Fabric JS - Issue in Scrollable Div

Fabric JS - Issue in Scrollable Div

HTML

<script src="https://www.deltalink.it/andreab/fabric/fabric.js"></script>
<canvas id="myCanvas" width="600" height="600"></canvas>

CSS

canvas {
    border: 1px solid #999;
}

.imp-modal {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  z-index:1002;
  display:block;
    background-color: #FFF;
}

.imp-modal .modal-header {
  position: absolute;
  top: 0;
  height: 50px;
  width: 100%;
    background-color: #f0f0f0;
}
.imp-modal .modal-body {
  position: absolute;
  top: 50px;
  bottom: 50px;
  width: 100%;
  overflow-y: auto;
        -webkit-overflow-scrolling: touch;
}
.imp-modal .modal-footer {
  position: absolute;
  bottom: 0;
  height: 50px;
  width: 100%;
    background-color: #f0f0f0;
}
.imp-modal .modal-content,
.imp-modal .modal-dialog {
  height: 100%;
  width: 70%;
}
.imp-modal .close {
  opacity: 1;
}

JavaScript

//Friend Image
var fReady = false; 
var fImage = new Image();
fImage.onload = function(){
      fReady = true;
}
fImage.src="http://vignette1.wikia.nocookie.net/finalfantasy/images/0/0a/FFTS_Fighter_Sprite.png";
var then = 0;
//Game objects
var hero = {
     speed:450,
     x:200,
     y:390
};

var keysDown = {};
addEventListener("keydown", function(e){
        keysDown[e.keyCode] = true;
    e.preventDefault();
}, false);
addEventListener("keyup", function(e){
        delete keysDown[e.keyCode];
         e.preventDefault();
}, false);


function update(modifier){

    if(38 in keysDown){
        hero.y -= hero.speed * modifier;
    }
    if(40 in keysDown){
        hero.y += hero.speed * modifier;
    }
    if(37 in keysDown){
        hero.x -= hero.speed * modifier;
    }
    if(39 in keysDown){
        hero.x += hero.speed * modifier;
    }
}

function render(c){
    c.clearRect(0,0,600,600)
    if(fReady == true){
        c.drawImage(fImage,hero.x,hero.y,100,100);
    }
}
function setImage(){
    var canvas = document.getElementById("myCanvas");
    var ctx = canvas.getContext("2d");
    var now = Date.now();
    var delta = now-then;

    update(delta/100);
    render(ctx);

    then = now;

    requestAnimationFrame(setImage);
}
    var w = window;
    requestAnimationFrame = w.requestAnimationFrame || w.webkitRequestAnimationFrame || w.msRequestAnimationFrame || w.mozRequestAnimationFrame;

function start(){
    console.log('starting');
    then = Date.now();
    setImage();
}

start();