Spark AR – Counter based on time.

script.js

const D = require('Diagnostics');
const Scene = require('Scene');
const Time = require('Time');
const R = require('Reactive');
const FaceTracking = require('FaceTracking');

//
// Define constants
// 
const OPENNESS_THRESHOLD = 0.5;
// How often it should count (miliseconds)
// This 👇 will increase the number every 100ms
const INTERVAL_TIME = 100;
// How much number should increase on each iteration
const INCREASE_VALUE = 1;

//
// Define varies
// 
let counterInterval;
let currentCount = 0;

//
// Get objects
//
const objCounter = Scene.root.find('counter');

// 
// Functions
//
// This function is called in intervals later on.
function increaseCount () {
	// Increase the current count
	currentCount += INCREASE_VALUE;
	// Update the text with new count
	objCounter.text = currentCount.toString();
}

//
// Facetracking shit
//
const trackedFace = FaceTracking.face(0);
const triggerMouthOpen = trackedFace.mouth.openness.gt(OPENNESS_THRESHOLD);

// Trigger mouth open
triggerMouthOpen.monitor().subscribe(e => {
	if (e.newValue) {
		// Mouth is open, start counter
		counterInterval = Time.setInterval(increaseCount, INTERVAL_TIME);
	} else {
		// Mouth is closed, stop counting
		Time.clearInterval(counterInterval);
	}
});