changeBackground

changeBackground.js

var colors = new Array(
	[58,96,115],
	[22,34,42],
	[0, 22, 8],
	[38,56,35],
	[32,24,82],
	[135, 129, 19]
	);

var step = 0;
var colorIndices = [0,1,2,3];
var gradientSpeed = 0.002;

function updateGradient() {

	if ( $===undefined ) return;

	var c0_0 = colors[colorIndices[0]];
	var c0_1 = colors[colorIndices[1]];
	var c1_0 = colors[colorIndices[2]];
	var c1_1 = colors[colorIndices[3]];

	var istep = 1 - step;
	var r1 = Math.round(istep * c0_0[0] + step * c0_1[0]);
	var g1 = Math.round(istep * c0_0[1] + step * c0_1[1]);
	var b1 = Math.round(istep * c0_0[2] + step * c0_1[2]);
	var color1 = "rgb("+r1+","+g1+","+b1+")";

	var r2 = Math.round(istep * c1_0[0] + step * c1_1[0]);
	var g2 = Math.round(istep * c1_0[1] + step * c1_1[1]);
	var b2 = Math.round(istep * c1_0[2] + step * c1_1[2]);
	var color2 = "rgb("+r2+","+g2+","+b2+")";

	$('body').css({
		background: "-webkit-gradient(linear, left top, right top, from("+color1+"), to("+color2+"))"}).css({
		background: "-moz-linear-gradient(left, "+color1+" 0%, "+color2+" 100%)"});

	step += gradientSpeed;
	if ( step >= 1 )
	{
		step %= 1;
		colorIndices[0] = colorIndices[1];
		colorIndices[2] = colorIndices[3];

		colorIndices[1] = ( colorIndices[1] + Math.floor( 1 + Math.random() * (colors.length - 1))) % colors.length;
		colorIndices[3] = ( colorIndices[3] + Math.floor( 1 + Math.random() * (colors.length - 1))) % colors.length;

	}
}