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| /* 这里的任何JavaScript将为所有用户在每次页面载入时加载。 */ | | /* 这里的任何JavaScript将为所有用户在每次页面载入时加载。 */ |
| ! function() {
| | alert("Js!"); |
| //封装方法，压缩之后减少文件大小
| |
| function get_attribute(node, attr, default_value) {
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| return node.getAttribute(attr) || default_value;
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| }
| |
| //封装方法，压缩之后减少文件大小
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| function get_by_tagname(name) {
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| return document.getElementsByTagName(name);
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| }
| |
| //获取配置参数
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| function get_config_option() {
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| var scripts = get_by_tagname("script"),
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| script_len = scripts.length,
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| script = scripts[script_len - 1]; //当前加载的script
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| return {
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| l: script_len, //长度，用于生成id用
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| z: get_attribute(script, "zIndex", -1), //z-index
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| o: get_attribute(script, "opacity", 0.5), //opacity
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| c: get_attribute(script, "color", "0,0,0"), //color
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| n: get_attribute(script, "count", 99) //count
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| };
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| }
| |
| //设置canvas的高宽
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| function set_canvas_size() {
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| canvas_width = the_canvas.width = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth,
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| canvas_height = the_canvas.height = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
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| }
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| | |
| //绘制过程
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| function draw_canvas() {
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| context.clearRect(0, 0, canvas_width, canvas_height);
| |
| //随机的线条和当前位置联合数组
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| var all_array = [current_point].concat(random_lines);
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| var e, i, d, x_dist, y_dist, dist; //临时节点
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| //遍历处理每一个点
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| random_lines.forEach(function(r) {
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| r.x += r.xa,
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| r.y += r.ya, //移动
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| r.xa *= r.x > canvas_width || r.x < 0 ? -1 : 1,
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| r.ya *= r.y > canvas_height || r.y < 0 ? -1 : 1, //碰到边界，反向反弹
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| context.fillRect(r.x - 0.5, r.y - 0.5, 1, 1); //绘制一个宽高为1的点
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| for (i = 0; i < all_array.length; i++) {
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| e = all_array[i];
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| //不是当前点
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| if (r !== e && null !== e.x && null !== e.y) {
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| x_dist = r.x - e.x, //x轴距离 l
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| y_dist = r.y - e.y, //y轴距离 n
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| dist = x_dist * x_dist + y_dist * y_dist; //总距离, m
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| dist < e.max && (e === current_point && dist >= e.max / 2 && (r.x -= 0.03 * x_dist, r.y -= 0.03 * y_dist), //靠近的时候加速
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| d = (e.max - dist) / e.max,
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| context.beginPath(),
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| context.lineWidth = d / 2,
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| context.strokeStyle = "rgba(" + config.c + "," + (d + 0.2) + ")",
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| context.moveTo(r.x, r.y),
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| context.lineTo(e.x, e.y),
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| context.stroke());
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| }
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| }
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| all_array.splice(all_array.indexOf(r), 1);
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| | |
| }), frame_func(draw_canvas);
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| }
| |
| //创建画布，并添加到body中
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| var the_canvas = document.createElement("canvas"), //画布
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| config = get_config_option(), //配置
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| canvas_id = "c_n" + config.l, //canvas id
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| context = the_canvas.getContext("2d"), canvas_width, canvas_height,
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| frame_func = window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame || function(func) {
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| window.setTimeout(func, 1000 / 45);
| |
| }, random = Math.random,
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| current_point = {
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| x: null, //当前鼠标x
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| y: null, //当前鼠标y
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| max: 20000
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| };
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| the_canvas.id = canvas_id;
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| the_canvas.style.cssText = "position:fixed;top:0;left:0;z-index:" + config.z + ";opacity:" + config.o;
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| get_by_tagname("body")[0].appendChild(the_canvas);
| |
| //初始化画布大小
| |
| | |
| set_canvas_size(), window.onresize = set_canvas_size;
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| //当时鼠标位置存储，离开的时候，释放当前位置信息
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| window.onmousemove = function(e) {
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| e = e || window.event, current_point.x = e.clientX, current_point.y = e.clientY;
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| }, window.onmouseout = function() {
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| current_point.x = null, current_point.y = null;
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| };
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| //随机生成config.n条线位置信息
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| for (var random_lines = [], i = 0; config.n > i; i++) {
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| var x = random() * canvas_width, //随机位置
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| y = random() * canvas_height,
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| xa = 2 * random() - 1, //随机运动方向
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| ya = 2 * random() - 1;
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| random_lines.push({
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| x: x,
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| y: y,
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| xa: xa,
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| ya: ya,
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| max: 6000 //沾附距离
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| });
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| }
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| //0.1秒后绘制
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| setTimeout(function() {
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| draw_canvas();
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| }, 100);
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| }();
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/* 这里的任何JavaScript将为所有用户在每次页面载入时加载。 */
alert("Js!");
