<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<canvas id="canvas" style="border: 1px #ddd solid;display: block;margin:0 auto"></canvas>
<script>
var tangram = [
{p:[{x:0,y:0},{x:800,y:0},{x:400,y:400}],color:"red"},
{p:[{x:0,y:0},{x:400,y:400},{x:0,y:800}],color:"blue"},
{p:[{x:800,y:0},{x:800,y:400},{x:600,y:600},{x:600,y:200}],color:"yellow"},
{p:[{x:600,y:200},{x:600,y:600},{x:400,y:400}],color:"green"},
{p:[{x:400,y:400},{x:600,y:600},{x:400,y:800},{x:200,y:600}],color:"pink"},
{p:[{x:200,y:600},{x:0,y:800},{x:400,y:800}],color:"orange"},
{p:[{x:800,y:400},{x:800,y:800},{x:400,y:800}],color:"purple"}
];
function draw(piece,cxt){
cxt.beginPath();
cxt.moveTo(piece.p[0].x , piece.p[0].y);
for(var i=1;i<piece.p.length;i++){
cxt.lineTo(piece.p[i].x , piece.p[i].y);
}
cxt.closePath();
cxt.fillStyle = piece.color;
cxt.fill();
}
window.onload = function(){
var canvas = document.getElementById('canvas');
canvas.width = 800;
canvas.height = 800;
if(canvas.getContext('2d')){
var context = canvas.getContext('2d');
for(var i=0;i<tangram.length;i++){
draw(tangram[i],context)
}
}else{
alert('当前游览器不支持Canvas，请更换游览器后再试！');
}
}
</script>
</body>
<script>
/*
总结 绘制七巧板
主要运用的js的for循环的巧妙
1.定义路径 trangram
2.第一层for，循环trangram[i]
3.函数draw,第二层for，循环取出绘制路径 trangram.p[i].x
*/
</script>
</html>
