var wheelHandler = function(ev) {
var dy;
if (ev.wheelDelta) { // Webkit
yRot = -ev.wheelDeltaX / 30;
dy = ev.wheelDeltaY / 30;
} else dy = ev.detail;
transl *= 1 + dy / 30;
drawScene();
ev.preventDefault();
};
canvas.addEventListener('DOMMouseScroll', wheelHandler, false);
canvas.addEventListener('mousewheel', wheelHandler, false);
They say that in Firefox DOMMouseScroll event has ev.axis field for horizontal and vertical scroll movement. Horizontal scrolling works in Firefox but I don't see this event in JS :(