ecmascript:

function initialize()
{
	outerRadius = -1.0;
	innerRadius = -1.0;

	animationDuration = defaultRange / transmissionPropagationSpeed + transmissionDuration;

	tracePrint('beamCount = ' + beamCount);
	tracePrint('defaultRange = ' + defaultRange);
	tracePrint('animationDuration=' + animationDuration);
	tracePrint('transmissionPropagationSpeed=' + transmissionPropagationSpeed);

	computeSpine(beamCount);

    updateCrossSection(0);

	updateExtrusionShape(crossSection, spine, color);
}
function updateRadii(fraction)
{
	_transmissionPropagationDuration = defaultRange / transmissionPropagationSpeed;
	_animationDuration = _transmissionPropagationDuration + transmissionDuration;
	_spineRadius = 1;
	
	outerRadius = fraction * _animationDuration * transmissionPropagationSpeed - _spineRadius;

	if (outerRadius > (defaultRange - _spineRadius)) {
		outerRadius = defaultRange - _spineRadius;
	}

	if ((fraction * _animationDuration) > (_transmissionPropagationDuration + transmissionDuration * 7/8)) 
	{
		transparency_changed = ( (fraction * _animationDuration) - (_transmissionPropagationDuration + transmissionDuration * 7/8) ) / (transmissionDuration * 1/8);
	}

	if ((fraction * _animationDuration) <= transmissionDuration)
	{
		innerRadius = -_spineRadius;
	} else {
		innerRadius = ((fraction * _animationDuration) - transmissionDuration) * transmissionPropagationSpeed - _spineRadius;
		if (innerRadius > defaultRange) {
			innerRadius = defaultRange;
		}
	}

	tracePrint('fraction = ' + fraction);
	tracePrint('outerRadius = ' + outerRadius);
	tracePrint('innerRadius = ' + innerRadius);
}
function set_beamCount (beamCount)
{
    alwaysPrint('set_beamCount(' + beamCount + '), beam spacing=' + (360/beamCount) + ' degrees');
    computeSpine(beamCount);
}
function computeSpine (beamCount)
{
	if (beamCount < 3)
    {
        alwaysPrint('** insufficient beamCount=' + beamCount + ', ignored, spine not recomputed');
        return;
    }
    newSpine = new MFVec3f ();
    for (index = 0; index <= beamCount; index++)
	{
		angle = 2.0 * Math.PI * index / beamCount;
        newSpine[index] = new SFVec3f (Math.sin(angle), 0.0, Math.cos(angle));
	}
    newSpine[beamCount] = newSpine[0]; // ensure beginning point matches end point
    spine = newSpine;
	tracePrint('spine.length=' + spine.length + ', spine=' + spine);
}
function updateCrossSection(fraction)
{
	updateRadii(fraction);

	_spineRadius = 1;
	_outerHeight = Math.abs((outerRadius + _spineRadius) * Math.tan(Math.PI/6));

	if (_outerHeight > height)
	{
		_outerHeight = height;
	}

	_innerHeight = Math.abs((innerRadius + _spineRadius) * Math.tan(Math.PI/6));

	if (_innerHeight > height)
	{
		_innerHeight = height;
	}

	index = 0;
	position[index]     = new SFVec2f(outerRadius, _outerHeight/2);
	crossSection[index] = new SFVec2f(position[index].x, position[index].y);
	index++;
	
	position[index]     = new SFVec2f(innerRadius, _innerHeight/2);
	crossSection[index] = new SFVec2f(position[index].x, position[index].y);
	index++;

	position[index]     = new SFVec2f(innerRadius, -_innerHeight/2);
	crossSection[index] = new SFVec2f(position[index].x, position[index].y);
	index++;

	position[index]     = new SFVec2f(outerRadius, -_outerHeight/2);
	crossSection[index] = new SFVec2f(position[index].x, position[index].y);
	index++;

	position[index]     = new SFVec2f(outerRadius, _outerHeight/2);
	crossSection[index] = new SFVec2f(position[index].x, position[index].y);
	
	tracePrint('position     = ' + position);
	tracePrint('crossSection = ' + crossSection);
}
function startTransmission(value, timeStamp)
{
	if (value == true)
	{
		loopAnimation = false;
		loopStartTime = -1;
		animationStartTime = timeStamp;
		tracePrint('startTransmission ()');
	}
}
function startContinuousTransmissions(value, timeStamp)
{
	if (value == true)
	{
		loopAnimation = true;
		loopStartTime = timeStamp;
		animationStartTime = timeStamp;
		tracePrint('startContinuousTransmissions ()');
	}
}
function set_range(value, timeStamp)
{
	if (value >= 0)
	{
		defaultRange = value;
		tracePrint('defaultRange = ' + defaultRange);
	}
	else tracePrint('set_range (' + value + '); // no response, negative');
}
function set_color(value, timeStamp)
{
	color = value;
	tracePrint('color = ' + color);
}
function set_transmissionDuration(value, timeStamp)
{
	if (value >= 0) 
	{
		transmissionDuration = value;
		animationDuration = defaultRange / transmissionPropagationSpeed + transmissionDuration;
		restartClockDuration = 2 * animationDuration;
		tracePrint('transmissionDuration = ' + transmissionDuration);
		tracePrint('animationDuration    = ' + animationDuration);
		tracePrint('restartClockDuration = ' + restartClockDuration);
	}
	else tracePrint('set_transmissionDuration (' + value + '); // no response, negative');
}
function set_fraction(value, timeStamp)
{
	updateCrossSection(value);

	updateExtrusionShape(crossSection, spine, color);
}
function updateExtrusionShape(crossSection, spine, color)
{
	// emissiveColor appears unaffected by transparency, unfortunately
	signalProfileMaterial.diffuseColor = color;
	signalProfileMaterial.transparency = transparency;

	tracePrint('Updating crossSection:');
	tracePrint('  crossSection = ' + crossSection);
	tracePrint('  spine = ' + spine);
	tracePrint('  transparency = ' + transparency);

	crossSection_changed = crossSection;
	spine_changed = spine;
}
function tracePrint(value)
{
  if (traceEnabled) alwaysPrint (value);
}
function alwaysPrint(value)
{
	Browser.println ('[AcousticTransmissionCylinderPrototype] ' + value);
}