Teraflopst
2/19/2016 - 2:44 PM

Lab: Make a tangram by Canvas

Lab: Make a tangram by Canvas

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>七巧板</title>
</head>
<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
        window.onload = function () {
            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>