Teraflopst
2/19/2016 - 2:44 PM

## Lab: Make a tangram by Canvas

Lab: Make a tangram by Canvas

``````<!DOCTYPE html>
<html lang="en">
<meta charset="UTF-8">
<title>七巧板</title>
<body>
<div style="width: 400px; height: 400px; margin: 0 auto;">
<canvas id="canvas"></canvas>
</div>

<script>
//设置七块碎片
var tangram = [
{p:[{x:0,y:0},{x:400,y:0},{x:200,y:200}],color:"#caff67"},
{p:[{x:0,y:0},{x:200,y:200},{x:0,y:400}],color:"#67becf"},
{p:[{x:400,y:0},{x:400,y:200},{x:300,y:300},{x:300,y:100}],color:"#ef3d61"},
{p:[{x:300,y:100},{x:300,y:300},{x:200,y:200}],color:"#f9f51a"},
{p:[{x:200,y:200},{x:300,y:300},{x:200,y:400},{x:100,y:300}],color:"#a594c0"},
{p:[{x:100,y:300},{x:200,y:400},{x:0,y:400}],color:"#fa8ecc"},
{p:[{x:400,y:200},{x:400,y:400},{x:200,y:400}],color:"#f6ca29"}
];

//调用函数：循环绘制七块
var canvas = document.getElementById('canvas');
canvas.width = 400;
canvas.height = 400;
var context = canvas.getContext('2d');
for (var i = 0; i < tangram.length; i++) {
draw(tangram[i], context);
}
};

//函数：绘制其中一块碎片
function draw(piece, ctx) {
ctx.beginPath();
ctx.moveTo(piece.p[0].x, piece.p[0].y);
for (var i = 1; i < piece.p.length; i++) {
ctx.lineTo(piece.p[i].x, piece.p[i].y);
}
ctx.closePath();
ctx.fillStyle = piece.color;
ctx.fill();
ctx.strokeStyle = "black";
ctx.lineWidth = 3;
ctx.stroke();
}
</script>
</body>
</html>``````