Touch screen zoom - any method to disable?

Hi,

I have a terminal with touch screen running luakit with custom
application. Basically, it works as intended, however, sometimes user
unknowingly zooms into part of screen.

While relatively easy, all that's necessary is unzoom it using two
fingers (the same way as used on smartphones), it scares this user a
bit. So the best way to handle it would be not allowing zoom to occur.

Is there a method to do this? Some configuration of X? My setup uses
webcamd to create event file for touch screen and libinput driver to
handle input event in X.

Regards,
Milan