window.requestAnimFrame = (function(){   return  window.requestAnimationFrame})();

var canvas = document.getElementById("space");

var c = canvas.getContext("2d");

​

var numStars = 1900;

var radius = '0.'+Math.floor(Math.random() * 9) + 1  ;

var focalLength = canvas.width *2;

var warp = 0;

var centerX, centerY;

​

var stars = [], star;

var i;

​

var animate = true;

​

initializeStars();

​

function executeFrame(){

  if(animate)

    requestAnimFrame(executeFrame);

  moveStars();

  drawStars();

}

​

function initializeStars(){

  centerX = canvas.width / 2;

  centerY = canvas.height / 2;

  stars = [];

  for(i = 0; i < numStars; i++){

    star = {

      x: Math.random() * canvas.width,

      y: Math.random() * canvas.height,

      z: Math.random() * canvas.width,

      o: '0.'+Math.floor(Math.random() * 99) + 1

    };

    stars.push(star);

  }

}

​

function moveStars(){

  for(i = 0; i < numStars; i++){

    star = stars[i];

    star.z--;

    if(star.z <= 0){

      star.z = canvas.width;

    }

  }

}

​

function drawStars(){

  var pixelX, pixelY, pixelRadius;

  // Resize to the screen

  if(canvas.width != window.innerWidth || canvas.width != window.innerWidth){

    canvas.width = window.innerWidth;

    canvas.height = window.innerHeight;

    initializeStars();

  }

  if(warp==0)

  {c.fillStyle = "rgba(0,0,0,1)";

  c.fillRect(0,0, canvas.width, canvas.height);}

  for(i = 0; i < numStars; i++){

    star = stars[i];

    pixelX = (star.x - centerX) * (focalLength / star.z);

    pixelX += centerX;

    pixelY = (star.y - centerY) * (focalLength / star.z);

    pixelY += centerY;

    pixelRadius = 1 * (focalLength / star.z);

    c.fillRect(pixelX, pixelY, pixelRadius, pixelRadius);

    c.fillStyle = "rgba(255, 255, 255, "+star.o+")";

  }

}

;

​

executeFrame();

​

​