Replacing pixel based thresholds with physical dimensions based ones

[horriblename]

Currently gesture detection works something like this:

when user swipes more than X pixels in one direction, we detect a swipe gesture and do gesture things.

the value of X is a base constant scaled by the config value sensitivity. This is awful because different devices will need different sensitivity values and makes gestures very inconsistent.

I plan to replace pixel thresholds with physical dimensions (e.g. millimeter). dp (density independent pixels) seems to be a preferred unit in android development so maybe I'll base it off that