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<link href="https://unpkg.com/material-components-web@latest/dist/material-components-web.min.css" rel="stylesheet">
<script src="https://unpkg.com/material-components-web@latest/dist/material-components-web.min.js"></script>

<h1>Recognize hand gestures using the MediaPipe HandGestureRecognizer task</h1>

<section id="demos" class="invisible">
  <h2>Demo: Recognize gestures</h2>
  <p><em>Click on an image below</em> to identify the gestures in the image.</p>

  <div class="detectOnClick">
    <img src="https://assets.codepen.io/9177687/idea-gcbe74dc69_1920.jpg" crossorigin="anonymous" title="Click to get recognize!" />
    <p class="classification removed">
  </div>
  <div class="detectOnClick">
    <img src="https://assets.codepen.io/9177687/thumbs-up-ga409ddbd6_1.png" crossorigin="anonymous" title="Click to get recognize!" />
    <p class="classification removed">
  </div>

  <h2><br>Demo: Webcam continuous hand gesture detection</h2>
  <p>Use your hand to make gestures in front of the camera to get gesture classification. </br>Click <b>enable webcam</b> below and grant access to the webcam if prompted.</p>

  <div id="liveView" class="videoView">
    <button id="webcamButton" class="mdc-button mdc-button--raised">
      <span class="mdc-button__ripple"></span>
      <span class="mdc-button__label">ENABLE WEBCAM</span>
    </button>
    <div style="position: relative;">
      <video id="webcam" autoplay playsinline></video>
      <canvas class="output_canvas" id="output_canvas" width="1280" height="720" style="position: absolute; left: 0px; top: 0px;"></canvas>
      <p id='gesture_output' class="output">
    </div>
  </div>
</section>

/* Copyright 2023 The MediaPipe Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License. */

@use "@material";
body {
  font-family: roboto;
  margin: 2em;
  color: #3d3d3d;
  --mdc-theme-primary: #007f8b;
  --mdc-theme-on-primary: #f1f3f4;
}

h1 {
  color: #007f8b;
}

h2 {
  clear: both;
}

video {
  clear: both;
  display: block;
  transform: rotateY(180deg);
  -webkit-transform: rotateY(180deg);
  -moz-transform: rotateY(180deg);
  height: 280px;
}

section {
  opacity: 1;
  transition: opacity 500ms ease-in-out;
}

.removed {
  display: none;
}

.invisible {
  opacity: 0.2;
}

.detectOnClick {
  position: relative;
  float: left;
  width: 48%;
  margin: 2% 1%;
  cursor: pointer;
}
.videoView {
  position: absolute;
  float: left;
  width: 48%;
  margin: 2% 1%;
  cursor: pointer;
  min-height: 500px;
}

.videoView p,
.detectOnClick p {
  padding-top: 5px;
  padding-bottom: 5px;
  background-color: #007f8b;
  color: #fff;
  border: 1px dashed rgba(255, 255, 255, 0.7);
  z-index: 2;
  margin: 0;
}

.highlighter {
  background: rgba(0, 255, 0, 0.25);
  border: 1px dashed #fff;
  z-index: 1;
  position: absolute;
}

.canvas {
  z-index: 1;
  position: absolute;
  pointer-events: none;
}

.output_canvas {
  transform: rotateY(180deg);
  -webkit-transform: rotateY(180deg);
  -moz-transform: rotateY(180deg);
}

.detectOnClick {
  z-index: 0;
  font-size: calc(8px + 1.2vw);
}

.detectOnClick img {
  width: 45vw;
}
.output {
  display: none;
  width: 100%;
  font-size: calc(8px + 1.2vw);
}

// Copyright 2023 The MediaPipe Authors.

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at

//      http://www.apache.org/licenses/LICENSE-2.0

// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
import {
  GestureRecognizer,
  FilesetResolver,
  DrawingUtils
} from "https://cdn.jsdelivr.net/npm/@mediapipe/tasks-vision@0.10.3";

const demosSection = document.getElementById("demos");
let gestureRecognizer: GestureRecognizer;
let runningMode = "IMAGE";
let enableWebcamButton: HTMLButtonElement;
let webcamRunning: Boolean = false;
const videoHeight = "360px";
const videoWidth = "480px";

// Before we can use HandLandmarker class we must wait for it to finish
// loading. Machine Learning models can be large and take a moment to
// get everything needed to run.
const createGestureRecognizer = async () => {
  const vision = await FilesetResolver.forVisionTasks(
    "https://cdn.jsdelivr.net/npm/@mediapipe/tasks-vision@0.10.3/wasm"
  );
  gestureRecognizer = await GestureRecognizer.createFromOptions(vision, {
    baseOptions: {
      modelAssetPath:
        "https://storage.googleapis.com/mediapipe-models/gesture_recognizer/gesture_recognizer/float16/1/gesture_recognizer.task",
      delegate: "GPU"
    },
    runningMode: runningMode
  });
  demosSection.classList.remove("invisible");
};
createGestureRecognizer();

/********************************************************************
// Demo 1: Detect hand gestures in images
********************************************************************/

const imageContainers = document.getElementsByClassName("detectOnClick");

for (let i = 0; i < imageContainers.length; i++) {
  imageContainers[i].children[0].addEventListener("click", handleClick);
}

async function handleClick(event) {
  if (!gestureRecognizer) {
    alert("Please wait for gestureRecognizer to load");
    return;
  }

  if (runningMode === "VIDEO") {
    runningMode = "IMAGE";
    await gestureRecognizer.setOptions({ runningMode: "IMAGE" });
  }
  // Remove all previous landmarks
  const allCanvas = event.target.parentNode.getElementsByClassName("canvas");
  for (var i = allCanvas.length - 1; i >= 0; i--) {
    const n = allCanvas[i];
    n.parentNode.removeChild(n);
  }

  const results = gestureRecognizer.recognize(event.target);

  // View results in the console to see their format
  console.log(results);
  if (results.gestures.length > 0) {
    const p = event.target.parentNode.childNodes[3];
    p.setAttribute("class", "info");

    const categoryName = results.gestures[0][0].categoryName;
    const categoryScore = parseFloat(
      results.gestures[0][0].score * 100
    ).toFixed(2);
    const handedness = results.handednesses[0][0].displayName;

    p.innerText = `GestureRecognizer: ${categoryName}\n Confidence: ${categoryScore}%\n Handedness: ${handedness}`;
    p.style =
      "left: 0px;" +
      "top: " +
      event.target.height +
      "px; " +
      "width: " +
      (event.target.width - 10) +
      "px;";

    const canvas = document.createElement("canvas");
    canvas.setAttribute("class", "canvas");
    canvas.setAttribute("width", event.target.naturalWidth + "px");
    canvas.setAttribute("height", event.target.naturalHeight + "px");
    canvas.style =
      "left: 0px;" +
      "top: 0px;" +
      "width: " +
      event.target.width +
      "px;" +
      "height: " +
      event.target.height +
      "px;";

    event.target.parentNode.appendChild(canvas);
    const canvasCtx = canvas.getContext("2d");
    const drawingUtils = new DrawingUtils(canvasCtx);
    for (const landmarks of results.landmarks) {
      drawingUtils.drawConnectors(
        landmarks,
        GestureRecognizer.HAND_CONNECTIONS,
        {
          color: "#00FF00",
          lineWidth: 5
        }
      );
      drawingUtils.drawLandmarks(landmarks, {
        color: "#FF0000",
        lineWidth: 1
      });
    }
  }
}

/********************************************************************
// Demo 2: Continuously grab image from webcam stream and detect it.
********************************************************************/

const video = document.getElementById("webcam");
const canvasElement = document.getElementById("output_canvas");
const canvasCtx = canvasElement.getContext("2d");
const gestureOutput = document.getElementById("gesture_output");

// Check if webcam access is supported.
function hasGetUserMedia() {
  return !!(navigator.mediaDevices && navigator.mediaDevices.getUserMedia);
}

// If webcam supported, add event listener to button for when user
// wants to activate it.
if (hasGetUserMedia()) {
  enableWebcamButton = document.getElementById("webcamButton");
  enableWebcamButton.addEventListener("click", enableCam);
} else {
  console.warn("getUserMedia() is not supported by your browser");
}

// Enable the live webcam view and start detection.
function enableCam(event) {
  if (!gestureRecognizer) {
    alert("Please wait for gestureRecognizer to load");
    return;
  }

  if (webcamRunning === true) {
    webcamRunning = false;
    enableWebcamButton.innerText = "ENABLE PREDICTIONS";
  } else {
    webcamRunning = true;
    enableWebcamButton.innerText = "DISABLE PREDICTIONS";
  }

  // getUsermedia parameters.
  const constraints = {
    video: true
  };

  // Activate the webcam stream.
  navigator.mediaDevices.getUserMedia(constraints).then(function (stream) {
    video.srcObject = stream;
    video.addEventListener("loadeddata", predictWebcam);
  });
}

let lastVideoTime = -1;
let results = undefined;
async function predictWebcam() {
  const webcamElement = document.getElementById("webcam");
  // Now let's start detecting the stream.
  if (runningMode === "IMAGE") {
    runningMode = "VIDEO";
    await gestureRecognizer.setOptions({ runningMode: "VIDEO" });
  }
  let nowInMs = Date.now();
  if (video.currentTime !== lastVideoTime) {
    lastVideoTime = video.currentTime;
    results = gestureRecognizer.recognizeForVideo(video, nowInMs);
  }

  canvasCtx.save();
  canvasCtx.clearRect(0, 0, canvasElement.width, canvasElement.height);
  const drawingUtils = new DrawingUtils(canvasCtx);

  canvasElement.style.height = videoHeight;
  webcamElement.style.height = videoHeight;
  canvasElement.style.width = videoWidth;
  webcamElement.style.width = videoWidth;

  if (results.landmarks) {
    for (const landmarks of results.landmarks) {
      drawingUtils.drawConnectors(
        landmarks,
        GestureRecognizer.HAND_CONNECTIONS,
        {
          color: "#00FF00",
          lineWidth: 5
        }
      );
      drawingUtils.drawLandmarks(landmarks, {
        color: "#FF0000",
        lineWidth: 2
      });
    }
  }
  canvasCtx.restore();
  if (results.gestures.length > 0) {
    gestureOutput.style.display = "block";
    gestureOutput.style.width = videoWidth;
    const categoryName = results.gestures[0][0].categoryName;
    const categoryScore = parseFloat(
      results.gestures[0][0].score * 100
    ).toFixed(2);
    const handedness = results.handednesses[0][0].displayName;
    gestureOutput.innerText = `GestureRecognizer: ${categoryName}\n Confidence: ${categoryScore} %\n Handedness: ${handedness}`;
  } else {
    gestureOutput.style.display = "none";
  }
  // Call this function again to keep predicting when the browser is ready.
  if (webcamRunning === true) {
    window.requestAnimationFrame(predictWebcam);
  }
}