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[ASP.net教程]js渲染canvas的问题??????依次开100朵花



    <!--[if IE]>

       <script src="http://html5shiv.googlecode.com/svn/trunk/html5.js"></script>

    <![endif]-->
    <script src="jquery-1.8.2.min.js"></script>
    <script>
        var show_demo = function (id) {
            var b = document.body;
            var c = document.getElementsByTagName('canvas')[id];
            var a = c.getContext('2d');
            document.body.clientWidth;
            var show = function () {
                with (m = Math)
                    C = cos, S = sin, P = pow, R = random;
                c.width = c.height = f = 500;
                h = -250;

            };
            show();
            var p = function (a, b, c) {

                if (c > 60)
                    return [S(a * 7) * (13 + 5 / (.2 + P(b * 4, 4))) - S(b) * 50, b * f + 50, 625 + C(a * 7) * (13 + 5 / (.2 + P(b * 4, 4))) + b * 400, a * 1 - b / 2, a];
                A = a * 2 - 1;
                B = b * 2 - 1;
                if (A * A + B * B < 1) {
                    if (c > 37) {
                        n = (j = c & 1) ? 6 : 4; o = .5 / (a + .01) + C(b * 125) * 3 - a * 300;
                        w = b * h;
                        return [o * C(n) + w * S(n) + j * 610 - 390, o * S(n) - w * C(n) + 550 - j * 350, 1180 + C(B + A) * 99 - j * 300, .4 - a * .1 + P(1 - B * B, -h * 6) * .15 - a * b * .4 + C(a + b) / 5 + P(C((o * (a + 1) + (B > 0 ? w : -w)) / 25), 30) * .1 * (1 - B * B), o / 1e3 + .7 - o * w * 3e-6]
                    }
                    if (c > 32) {
                        c = c * 1.16 - .15; o = a * 45 - 20;
                        w = b * b * h;
                        z = o * S(c) + w * C(c) + 620;
                        return [o * C(c) - w * S(c), 28 + C(B * .5) * 99 - b * b * b * 60 - z / 2 - h, z, (b * b * .3 + P((1 - (A * A)), 7) * .15 + .3) * b, b * .7]
                    }
                    o = A * (2 - b) * (80 - c * 2);
                    w = 99 - C(A) * 120 - C(b) * (-h - c * 4.9) + C(P(1 - b, 7)) * 50 + c * 2; z = o * S(c) + w * C(c) + 700;
                    return [o * C(c) - w * S(c), B * 99 - C(P(b, 7)) * 50 - c / 3 - z / 1.35 + 450, z, (1 - b / 1.2) * .9 + a * .1, P((1 - b), 20) / 4 + .05]
                }
            };
            var my_for = function () {
                console.log("当前计时器"+id);
                for (i = 0; i < 1e4; i++)
                    if (s = p(R(), R(), i % 46 / .74)) {

                        z = s[2];
                        x = ~~(s[0] * f / z - h);
                        y = ~~(s[1] * f / z - h);
                        if (!m[q = y * f + x] | m[q] > z)
                            m[q] = z, a.fillStyle = "rgb(" + ~(s[3] * h) + "," + ~(s[4] * h) + "," + ~(s[3] * s[3] * -80) + ")", a.fillRect(x, y, 1, 1)
                    }
            }
            return setInterval(my_for, 0);
        }
        var gg = undefined;
        $(function () {

            for (var i = 0; i < 2; i++) {
                if (i % 3 == 0) $("body center").append("<br>")
                $("body center").append($('<canvas id="' + i + '" ></canvas>'));
                gg = show_demo(i);
                clear(gg);
               
            }
        });
        function clear(t)
        {
            setTimeout("clearInterval("+t+")", 5000)
        }

    </script>


</head>

<body>

    <center><marquee scrollamount=2 width=400>测试</marquee></center>
    <h1></h1>
    <center></center>
</body>

</html>