What does this tool do?

This tool aggregates or "flattens" out turf_decal tiles on a map. For example, let's assume you have this map key:

"qp" = (
/obj/effect/decal/cleanable/dirt,
/obj/machinery/atmospherics/pipe/smart/manifold4w/supply/hidden,
/obj/effect/turf_decal/tile/blue,
/obj/effect/turf_decal/tile/blue{
    dir = 4
    },
/turf/open/floor/iron{
    initial_gas_mix = "TEMP=2.7"
    },
/area/shuttle/caravan/freighter1)

This tool will just turn those two separate /obj/effect/turf_decal/tile/blue into one /obj/effect/turf_decal/tile/blue/half/contrasted with the correct dir, like so:

"qp" = (
/obj/effect/decal/cleanable/dirt,
/obj/machinery/atmospherics/pipe/smart/manifold4w/supply/hidden,
/obj/effect/turf_decal/tile/blue/half/contrasted{
    dir = 4
    },
/turf/open/floor/iron{
    initial_gas_mix = "TEMP=2.7"
    },
/area/shuttle/caravan/freighter1)

Simple! This goes for any possible permuation of turf decals in a map key, respecting any possible color and combination thereof.

click me if you don't understand what you just saw

How do I use this tool?

Just double-click the MapTileAggregator.bat file in this directory and it'll automatically run the Python tool on all of the .dmm files in the /_maps directory. It'll also automatically run the MapMerge tool once it's done to keep everything nice and tidy.