Calculate the position of a click inside an element

compute-xy-click

$(document).on('click', '.my-class', function(event) {
 var position = compute_xy_click(event, this);
});

function compute_xy_click(event, element) {
  var position = [];
  var gardientPos = $(element).offset();
	var posx = 0;
	var posy = 0;
	if ( !event ) var event = window.event;
	if ( event.pageX || event.pageY ) {
		posx = event.pageX;
		posy = event.pageY;
	}
	else if ( event.clientX || event.clientY ) {
		posx = event.clientX + document.body.scrollLeft + document.documentElement.scrollLeft;
		posy = event.clientY + document.body.scrollTop + document.documentElement.scrollTop;
	}
   posx = Math.floor(posx - gardientPos.left);
   posy = Math.floor(posy - gardientPos.top);
   position['xpos'] = posx;
   position['ypos'] = posy;
   return position;
}