OpenTTD Landscape Internals - #2

Landscape

Five attributes hold the information about a 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 attribute is abused for different purposes

type_height - 8 bits in size, stores tile height (lower 4 bits) and tile class (upper 4 bits)
m1 - 8 bits in size, used to identify the owner of that tile (eg piece of rail, bridge, etc.)
m2 - 16 bits in size, used to identify the index of the given tile (object) in the (object-)array
m3 - 8 bits in size, is used for general storage
m4 - 8 bits in size, is used for general storage
m5 - 8 bits in size, is used for general storage

class		m1 (8)	m2 (16)	m3 (8)	m4 (8)	type_height (8)	m5 (8)
bits		7654 3210	FEDC BA98 7654 3210	7654 3210	7654 3210	7654 3210	7654 3210
0	ground	XXXX XXXX	OOOO OOOO OOOO OOOO	OOOO OOOO	XXXX XXOO	XXXX XXXX	XXXX XXXX
0	farmland	-inherit-	XXXX XXXX XXXX XXXX	OOOO XXXX	-inherit-	-inherit-	OOOX XXXX
1	rail	XXXX XXXX	OOOO OOOO XXXX XXXX	XXXX XXXX	OOOO OXXX	XXXX XXXX	XXXX XXXX
	depot	-inherit-	OOOO OOOO OOOO OOOO	OOOO XXXX	OOOO XXXX	-inherit-	XXOO OXXX
	waypoint	-inherit-	XXXX XXXX XXXX XXXX	OOOO XXXX	OOOO XXXX	-inherit-	XXOO OXXX
2	road	XXXX XXXX	XXXX XXXX XXXX XXXX	OOOO OOOO	XXXX XXXX	XXXX XXXX	XXXX XXXX
	level crossing	-inherit-	-inherit-	XXXX XXXX	XXXX XXXX	-inherit-	XXXX XXOO
	road depot	-inherit-	OOOO OOOO OOOO OOOO	OOOO OOOO	XOOO OOOO	-inherit-	XXXX XXXX
3	town	XXXX XXXX	XXXX XXXX XXXX XXXX	XXOO OOOO	XXXX XXXX	XXXX XXXX	XOXX XXXX
4	trees	XXXX XXXX	OOOO OOOO XXXX XXXX	XXXX XXXX	XXXX XXOO	XXXX XXXX	XXOO OXXX
5	station	XXXX XXXX	XXXX XXXX XXXX XXXX	XXXX XXXX	XXXX XXXX	XXXX XXXX	XXXX XXXX
6	water	XXXX XXXX	OOOO OOOO OOOO OOOO	OOOO OOOO	OOOO OOOO	XXXX XXXX	XXXX XXXX
8	industry	XOOX XXXX	XXXX XXXX XXXX XXXX	OOOO OOOO	OOOO OOOO	XXXX XXXX	XXXX XXXX
	bubble/sugar/toffee, gold/copper/coal, oil wells, power station	XOOO OOOO	-inherit-	XXXX XXXX	OOOO OOOO	-inherit-	-inherit-
	toy factory	XOOO OOOO	-inherit-	XXXX XXXX	XXXX XXXX	-inherit-	-inherit-
9	tunnel	XXXX XXXX	OOOO OOOO OOOO OOOO	OOOO XXXX	XOOO OOOO	XXXX XXXX	XOOO XXXX
9	bridge ramp	XXXX XXXX	OOOO OOOO XXXX OOOO	OOOO XXXX	XOOO OOOO	XXXX XXXX	XOOO XXXX
A	various (HQ)	XXXX XXXX	OOOO OOOO OOOO OOOO	OOOO OOOO	OOOO OOOO	XXXX XXXX	XXXX XXXX