canvas实现彩色线条运动的屏幕保护动画效果代码-html代码-BFW代码库

代码语言：html

所属分类：动画

代码描述：canvas实现彩色线条运动的屏幕保护动画效果代码

下面为部分代码预览，完整代码请点击下载或在bfwstudio webide中打开

<!DOCTYPE html>
<html lang="en">

<head>

    <meta charset="UTF-8">



    <style>
        body{
            padding: 0;
            margin: 0;
        }
        #world{
            display: block;
            background-color: #000000;
            
        }
    </style>



</head>

<body>
    <canvas id='world'></canvas>

    <script>
        !+-+-+!+-+-+!+-+-+!+-+-+!+-+-+!+-+-+!+-+-+!+-+-+!
        function (d, w) {
          var FPS = 30; //FPS
          var F = 300; //焦点距離
          var N = 3; //軌跡の本数
          var VERTEX_MAX = 10; //軌跡の長さ
          var TRAIL_QUALITY = 4000; //軌跡のクオリティ
          var mu = 0.5; //前のアンカーポイントへの依存具合
          var bmRandom = function (mu, sigma) {
            var x,y,r,tmp = null,tmp2;
            return function () {
              if (tmp !== null) {
                tmp2 = tmp;
                tmp = null;
                return y * tmp2 + mu;
              }
              do {
                x = Math.random() * 2 - 1;
                y = Math.random() * 2 - 1;
                r = x * x + y * y;
              } while (r >= 1);
              tmp = sigma * Math.sqrt(-2 * Math.log(r) / r);
              return x * tmp + mu;
            };
          };
          pointCopy = function (src, dst) {
            dst.x = src.x;
            dst.y = src.y;
            dst.z = src.z;
            return dst;
          };
          Trail = function (pos, t, color_f) {
            this.pos = { x: 0, y: 0, z: 0 };
            this.start = { x: 0, y: 0, z: 0 };
            this.goal = { x: 0, y: 0, z: 0 };
            this.anchor_1 = { x: 0, y: 0, z: 0 };
            this.anchor_2 = { x: 0, y: 0, z: 0 };
            this.start_time = 0;
            this.take_time = 1;
            this.vertexes = [];
            this.anchors_1 = [];
            this.anchors_2 = [];
            this.color_f = color_f;
            pointCopy(pos, this.pos);
            pointCopy(pos, this.start);
            pointCopy(pos, this.goal);
            this.setNextGoal(t);
          };
          Trail.prototype.setNextGoal = function (t, target) {
            pointCopy(this.goal, this.start);
            this.anchor_1.x = this.start.x + (this.start.x - this.anchor_2.x) * mu;
            this.anchor_1.y = this.start.y + (this.start.y - this.anchor_2.y) * mu;
            this.anchor_1.z = this.start.z + (this.start.z - this.anchor_2.z) * mu;
            if (target) {
              this.anchor_2.x = (this.anchor_1.x + target.x) / 2 + myrand();
              this.anchor_2.y = (this.anchor_1.y + target.y) / 2 + myrand();
              this.anchor_2.z = (this.anchor_1.z + target.z) / 2 + myrand();
              this.goal.x = target.x;
              this.goal.y = target.y;
              this.goal.z = target.z;
            } else {
              this.anchor_2.x = this.anchor_1.x + myrand();
              this.anchor_2.y = this.anchor_1.y + myrand();
              this.anchor_2.z = this.anchor_1.z + myrand();
              this.goal.x = this.anchor_2.x + myrand();
              this.goal.y = this.anchor_2.y + myrand();
              this.goal.z = this.anchor_2.z + myrand();
            }
            this.start_time = t;
            this.take_time = 200 + Math.random() * 200;
            this.vertexes.push(pointCopy(this.start, { x: 0, y: 0, z: 0 }));
            this.anchors_1.push(pointCopy(this.anchor_1, { x: 0, y: 0, z: 0 }));
            this.anchors_2.push(pointCopy(this.anchor_2, { x: 0, y: 0, z: 0 }));
            if (this.vertexes.length > VERTEX_MAX) {
              this.vertexes.splice(0, this.vertexes.length - VERTEX_MAX);
              this.anchors_1.splice(0, this.anchors_1.length - VERTEX_MAX);
              this.anchors_2.splice(0, this.anchors_2.length - VERTEX_MAX);
            }
          };
          Trail.prototype.update = function (t, target) {
            bezier3(
            t - this.start_time,
            this.start,
            this.anchor_1,
            this.anchor_2,
            this.goal,
            this.take_time,
            this.pos);
        
            if (t - this.start_time > this.take_time) {
              this.setNextGoal(this.start_time + this.take_time, target);
              this.update(t, target);
            }
          };
          Trail.prototype.draw = function (ctx, camera, t) {
            var i,dz,dt,ddt,rt,a,v = { x: 0, y: 0, z: 0 };
            var ps = { x: 0, y: 0 };
            ctx.beginPath();
            if (perspective(this.vertexes[0], camera, ps)) {
              ctx.moveTo(ps.x, ps.y);
            }
            var x0 = ps.x;
            rt = (t - this.start_time) / this.take_time;
            for (i = 1; i < this.vertexes.length; i++) {
              ddt = 0.01;
              for (dt = 0; dt < 1; dt += ddt) {
                bezier3(dt,
                this.vertexes[i - 1],
                this.anchors_1[i - 1],
                this.anchors_2[i - 1],
                this.vertexes[i],
                1,
                v);
                if (perspective(v, camera, ps)) {
                  dz = v.z - camera.z;
                  a = 1 - (this.vertexes.length - i + 1 - dt + rt) / VERTEX_MAX;
                  this.color_f(ctx, a, dz);
                  ctx.lineTo(ps.x, ps.y);
                  ctx.stroke();
                  ctx.beginPath();
                  ctx.moveTo(ps.x, ps.........完整代码请登录后点击上方下载按钮下载查看