李峋同款爱心特效

272 阅读2分钟

只有程序员才懂得浪漫,赶快给女朋友安排起来 直接拿来可用,喜欢点赞关注哦,不定期发

<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
			html,body {
				height: 95%;
				padding: 0;
				margin: 0;
				background: #000;
			}
			canvas {
				width: 100%;
				height: 100%;
			}
		</style>
	</head>
	<body>
		<canvas id="cqp"></canvas>
		<script>
			let settings = {
				particles: {
					length: 500,
					duration: 2,
					velocity: 100,
					effect: -0.75,
					size: 30,
				}
			};
			(function() {
				let b = 0;
				let c = ["ms", "moz", "webkit", "o"];
				for (let 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) {
						let d = new Date().getTime();
						let f = Math.max(0, 16 - (d - b));
						let g = window.setTimeout(function() {
							h(d + f)
						}, f);
						b = d + f;
						return g
					}
				}
				if (!window.cancelAnimationFrame) {
					window.cancelAnimationFrame = function(d) {
						clearTimeout(d)
					}
				}
			}());
			let 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() {
					let length = this.length();
					this.x /= length;
					this.y /= length;
					return this;
				};
				return Point;
			})();
			let 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;
					}
					let 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;
			})();
			let ParticlePool = (function() {
				let particles,
					firstActive = 0,
					firstFree = 0,
					duration = settings.particles.duration;
				function ParticlePool(length) {
					particles = new Array(length);
					for (let 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);
					firstFree++;
					if (firstFree == particles.length) firstFree = 0;
					if (firstActive == firstFree) firstActive++;
					if (firstActive == particles.length) firstActive = 0;
				};
				ParticlePool.prototype.update = function(deltaTime) {
					let i;
					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);
					}
					while (particles[firstActive].age >= duration && firstActive != firstFree) {
						firstActive++;
						if (firstActive == particles.length) firstActive = 0;
					}
				};
				ParticlePool.prototype.draw = function(context, image) {
					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) {
				let context = canvas.getContext('2d'),
					particles = new ParticlePool(settings.particles.length),
					particleRate = settings.particles.length / settings.particles.duration, // particles/sec
					time;
				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
					);
				}
				let image = (function() {
					let canvas = document.createElement('canvas'),
						context = canvas.getContext('2d');
					canvas.width = settings.particles.size;
					canvas.height = settings.particles.size;
 
					function to(t) {
						let 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;
					}
					context.beginPath();
					let t = -Math.PI;
					let 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();
					context.fillStyle = '#ea80b0';
					context.fill();
					let image = new Image();
					image.src = canvas.toDataURL();
					return image;
				})();
 
				function render() {
					requestAnimationFrame(render);
					let newTime = new Date().getTime() / 1000,
						deltaTime = newTime - (time || newTime);
					time = newTime;
					context.clearRect(0, 0, canvas.width, canvas.height);
					let amount = particleRate * deltaTime;
					for (let i = 0; i < amount; i++) {
						let pos = pointOnHeart(Math.PI - 2 * Math.PI * Math.random());
						let dir = pos.clone().length(settings.particles.velocity);
						particles.add(canvas.width / 2 + pos.x, canvas.height / 2 - pos.y, dir.x, -dir.y);
					}
					particles.update(deltaTime);
					particles.draw(context, image);
				}
				function onResize() {
					canvas.width = canvas.clientWidth;
					canvas.height = canvas.clientHeight;
				}
				window.onresize = onResize;
				setTimeout(function() {
					onResize();
					render();
				}, 10);
			})(document.getElementById('cqp'));
		</script>
	</body>
</html>

运行结果

025dc5a549024b6891b499a12d28bf7c.png