HTML5 Canvas表白愛心動畫特效

2024-09-05 12:19:12

字體：大中小

來源：轉載

供稿：網友

HTML5 Canvas表白愛心動畫特效是一款浪漫酷炫的情人節告白愛心動畫特效。

<!doctype html><html><head><meta charset="utf-8"><title>canvas 心</title><style>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>/* * Settings */var settings = {  particles: {    length:   500, // maximum amount of particles    duration:   2, // particle duration in sec    velocity: 100, // particle velocity in pixels/sec    effect: -0.75, // play with this for a nice effect    size:      30, // particle size in pixels  },};/* * RequestAnimationFrame polyfill by Erik M?ller */(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)}}}());/* * Point class */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;})();/* * Particle class */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;})();/* * ParticlePool class */var ParticlePool = (function() {  var particles,      firstActive = 0,      firstFree   = 0,      duration    = settings.particles.duration;    function ParticlePool(length) {    // create and populate particle pool    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);        // handle circular queue    firstFree++;    if (firstFree   == particles.length) firstFree   = 0;    if (firstActive == firstFree       ) firstActive++;    if (firstActive == particles.length) firstActive = 0;  };  ParticlePool.prototype.update = function(deltaTime) {    var i;        // update active particles    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);    }        // remove inactive particles    while (particles[firstActive].age >= duration && firstActive != firstFree) {      firstActive++;      if (firstActive == particles.length) firstActive = 0;    }          };  ParticlePool.prototype.draw = function(context, image) {    // draw active particles    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;})();/* * Putting it all together */(function(canvas) {  var context = canvas.getContext('2d'),      particles = new ParticlePool(settings.particles.length),      particleRate = settings.particles.length / settings.particles.duration, // particles/sec      time;    // get point on heart with -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    );  }    // creating the particle image using a dummy canvas  var image = (function() {    var canvas  = document.createElement('canvas'),        context = canvas.getContext('2d');    canvas.width  = settings.particles.size;    canvas.height = settings.particles.size;    // helper function to create the path    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;    }    // create the path    context.beginPath();    var t = -Math.PI;    var point = to(t);    context.moveTo(point.x, point.y);    while (t < Math.PI) {      t += 0.01; // baby steps!      point = to(t);      context.lineTo(point.x, point.y);    }    context.closePath();    // create the fill    context.fillStyle = '#ea80b0';    context.fill();    // create the image    var image = new Image();    image.src = canvas.toDataURL();    return image;  })();    // render that thing!  function render() {    // next animation frame    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);        // create new particles    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);    }        // update and draw particles    particles.update(deltaTime);    particles.draw(context, image);  }    // handle (re-)sizing of the canvas  function onResize() {    canvas.width  = canvas.clientWidth;    canvas.height = canvas.clientHeight;  }  window.onresize = onResize;    // delay rendering bootstrap  setTimeout(function() {    onResize();    render();  }, 10);})(document.getElementById('pinkboard'));</script><div style="text-align:center;margin:10px 0; font:normal 14px/24px 'MicroSoft YaHei';color:#ffffff"><p>適用瀏覽器：360、FireFox、Chrome、Safari、Opera、傲游、搜狗、世界之窗. 不支持IE8及以下瀏覽器。</p><p>來源：站長素材</p></div></body></html>

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