使用javascript生成的植物显示过程特效_H5之家 - 中国HTML5教程资源分享第一站

查看效果：http://keleyi.com/keleyi/phtml/html5/33.htm

.NET版本：http://keleyi.com/a/bjac/66mql4bc.htm
完整HTML文件代码：
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>使用javascript生成的植物显示过程特效 - 柯乐义</title><base target="_blank" />
<style>html, body {background: black;}a{color:white;text-decoration:none}
.hovertreefrme{height:700px;width:760px;border:solid 1px red; }
</style>
</head>
<body>
<div class="hovertreefrme"><div><a href="http://keleyi.com">首页</a> <a href="http://keleyi.com/a/bjae/4d3jagcj.htm">原文</a> <a href="http://keleyi.com/keleyi/phtml/">特效库</a> <a href="http://hovertree.com">HoverTree</a> <a href="http://keleyi.com/a/bjac/66mql4bc.htm">参考</a></div>
<canvas id="hovertree"></canvas>
</div>
<script>
(function () {
var H, W, animationCurve, keleyicanvas, colorStops, getColors, i, k, lut, maxDraws, numDraws, pMax, rand, render, row, speed, step, styles, transformations, v, xRange, xSpan, yRange, ySpan, _i, _len, _ref;

speed = 1;

W = 350;

H = 500;

transformations = [
[
(function (x, y) {
return 0;
}), (function (x, y) {
return 0.16 * y;
}), 1
], [
(function (x, y) {
return 0.2 * x - 0.26 * y;
}), (function (x, y) {
return 0.23 * x + 0.22 * y + 1.6;
}), 7
], [
(function (x, y) {
return -0.15 * x + 0.28 * y;
}), (function (x, y) {
return 0.26 * x + 0.24 * y + 0.44;
}), 7
], [
(function (x, y) {
return 0.85 * x + 0.04 * y;
}), (function (x, y) {
return -0.04 * x + 0.85 * y + 1.6;
}), 85
]
];

maxDraws = 200000;

xRange = [-2.182, 2.6558];

yRange = [0, 9.9983];

keleyicanvas = document.getElementById("hover"+"tree");

keleyicanvas.width = W;

keleyicanvas.height = H;

styles = {
position: "absolute",
top: "400px",
left: "300px",
margin: "-" + (~~(H / 2)) + "px 0 0 -" + (~~(W / 2)) + "px"
};

colorStops = [[0, "rgba(255,255,255,1)"], [1000, "rgba(253,253,52,0.6)"], [5000, "rgba(0,171,56,0.7)"], [10000, "rgba(168,210,110,0.7)"], [20000, "rgba(246,243,27,0.6)"], [40000, "rgba(138,215,39,0.7)"], [65000, "rgba(243,205,8,0.5)"], [90000, "rgba(150,204,104,0.4)"], [125000, "rgba(137,230,101,0.5)"], [150000, "rgba(246,243,27,0.5)"], [190000, "rgba(255,255,255,0.8)"]];

animationCurve = function (frame) {
if (frame < 1000) return 25;
if (frame < 5000) return 50;
if (frame < 10000) return 75;
if (frame < 20000) return 100;
if (frame < 40000) return 150;
if (frame < 65000) return 250;
if (frame < 90000) return 400;
if (frame < 150000) return 600;
if (frame < 190000) return 400;
if (frame < 200000) return 100;
};

lut = {};

numDraws = 0;

pMax = 0;

for (_i = 0, _len = transformations.length; _i < _len; _i++) {
row = transformations[_i];
for (i = pMax, _ref = row[2] + pMax - 1; pMax <= _ref ? i <= _ref : i >= _ref; pMax <= _ref ? i++ : i--) {
lut[i] = [row[0], row[1]];
}
pMax += row[2];
}

getColors = function () {
var colors;
colors = colorStops.slice();
return function () {
var colorStop;
if (!(colors[0] && numDraws >= colors[0][0])) return;
colorStop = colors.shift();
return ctx.fillStyle = colorStop[1];
};
};

for (k in styles) {
v = styles[k];
keleyicanvas.style[k] = v;
}

window.ctx = keleyicanvas.getContext("2d");

xSpan = xRange[1] - xRange[0];

ySpan = yRange[1] - yRange[0];

window.updateColor = getColors();

render = function () {
var drawsPerFrame, f, i, iter, x, y, _ref2, _ref3;
if (numDraws > maxDraws) return;
updateColor();
drawsPerFrame = speed * animationCurve(numDraws);
for (i = 0; 0 <= drawsPerFrame ? i <= drawsPerFrame : i >= drawsPerFrame; 0 <= drawsPerFrame ? i++ : i--) {
iter = 0;
_ref2 = [rand(xRange[0], xRange[1]), rand(yRange[0], yRange[1])], x = _ref2[0], y = _ref2[1];
while (iter++ < 50) {
f = lut[~~rand(0, pMax)];
_ref3 = [f[0](x, y), f[1](x, y)], x = _ref3[0], y = _ref3[1];
}
x = W * (x - xRange[0]) / xSpan;
y = H * (1 - y / ySpan);
ctx.fillRect(x, y, 1, 1);
}
return numDraws += drawsPerFrame;
};

window.onclick = function () {
numDraws = 0;
window.updateColor = getColors();
return ctx.clearRect(0, 0, W, H);
};

rand = function (a, b) {
return (b - a) * Math.random() + a;
};

window.requestAnimationFrame || (window.requestAnimationFrame = (function () {
var prefix, r, _j, _len2, _ref2;
_ref2 = ['webkit', 'moz', 'ms', 'o'];
for (_j = 0, _len2 = _ref2.length; _j < _len2; _j++) {
prefix = _ref2[_j];
if (r = window["" + prefix + "RequestAnimationFrame"]) return r;
}
return function (callback) {
return window.setTimeout(callback, 1000 / 60);
};
})());

(step = function () {
return requestAnimationFrame(step) && render();
})();

}).call(this);


</script>
</body>
</html>