ml5/demos/03-handpose-vanilla-js.html

<!DOCTYPE html>
<html lang="en" class="loading">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>HandPose</title>
  <link rel="stylesheet" href="css/normalize.css">
  <link rel="stylesheet" href="css/style.css">
  <style>
    .hidden {
      display: none;
    }
    .loading .display-loading {
      display: block;
    }
    .running .display-running {
      display: block;
    }
  </style>
</head>
<body>
  <h1 class="h1">HandPose</h1>
  <h2 id="state"></h2>
  <canvas id="canvas" class="fancy-shadow hidden display-running"></canvas>
  <script src="https://unpkg.com/ml5@1/dist/ml5.js"></script>
  <script>

    const $canvas = document.querySelector('#canvas');
    const $state = document.querySelector('#state');

    let video, ctx;
    let handPose;
    let hands = [];

    const STATE_LOADING = "loading";
    const STATE_RUNNING = "running";
    const ALL_STATES = [STATE_LOADING, STATE_RUNNING];
    let state = STATE_LOADING;

    const setState = (value) => {
      console.log('setState', value);
      state = value;
      $state.textContent = state;
      document.documentElement.classList.remove(...ALL_STATES);
      document.documentElement.classList.add(state);
    };

    const preload = async () => {
      setState(STATE_LOADING);
      requestAnimationFrame(draw);
      handPose = ml5.handPose();
      await handPose.ready;
      console.log('model ready');
      setup();
    }

    const setup = async () => {
      console.log('setup');
      ctx = $canvas.getContext('2d');
      // create a video stream - specify a fixed size
      const stream = await navigator.mediaDevices.getUserMedia({ video: {
        width: 640,
        height: 480
      } });
      video = document.createElement('video');
      video.srcObject = stream;
      video.play();
      // set canvas & video size
      $canvas.width = video.width = 640;
      $canvas.height = video.height = 480;
      // start detecting poses
      handPose.detectStart(video, (results) => {
        // store the results in a global
        hands = results;
      });
      // start the app
      setState(STATE_RUNNING);
    }

    const draw = () => {
      if (state === STATE_RUNNING) {
        ctx.drawImage(video, 0, 0, $canvas.width, $canvas.height);
        ctx.fillStyle = 'red';
        hands.forEach(hand => {
          hand.keypoints.forEach(keypoint => {
            // no confidence score for handPose
            ctx.beginPath();
            ctx.arc(keypoint.x, keypoint.y, 10, 0, 2 * Math.PI);
            ctx.fill();
          });
        });
      }
      requestAnimationFrame(draw);
    }

    preload();
  </script>
</body>
</html>