Code Playground

console.log("Event Fired")
"use strict"; // Paul Slaymaker, paul25882@gmail.com
const body=document.getElementsByTagName("body").item(0);
body.style.background="#000";
const TP=2*Math.PI;
const CSIZE=400;

const ctx=(()=>{
  let d=document.createElement("div");
  d.style.textAlign="center";
  body.append(d);
  let c=document.createElement("canvas");
  c.width=c.height=2*CSIZE;
  d.append(c);
  return c.getContext("2d");
})();
ctx.setTransform(1,0,0,1,CSIZE,CSIZE);
ctx.globalAlpha=0.7;

onresize=()=>{ 
  let D=Math.min(window.innerWidth,window.innerHeight)-40; 
  ctx.canvas.style.width=ctx.canvas.style.height=D+"px";
}

const getRandomInt=(min,max,low)=>{
  if (low) return Math.floor(Math.random()*Math.random()*(max-min))+min;
  else return Math.floor(Math.random()*(max-min))+min;
}

function Color() {
  const CBASE=159;
  const CT=255-CBASE;
  this.RK1=80+80*Math.random();
  this.GK1=80+80*Math.random();
  this.BK1=80+80*Math.random();
  this.RK2=TP*Math.random();
  this.GK2=TP*Math.random();
  this.BK2=TP*Math.random();
  this.set=()=>{
    let red=Math.round(CBASE+CT*Math.cos(this.RK2+t/this.RK1));
    let grn=Math.round(CBASE+CT*Math.cos(this.GK2+t/this.GK1));
    let blu=Math.round(CBASE+CT*Math.cos(this.BK2+t/this.BK1));
    this.v="rgb("+red+","+grn+","+blu+")";
  }
  this.set();
}

var pauseTS=1000;
var pause=(ts)=>{
  if (stopped) return;
  if (ts<pauseTS) {
    requestAnimationFrame(pause);
  } else {
    requestAnimationFrame(animate);
  }
}

var start=()=>{
  if (stopped) {
    stopped=false;
    requestAnimationFrame(animate);
  } else {
    stopped=true;
  }
}
ctx.canvas.addEventListener("click", start, false);

const count=5; //getRandomInt(4,7);
let ca=new Array(count);
for (let i=0; i<count; i++) { ca[i]=new Color(); }

onresize();

var K1a=new Array(count);
var setK1a=()=>{
  let sum=0;
  for (let i=0; i<K1a.length; i++) { 
    if (Math.random()<0.5) K1a[i]=800;
    else K1a[i]=1600;
    sum+=K1a[i];
  }
  if (sum==count*1600 || sum==count*800) K1a=[1600, 800, 1600, 800, 1600];
}
setK1a();

var kxa=new Array(count);

const setNormalizedFactors=()=>{
  let sum=0;
  for (let i=0; i<count; i++) {
    kxa[i]=(1+Math.cos(TP*t/K1a[i]))/2;
    sum+=kxa[i];
  }
  for (let i=0; i<count; i++) kxa[i]=kxa[i]/sum;
}
setNormalizedFactors();

var pa=new Array(count);

start();

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