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  • 实现我博客旁边的线条效果 html canvas-nest.js 源码

    canvas-nest.js 这个js文件可以用来实现炫酷的线条与鼠标进行交互的功能,具体效果如图所示

    js具体源码如下:

    /**
         * Copyright (c) 2016 hustcc
         * License: MIT
         * Version: %%GULP_INJECT_VERSION%%
         * GitHub: https://github.com/hustcc/canvas-nest.js
        **/
        ! function() {
          //封装方法,压缩之后减少文件大小
          function get_attribute(node, attr, default_value) {
            return node.getAttribute(attr) || default_value;
          }
          //封装方法,压缩之后减少文件大小
          function get_by_tagname(name) {
            return document.getElementsByTagName(name);
          }
          //获取配置参数
          function get_config_option() {
            var scripts = get_by_tagname("script"),
              script_len = scripts.length,
              script = scripts[script_len - 1]; //当前加载的script
            return {
              l: script_len, //长度,用于生成id用
              z: get_attribute(script, "zIndex", -1), //z-index
              o: get_attribute(script, "opacity", 0.5), //opacity
              c: get_attribute(script, "color", "0,0,0"), //color
              n: get_attribute(script, "count", 99) //count
            };
          }
          //设置canvas的高宽
          function set_canvas_size() {
            canvas_width = the_canvas.width = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth,
            canvas_height = the_canvas.height = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
          }
        
          //绘制过程
          function draw_canvas() {
            context.clearRect(0, 0, canvas_width, canvas_height);
            //随机的线条和当前位置联合数组
            var e, i, d, x_dist, y_dist, dist; //临时节点
            //遍历处理每一个点
            random_points.forEach(function(r, idx) {
              r.x += r.xa,
              r.y += r.ya, //移动
              r.xa *= r.x > canvas_width || r.x < 0 ? -1 : 1,
              r.ya *= r.y > canvas_height || r.y < 0 ? -1 : 1, //碰到边界,反向反弹
              context.fillRect(r.x - 0.5, r.y - 0.5, 1, 1); //绘制一个宽高为1的点
              //从下一个点开始
              for (i = idx + 1; i < all_array.length; i++) {
                e = all_array[i];
                // 当前点存在
                if (null !== e.x && null !== e.y) {
                  x_dist = r.x - e.x; //x轴距离 l
                  y_dist = r.y - e.y; //y轴距离 n
                  dist = x_dist * x_dist + y_dist * y_dist; //总距离, m
        
                  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
                    d = (e.max - dist) / e.max,
                    context.beginPath(),
                    context.lineWidth = d / 2,
                    context.strokeStyle = "rgba(" + config.c + "," + (d + 0.2) + ")",
                    context.moveTo(r.x, r.y),
                    context.lineTo(e.x, e.y),
                    context.stroke());
                }
              }
            }), frame_func(draw_canvas);
          }
          //创建画布,并添加到body中
          var the_canvas = document.createElement("canvas"), //画布
            config = get_config_option(), //配置
            canvas_id = "c_n" + config.l, //canvas id
            context = the_canvas.getContext("2d"), canvas_width, canvas_height,
            frame_func = window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame || function(func) {
              window.setTimeout(func, 1000 / 45);
            }, random = Math.random,
            current_point = {
              x: null, //当前鼠标x
              y: null, //当前鼠标y
              max: 20000 // 圈半径的平方
            },
            all_array;
          the_canvas.id = canvas_id;
          the_canvas.style.cssText = "position:fixed;top:0;left:0;z-index:" + config.z + ";opacity:" + config.o;
          get_by_tagname("body")[0].appendChild(the_canvas);
        
          //初始化画布大小
          set_canvas_size();
          window.onresize = set_canvas_size;
          //当时鼠标位置存储,离开的时候,释放当前位置信息
          window.onmousemove = function(e) {
            e = e || window.event;
            current_point.x = e.clientX;
            current_point.y = e.clientY;
          }, window.onmouseout = function() {
            current_point.x = null;
            current_point.y = null;
          };
          //随机生成config.n条线位置信息
          for (var random_points = [], i = 0; config.n > i; i++) {
            var x = random() * canvas_width, //随机位置
              y = random() * canvas_height,
              xa = 2 * random() - 1, //随机运动方向
              ya = 2 * random() - 1;
            // 随机点
            random_points.push({
              x: x,
              y: y,
              xa: xa,
              ya: ya,
              max: 6000 //沾附距离
            });
          }
          all_array = random_points.concat([current_point]);
          //0.1秒后绘制
          setTimeout(function() {
            draw_canvas();
          }, 100);
        }();

    在html网页中body的标签中添加script标签,如下所示

    <script type="text/javascript" color="208,55,66" opacity="0.5"count="99"src="test.js"></script>
    

     

    color 颜色自定义,opactity 是透明度,一般来说0.5-1就可以了,count的是数量,不要太大,太大可能会使得用户的浏览器卡顿,src后为该js文件的所在路径。

    PS:

    我直接用test命令了那个js文件

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  • 原文地址:https://www.cnblogs.com/stars-one/p/7264753.html
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