Add two new maps arrays each one byte.

Regions

Regions are territories/zones mainly thought for game script use. They represent political boundaries, e.g. a metropolis area with suburbs, a county, or a nation state. Each company can have restrictions and modifiers in each region, e.g. permission or refusal to build railroad or stations, or increased/decreased costs and incomes. Each region can have a capital city.

Regions are created either by the map generator, or by a scenario designer.

The meaning of a region is defined only by game script, and company access to each region can change during gameplay.

Terrain types

Terrain types are natural features mainly thought for NewGRF industries to use, and to some extent for construction limitations. Terrain types can have alternate ground tiles. They can have restrictions on construction types made on top of them and restrictions on landscape modification, and have cost modifiers applied. Industries can have rules for only being built in certain terrain types.

Terrain types are possibly defined by NewGRF.

Example uses:

• Deep sea, cannot be filled in to land and some industries (oil rigs) can only be built in deep sea.
• Arable land, farms built here have better production.
• Desert could be converted to a terrain type.
• Bedrock mountains, extremely expensive to terraform, more expensive to tunnel below, but can build cheaper foundations and bridges on them as the terrain is stable. Certain mine types can only be built here.
• Bogs, can bridge over but expensive to convert to regular terrain if you want to build networks directly on top. May anger local authorities if bogs are destroyed.