Adding deltaX and deltaY for horizontal scrolling

Author: Seamus Leahy

jquery.mousewheel.js

@@ -43,16 +43,31 @@ $.fn.extend({
 
 
 function handler(event) {
-    var args = [].slice.call( arguments, 1 ), delta = 0, returnValue = true;
+	var orgEvent = event;
+    var args = [].slice.call( arguments, 1 ), delta = 0, returnValue = true, deltaX = 0, deltaY = 0;
 
     event = $.event.fix(event || window.event);
     event.type = "mousewheel";
 
+    // Old school scrollwheel delta
     if ( event.wheelDelta ) delta = event.wheelDelta/120;
     if ( event.detail     ) delta = -event.detail/3;
 
+    // New school multidimensional scroll (touchpads) deltas
+    deltaY = delta;
+    
+    // Gecko
+    if( orgEvent.axis !== undefined && orgEvent.axis === orgEvent.HORIZONTAL_AXIS ) {
+    	deltaY = 0;
+    	deltaX = -1*delta;
+    }
+    
+    // Webkit
+    if( orgEvent.wheelDeltaY !== undefined ) deltaY = orgEvent.wheelDeltaY/120;
+    if( orgEvent.wheelDeltaX !== undefined ) deltaX = -1*orgEvent.wheelDeltaX/120;
+    
     // Add event and delta to the front of the arguments
-    args.unshift(event, delta);
+    args.unshift(event, delta, deltaX, deltaY);
 
     return $.event.handle.apply(this, args);
 }