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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Beyond Reality Face SDK - BRFv5 - Face Tracking for Browser/JavaScript - Minimal WebWorker Example (no modules)</title>
<style>
html, body { width: 100%; height: 100%; background-color: #ffffff; margin: 0; padding: 0; overflow: hidden; }
canvas {position: absolute; }
</style>
</head>
<body>
<!--
WebWorker example.
The UI side includes the webcam video as well as two
canvases, one for the image data and one for drawing the results.
In this main thread we activate the camera and draw the stream to the imageData canvas.
The pixel data is send to the worker for analysis.
The UI side waits for the results of the last sent pixel data before sending new data.
The worker will send the results once it's finished.
The webcam image will be slightly out of sync with the results, of course.
-->
<video id="_webcam" style="display: none;" playsinline></video>
<canvas id="_imageData"></canvas>
<canvas id="_resultData"></canvas>
<script>
if(!window.Worker) { throw "No worker support" }
const worker = new Worker("./js/worker/setup__worker.js")
worker.addEventListener("error", e => console.error(e), false)
const sendSize = function() {
const sizeData = new Uint32Array(2)
sizeData.set([_width, _height])
worker.postMessage(sizeData.buffer, [sizeData.buffer])
}
worker.addEventListener('message', function(e) {
// console.log("js message", e)
if(e.data === "trackFaces") {
// start signal, brf lib is ready.
trackFaces()
} else {
// Got results (vertices) for the last sent pixel data. Draw it.
_resultDataCtx.clearRect(0, 0, _width, _height);
drawVertices(_resultDataCtx, new Float32Array(e.data), '#00a0ff', 2.0)
_gotResults = true // unlock
}
}, false)
// References to the video and canvases.
const _webcam = document.getElementById('_webcam')
const _imageData = document.getElementById('_imageData')
const _resultData = document.getElementById('_resultData')
let _imageDataCtx = null
let _resultDataCtx = null
let _width = 0
let _height = 0
let _gotResults = true
const openCamera = () => {
console.log('openCamera')
return new Promise((resolve, reject) => {
//1280x720 to better see the lag caused by the communication.
//640x480: results will be more in sync.
// window.navigator.mediaDevices.getUserMedia({ video: { width: 1280, height: 720, frameRate: 30, facingMode: 'user'} })
window.navigator.mediaDevices.getUserMedia({ video: { width: 640, height: 480, frameRate: 30, facingMode: 'user'} })
.then((mediaStream) => {
_webcam.srcObject = mediaStream
_webcam.play().then(() => { resolve({ width: _webcam.videoWidth, height: _webcam.videoHeight }) }).catch((e) => { reject(e) })
}).catch((e) => { reject(e) })
})
}
const trackFaces = () => {
if(!_imageData) { return }
const ctx = _imageDataCtx
ctx.setTransform(-1.0, 0, 0, 1, _width, 0) // A virtual mirror should be... mirrored
ctx.drawImage(_webcam, 0, 0, _width, _height)
ctx.setTransform(1.0, 0, 0, 1, 0, 0) // unmirror to draw the results
if(_gotResults) {
_gotResults = false
const _dataArray = new Uint8ClampedArray(_width * _height * 4)
_dataArray.set(ctx.getImageData(0, 0, _width, _height).data)
worker.postMessage(_dataArray.buffer, [_dataArray.buffer])
}
requestAnimationFrame(trackFaces)
}
openCamera().then(({ width, height }) => {
console.log('openCamera: done: ' + width + 'x' + height)
_width = width
_height = height
_imageData.width = _width
_imageData.height = _height
_imageDataCtx = _imageData.getContext("2d")
_resultData.width = _width
_resultData.height = _height
_resultDataCtx = _resultData.getContext("2d")
sendSize()
}).catch((e) => { if(e) { console.error('Camera failed: ', e) } })
const drawVertices = (ctx, vertices, color, radius) => {
ctx.strokeStyle = null
ctx.fillStyle = getColor(color, 1.0)
let _radius = radius || 2.0
for(let i = 0; i < vertices.length; i += 2) {
ctx.beginPath()
ctx.arc(vertices[i], vertices[i + 1], _radius, 0, 2 * Math.PI)
ctx.fill()
}
}
const getColor = (color, alpha) => {
const colorStr = color + ''
if(colorStr.startsWith('rgb')) {
return color
}
if(colorStr.startsWith('#')) {
color = parseInt('0x' + colorStr.substr(1))
}
return 'rgb(' +
(((color >> 16) & 0xff).toString(10)) + ', ' +
(((color >> 8) & 0xff).toString(10)) + ', ' +
(((color) & 0xff).toString(10)) + ', ' + alpha +')'
}
</script>
</body>
</html>