// ==UserScript==
// @name         Mouse Wheel Event Inverter
// @namespace    lainscripts_mouse_wheel_event_inverter
// @description  Inverts values returned by 'wheel' event.
// @version      0.2
// @author       lainverse
// @grant        none
// @run-at       document-start
// Google Maps, Yandex Maps
// @match        *://*/maps/*
// ==/UserScript==
(function() {
'use strict';
let descriptor,
debug = false;
for (let prop of ['deltaX', 'deltaY', 'deltaZ']) {
descriptor = Object.getOwnPropertyDescriptor(WheelEvent.prototype, prop);
let getter = descriptor.get;
descriptor.get = function() {
return -getter.call(this);
};
Object.defineProperty(WheelEvent.prototype, prop, descriptor);
}
if (debug)
window.addEventListener('wheel', function(e) {
console.log(e.deltaX, e.deltaY, e.deltaZ, e.deltaMode);
}, false);
})();