爱心代码
效果：
代码
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <html> <head> <title>New Document</title> <meta name="Generator" content="EditPlus" /> <meta name="Author" content="" /> <meta name="Keywords" content="" /> <meta name="Description" content="" /> <style> html, body { height: 100%; padding: 0; margin: 0; background: #000; } .color { color: rgb(250, 59, 231); } canvas { position: absolute; width: 100%; height: 100%; } .my_img { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); width: 150px; color: #fff; } </style> </head> <body> <!-- <img src="./my_img.jpg" alt="" class="my_img"> --> <canvas id="pinkboard"></canvas> <script> /* * Settings */ var settings = { particles: { length: 500, // 最大多少粒子 duration: 2, // 粒子持续时间(秒) velocity: 200, // 粒子速度(像素/秒) effect: -0.75, // 粒子散开的晕 size: 30, // 粒子尺寸(像素) color: 'rgb(250, 59, 231)', // 粒子颜色 }, }; /* * RequestAnimationFrame polyfill by Erik Möller */ (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 = settings.particles.color; 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> </body> </html>
