一款酷炫的动态背景(h5 canvas+js)
废话不多说 ，分享一款酷炫的页面动态背景 效果见下图。
查看 demo
背景图效果：
实例效果
点击效果：
背景css
*{ margin: 0; padding: 0; } #canvas{ position: fixed; background: #ccc; overflow: auto; z-index: -1; }
背景html
<canvas id="canvas"></canvas>
背景js
<script> window.requestAnimationFrame = (function(){ return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || function( callback ){ window.setTimeout( callback, 1000/2 ); }; })(); var myCanvas = document.getElementById("canvas"); var ctx = myCanvas.getContext("2d"); var num; var w,h; var duixiang = []; var move = {}; function widthheight(){ w = myCanvas.width = window.innerWidth; h = myCanvas.height = window.innerHeight; num= Math.floor(w*h*0.00028); for(var i = 0;i < num;i++){ duixiang[i] = { x:Math.random()*w, y:Math.random()*h, cX:Math.random()*0.6-0.3, cY:Math.random()*0.6-0.3, R:Math.floor(Math.random()*5)+2, r: Math.floor(Math.random() * 254), g: Math.floor(Math.random() * 254), b:Math.floor(Math.random() * 254) } Cricle(duixiang[i].x,duixiang[i].y,duixiang[i].R,duixiang[i].r,duixiang[i].g,duixiang[i].b); } };widthheight(); function Cricle(x,y,R,r,g,b){ ctx.save(); if(Math.random()>0.991) {ctx.globalAlpha= 0.9;} else { ctx.globalAlpha=0.47;} ctx.fillStyle = "rgb("+ r +","+ g +","+ b +")"; ctx.beginPath(); ctx.arc(x,y,R,Math.PI*2,0); ctx.closePath(); ctx.fill(); ctx.restore(); };Cricle(); !function draw(){ ctx.clearRect(0,0,w,h) for(var i = 0;i < num;i++){ duixiang[i].x += duixiang[i].cX; duixiang[i].y += duixiang[i].cY; if(duixiang[i].x>w || duixiang[i].x<0){ duixiang[i].cX = -duixiang[i].cX; } if(duixiang[i].y>h || duixiang[i].y<0){ duixiang[i].cY = -duixiang[i].cY; } Cricle(duixiang[i].x,duixiang[i].y,duixiang[i].R,duixiang[i].r,duixiang[i].g,duixiang[i].b); for(var j = i + 1;j < num;j++){ if( (duixiang[i].x-duixiang[j].x)*(duixiang[i].x-duixiang[j].x)+(duixiang[i].y-duixiang[j].y)*(duixiang[i].y-duixiang[j].y) <= 55*55 ){ line(duixiang[i].x,duixiang[i].y,duixiang[j].x,duixiang[j].y,0,i,j) } if(move.x){ if( (duixiang[i].x-move.x)*(duixiang[i].x-move.x)+(duixiang[i].y-move.y)*(duixiang[i].y-move.y) <= 100*100 ){ line(duixiang[i].x,duixiang[i].y,move.x,move.y,1,i,1) } } } } window.requestAnimationFrame(draw) }(); function line(x1,y1,x2,y2,flag,i,j){ if (flag){var color = ctx.createLinearGradient(x1,y1,x2,y2); ctx.globalAlpha=0.5; color.addColorStop(0,"rgb("+ duixiang[i].r +","+ duixiang[i].g +","+ duixiang[i].b +")"); color.addColorStop(0.8,"#019ee5"); } else { var color = ctx.createLinearGradient(x1,y1,x2,y2); ctx.globalAlpha=0.9; color.addColorStop(0,"rgb("+ duixiang[i].r +","+ duixiang[i].g +","+ duixiang[i].b +")"); color.addColorStop(1,"rgb("+ duixiang[j].r +","+ duixiang[j].g +","+ duixiang[j].b +")"); } ctx.save(); ctx.strokeStyle = color; ctx.lineWidth = 0.5; ctx.beginPath(); ctx.moveTo(x1,y1); ctx.lineTo(x2,y2); ctx.stroke(); } window.onresize = function(){ location.reload(); }</script>
点击效果CSS
#canvas1 { position: fixed; pointer-events:none;//鼠标多层响应事件 width: 100%; height: 100%; overflow: auto; z-index: 999; }
点击效果HTML
<canvas id="canvas1" style="whdth: 100%;height: 100%"></canvas>
点击效果js
<script>var _createClass = function () {function defineProperties(target, props) { for (var i = 0; i < props.length; i++) {var descriptor = props[i];descriptor.enumerable = descriptor.enumerable || false;descriptor.configurable = true;if ("value" in descriptor) descriptor.writable = true;Object.defineProperty(target, descriptor.key, descriptor);}} return function (Constructor, protoProps, staticProps) {if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor;};}();function _classCallCheck(instance, Constructor) {if (!(instance instanceof Constructor)) {throw new TypeError("Cannot call a class as a function");}} var getRandom = function getRandom(min, max) { return Math.random() * (max - min) + min;};var getRandomInt = function getRandomInt(min, max) {
return Math.floor(Math.random() * (max - min)) + min;
};
var getRandomColor = function getRandomColor() {
var colors = [
‘rgba(231, 76, 60, 1)’,
‘rgba(241, 196, 15, 1)’,
‘rgba(46, 204, 113, 1)’,
‘rgba(52, 152, 219, 1)’,
‘rgba(155, 89, 182, 1)’
];
return colors[getRandomInt(0, colors.length)];
};
var
Particle = function () {
function Particle(system, x, y) {_classCallCheck(this, Particle);
this.system = system;
this.universe = this.system.world.universe;
this.x = x;
this.y = y;
this.color = getRandomColor();
this.life = 1;
this.aging = getRandom(0.990, 0.999);
this.r = getRandomInt(12, 16);
this.speed = getRandom(18, 18.5);
this.velocity = [
getRandom(-this.speed, this.speed),
getRandom(-this.speed, this.speed)];
}_createClass(Particle, [{ key: ‘update’, value: function update(
dt) {
this.life *= this.aging;
if (
this.r < 0.1 ||
this.life === 0 ||
this.x + this.r < 0 ||
this.x - this.r > this.universe.width ||
this.y + this.r < 0 ||
this.y - this.r > this.universe.height)
{
this.system.removeObject(this);
}
this.r *= this.life;
this.x += this.velocity[0];
this.y += this.velocity[1];
} }, { key: ‘render’, value: function render(
ctx) {
ctx.fillStyle = this.color;
ctx.beginPath();
ctx.arc(this.x, this.y, this.r*1.2, 0, 2 * Math.PI, false);
ctx.fill();
ctx.closePath();
var r = this.color.match(/([0-9]+)/g)[0];
var g = this.color.match(/([0-9]+)/g)[1];
var b = this.color.match(/([0-9]+)/g)[2];
var spread = 1.5;
var gradient = ctx.createRadialGradient(
this.x, this.y, this.r,
this.x, this.y, this.r * spread);
gradient.addColorStop(0, ‘rgba(‘ + r + ‘, ‘ + g + ‘, ‘ + b + ‘, 0.5)’);
gradient.addColorStop(1, ‘rgba(‘ + r + ‘, ‘ + g + ‘, ‘ + b + ‘, 0)’);
ctx.globalCompositeOperation = ‘lighter’;
ctx.fillStyle = gradient;
ctx.beginPath();
ctx.arc(this.x, this.y, this.r * spread, 0, 2 * Math.PI, false);
ctx.fill();
ctx.closePath();
ctx.globalCompositeOperation = ‘source-over’;
var offset = this.r * 0.5;
var color = ‘rgba(‘ + g + ‘, ‘ + b + ‘, ‘ + r + ‘, 0.5)’;
ctx.globalCompositeOperation = ‘lighter’;
ctx.fillStyle = color;
ctx.beginPath();
ctx.arc(this.x + offset, this.y + offset, this.r, 0, 2 * Math.PI, false);
ctx.fill();
ctx.closePath();
ctx.globalCompositeOperation = ‘source-over’;
} }]);return Particle;}();
var
Crown = function () {
function Crown(system, x, y) {_classCallCheck(this, Crown);
this.system = system;
this.x = x;
this.y = y;
this.r = getRandomInt(5, 15);
this.mod = 1.1;
this.life = 0.5;
this.aging = getRandom(0.830, 0.899);
this.speed = getRandom(8, 9);
this.color = {
r: getRandomInt(236, 242),
g: getRandomInt(70, 80),
b: getRandomInt(50, 70) };
this.angle1 = Math.PI * getRandom(0, 2);
this.angle2 = this.angle1 + Math.PI * getRandom(0.3, 0.4);
}_createClass(Crown, [{ key: ‘update’, value: function update(
dt) {
this.life *= this.aging;
if (this.life <= 0.0001) this.system.removeObject(this);
this.r += Math.abs(1 - this.life) * this.speed;
this.x1 = this.x + this.r * Math.cos(this.angle1);
this.y1 = this.y + this.r * Math.sin(this.angle1);
this.angle3 = this.angle1 + (this.angle2 - this.angle1) / 2;
this.x2 = this.x + this.r * this.mod * Math.cos(this.angle3);
this.y2 = this.y + this.r * this.mod * Math.sin(this.angle3);
} }, { key: ‘render’, value: function render(
ctx) {
var gradient = ctx.createRadialGradient(
this.x, this.y, this.r * 0.9,
this.x, this.y, this.r);
gradient.addColorStop(0, ‘rgba(‘ + this.color.r + ‘, ‘ + this.color.g + ‘, ‘ + this.color.b + ‘, ‘ + this.life + ‘)’);
gradient.addColorStop(1, ‘rgba(‘ + this.color.r + ‘, ‘ + this.color.g + ‘, ‘ + this.color.b + ‘, ‘ + this.life * 0.5 + ‘)’);
ctx.fillStyle = gradient;
ctx.beginPath();
ctx.arc(this.x, this.y, this.r, this.angle1, this.angle2, false);
ctx.quadraticCurveTo(this.x2, this.y2, this.x1, this.y1);
ctx.fill();
ctx.closePath();
} }]);return Crown;}();
var
Explosion = function () {
function Explosion(world, x, y) {_classCallCheck(this, Explosion);
this.world = world;
this.x = x;
this.y = y;
this.objects = [];
var particles = getRandomInt(10, 30);
var crowns = particles * getRandom(0.4, 0.5);
while (crowns– > 0) {this.addCrown();}
while (particles– > 0) {this.addParticle();}
}_createClass(Explosion, [{ key: ‘update’, value: function update(
dt) {
this.objects.forEach(function (obj) {
if (obj) obj.update(dt);
});
if (this.objects.length <= 0) {
this.world.clearExplosion(this);
}
} }, { key: ‘render’, value: function render(
ctx) {
this.objects.forEach(function (obj) {
if (obj) obj.render(ctx);
});
} }, { key: ‘addCrown’, value: function addCrown()
{
this.objects.push(new Crown(this, this.x, this.y));
} }, { key: ‘addParticle’, value: function addParticle()
{
this.objects.push(new Particle(this, this.x, this.y));
} }, { key: ‘removeObject’, value: function removeObject(
obj) {
var index = this.objects.indexOf(obj);
if (index !== -1) {
this.objects.splice(index, 1);
}
} }]);return Explosion;}();
var
ConfettiWorld = function () {function ConfettiWorld()
{_classCallCheck(this, ConfettiWorld);}_createClass(ConfettiWorld, [{ key: ‘init’, value: function init()
{
this.objects = [];
window.addEventListener(‘click’, this.explode.bind(this));
var counter = 0;
while (counter– > 0) {
this.explode({
clientX: window.event.clientX,
clientY: window.event.clientY
});
}
} }, { key: ‘update’, value: function update(
dt) {
this.objects.forEach(function (obj) {
if (obj) obj.update(dt);
});
var amount = this.objects.reduce(function (sum, explosion) {
return sum += explosion.objects.length;
}, 0);
} }, { key: ‘render’, value: function render(
ctx) {
this.objects.forEach(function (obj) {
if (obj) obj.render(ctx);
});
} }, { key: ‘explode’, value: function explode(
event) {
var x = event.clientX;
var y = event.clientY;
this.objects.push(new Explosion(this, x, y));
} }, { key: ‘clearExplosion’, value: function clearExplosion(
explosion) {
var index = this.objects.indexOf(explosion);
if (index !== -1) {
this.objects.splice(index, 1);
}
} }]);return ConfettiWorld;}();
var
Time = function () {
function Time() {_classCallCheck(this, Time);
this.now = 0;
this.prev = 0;
this.elapsed = 0;
this.delta = 0;
this.fps = 60;
this.step = 1 / 60;
}_createClass(Time, [{ key: ‘update’, value: function update(
time) {
this.now = time;
this.elapsed = (this.now - this.prev) / 1000;
this.prev = this.now;
this.delta += this.elapsed;
} }, { key: ‘raf’, value: function raf(
func) {
window.requestAnimationFrame(func);
} }, { key: ‘hasFrames’, value: function hasFrames()
{
return this.delta >= this.step;
} }, { key: ‘processFrame’, value: function processFrame()
{
this.delta -= this.step;
} }]);return Time;}();
var
Universe = function () {
function Universe(element) {_classCallCheck(this, Universe);
this.el = element;
this.ctx = this.el.getContext(‘2d’);
this.pixelRatio = window.devicePixelRatio;
this.time = new Time();
this.worlds = {};
this.world = null;
this.updateSize();
window.addEventListener(‘resize’, this.updateSize.bind(this));
this.addWorld(‘confetti’, ConfettiWorld);
this.setWorld(‘confetti’);
this.start();
}_createClass(Universe, [{ key: ‘start’, value: function start()
{
this.time.raf(this.tick.bind(this));
} }, { key: ‘tick’, value: function tick(
time) {
this.time.update(time);
if (this.time.hasFrames()) {
this.update();
this.time.processFrame();
}
this.render();
this.time.raf(this.tick.bind(this));
} }, { key: ‘update’, value: function update()
{
this.world.update(this.time.step);
} }, { key: ‘render’, value: function render()
{
var gradient = this.ctx.createLinearGradient(0, 0, this.width, this.height);
this.ctx.clearRect(0, 0, this.width, this.height);
this.world.render(this.ctx);
}
<span class="token comment" spellcheck="true">// Helpers 库</span>
}, { key: ‘updateSize’, value: function updateSize()
{
this.width = window.innerWidth;
this.height = window.innerHeight;
this.el.width = this.width * this.pixelRatio;
this.el.height = this.height * this.pixelRatio;
this.el.style.width = window.innerWidth + ‘px’;
this.el.style.height = window.innerHeight + ‘px’;
this.ctx.scale(this.pixelRatio, this.pixelRatio);
} }, { key: ‘addWorld’, value: function addWorld(
worldName, World) {
this.worlds[worldName] = new World();
this.worlds[worldName].universe = this;
this.worlds[worldName].init();
} }, { key: ‘setWorld’, value: function setWorld(
worldName) {
this.world = this.worlds[worldName];
} }]);return Universe;}();
console.clear();
var element = document.querySelector(‘#canvas1’);
window.Canvas= new Universe(element);
</script>
]]>
层 碎了，那么只好 从第1层 开始扔了 
层 碎了，那么只好 从第 
层 碎了，那么只好 从第
层 碎了，那么只好 从第
+1层 开始扔了
