Defining custom units

The Unit system makes it easy to define your own custom Units in a pre-existing Unit family.

Lets look at defining our own DistanceUnits for use with Distances

DistanceUnit is the unit family that Distance uses. Its an interface, so we can implement it on an enum.

All we need to do is define a ratio of this unit, to millimeters.

Essentially: let x be some value represented in unit u, r be unit u’s toCommonRatio, c be the common unit for the unit family u belongs to. Then, x / r is equal to x in c.

For example: DistanceUnits.METER has a toCommonRatio of 1000.0 as to convert Meters to Millimeters, you divide by 1000.

Dairy does this for the enums DistanceUnits, CurrentUnits and AngleUnits.

now:

While FATHOM and LEAGUE might be totally useless units, TILE is genuinely useful! This season, try doing all your pathplanning using Distances using measurements relative to the size of your practice field’s tiles, then, when you go to competition, remeasure the size of the tiles, and update a single number in your code, to instantly remap your auto to the changed tile size. Just remember to reset it after the event.