colored-parallax-primes

packSize=100; // Number of integers per cell
cellSize=5; // Number of pixels per cell

window.isPrime=function(n)
{
 for(var i = 2, s = Math.sqrt(n); i <= s; i++)
  if(n % i === 0) return false;
 return n !== 1;
}

window.numberOfPrimes=function()
{
 var primes = 0;
 var myNum=curNum+x;
 for (var i=0;i<packSize;i++)
 {
  if (isPrime(myNum))primes +=1 ;
  myNum+=y;
 }
 return primes;
}

window.drawLine=function()
{
 for (x=0;x<y;x++)
 {
var primes = numberOfPrimes();
var ratio = primes/packSize;
var color = ratio * 0xffffff;
console.log(primes);
console.log(ratio);
console.log(Math.round(color).toString(16));
ctx.fillStyle="#" + Math.round(color).toString(16);
  ctx.fillRect (500+x*cellSize-y*cellSize/2,y*cellSize,cellSize+1,cellSize+1);
 }
 curNum+=packSize*y;
 y++;
 if (y<1000/cellSize) setTimeout("drawLine()",10);
}

curNum=1;
canvas = document.getElementById("canvas");
ctx = canvas.getContext("2d");
y=1;
drawLine();