How to build a Gesture Controlled Web based Game using Tensorflow Object Detection Api | by Victor Dibia | Towards Data Science

Control the game paddle by waving your hand in front of your web cam.
With the TensorFlow object detection api, we have seen examples where models are trained to detect custom objects in images (e.g. detecting hands, toys, racoons, mac n cheese). Naturally, an interesting next step is to explore how these models can be deployed in real world use cases — for example, interaction design.
In this post, I cover a basic body-as-input interaction example where real time results from a hand tracking model (web cam stream as input) is mapped to the controls of a web-based game (Skyfall). The system demonstrates how the integration of a fairly accurate, light weight hand detection model can be used to track player hands and enable realtime body-as-input interactions.
Want to try it out? Project code is available on Github.
github.com
Using parts of the human body as input has the benefit of being always available as the user is not required to carry any secondary device. Importantly, appropriating parts of the human body for gesture based interaction has been shown to improve user experience [2] and overall engagement [1]. While the idea of body as input is not entirely new, existing approaches which leverage computer vision, wearables and sensors (kinect, wii, [5]) etc sometimes suffer from accuracy challenges, are not always portable and can be challenging to integrate with 3rd party software. Advances in light-weight deep neural networks (DNNs), specifically models for object detection (see [3]) and key point extraction (see [4]) hold promise in addressing these issues and furthering the goal of always available (body as) input. These models allow us track the human body with good accuracy using 2D images and with the benefit of easy integration with a range of applications and devices (desktop, web, mobile). While tracking from 2D images does not give us much depth information, it is still surprisingly valuable in building interactions as shown in the Skyfall game example.
Skyfall is a simple web based game created using planck.js — a 2D physics engine. The play mechanism for SkyFall is simple. 3 types of balls fall from the top of the screen in random order — white balls (worth 10 points), green balls (worth 10 points) and red balls (worth -10 points). Players earn points by moving a paddle to catch the good balls (white and green balls) and avoid bad balls (red balls). In the example below, the player can control the paddle by moving the mouse or by touch (drag) on a mobile device.


HTML




CSS




JS




Result



Skip Results Iframe

     <div class="infordisplay ">
        <div class="toprow">
            <img src="http://victordibia.com/skyfall/icon.png" class="icon  floatleft " />
            <div class="scorebox  iblock ">
                <div class="scorevalue inscore"> 0 </div>
                <div class="scorelabel inscore"> pts </div>
                <div class="scoreadded inscore"> </div>
            </div>
            <div class="clear"></div>
        </div>


        <div class="settingsswitches">
            <div class=" ">
                <div class="iblock floatleft">
                    <label class="switch">
                        <input type="checkbox" id="sound">
                        <span class="slider round"></span>
                    </label>
                </div>
                <div class="  iblock soundofftext"> sound off</div>
                <div class="clear"></div>
            </div>

        </div>

        <div class="pausetext">
            <div>Sound (s) </div>
            <div>Pause (space bar) </div>
        </div>

        <div id="updatenote" class="updatenote mt10"> loading model ..</div>
        <button  id="trackbutton" class="bx--btn bx--btn--secondary mt10 trackbutton" type="button" disabled>
                Toggle Video Control ..
              </button>


    </div>
    <video class="videobox canvasbox" autoplay="autoplay" id="myvideo"></video>
  <canvas id="canvas" class="border canvasbox"></canvas>

    <div class="pauseoverlay">
        <div class="overlaycenter">
            Loading  Handtrack.js Model ..
        </div>
    </div>
body {
    font-family: Verdana, Geneva, Tahoma, sans-serif;
}

.infordisplay {
    position: absolute;
    margin: 2vw;
    top: 0.0vw;
    color: #fff;
}

.floatleft {
    float: left;
}

.clear {
    clear: both;
}

.dispblock {
    display: block;
}

.scorebox {
    height: 100%;
    border-bottom: 0.1vw solid #ff8800;
    padding: 1vw;
    font-size: 1.3vw;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    color: #fff;
    margin: 0vw 0vw 0vw 0vw;
}

.iblock {
    display: inline-block;
}

.inscore {
    display: inline-block;
}

.scorevalue {
    font-size: 2vw;
    font-weight: bold;
}

.scoreadded {
    position: absolute;
    font-size: 2vw;
    font-weight: bold;
    padding: 0vw 0vw 0vw 1vw
}

.scoreanimate {
    transform: scale(3);
    transition: all 2s;
}

.icon {
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    width: 4.2vw;
    margin: 0vw;
}

.border {
    border: 2px solid #fff;
}

.settingsswitches {
    margin: 1vw 0vw 0vw 0vw;
}

.soundofftext {
    padding: 0.1vw 1vw 0vw 0.5vw;
    height: 100%;
    font-size: 1.2vw;
}

.pausetext {
    padding: 1vw 0vw 0vw 0vw;
    font-size: 1vw;
}

.pauseoverlay {
    position: fixed;
    /* Sit on top of the page content */
    /* display: none; */
    /* Hidden by default */
    width: 100%;
    /* Full width (cover the whole page) */
    height: 100%;
    /* Full height (cover the whole page) */
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    /* Black background with opacity */
    z-index: 2;
    /* Specify a stack order in case you're using a different order for other elements */
    cursor: pointer;
    /* Add a pointer on hover */
}

.overlaycenter {
    position: absolute;
    top: 50%;
    left: 50%;
    margin-top: -3vw;
    margin-left: -15vw;
    font-size: 0.1vw;
    color: #ff8800;
    opacity: 0;
    font-weight: bold;
}

/* ============= switches ================== */

/* The switch - the box around the slider */
.switch {
    position: relative;
    display: inline-block;
    width: 4vw;
    height: 1.8vw;
}

/* Hide default HTML checkbox */
.switch input {
    display: none;
}

/* The slider */
.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    -webkit-transition: .4s;
    transition: .4s;
}

.slider:before {
    position: absolute;
    content: "";
    height: 1.2vw;
    width: 1.2vw;
    left: 0.4vw;
    bottom: 0.3vw;
    background-color: white;
    -webkit-transition: .4s;
    transition: .4s;
}

input:checked+.slider {
    background-color: #ff8800;
}

input:focus+.slider {
    box-shadow: 0 0 1px #ff8800;
}

input:checked+.slider:before {
    -webkit-transform: translateX(2vw);
    -ms-transform: translateX(2vw);
    transform: translateX(2vw);
}

/* Rounded sliders */
.slider.round {
    border-radius: 2vw;
}

.slider.round:before {
    border-radius: 50%;
}

.mt10 {
    margin-top: 10px;
}

.canvasbox {
    position: absolute;
    right: 10px;
    top: 10px;
    border-radius: 3px;
    margin-right: 10px;
    width: 215px;
    height: 162px;
    border-bottom: 3px solid #0063FF;
    box-shadow: 0 2px 3px 0 rgba(0, 0, 0, 0.2), 0 4px 10px 0 #00000030;

}


.updatenote{
    padding: 12px;
    background: #ff8800;
    color: #fff;
  display: inline-block;
    /* font-weight: bold; */

}

.trackbutton{
    /* background: #ff8800;
    color: #fff; */
}
const video = document.getElementById("myvideo");
const canvas = document.getElementById("canvas");
const context = canvas.getContext("2d");
let trackButton = document.getElementById("trackbutton");
let updateNote = document.getElementById("updatenote");

let imgindex = 1
let isVideo = false;
let model = null;
let videoInterval = 100

// video.width = 500
// video.height = 400

$(".pauseoverlay").show()
// $(".overlaycenter").text("Game Paused")
$(".overlaycenter").animate({
    opacity: 1,
    fontSize: "4vw"
}, pauseGameAnimationDuration, function () {});

const modelParams = {
    flipHorizontal: true, // flip e.g for video  
    maxNumBoxes: 1, // maximum number of boxes to detect
    iouThreshold: 0.5, // ioU threshold for non-max suppression
    scoreThreshold: 0.6, // confidence threshold for predictions.
}

function startVideo() {
    handTrack.startVideo(video).then(function (status) {
        console.log("video started", status);
        if (status) {
            updateNote.innerText = "Now tracking"
            isVideo = true
            runDetection()
        } else {
            updateNote.innerText = "Please enable video"
        }
    });
}

function toggleVideo() {
    if (!isVideo) {
        updateNote.innerText = "Starting video"
        startVideo();
    } else {
        updateNote.innerText = "Stopping video"
        handTrack.stopVideo(video)
        isVideo = false;
        updateNote.innerText = "Video stopped"
    }
}



trackButton.addEventListener("click", function () {
    toggleVideo();
});



function runDetection() {
    model.detect(video).then(predictions => {
        // console.log("Predictions: ", predictions);
        // get the middle x value of the bounding box and map to paddle location
        model.renderPredictions(predictions, canvas, context, video);
        if (predictions[0]) {
            let midval = predictions[0].bbox[0] + (predictions[0].bbox[2] / 2)
            gamex = document.body.clientWidth * (midval / video.width)
            updatePaddleControl(gamex)
            console.log('Predictions: ', gamex);

        }
        if (isVideo) {
            setTimeout(() => {
                runDetection(video)
            }, videoInterval);
        }
    });
}

// Load the model.
handTrack.load(modelParams).then(lmodel => {
    // detect objects in the image.
    model = lmodel
    updateNote.innerText = "Loaded Model!"
    trackButton.disabled = false

    $(".overlaycenter").animate({
        opacity: 0,
        fontSize: "0vw"
    }, pauseGameAnimationDuration, function () {
        $(".pauseoverlay").hide()
    });
});

// ===============================

var colors = ["#69d2e7", "#a7dbd8", "#e0e4cc", "#f38630", "#fa6900", "#fe4365", "#fc9d9a", "#f9cdad", "#c8c8a9", "#83af9b", "#ecd078", "#d95b43", "#c02942", "#542437", "#53777a", "#556270", "#4ecdc4", "#c7f464", "#ff6b6b", "#c44d58", "#774f38", "#e08e79", "#f1d4af", "#ece5ce", "#c5e0dc", "#e8ddcb", "#cdb380", "#036564", "#033649", "#031634", "#490a3d", "#bd1550", "#e97f02", "#f8ca00", "#8a9b0f", "#594f4f", "#547980", "#45ada8", "#9de0ad", "#e5fcc2", "#00a0b0", "#6a4a3c", "#cc333f", "#eb6841", "#edc951", "#e94e77", "#d68189", "#c6a49a", "#c6e5d9", "#f4ead5", "#3fb8af", "#7fc7af", "#dad8a7", "#ff9e9d", "#ff3d7f", "#d9ceb2", "#948c75", "#d5ded9", "#7a6a53", "#99b2b7", "#ffffff", "#cbe86b", "#f2e9e1", "#1c140d", "#cbe86b", "#efffcd", "#dce9be", "#555152", "#2e2633", "#99173c", "#343838", "#005f6b", "#008c9e", "#00b4cc", "#00dffc", "#413e4a", "#73626e", "#b38184", "#f0b49e", "#f7e4be", "#ff4e50", "#fc913a", "#f9d423", "#ede574", "#e1f5c4", "#99b898", "#fecea8", "#ff847c", "#e84a5f", "#2a363b", "#655643", "#80bca3", "#f6f7bd", "#e6ac27", "#bf4d28", "#00a8c6", "#40c0cb", "#f9f2e7", "#aee239", "#8fbe00", "#351330", "#424254", "#64908a", "#e8caa4", "#cc2a41", "#554236", "#f77825", "#d3ce3d", "#f1efa5", "#60b99a", "#ff9900", "#424242", "#e9e9e9", "#bcbcbc", "#3299bb", "#5d4157", "#838689", "#a8caba", "#cad7b2", "#ebe3aa", "#8c2318", "#5e8c6a", "#88a65e", "#bfb35a", "#f2c45a", "#fad089", "#ff9c5b", "#f5634a", "#ed303c", "#3b8183", "#ff4242", "#f4fad2", "#d4ee5e", "#e1edb9", "#f0f2eb", "#d1e751", "#ffffff", "#000000", "#4dbce9", "#26ade4", "#f8b195", "#f67280", "#c06c84", "#6c5b7b", "#355c7d", "#1b676b", "#519548", "#88c425", "#bef202", "#eafde6", "#bcbdac", "#cfbe27", "#f27435", "#f02475", "#3b2d38", "#5e412f", "#fcebb6", "#78c0a8", "#f07818", "#f0a830", "#452632", "#91204d", "#e4844a", "#e8bf56", "#e2f7ce", "#eee6ab", "#c5bc8e", "#696758", "#45484b", "#36393b", "#f0d8a8", "#3d1c00", "#86b8b1", "#f2d694", "#fa2a00", "#f04155", "#ff823a", "#f2f26f", "#fff7bd", "#95cfb7", "#2a044a", "#0b2e59", "#0d6759", "#7ab317", "#a0c55f", "#bbbb88", "#ccc68d", "#eedd99", "#eec290", "#eeaa88", "#b9d7d9", "#668284", "#2a2829", "#493736", "#7b3b3b", "#b3cc57", "#ecf081", "#ffbe40", "#ef746f", "#ab3e5b", "#a3a948", "#edb92e", "#f85931", "#ce1836", "#009989", "#67917a", "#170409", "#b8af03", "#ccbf82", "#e33258", "#e8d5b7", "#0e2430", "#fc3a51", "#f5b349", "#e8d5b9", "#aab3ab", "#c4cbb7", "#ebefc9", "#eee0b7", "#e8caaf", "#300030", "#480048", "#601848", "#c04848", "#f07241", "#ab526b", "#bca297", "#c5ceae", "#f0e2a4", "#f4ebc3", "#607848", "#789048", "#c0d860", "#f0f0d8", "#604848", "#a8e6ce", "#dcedc2", "#ffd3b5", "#ffaaa6", "#ff8c94", "#3e4147", "#fffedf", "#dfba69", "#5a2e2e", "#2a2c31", "#b6d8c0", "#c8d9bf", "#dadabd", "#ecdbbc", "#fedcba", "#fc354c", "#29221f", "#13747d", "#0abfbc", "#fcf7c5", "#1c2130", "#028f76", "#b3e099", "#ffeaad", "#d14334", "#edebe6", "#d6e1c7", "#94c7b6", "#403b33", "#d3643b", "#cc0c39", "#e6781e", "#c8cf02", "#f8fcc1", "#1693a7", "#dad6ca", "#1bb0ce", "#4f8699", "#6a5e72", "#563444", "#a7c5bd", "#e5ddcb", "#eb7b59", "#cf4647", "#524656", "#fdf1cc", "#c6d6b8", "#987f69", "#e3ad40", "#fcd036", "#5c323e", "#a82743", "#e15e32", "#c0d23e", "#e5f04c", "#230f2b", "#f21d41", "#ebebbc", "#bce3c5", "#82b3ae", "#b9d3b0", "#81bda4", "#b28774", "#f88f79", "#f6aa93", "#3a111c", "#574951", "#83988e", "#bcdea5", "#e6f9bc", "#5e3929", "#cd8c52", "#b7d1a3", "#dee8be", "#fcf7d3", "#1c0113", "#6b0103", "#a30006", "#c21a01", "#f03c02", "#382f32", "#ffeaf2", "#fcd9e5", "#fbc5d8", "#f1396d", "#e3dfba", "#c8d6bf", "#93ccc6", "#6cbdb5", "#1a1f1e", "#000000", "#9f111b", "#b11623", "#292c37", "#cccccc", "#c1b398", "#605951", "#fbeec2", "#61a6ab", "#accec0", "#8dccad", "#988864", "#fea6a2", "#f9d6ac", "#ffe9af", "#f6f6f6", "#e8e8e8", "#333333", "#990100", "#b90504", "#1b325f", "#9cc4e4", "#e9f2f9", "#3a89c9", "#f26c4f", "#5e9fa3", "#dcd1b4", "#fab87f", "#f87e7b", "#b05574", "#951f2b", "#f5f4d7", "#e0dfb1", "#a5a36c", "#535233", "#413d3d", "#040004", "#c8ff00", "#fa023c", "#4b000f", "#eff3cd", "#b2d5ba", "#61ada0", "#248f8d", "#605063", "#2d2d29", "#215a6d", "#3ca2a2", "#92c7a3", "#dfece6", "#cfffdd", "#b4dec1", "#5c5863", "#a85163", "#ff1f4c", "#4e395d", "#827085", "#8ebe94", "#ccfc8e", "#dc5b3e", "#9dc9ac", "#fffec7", "#f56218", "#ff9d2e", "#919167", "#a1dbb2", "#fee5ad", "#faca66", "#f7a541", "#f45d4c", "#ffefd3", "#fffee4", "#d0ecea", "#9fd6d2", "#8b7a5e", "#a8a7a7", "#cc527a", "#e8175d", "#474747", "#363636", "#ffedbf", "#f7803c", "#f54828", "#2e0d23", "#f8e4c1", "#f8edd1", "#d88a8a", "#474843", "#9d9d93", "#c5cfc6", "#f38a8a", "#55443d", "#a0cab5", "#cde9ca", "#f1edd0", "#4e4d4a", "#353432", "#94ba65", "#2790b0", "#2b4e72", "#0ca5b0", "#4e3f30", "#fefeeb", "#f8f4e4", "#a5b3aa", "#a70267", "#f10c49", "#fb6b41", "#f6d86b", "#339194", "#9d7e79", "#ccac95", "#9a947c", "#748b83", "#5b756c", "#edf6ee", "#d1c089", "#b3204d", "#412e28", "#151101", "#046d8b", "#309292", "#2fb8ac", "#93a42a", "#ecbe13", "#4d3b3b", "#de6262", "#ffb88c", "#ffd0b3", "#f5e0d3", "#fffbb7", "#a6f6af", "#66b6ab", "#5b7c8d", "#4f2958", "#ff003c", "#ff8a00", "#fabe28", "#88c100", "#00c176", "#fcfef5", "#e9ffe1", "#cdcfb7", "#d6e6c3", "#fafbe3", "#9cddc8", "#bfd8ad", "#ddd9ab", "#f7af63", "#633d2e", "#30261c", "#403831", "#36544f", "#1f5f61", "#0b8185", "#d1313d", "#e5625c", "#f9bf76", "#8eb2c5", "#615375", "#ffe181", "#eee9e5", "#fad3b2", "#ffba7f", "#ff9c97", "#aaff00", "#ffaa00", "#ff00aa", "#aa00ff", "#00aaff"]
var colorindex = 0;


let windowXRange, worldXRange = 0
let paddle
let Vec2
let accelFactor

// TestBed Details
windowHeight = $(document).height()
windowWidth = document.body.clientWidth

console.log(windowHeight, windowWidth);

var scale_factor = 10
var SPACE_WIDTH = windowWidth / scale_factor;
var SPACE_HEIGHT = windowHeight / scale_factor;


// Bead Details
var NUM_BEADS = 6
var BEAD_RESTITUTION = 0.7

// Paddle Details
accelFactor = 0.042 * SPACE_WIDTH;




var paddleMap = new Map();
var maxNumberPaddles = 10;
windowHeight = window.innerHeight
windowWidth = window.innerWidth

var bounceClip = new Audio('http://victordibia.com/skyfall/bounce.wav');
bounceClip.type = 'audio/wav';
var enableAudio = false;
var pauseGame = false;
var pauseGameAnimationDuration = 500;

$("input#sound").click(function () {
    enableAudio = $(this).is(':checked')
    soundtext = enableAudio ? "sound on" : "sound off";
    $(".soundofftext").text(soundtext)
});


function updatePaddleControl(x) {
    // gamex = x;
    let mouseX = convertToRange(x, windowXRange, worldXRange);
    let lineaVeloctiy = Vec2((mouseX - paddle.getPosition().x) * accelFactor, 0)
    // paddle.setLinearVelocity(lineaVeloctiy)
    // paddle.setLinearVelocity(lineaVeloctiy)
    lineaVeloctiy.x = isNaN(lineaVeloctiy.x) ? 0 : lineaVeloctiy.x
    paddle.setLinearVelocity(lineaVeloctiy)
    console.log("linear velocity", lineaVeloctiy.x, lineaVeloctiy.y)
}



planck.testbed(function (testbed) {
    var pl = planck;
    Vec2 = pl.Vec2;

    var world = pl.World(Vec2(0, -30));
    var BEAD = 4
    var PADDLE = 5


    var beadFixedDef = {
        density: 1.0,
        restitution: BEAD_RESTITUTION,
        userData: {
            name: "bead",
            points: 3
        }
    };
    var paddleFixedDef = {
        // density : 1.0,
        // restitution : BEAD_RESTITUTION,
        userData: {
            name: "paddle"
        }
    };

    var self;

    testbed.step = tick;
    testbed.width = SPACE_WIDTH;
    testbed.height = SPACE_HEIGHT;

    var playerScore = 0;
    windowXRange = [0, windowWidth]
    worldXRange = [-(SPACE_WIDTH / 2), SPACE_WIDTH / 2]


    var characterBodies = [];
    var paddleBodies = new Map();

    var globalTime = 0;
    var CHARACTER_LIFETIME = 6000

    start()

    $(function () {
        console.log("ready!");
        scoreDiv = document.createElement('div');
        $(scoreDiv).addClass("classname")
            .text("bingo")
            .appendTo($("body")) //main div
    });

    function start() {
        addUI()
    }



    // Remove paddles that are no longer in frame.
    function refreshMap(currentMap) {
        paddleBodies.forEach(function (item, key, mapObj) {
            if (!currentMap.has(key)) {
                world.destroyBody(paddleBodies.get(key).paddle);
                paddleBodies.delete(key)
            }
        });
    }

    world.on('pre-solve', function (contact) {

        var fixtureA = contact.getFixtureA();
        var fixtureB = contact.getFixtureB();

        var bodyA = contact.getFixtureA().getBody();
        var bodyB = contact.getFixtureB().getBody();

        var apaddle = bpaddle = false
        if (fixtureA.getUserData()) {
            apaddle = fixtureA.getUserData().name == paddleFixedDef.userData.name;
        }

        if (fixtureB.getUserData()) {
            bpaddle = fixtureB.getUserData().name == paddleFixedDef.userData.name;
        }
        if (apaddle || bpaddle) {
            // Paddle collided with something
            var paddle = apaddle ? fixtureA : fixtureB;
            var bead = !apaddle ? fixtureA : fixtureB;

            // console.log(paddle, bead);

            setTimeout(function () {
                paddleBeadHit(paddle, bead);
            }, 1);
        }

    })

    function paddleBeadHit(paddle, bead) {
        // console.log("attempting stroke change", bead.getUserData());
        //console.log("bead points ",bead.getUserData().points);
        playClip(bounceClip)
        updateScoreBox(bead.getUserData().points);

    }

    function playClip(clip) {
        if (enableAudio) {
            clip.play()
        }
    }

    function updateScoreBox(points) {
        if (!pauseGame) {
            playerScore += points;
            $(".scorevalue").text(playerScore)
            pointsAdded = points > 0 ? "+" + points : points
            $(".scoreadded").text(pointsAdded)
            $(".scoreadded").show().animate({
                opacity: 0,
                fontSize: "4vw",
                color: "#ff8800"
            }, 500, function () {
                $(this).css({
                    fontSize: "2vw",
                    opacity: 1
                }).hide()
            });
        }
    }

    function pauseGamePlay() {
        pauseGame = !pauseGame
        if (pauseGame) {
            paddle.setLinearVelocity(Vec2(0, 0))
            $(".pauseoverlay").show()
            $(".overlaycenter").text("Game Paused")
            $(".overlaycenter").animate({
                opacity: 1,
                fontSize: "4vw"
            }, pauseGameAnimationDuration, function () {});
        } else {
            paddle.setLinearVelocity(Vec2(3, 0))

            $(".overlaycenter").animate({
                opacity: 0,
                fontSize: "0vw"
            }, pauseGameAnimationDuration, function () {
                $(".pauseoverlay").hide()
            });
        }

    }

    // process mouse move and touch events
    function mouseMoveHandler(event) {
        if (!pauseGame) {
            mouseX = convertToRange(event.clientX, windowXRange, worldXRange);
            if (!isNaN(mouseX)) {
                lineaVeloctiy = Vec2((mouseX - paddle.getPosition().x) * accelFactor, 0)
                paddle.setLinearVelocity(lineaVeloctiy)
                // xdiff = mouseX - paddle.getPosition().x > 0 ? 100 : -100
                // paddle.setPosition(Vec2(mouseX,0))
            }
        } else {

        }
    }

    function addUI() {
        addPaddle()

        // Add mouse movement listener to move paddle
        // Add mouse movement listener to move paddle
        $(document).bind('touchmove touchstart mousemove', function (e) {
            e.preventDefault();
            var touch
            if (e.type == "touchmove") {
                touch = e.originalEvent.touches[0] || e.originalEvent.changedTouches[0];
            } else if (e.type == "touchstart") {
                touch = e.targetTouches[0]
            } else if (e.type == "mousemove") {
                touch = e
            }
            mouseMoveHandler(touch)
        });

        // Add keypress event listener to pause game
        document.onkeyup = function (e) {
            var key = e.keyCode ? e.keyCode : e.which;
            if (key == 32) {
                console.log("spacebar pressed")
                pauseGamePlay()
            }
            if (key == 83) {
                $("input#sound").click()
            }
        }

        var ground = world.createBody();
        var groundY = -(0.3 * SPACE_HEIGHT)
        // ground.createFixture(pl.Edge(Vec2(-(0.95 * SPACE_WIDTH / 2), groundY), Vec2((0.95 * SPACE_WIDTH / 2), groundY)), 0.0);
    }

    function addPaddle() {
        paddle = world.createBody({
            type: "kinematic",
            filterCategoryBits: PADDLE,
            filterMaskBits: BEAD,
            position: Vec2(-(0.4 * SPACE_WIDTH / 2), -(0.25 * SPACE_HEIGHT))
        })
        paddleLines = [
            [1.8, -0.1],
            [1.8, 0.1],
            [1.2, 0.4],
            [0.4, 0.6],
            [-2.4, 0.6],
            [-3.2, 0.4],
            [-3.8, 0.1],
            [-3.8, -0.1]
        ]

        n = 10, radius = SPACE_WIDTH * 0.03, paddlePath = [], paddlePath = []

        paddleLines.forEach(function (each) {
            paddlePath.push(Vec2(radius * each[0], radius * each[1]))
        })

        paddle.createFixture(pl.Polygon(paddlePath), paddleFixedDef)
        paddle.render = {
            fill: '#ff8800',
            stroke: '#000000'
        }
    }

    // Generate Beeds falling from sky
    function generateBeads(numCharacters) {

        for (var i = 0; i < numCharacters; ++i) {
            var characterBody = world.createBody({
                type: 'dynamic',
                filterCategoryBits: BEAD,
                filterMaskBits: PADDLE,
                position: Vec2(pl.Math.random(-(SPACE_WIDTH / 2), (SPACE_WIDTH / 2)), pl.Math.random((0.5 * SPACE_HEIGHT), 0.9 * SPACE_HEIGHT))
            });


            var beadWidthFactor = 0.005
            var beadColor = {
                fill: '#fff',
                stroke: '#000000'
            };

            var fd = {
                density: beadFixedDef.density,
                restitution: BEAD_RESTITUTION,
                userData: {
                    name: beadFixedDef.userData.name,
                    points: 3
                }
            };

            var randVal = Math.random();

            if (randVal > 0.8) {
                //   green ball, + 20
                beadColor.fill = '#32CD32'
                beadWidthFactor = 0.007
                fd.userData.points = 20;
            } else if (randVal < 0.2) {
                //  Red Ball, - 10
                beadWidthFactor = 0.007
                beadColor.fill = '#ff0000'
                fd.userData.points = -10;
            } else {
                // White ball +10
                beadColor.fill = '#fff'
                beadWidthFactor = 0.007
                fd.userData.points = 10;
            }


            var shape = pl.Circle(SPACE_WIDTH * beadWidthFactor);
            characterBody.createFixture(shape, fd);

            characterBody.render = beadColor

            characterBody.dieTime = globalTime + CHARACTER_LIFETIME

            characterBodies.push(characterBody);
        }

    }

    function tick(dt) {

        globalTime += dt;
        if (world.m_stepCount % 80 == 0) {
            if (!pauseGame) {
                generateBeads(NUM_BEADS);
                //console.log("car size", characterBodies.length);
                for (var i = 0; i !== characterBodies.length; i++) {
                    var characterBody = characterBodies[i];
                    //If the character is old, delete it
                    if (characterBody.dieTime <= globalTime) {
                        characterBodies.splice(i, 1);
                        world.destroyBody(characterBody);
                        i--;
                        continue;
                    }

                }
            }
        }
        // wrap(box)
        wrap(paddle)
        paddleBodies.forEach(function (item, key, mapObj) {
            stayPaddle(item.paddle)
        });


    }

    function stayPaddle(paddle) {
        var p = paddle.getPosition()

        if (p.x < -SPACE_WIDTH / 2) {
            p.x = -SPACE_WIDTH / 2
            paddle.setPosition(p)
        } else if (p.x > SPACE_WIDTH / 2) {
            p.x = SPACE_WIDTH / 2
            paddle.setPosition(p)
        }
    }

    // Returns a random number between -0.5 and 0.5
    function rand(value) {
        return (Math.random() - 0.5) * (value || 1);
    }

    // If the body is out of space bounds, wrap it to the other side
    function wrap(body) {
        var p = body.getPosition();
        p.x = wrapNumber(p.x, -SPACE_WIDTH / 2, SPACE_WIDTH / 2);
        p.y = wrapNumber(p.y, -SPACE_HEIGHT / 2, SPACE_HEIGHT / 2);
        body.setPosition(p);
    }


    function wrapNumber(num, min, max) {
        if (typeof min === 'undefined') {
            max = 1, min = 0;
        } else if (typeof max === 'undefined') {
            max = min, min = 0;
        }
        if (max > min) {
            num = (num - min) % (max - min);
            return num + (num < 0 ? max : min);
        } else {
            num = (num - max) % (min - max);
            return num + (num <= 0 ? min : max);
        }
    }

    // rest of your code
    return world; // make sure you return the world
});


function convertToRange(value, srcRange, dstRange) {
    // value is outside source range return
    if (value < srcRange[0] || value > srcRange[1]) {
        return NaN;
    }

    var srcMax = srcRange[1] - srcRange[0],
        dstMax = dstRange[1] - dstRange[0],
        adjValue = value - srcRange[0];

    return (adjValue * dstMax / srcMax) + dstRange[0];

}

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