动态爱心（html版）

最新推荐文章于 2025-03-16 15:09:47 发布
原创最新推荐文章于 2025-03-16 15:09:47 发布 · 4.6k 阅读
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<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <title>炫酷的心</title>
  <style type="text/css">
    html,
    body {
      height: 100%;
      padding: 0;
      margin: 0;
      background: #000;
    }

    canvas {
      position: absolute;
      width: 100%;
      height: 100%;
    }
  </style>
</head>

<body>
<canvas id="pinkboard"></canvas>
<script src="https://code.jquery.com/jquery-3.2.1.min.js"></script>
<script type="text/javascript">
  var settings = {
    particles: {
      length: 500, //最大粒子数
      duration: 2, //粒子持续时间
      velocity: 50, //粒子速度，像素/秒
      effect: -0.75,
      size: 30, //粒子大小
    }
  };
  (function() {
    var b = 0;
    var c = ["ms", "moz", "webkit", "o"];
    for (var a = 0; a < c.length && !window.requestAnimationFrame; ++a) {
      window.requestAnimationFrame = window[c[a] + "RequestAnimationFrame"];
      window.cancelAnimationFrame = window[c[a] + "CancelAnimationFrame"] || window[c[a] + "CancelRequestAnimationFrame"]
    }
    if (!window.requestAnimationFrame) {
      window.requestAnimationFrame = function(h, e) {
        var d = new Date().getTime();
        var f = Math.max(0, 16 - (d - b));
        var g = window.setTimeout(function() {
          h(d + f)
        }, f);
        b = d + f;
        return g
      }
    }
    if (!window.cancelAnimationFrame) {
      window.cancelAnimationFrame = function(d) {
        clearTimeout(d)
      }
    }
  }());

  var Point = (function() {
    function Point(x, y) {
      this.x = (typeof x !== 'undefined') ? x : 0;
      this.y = (typeof y !== 'undefined') ? y : 0;
    }
    Point.prototype.clone = function() {
      return new Point(this.x, this.y);
    };
    Point.prototype.length = function(length) {
      if (typeof length == 'undefined')
        return Math.sqrt(this.x * this.x + this.y * this.y);
      this.normalize();
      this.x *= length;
      this.y *= length;
      return this;
    };
    Point.prototype.normalize = function() {
      var length = this.length();
      this.x /= length;
      this.y /= length;
      return this;
    };
    return Point;
  })();
  var Particle = (function() {
    function Particle() {
      this.position = new Point();
      this.velocity = new Point();
      this.acceleration = new Point();
      this.age = 0;
    }
    Particle.prototype.initialize = function(x, y, dx, dy) {
      this.position.x = x;
      this.position.y = y;
      this.velocity.x = dx;
      this.velocity.y = dy;
      this.acceleration.x = dx * settings.particles.effect;
      this.acceleration.y = dy * settings.particles.effect;
      this.age = 0;
    };
    Particle.prototype.update = function(deltaTime) {
      this.position.x += this.velocity.x * deltaTime;
      this.position.y += this.velocity.y * deltaTime;
      this.velocity.x += this.acceleration.x * deltaTime;
      this.velocity.y += this.acceleration.y * deltaTime;
      this.age += deltaTime;
    };
    Particle.prototype.draw = function(context, image) {
      function ease(t) {
        return (--t) * t * t + 1;
      }
      var size = image.width * ease(this.age / settings.particles.duration);
      context.globalAlpha = 1 - this.age / settings.particles.duration;
      context.drawImage(image, this.position.x - size / 2, this.position.y - size / 2, size, size);
    };
    return Particle;
  })();
  var ParticlePool = (function() {
    var particles,
            firstActive = 0,
            firstFree = 0,
            duration = settings.particles.duration;

    function ParticlePool(length) {
      // 创建和填充粒子库
      particles = new Array(length);
      for (var i = 0; i < particles.length; i++)
        particles[i] = new Particle();
    }
    ParticlePool.prototype.add = function(x, y, dx, dy) {
      particles[firstFree].initialize(x, y, dx, dy);

      // 处理循环队列
      firstFree++;
      if (firstFree == particles.length) firstFree = 0;
      if (firstActive == firstFree) firstActive++;
      if (firstActive == particles.length) firstActive = 0;
    };
    ParticlePool.prototype.update = function(deltaTime) {
      var i;

      // 更新活动粒子
      if (firstActive < firstFree) {
        for (i = firstActive; i < firstFree; i++)
          particles[i].update(deltaTime);
      }
      if (firstFree < firstActive) {
        for (i = firstActive; i < particles.length; i++)
          particles[i].update(deltaTime);
        for (i = 0; i < firstFree; i++)
          particles[i].update(deltaTime);
      }

      // 删除不活动的粒子
      while (particles[firstActive].age >= duration && firstActive != firstFree) {
        firstActive++;
        if (firstActive == particles.length) firstActive = 0;
      }


    };
    ParticlePool.prototype.draw = function(context, image) {
      // 画活动粒子
      if (firstActive < firstFree) {
        for (i = firstActive; i < firstFree; i++)
          particles[i].draw(context, image);
      }
      if (firstFree < firstActive) {
        for (i = firstActive; i < particles.length; i++)
          particles[i].draw(context, image);
        for (i = 0; i < firstFree; i++)
          particles[i].draw(context, image);
      }
    };
    return ParticlePool;
  })();
  (function(canvas) {
    var context = canvas.getContext('2d'),
            particles = new ParticlePool(settings.particles.length),
            particleRate = settings.particles.length / settings.particles.duration, // particles/sec
            time;

    // 获取heart点位 -PI <= t <= PI
    function pointOnHeart(t) {
      return new Point(
              160 * Math.pow(Math.sin(t), 3),
              130 * Math.cos(t) - 50 * Math.cos(2 * t) - 20 * Math.cos(3 * t) - 10 * Math.cos(4 * t) + 25
      );
    }

    // 使用canvas创建粒子图像
    var image = (function() {
      var canvas = document.createElement('canvas'),
              context = canvas.getContext('2d');
      canvas.width = settings.particles.size;
      canvas.height = settings.particles.size;
      // 创建路径的辅助函数
      function to(t) {
        var point = pointOnHeart(t);
        point.x = settings.particles.size / 2 + point.x * settings.particles.size / 350;
        point.y = settings.particles.size / 2 - point.y * settings.particles.size / 350;
        return point;
      }
      // 创建路径
      context.beginPath();
      var t = -Math.PI;
      var point = to(t);
      context.moveTo(point.x, point.y);
      while (t < Math.PI) {
        t += 0.01;
        point = to(t);
        context.lineTo(point.x, point.y);
      }
      context.closePath();
      // 填充
      context.fillStyle = '#ea80b0';
      context.fill();
      // 创建图片
      var image = new Image();
      image.src = canvas.toDataURL();
      return image;
    })();

    // 渲染
    function render() {
      requestAnimationFrame(render);

      // update time
      var newTime = new Date().getTime() / 1000,
              deltaTime = newTime - (time || newTime);
      time = newTime;

      // clear canvas
      context.clearRect(0, 0, canvas.width, canvas.height);

      // 创建新的粒子
      var amount = particleRate * deltaTime;
      for (var i = 0; i < amount; i++) {
        var pos = pointOnHeart(Math.PI - 2 * Math.PI * Math.random());
        var dir = pos.clone().length(settings.particles.velocity);
        particles.add(canvas.width / 2 + pos.x, canvas.height / 2 - pos.y, dir.x, -dir.y);
      }

      // 更新并绘制
      particles.update(deltaTime);
      particles.draw(context, image);
    }

    // 处理canvas大小
    function onResize() {
      canvas.width = canvas.clientWidth;
      canvas.height = canvas.clientHeight;
    }
    window.onresize = onResize;

    // 延迟渲染
    setTimeout(function() {
      onResize();
      render();
    }, 10);
  })(document.getElementById('pinkboard'));
</script>
</body>

</html>