jQuery blockPosition

blockPosition.js

// jQuery function to center the image and stretch it to completely fill
// the parent, stretchin either height or width, when needed
//
// originally written by Ivan Ryzhenko
// https://gist.github.com/beshur/7706062
//
// Usage:
// blockPosition($(img_you_need_to_center), $(optional_relative));
function blockPosition(obj, relative){
	obj.each(function(index, element) {
		$(this).css({'width': '', 'height': ''});
		// var w = $(this).width();
		// var h = $(this).height();
		var w = $(this).outerWidth();
		var h = $(this).outerHeight();
		// console.log(w,h);

		var d = w/h;
		if(relative) {
			var parent = relative;
		} else {
			var parent = $(this).parent();
		}
		var w_p = parent.width();
		var h_p = parent.height();
		var d_p = w_p/h_p;
		
		if(d > d_p) {
			h = h_p;
			w = h*d;
			m = "0 0 0 " + (-w/2) + "px";
			l = "50%";
			t = 0;
		} else {
			w = w_p;
			h = w/d;    
			m = -h/2 + "px 0 0 0";
			t = "50%";
			l = 0;
		}
		$(this).css({"width": w + "px", "height" : h + "px", "margin": m, "top": t, "left": l, "position": "relative"}).addClass("is_blockpos");
	});    
}