Created
February 17, 2012 14:05
-
-
Save sanderversluys/1853604 to your computer and use it in GitHub Desktop.
FractalAnimation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
<!DOCTYPE html> | |
<html> | |
<head> | |
<script> | |
// http://paulirish.com/2011/requestanimationframe-for-smart-animating/ | |
// http://my.opera.com/emoller/blog/2011/12/20/requestanimationframe-for-smart-er-animating | |
// requestAnimationFrame polyfill by Erik Mˆller | |
// fixes from Paul Irish and Tino Zijdel | |
(function() { | |
var lastTime = 0; | |
var vendors = ['ms', 'moz', 'webkit', 'o']; | |
for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) { | |
window.requestAnimationFrame = window[vendors[x]+'RequestAnimationFrame']; | |
window.cancelAnimationFrame = window[vendors[x]+'CancelAnimationFrame'] | |
|| window[vendors[x]+'CancelRequestAnimationFrame']; | |
} | |
if (!window.requestAnimationFrame) | |
window.requestAnimationFrame = function(callback, element) { | |
var currTime = new Date().getTime(); | |
var timeToCall = Math.max(0, 16 - (currTime - lastTime)); | |
var id = window.setTimeout(function() { callback(currTime + timeToCall); }, | |
timeToCall); | |
lastTime = currTime + timeToCall; | |
return id; | |
}; | |
if (!window.cancelAnimationFrame) | |
window.cancelAnimationFrame = function(id) { | |
clearTimeout(id); | |
}; | |
}()); | |
window.addEventListener('load', function() { | |
var canvas = document.getElementById('canvas'); | |
var ctx = canvas.getContext('2d'); | |
var canvasData = ctx.getImageData(0, 0, canvas.width, canvas.height); | |
var i = 0, links=-2.2, rechts= 1, onder=-1.2, boven=1.2, zoomx=-.58, zoomy=.37; | |
// Mandelbrot | |
function computeColor(x, y) { | |
x = links + x/canvas.width *(rechts-links); | |
y = onder + y/canvas.height * (boven - onder); | |
var x0 = x ; | |
var y0 = y; | |
var iteration = 0; | |
var max_iteration = 100; | |
while (x * x + y * y <= 4 && iteration < max_iteration ) { | |
var xtemp = x*x - y*y + x0; | |
y = 2*x*y + y0; | |
x = xtemp; | |
iteration++; | |
} | |
return Math.round(767 * iteration / max_iteration); | |
} | |
function render() { | |
for (var x = 0; x < canvasData.width; x++) { | |
for (var y = 0; y < canvasData.height; y++) { | |
var color = computeColor(x, y); | |
// Index of the pixel in the array | |
var idx = (x + y * canvas.width) * 4; | |
// Update the values of the pixel; | |
canvasData.data[idx + 1] = Math.min(255,color); | |
canvasData.data[idx + 0] = Math.max(0,Math.min(255,color-256)); | |
canvasData.data[idx + 2] = Math.max(0,color-512); | |
canvasData.data[idx + 3] = 255; | |
} | |
} | |
ctx.putImageData(canvasData, 0, 0); | |
} | |
(function animloop(){ | |
window.requestAnimationFrame(animloop); | |
render(); | |
i++; | |
links=links+(zoomx-links)*.05; rechts=rechts-(rechts-zoomx)*.05; | |
onder=onder+(zoomy-onder)*.05; boven=boven-(boven-zoomy)*.05; | |
})(); | |
}); | |
</script> | |
</head> | |
<body> | |
<canvas id="canvas" width="640" height="480"/> | |
</body> | |
</html> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment