   // iff events are sent simultaneously, could use either array with start/stop times synchronized
   // however that might be a bad assumption...  so reset start times to match
   if (positionTimeArray[0] > orientationTimeArray[0])    positionTimeArray[0] = orientationTimeArray[0];
   if (positionTimeArray[0] < orientationTimeArray[0]) orientationTimeArray[0] = positionTimeArray[0];

   startTime = positionTimeArray[0];
   stopTime  = positionTimeArray[positionTimeArray.length-1];
   interval  = stopTime - startTime;

   x3dString =
   '    <!-- ********** start recorded Animated Tour ' + numberOfToursCreated + ' using .x3d syntax ********** -->' +
   '    <Group>\n' +
   '      <Viewpoint DEF=\"AnimatedViewpointRecorderViewpoint' + numberOfToursCreated + '\" description=\"Animated Tour ' + numberOfToursCreated + '\"\n' +
   '         position=\"'    + positionArray[0].x + ' '    + positionArray[0].y + ' '    + positionArray[0].z + '\" \n' +
   '         orientation=\"' + orientationArray[0].x + ' ' + orientationArray[0].y + ' ' + orientationArray[0].z + ' ' + orientationArray[0].angle + '\"/>\n' +
   '      <!-- samplingInterval=' + samplingInterval + ' seconds, default TimeSensor loop=true -->' +
   '      <TimeSensor DEF=\"AnimatedViewpointRecorderTimer' + numberOfToursCreated + '\" cycleInterval=\"' + interval + '\"\n' +
   '        enabled=\"true\" loop=\"true\"/>\n' +
   '      <PositionInterpolator DEF=\"AnimatedViewpointRecorderPosition' + numberOfToursCreated + '\" key=\"\n' ;
   for (counter = 0; counter < positionTimeArray.length; counter++)
   {
    x3dString = x3dString +  roundoff(((positionTimeArray[counter] - positionTimeArray[0]) / interval),5) + ' \n';
   }
   x3dString = x3dString + '\"      keyValue=\"\n';
   for (counter = 0; counter < positionArray.length; counter++)
   {
      x3dString = x3dString +   positionArray[counter].x + ' ' + positionArray[counter].y + ' ' + positionArray[counter].z + ', \n';
   }
   x3dString = x3dString + '         \"/>\n' +
   '      <OrientationInterpolator DEF=\"AnimatedViewpointRecorderOrientation' + numberOfToursCreated + '\" key=\"\n';
   for (counter = 0; counter < orientationTimeArray.length; counter++)
   {
    x3dString = x3dString +   roundoff(((orientationTimeArray[counter] - orientationTimeArray[0]) / interval),5) + ' \n';
   }
   x3dString = x3dString +   '\"      keyValue=\"\n';
   for (counter = 0; counter < orientationArray.length; counter++)
   {
      var r = Math.sqrt(orientationArray[counter].x*orientationArray[counter].x + orientationArray[counter].y*orientationArray[counter].y + orientationArray[counter].z*orientationArray[counter].z); // normalize
      if (r == 0) r = 1; // avoid divide by zero
      x3dString = x3dString + (orientationArray[counter].x / r) + ' ' + (orientationArray[counter].y / r) + ' ' + (orientationArray[counter].z / r) + ' ' + orientationArray[counter].angle + ', \n';
   }
   x3dString = x3dString + '         \"/>\n' +
   '      <Group>\n' +
   '        <ROUTE fromField=\"bindTime\" fromNode=\"AnimatedViewpointRecorderViewpoint' + numberOfToursCreated + '\"\n' +
   '          toField=\"startTime\" toNode=\"AnimatedViewpointRecorderTimer' + numberOfToursCreated + '\"/>\n' +
   '        <ROUTE fromField=\"fraction_changed\" fromNode=\"AnimatedViewpointRecorderTimer' + numberOfToursCreated + '\"\n' +
   '          toField=\"set_fraction\" toNode=\"AnimatedViewpointRecorderPosition' + numberOfToursCreated + '\"/>\n' +
   '        <ROUTE fromField=\"fraction_changed\" fromNode=\"AnimatedViewpointRecorderTimer' + numberOfToursCreated + '\"\n' +
   '          toField=\"set_fraction\" toNode=\"AnimatedViewpointRecorderOrientation' + numberOfToursCreated + '\"/>\n' +
   '        <ROUTE fromField=\"value_changed\" fromNode=\"AnimatedViewpointRecorderPosition' + numberOfToursCreated + '\"\n' +
   '          toField=\"position\" toNode=\"AnimatedViewpointRecorderViewpoint' + numberOfToursCreated + '\"/>\n' +
   '        <ROUTE fromField=\"value_changed\"\n' +
   '          fromNode=\"AnimatedViewpointRecorderOrientation' + numberOfToursCreated + '\" toField=\"orientation\" toNode=\"AnimatedViewpointRecorderViewpoint' + numberOfToursCreated + '\"/>\n' +
   '      </Group>\n' +
   '    </Group>\n';

   if (outputX3D) Browser.println (x3dString);

   vrmlString =
      '# ********** start recorded Animated Tour ' + numberOfToursCreated + ' using .x3dv syntax ********** \n' +
      'Group {\n' +
      '  children [\n' +
      '      DEF AnimatedViewpointRecorderViewpoint' + numberOfToursCreated + ' Viewpoint {\n' +
      '        description \"Animated Tour ' + numberOfToursCreated + '\"\n' +
      '        orientation ' + orientationArray[0].x + ' ' + orientationArray[0].y + ' ' + orientationArray[0].z + ' ' + orientationArray[0].angle + '\n' +
      '        position ' + positionArray[0].x + ' '    + positionArray[0].y + ' '    + positionArray[0].z + '\n' +
      '      }\n' +
      '      DEF AnimatedViewpointRecorderTimer' + numberOfToursCreated + ' TimeSensor {\n' +
      '        cycleInterval ' + interval +  '\n' +
      '        loop TRUE\n' +
      '      }\n' +
      '      DEF AnimatedViewpointRecorderPosition' + numberOfToursCreated + ' PositionInterpolator {\n' +
      '        key [\n';
   for (counter = 0; counter < positionTimeArray.length; counter++)
   {
      vrmlString = vrmlString + roundoff(((positionTimeArray[counter] - positionTimeArray[0]) / interval),5) + ' \n';
   }
   vrmlString = vrmlString + '         ]\n' +
      '        keyValue [\n';
   for (counter = 0; counter < positionArray.length; counter++)
   {
      vrmlString = vrmlString +   positionArray[counter].x + ' ' + positionArray[counter].y + ' ' + positionArray[counter].z + ', \n';
   }
   vrmlString = vrmlString + '         ]\n' +
      '      }\n' +
      '      DEF AnimatedViewpointRecorderOrientation' + numberOfToursCreated + ' OrientationInterpolator {\n' +
      '        key [\n';
   for (counter = 0; counter < orientationTimeArray.length; counter++)
   {
    vrmlString = vrmlString +   roundoff(((orientationTimeArray[counter] - orientationTimeArray[0]) / interval),5) + ' \n';
   }
   vrmlString = vrmlString + '         ]\n' +
      '        keyValue [\n';
   for (counter = 0; counter < orientationArray.length; counter++)
   {
      vrmlString = vrmlString + orientationArray[counter].x + ' ' + orientationArray[counter].y + ' ' + orientationArray[counter].z + ' ' + orientationArray[counter].angle + ', \n';
   }
   vrmlString = vrmlString + '         ]\n' +
      '      }\n' +
      '      Group {\n' +
      '         ROUTE AnimatedViewpointRecorderViewpoint' + numberOfToursCreated + '.bindTime TO AnimatedViewpointRecorderTimer' + numberOfToursCreated + '.startTime\n' +
      '         ROUTE AnimatedViewpointRecorderTimer' + numberOfToursCreated + '.fraction_changed TO AnimatedViewpointRecorderPosition' + numberOfToursCreated + '.set_fraction\n' +
      '         ROUTE AnimatedViewpointRecorderTimer' + numberOfToursCreated + '.fraction_changed TO AnimatedViewpointRecorderOrientation' + numberOfToursCreated + '.set_fraction\n' +
      '         ROUTE AnimatedViewpointRecorderPosition' + numberOfToursCreated + '.value_changed TO AnimatedViewpointRecorderViewpoint' + numberOfToursCreated + '.position\n' +
      '         ROUTE AnimatedViewpointRecorderOrientation' + numberOfToursCreated + '.value_changed TO AnimatedViewpointRecorderViewpoint' + numberOfToursCreated + '.orientation\n' +
      '      }\n' +
      '   ]\n' +
      '}\n';

   Browser.println ();
   if (outputClassicVRML) Browser.println (vrmlString);

   numberOfToursCreated++;
   // TODO
   // newNode = new SFNode(vrmlString);
   // newViewpointGroup.children[numberOfToursCreated] = newNode;
}