OpenTTD Landscape Internals

Landscape

Five arrays are used to encode the information of the contents of the tile. This can be seen in the Landscape document. This page tries to give an overview of used and free bits of the array so you can quickly see what is used and what is not.

O - bit is free
X - bit is used
- bit of _map_* is abused for different purposes

_map_owner[] - 8 bits in size, used to identify the owner of that tile (eg piece of rail, bridge, etc.).
_map2[] - 16 bits in size, used to identify the index of the given tile (object) in the (object-)array.
_map3[] - 16 bits in size, which is split up into _map3lo[] and _map3hi[] is used for general storage.
_map_type_and_height[] - 8 bits in size, stores tile height (lower 4 bits) and tile class (upper 4 bits).
_map5[] - 8 bits in size, is used for general storage.

class	_map_owner[L1] (8)	_map2[L2] (16)	_map3[lo& hi,L3] (16)	_map_type_and_height[L4] (8)	_map5[L5] (8)
(0) ground	XXXX XXXX	OOOO OOOO OOOO OOOO	XXXX OOOO OOXX XXXX	XXXX XXXX	XXXX XOXX
(1) rail	XXXX XXXX	XXXX XXXX OOOO OOOO	XXXX XXXX XXXO OOOO	XXXX XXXX	XXXX XXXX
depot/checkpoint	-inherit-	OOOO OOOO OOOO OOOO	XXXX XOOO XXXX XXXX	-inherit-	XXXO OOXX
(2) road	XXXX XXXX	XXXX XXXX XXXX XXXX	OOOO OOOO XXXX XXXX	XXXX XXXX	XXXX XXXX
level crossing	-inherit-	XXXX XXXX XXXX XXXX	XXXX XXXX XXXX XXXX	-inherit-	OOXX XXXX
road depot	-inherit-	OOOO OOOO OOOO OOOO	OOOO OOOO OOOO OOOX	-inherit-	XXXX XXXX
(3) town	XXXX XXXX	XXXX XXXX XXXX XXXX	XXXX XXXX XXXX XXXX	XXXX XXXX	XXXX XXOX
(4) trees	XXXX XXXX	XXXX XXOO OOOO OOOO	XXXX XXXX OOXX XXXX	XXXX XXXX	XXXO OOXX
(5) station	XXXX XXXX	XXXX XXXX XXXX XXXX	XXXX XOOO XXXX XXXX	XXXX XXXX	XXXX XXXX
(6) water	XXXX XXXX	OOOO OOOO OOOO OOOO	OOOO OOOO OOOO OOOO	XXXX XXXX	XXXX XXXX
(8) industry	XXXX XOOX	XXXX XXXX XXXX XXXX	OOOO OOOO OOOO OOOO	XXXX XXXX	XXXX XXXX
bubble/sugar/toffee	-inherit-	-inherit-	XXXX XXXX OOOO OOOO	-inherit-	-inherit-
toy factory	-inherit-	-inherit-	XXXX XXXX XXXX XXXX	-inherit-	-inherit-
gold/copper/coal	XXXX XXXX	-inherit-	-inherit-	-inherit-	-inherit-
oil wells	-inherit-	-inherit-	-inherit-	-inherit-	-inherit-
power station	XXXX XXOX	-inherit-	-inherit-	-inherit-	-inherit-
(9) tunnel	XXXX XXXX	OOOO OOOO OOOO OOOO	XXXX OOOO OOOO OOOX	XXXX XXXX	XXXX XXXX
bridge	XXXX XXXX	XXXX XXXX OOOO OOOO	XXXX XXXX OOOO OOOX	XXXX XXXX	XXXX XXXX
(10) various (HQ)	XXXX XXXX	OOOO OOOO OOOO OOOO	OOOO OOOO OOOO OOOO	XXXX XXXX	XXXX XXXX