Kesan putaran kanvas HTML5 example_html5 kemahiran tutorial

< "text/javascript" src ="/jquery-1.10.2.min.js">

/*
* Fungsi: putaran kanvas
*/
(function(){
var canvas=null,
context=null,
sudut =0;
function resetCanvas(){
canvas=document.getElementById("jb51");
canvas.width=window.innerWidth;
canvas.height=window.innerHeight;
context=canvas.getContext(" 2d");
}
function animate(){
context.save();
cuba{
//Kosongkan kanvas
context.clearRect (0, 0, kanvas. lebar, kanvas.tinggi);
//Tetapkan asal
context.translate(canvas.width * 0.5, canvas.height * 0.5);
//Putar sudut
context.rotate(angle) ;
//Tetapkan warna isian
context.fillStyle = "#FF0000";
//Lukis segi empat tepat
context.fillRect(-30, -30, 60 , 60);
sudut = 0.05 * Math.PI;
}
akhirnya{
context.restore();
}
}
$(window).bind ("resize",resetCanvas).bind("reorient",resetCanvas);
$(document).ready(function(){
window.scrollTo(0,1);
resetCanvas();
setInterval(animate,40 );
});
})();