JavaScript烟花特效

<div>
    <canvas id="canvas"></canvas>
</div>

body{
  background:black;
  overflow:hidden;
  margin:0;
}
canvas{
  background:#000;
}

window.addEventListener("resize", resizeCanvas, false);
window.addEventListener("DOMContentLoaded", onLoad, false);
window.requestAnimationFrame = 
window.requestAnimationFrame       || 
window.webkitRequestAnimationFrame || 
window.mozRequestAnimationFrame    || 
window.oRequestAnimationFrame      || 
window.msRequestAnimationFrame     || 
function (callback) {
    window.setTimeout(callback, 1000/60);
};
 var canvas, ctx, w, h, particles = [], probability = 0.04,
     xPoint, yPoint;
 function onLoad() {
     canvas = document.getElementById("canvas");
     ctx = canvas.getContext("2d");
     resizeCanvas();     
     window.requestAnimationFrame(updateWorld);
 } 
 
 function resizeCanvas() {
     if (!!canvas) {
         w = canvas.width = window.innerWidth;
         h = canvas.height = window.innerHeight;
     }
 } 
 
 function updateWorld() {
     update();
     paint();
     window.requestAnimationFrame(updateWorld);
 } 
 
 function update() {
     if (particles.length < 500 && Math.random() < probability) {
         createFirework();
     }
     var alive = [];
     for (var i=0; i<particles.length; i++) {
         if (particles[i].move()) {
             alive.push(particles[i]);
         }
     }
     particles = alive;
 } 
 
 function paint() {
     ctx.globalCompositeOperation = 'source-over';
     ctx.fillStyle = "rgba(0,0,0,0.2)";
     ctx.fillRect(0, 0, w, h);
     ctx.globalCompositeOperation = 'lighter';
     for (var i=0; i<particles.length; i++) {
         particles[i].draw(ctx);
     }
 } 
 
 function createFirework() {
     xPoint = Math.random()*(w-200)+100;
     yPoint = Math.random()*(h-200)+100;
     var nFire = Math.random()*50+100;
     var c = "rgb("+(~~(Math.random()*200+55))+","
          +(~~(Math.random()*200+55))+","+(~~(Math.random()*200+55))+")";
     for (var i=0; i<nFire; i++) {
         var particle = new Particle();
         particle.color = c;
         var vy = Math.sqrt(25-particle.vx*particle.vx);
         if (Math.abs(particle.vy) > vy) {
             particle.vy = particle.vy>0 ? vy: -vy;
         }
         particles.push(particle);
     }
 } 
 
 function Particle() {
     this.w = this.h = Math.random()*4+1;  
     this.x = xPoint-this.w/2;
     this.y = yPoint-this.h/2;     
     this.vx = (Math.random()-0.5)*10;
     this.vy = (Math.random()-0.5)*10;    
     this.alpha = Math.random()*.5+.5;     
     this.color;
 } 
 
 Particle.prototype = {
     gravity: 0.05,
     move: function () {
         this.x += this.vx;
         this.vy += this.gravity;
         this.y += this.vy;
         this.alpha -= 0.01;
         if (this.x <= -this.w || this.x >= screen.width ||
             this.y >= screen.height ||
             this.alpha <= 0) {
                 return false;
         }
         return true;
     },
     draw: function (c) {
         c.save();
         c.beginPath();         
         c.translate(this.x+this.w/2, this.y+this.h/2);
         c.arc(0, 0, this.w, 0, Math.PI*2);
         c.fillStyle = this.color;
         c.globalAlpha = this.alpha;         
         c.closePath();
         c.fill();
         c.restore();
     }
 } 

<div id="jsi-fireworks-container" class="container"></div>

html, body{
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: #101010;
}
.container{
    position: absolute;
    width: 500px;
    height: 500px;
    top: 50%;
    left: 50%;
    margin-top: -250px;
    margin-left: -250px;
}
canvas{
    position: absolute;
    top: 0;
    left: 0;
}

var RENDERER = {
    LEAF_INTERVAL_RANGE : {min : 100, max : 200},
    FIREWORK_INTERVAL_RANGE : {min : 20, max : 200},
    SKY_COLOR : 'hsla(210, 60%, %luminance%, 0.2)',
    STAR_COUNT : 100,
    
    init : function(){
        this.setParameters();
        this.reconstructMethod();
        this.createTwigs();
        this.createStars();
        this.render();
    },
    setParameters : function(){
        this.$container = $('#jsi-fireworks-container');
        this.width = this.$container.width();
        this.height = this.$container.height();
        this.distance = Math.sqrt(Math.pow(this.width / 2, 2) + Math.pow(this.height / 2, 2));
        this.contextFireworks = $('<canvas />').attr({width : this.width, height : this.height}).appendTo(this.$container).get(0).getContext('2d');
        this.contextTwigs = $('<canvas />').attr({width : this.width, height : this.height}).appendTo(this.$container).get(0).getContext('2d');
        
        this.twigs = [];
        this.leaves = [new LEAF(this.width, this.height, this)];
        this.stars = [];
        this.fireworks = [new FIREWORK(this.width, this.height, this)];
        
        this.leafInterval = this.getRandomValue(this.LEAF_INTERVAL_RANGE) | 0;
        this.maxFireworkInterval = this.getRandomValue(this.FIREWORK_INTERVAL_RANGE) | 0;
        this.fireworkInterval = this.maxFireworkInterval;
    },
    reconstructMethod : function(){
        this.render = this.render.bind(this);
    },
    getRandomValue : function(range){
        return range.min + (range.max - range.min) * Math.random();
    },
    createTwigs : function(){
        this.twigs.push(new TWIG(this.width, this.height, 0, 0, Math.PI * 3 / 4, 0));
        this.twigs.push(new TWIG(this.width, this.height, this.width, 0, -Math.PI * 3 / 4, Math.PI));
        this.twigs.push(new TWIG(this.width, this.height, 0, this.height, Math.PI / 4, Math.PI));
        this.twigs.push(new TWIG(this.width, this.height, this.width, this.height, -Math.PI / 4, 0));
    },
    createStars : function(){
        for(var i = 0, length = this.STAR_COUNT; i < length; i++){
            this.stars.push(new STAR(this.width, this.height, this.contextTwigs, this));
        }
    },
    render : function(){
        requestAnimationFrame(this.render);
        
        var maxOpacity = 0,
            contextTwigs = this.contextTwigs,
            contextFireworks = this.contextFireworks;
        
        for(var i = this.fireworks.length - 1; i >= 0; i--){
            maxOpacity = Math.max(maxOpacity, this.fireworks[i].getOpacity());
        }
        contextTwigs.clearRect(0, 0, this.width, this.height);
        contextFireworks.fillStyle = this.SKY_COLOR.replace('%luminance', 5 + maxOpacity * 15);
        contextFireworks.fillRect(0, 0, this.width, this.height);
        
        for(var i = this.fireworks.length - 1; i >= 0; i--){
            if(!this.fireworks[i].render(contextFireworks)){
                this.fireworks.splice(i, 1);
            }
        }
        for(var i = this.stars.length - 1; i >= 0; i--){
            this.stars[i].render(contextTwigs);
        }
        for(var i = this.twigs.length - 1; i >= 0; i--){
            this.twigs[i].render(contextTwigs);
        }
        for(var i = this.leaves.length - 1; i >= 0; i--){
            if(!this.leaves[i].render(contextTwigs)){
                this.leaves.splice(i, 1);
            }
        }
        if(--this.leafInterval == 0){
            this.leaves.push(new LEAF(this.width, this.height, this));
            this.leafInterval = this.getRandomValue(this.LEAF_INTERVAL_RANGE) | 0;
        }
        if(--this.fireworkInterval == 0){
            this.fireworks.push(new FIREWORK(this.width, this.height, this));
            this.maxFireworkInterval = this.getRandomValue(this.FIREWORK_INTERVAL_RANGE) | 0;
            this.fireworkInterval = this.maxFireworkInterval;
        }
    }
};

<canvas id="canvas"></canvas>

body{
  background-color: #000;
}

canvas{
  display: block;
  margin: auto;
  -webkit-tap-highlight-color:rgba(0,0,0,0);
  -webkit-user-select:none; 
}

(function() {
  var Fireworks, GRAVITY, K, SPEED, ToRadian, canvas, context, ctx, fireBoss, repeat, stage;            
  canvas = document.getElementById("canvas");            
  context = canvas.getContext("2d");            
  canvas.width = window.innerWidth;            
  canvas.height = window.innerHeight;            
  stage = new createjs.Stage(canvas);            
  stage.autoClear = false;            
  ctx = canvas.getContext("2d");            
  ctx.fillStyle = "rgba(0, 0, 0, 0)";            
  ctx.fillRect(0, 0, canvas.width, canvas.height);            
  createjs.Ticker.setFPS(50);            
  createjs.Touch.enable(stage);            
  stage.update();

  // 重力
  GRAVITY = 1;

  // 抵抗
  K = 0.9;

  // 速度
  SPEED = 12;

  // 从度数转换为弧度
  ToRadian = function(degree) {
    return degree * Math.PI / 180.0;
  };

  // 制作烟花的class
  Fireworks = class Fireworks {
    constructor(sx = 100, sy = 100, particles = 70) {
      var circle, i, j, rad, ref, speed;
      this.sx = sx;
      this.sy = sy;
      this.particles = particles;
      this.sky = new createjs.Container();
      this.r = 0;
      this.h = Math.random() * 360 | 0;
      this.s = 100;
      this.l = 50;
      this.size = 3;
      for (i = j = 0, ref = this.particles; (0 <= ref ? j < ref : j > ref); i = 0 <= ref ? ++j : --j) {
        speed = Math.random() * 12 + 2;
        circle = new createjs.Shape();
        circle.graphics.f(`hsla(${this.h}, ${this.s}%, ${this.l}%, 1)`).dc(0, 0, this.size);
        circle.snapToPixel = true;
        circle.compositeOperation = "lighter";
        rad = ToRadian(Math.random() * 360 | 0);
        circle.set({
          x: this.sx,
          y: this.sy,
          vx: Math.cos(rad) * speed,
          vy: Math.sin(rad) * speed,
          rad: rad
        });
        this.sky.addChild(circle);
      }
      stage.addChild(this.sky);
    }

    explode() {
      var circle, j, p, ref;
      if (this.sky) {
        ++this.h;
        for (p = j = 0, ref = this.sky.getNumChildren(); (0 <= ref ? j < ref : j > ref); p = 0 <= ref ? ++j : --j) {
          circle = this.sky.getChildAt(p);
          // 加速度
          circle.vx = circle.vx * K;
          circle.vy = circle.vy * K;
          // 位置计算
          circle.x += circle.vx;
          circle.y += circle.vy + GRAVITY;

          this.l = Math.random() * 100;
          // 粒度
          this.size = this.size - 0.001;
          if (this.size > 0) {
            circle.graphics.c().f(`hsla(${this.h}, 100%, ${this.l}%, 1)`).dc(0, 0, this.size);
          }
        }
        if (this.sky.alpha > 0.1) {
          this.sky.alpha -= K / 50;
        } else {
          stage.removeChild(this.sky);
          this.sky = null;
        }
      } else {        
      }
    }        
  };

  fireBoss = [];

  setInterval(function() {
    ctx.fillStyle = "rgba(0, 0, 0, 0.1)";
    ctx.fillRect(0, 0, canvas.width, canvas.height);
  }, 40);

  setInterval(function() {
    var x, y;
    x = Math.random() * canvas.width | 0;
    y = Math.random() * canvas.height | 0;
    fireBoss.push(new Fireworks(x, y));
    return fireBoss.push(new Fireworks(x, y));
  }, 1300);

  repeat = function() {
    var fireworks, j, ref;
    for (fireworks = j = 0, ref = fireBoss.length; (0 <= ref ? j < ref : j > ref); fireworks = 0 <= ref ? ++j : --j) {
      if (fireBoss[fireworks].sky) {
        fireBoss[fireworks].explode();
      }
    }
    stage.update();
  };

  createjs.Ticker.on("tick", repeat);

  stage.addEventListener("stagemousedown", function() {
    fireBoss.push(new Fireworks(stage.mouseX, stage.mouseY));
    return fireBoss.push(new Fireworks(stage.mouseX, stage.mouseY));
  });            
}).call(this);

<canvas id="canvas"></canvas>

html,body{
  margin:0px;
  width:100%;
  height:100%;
  overflow:hidden;
  background:#000;
}

#canvas{
  width:100%;
  height:100%;
}

 function initVars(){

  pi=Math.PI;
  ctx=canvas.getContext("2d");
  canvas.width=canvas.clientWidth;
  canvas.height=canvas.clientHeight;
  cx=canvas.width/2;
  cy=canvas.height/2;
  playerZ=-25;
  playerX=playerY=playerVX=playerVY=playerVZ=pitch=yaw=pitchV=yawV=0;
  scale=600;
  seedTimer=0;seedInterval=5,seedLife=100;gravity=.02;
  seeds=new Array();
  sparkPics=new Array();
  s="https://cantelope.org/NYE/";
  for(i=1;i<=10;++i){
    sparkPic=new Image();
    sparkPic.src=s+"spark"+i+".png";
    sparkPics.push(sparkPic);
  }
  sparks=new Array();
  pow1=new Audio(s+"pow1.ogg");
  pow2=new Audio(s+"pow2.ogg");
  pow3=new Audio(s+"pow3.ogg");
  pow4=new Audio(s+"pow4.ogg");
  frames = 0;
}

function rasterizePoint(x,y,z){

  var p,d;
  x-=playerX;
  y-=playerY;
  z-=playerZ;
  p=Math.atan2(x,z);
  d=Math.sqrt(x*x+z*z);
  x=Math.sin(p-yaw)*d;
  z=Math.cos(p-yaw)*d;
  p=Math.atan2(y,z);
  d=Math.sqrt(y*y+z*z);
  y=Math.sin(p-pitch)*d;
  z=Math.cos(p-pitch)*d;
  var rx1=-1000,ry1=1,rx2=1000,ry2=1,rx3=0,ry3=0,rx4=x,ry4=z,uc=(ry4-ry3)*(rx2-rx1)-(rx4-rx3)*(ry2-ry1);
  if(!uc) return {x:0,y:0,d:-1};
  var ua=((rx4-rx3)*(ry1-ry3)-(ry4-ry3)*(rx1-rx3))/uc;
  var ub=((rx2-rx1)*(ry1-ry3)-(ry2-ry1)*(rx1-rx3))/uc;
  if(!z)z=.000000001;
  if(ua>0&&ua<1&&ub>0&&ub<1){
    return {
      x:cx+(rx1+ua*(rx2-rx1))*scale,
      y:cy+y/z*scale,
      d:Math.sqrt(x*x+y*y+z*z)
    };
  }else{
    return {
      x:cx+(rx1+ua*(rx2-rx1))*scale,
      y:cy+y/z*scale,
      d:-1
    };
  }
}

function spawnSeed(){
  
  seed=new Object();
  seed.x=-50+Math.random()*100;
  seed.y=25;
  seed.z=-50+Math.random()*100;
  seed.vx=.1-Math.random()*.2;
  seed.vy=-1.5;//*(1+Math.random()/2);
  seed.vz=.1-Math.random()*.2;
  seed.born=frames;
  seeds.push(seed);
}

 <div id="WebGL-output"></div>

body {
     margin: 0;
     overflow: hidden;
     background: -webkit-linear-gradient(0deg, rgb(0, 12, 91), rgb(0, 0, 0));
     background: linear-gradient(0deg, rgb(0, 12, 91), rgb(0, 0, 0));
 }

let scene,
camera,
renderer,
orbitControls,
planeMesh,
canvasTexture,
isAutoLaunch = true;

const gravity = new THREE.Vector3(0, -0.005, 0);
const friction = 0.998;
const noise = new SimplexNoise();
const textureSize = 128.0;
const fireworksInstances = [];

let outputDom;

const getOffsetXYZ = i => {
  const offset = 3;
  const index = i * offset;
  const x = index;
  const y = index + 1;
  const z = index + 2;
  return { x, y, z };
};

const getOffsetRGBA = i => {
  const offset = 4;
  const index = i * offset;
  const r = index;
  const g = index + 1;
  const b = index + 2;
  const a = index + 3;
  return { r, g, b, a };
};

const gui = new dat.GUI();
const guiControls = new function () {
  this.ParticleSize = 300;
  this.AutoLaunch = true;
}();
gui.add(guiControls, 'ParticleSize', 100, 600);
gui.add(guiControls, 'AutoLaunch').onChange(e => {
  isAutoLaunch = e;
  outputDom.style.cursor = isAutoLaunch ? 'auto' : 'pointer';
});

const getRandomNum = (max = 0, min = 0) => Math.floor(Math.random() * (max + 1 - min)) + min;

const launchFireWorks = () => {
  if (fireworksInstances.length > 5) return;
  const fw = Math.random() > 8 ? new BasicFIreWorks() : new RichFIreWorks();
  fireworksInstances.push(fw);
  scene.add(fw.meshGroup);
};

const autoLaunch = () => {
  if (!isAutoLaunch) return;
  if (Math.random() > 0.7) launchFireWorks();
};

const drawRadialGradation = (ctx, canvasRadius, canvasW, canvasH) => {
  ctx.save();
  const gradient = ctx.createRadialGradient(canvasRadius, canvasRadius, 0, canvasRadius, canvasRadius, canvasRadius);
  gradient.addColorStop(0.0, 'rgba(255,255,255,1.0)');
  gradient.addColorStop(0.5, 'rgba(255,255,255,0.5)');
  gradient.addColorStop(1.0, 'rgba(255,255,255,0)');
  ctx.fillStyle = gradient;
  ctx.fillRect(0, 0, canvasW, canvasH);
  ctx.restore();
};

const getTexture = () => {
  const canvas = document.createElement('canvas');
  const ctx = canvas.getContext('2d');

  const diameter = textureSize;
  canvas.width = diameter;
  canvas.height = diameter;
  const canvasRadius = diameter / 2;

  drawRadialGradation(ctx, canvasRadius, canvas.width, canvas.height);
  const texture = new THREE.Texture(canvas);
  texture.type = THREE.FloatType;
  texture.needsUpdate = true;
  return texture;
};

canvasTexture = getTexture();

const getPointMesh = (num, vels, type) => {

  const bufferGeometry = new THREE.BufferGeometry();
  const vertices = [];
  const velocities = [];
  const colors = [];
  const adjustSizes = [];
  const masses = [];
  const colorType = Math.random() > 0.3 ? 'single' : 'multiple';
  const singleColor = getRandomNum(100, 20) * 0.01;
  const multipleColor = () => getRandomNum(100, 1) * 0.01;
  let rgbType;
  const rgbTypeDice = Math.random();
  if (rgbTypeDice > 0.66) {
    rgbType = 'red';
  } else if (rgbTypeDice > 0.33) {
    rgbType = 'green';
  } else {
    rgbType = 'blue';
  }
  for (let i = 0; i < num; i++) {
    const pos = new THREE.Vector3(0, 0, 0);
    vertices.push(pos.x, pos.y, pos.z);
    velocities.push(vels[i].x, vels[i].y, vels[i].z);
    if (type === 'seed') {
      let size;
      if (type === 'trail') {
        size = Math.random() * 0.1 + 0.1;
      } else {
        size = Math.pow(vels[i].y, 2) * 0.04;
      }
      if (i === 0) size *= 1.1;
      adjustSizes.push(size);
      masses.push(size * 0.017);
      colors.push(1.0, 1.0, 1.0, 1.0);
    } else {
      const size = getRandomNum(guiControls.ParticleSize, 10) * 0.001;
      adjustSizes.push(size);
      masses.push(size * 0.017);
      if (colorType === 'multiple') {
        colors.push(multipleColor(), multipleColor(), multipleColor(), 1.0);
      } else {
        switch (rgbType) {
          case 'red':
            colors.push(singleColor, 0.1, 0.1, 1.0);
            break;
          case 'green':
            colors.push(0.1, singleColor, 0.1, 1.0);
            break;
          case 'blue':
            colors.push(0.1, 0.1, singleColor, 1.0);
            break;
          default:
            colors.push(singleColor, 0.1, 0.1, 1.0);}

      }
    }
  }
  bufferGeometry.addAttribute('position', new THREE.Float32BufferAttribute(vertices, 3).setDynamic(true));
  bufferGeometry.addAttribute('velocity', new THREE.Float32BufferAttribute(velocities, 3).setDynamic(true));
  bufferGeometry.addAttribute('color', new THREE.Float32BufferAttribute(colors, 4).setDynamic(true));
  bufferGeometry.addAttribute('adjustSize', new THREE.Float32BufferAttribute(adjustSizes, 1).setDynamic(true));
  bufferGeometry.addAttribute('mass', new THREE.Float32BufferAttribute(masses, 1).setDynamic(true));