<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>canvas</title>
<script type="text/javascript" src="../js/jQuery.js"></script>
<style type="text/css">
*{
margin: 0;
padding: 0;
outline: none;
border: none;
}
#canvas{
width: 7rem;
margin: .25rem 0 0 1.5rem;
border: 1px solid black;
}
</style>
</head>
<body>
<canvas id="canvas" width="1000" height="600"></canvas>
</body>
</html>
<script type="text/javascript">
/**
* rem 布局初始化
*/
$('html').css('font-size', $(window).width()/10);
/**
* 获取 canvas 画布
* 获取 canvas 绘图上下文环境
*/
var canvas = $('#canvas')[0];
var cxt = canvas.getContext('2d');
/**
* 创建图片填充样式
* 一: createPattern( 图片对象, 重复方式 )
* 二: createPattern( canvas对象, 重复方式)
* 三: createPattern( 视频对象, 重复方式)
*/
/*
var img = new Image();
img.src = "../img/favicon.ico";
img.onload = function(){
var pattern = cxt.createPattern(img, "repeat");
cxt.fillStyle = pattern;
cxt.fillRect(0, 0, 1000, 600);
}
*/
var fiveStartPath = function(cxt){
cxt.beginPath();
var x = 0; y = 0;
for(var i = 0; i < 5; i++){
x = Math.cos((18+72*i)/180*Math.PI);
y = Math.sin((18+72*i)/180*Math.PI);
cxt.lineTo(x, 0-y);
x = Math.cos((54+72*i)/180*Math.PI)/2.0;
y = Math.sin((54+72*i)/180*Math.PI)/2.0;
cxt.lineTo(x, 0-y);
}
cxt.closePath();
}
var drawFiveStar = function(cxt, fiveStart){
cxt.save();
cxt.translate(fiveStart.offsetX, fiveStart.offsetY);
cxt.rotate(fiveStart.RotationAngle/180*Math.PI);
cxt.scale(fiveStart.Radius, fiveStart.Radius);
fiveStartPath(cxt);
cxt.fillStyle = "yellow";
cxt.fill();
cxt.restore();
}
var createCanvas = function(){
var canvas = document.createElement("canvas");
canvas.width = 100;
canvas.height = 100;
var cxt = canvas.getContext('2d');
var fiveStart = {
Radius: 50,
offsetX: 50,
offsetY: 50,
RotationAngle: 0
}
drawFiveStar(cxt, fiveStart);
return canvas;
}
var canvasBackground = createCanvas();
var patten = cxt.createPattern(canvasBackground, "repeat");
cxt.fillStyle = patten;
cxt.fillRect(0, 0, 1000, 600);
</script>