how do i go about obtaining the physical distance traveled by an input-device specifically for trackpad (and magicmouse if possible) and specifically in a multi-touch scenario if possible (for example, the physical distance each finger on the trackpad has traveled) this is for NSView in a custom Xamarin.Forms renderer specifically i am attempting to implement a cross-platform Gesture API that does not depend on surface area size, specifically targeting Windows, Linux, MacOS, and Android i CANNOT use the mouse cursor position to implement the gestures since on a trackpad only the first finger down is mapped to the cursor position while all other fingers do not contain a cursor position for example small area on built-in trackpad's large area on external trackpads and mobile devices infinite area on magic-mouse or other external mice this, combined with a sensitivity setting to account for large displays where the use may want a higher sensitivity on a larger display and a smaller sensitivity on a smaller display, should be sufficent to implement cross-platform gestures that can work in a portable way without too much effort to implement with the api (tho i suspect this sensitivity will be minor changes unless a very large surface area where the sensitivity difference would be noticible)