Menggerakkan grafik html5 jam example_html5 kemahiran tutorial

var Jam = fungsi (kanvas, pilihan) {
this.canvas = kanvas;
this.ctx = this.canvas.getContext("2d");
this.options = pilihan;
};

Clock.prototype = {
constructor: Clock,
drawCircle: function () {
var ctx = this.ctx;
ctx.strokeStyle = "black";
ctx.arc(this .canvas.width / 2, this.canvas.height / 2, 50, 0, 2 * Math.PI, false);
ctx.stroke();
},
drawNum: function () {
var ctx = this.ctx;
var angle = Math.PI * 2 / 12;
untuk (var i = 1; i <= 12; i = 1) {
ctx .font = "20px Georgia";
ctx.textAlign = "center";
ctx.textBaseline = 'middle';
ctx.fillText(String(i), this.canvas.width / 2 Math .cos(3 *Math.PI / 2 sudut * i) * 40, this.canvas.height / 2 Math.sin(3 * Math.PI / 2 sudut * i) * 40);
}
},
drawPointer: function () {
var ctx = this.ctx;
var that = this;
var date, jam, minit, saat;
date = new Date() ;
jam = date.getHours();
jika (jam > 12) {
jam = jam % 12;
}
minit = tarikh.getMinutes();
saat = date.getSeconds();

var b = minit * Math.PI / 30;
var c = second * Math.PI / 30;
var a = jam * Math.PI / 6 Math.PI / 6 * minit / 60;
var minuteAngle = Math.PI * 2 / 3600;
var secondAngle = Math.PI * 2 / 60;
var hourAngle = Math.PI * 2 / 12 / 3600;

ctx.beginPath();
ctx.save();
ctx.translate(that.canvas.width / 2, that.canvas.height / 2);
ctx.arc(0, 0, 3, 0, 2 * Math.PI, false);
ctx.fill();
ctx.closePath();
ctx.beginPath();
a = hourAngle;
ctx.rotate(a);
ctx.fillRect(-2, -22, 4, 30);
ctx.closePath();
ctx.beginPath();
b = minuteAngle;
ctx.rotate(b - a);
ctx.fillRect(-1.5, -26, 3, 35);
ctx.closePath();
ctx.beginPath();
c = secondAngle;
ctx.rotate(c - b);
ctx.fillRect(-1, -30, 2, 40);
ctx.closePath();
ctx.restore ();
},
Repaint: function () {
this.drawPointer();
this.drawCircle();
this.drawNum();
},
tik: function () {
var that = this;
var ctx = this.ctx;
this.rePaint();
window.timer = setInterval(function () {
ctx.clearRect(0, 0, that.canvas.width, that.canvas.height);
that.rePaint();
}, 1000);
}
};< /p>

var options;
var clock = new Clock(document.getElementById("canvas"), options);
clock.tik();