OpenTTD Landscape Internals
Author: Marcin Grzegorczyk
Description: Structure of OpenTTD (OTTD) landscape arrays

### Landscape

For a graphical representation of the tile-layout have a look at Landscape grid page.

Nine attributes (counting "type" and "height") hold the informations about a tile.
These attributes are referred to as "type", "height", "m1", "m2", "m3", "m4", "m5", "m6" and "m7".
The most important value is the class of a tile, stored in the upper 4 bits of the type attribute.

Frequently repeating patterns:

- type
  - Bits 7..4:

    The tile type.
    `00` | Ground
    `01` | Railway tracks
    `02` | Roads
    `03` | Town building
    `04` | Trees
    `05` | Station tiles
    `06` | Water
    `07` | Void
    `08` | Industries
    `09` | Tunnel / bridge
    `0A` | Objects

  Bits 3..2:

  Presence and direction of bridge above.
  `00` | no bridge
  `01` | Axis X (North-East)
  `02` | Axis Y (South-West)

  - Bits 1..0:

    Only meaningfull in tropic climate. It contains the definition of the available zones
    `00` | normal
    `01` | desert
    `02` | rain forest

    In any other climate these 2 bits are theoretically free of use, however using them does not seem useful.
- m1
  - Bits 6..5:

    The type of water that is on a tile.
    `00` | Sea
    `01` | Canal
    `02` | River
    `03` | Invalid, i.e. no water on this tile

    Some tiles, such as houses, reuse these bits of other purposes.
  - Bits 4..0:

    The owner of a tile can be either companies (human or AI) or "Game entities".
    `00..0E` | Normal companies
    `0F` | a town owns the tile
    `10` | nobody owns the tile
    `11` | "water" owns the tile
    `FF` | spectator in MP or in scenario editor

    Some tiles, such as houses and industries, reuse these bits of other purposes.
- m7:
  Animation frame/state. Used for houses, industries, objects and stations.

OTTD's class-specific periodic tile processing routine is called once every +256 ticks for each tile.

Class | Meaning & details of encoding
--- | ---
`0` | Ground
- | m1 bits 4..0: owner of the tile (normally `10`) m2: see fields m3 bits 7..5: type of hedge on NE border of the tile m3 bits 3..0: see fields m3 bit 4: set if the tile is covered with snow m4 bits 7..5: type of hedge on the SW border of the tile (1 through 6, or 0=none) m4 bits 4..2: same as 7..5, but for the SE border m5 bits 7..5: update counter, incremented on every periodic processing for tile types, other than `03`, `07`, `0B`, `10` and above. on wraparound, the tile is updated (for fields, the type of fields in m3 is increased, for other types the tile type in m5 is increased). For snow and desert, these bits are not used, tile is updated on every periodic processing. m5 bits 4..2: tile type:
  `0` | bare land / grass
  `1` | rough land (density must be 3)
  `2` | rocks (density must be 3)
  `3` | fields (density must be 3) m2: index into the array of industries (farms), INVALID_INDUSTRY (0xFFFF) if farm has been removed m3 bits 3..0: field type (legal values: 0 through 9)
  `4` | snow
  `5` | desert (density must be 1 or 3)
- m5 bits 1..0: density:
  `0` | bare land |  |  |  | 1/4 snow |
  `1` | 1/3 grass |  |  |  | 2/4 snow; | 1/2 desert
  `2` | 2/3 grass |  |  |  | 3/4 snow |
  `3` | full grass; | rough land; | rocks; | fields; | full snow; | full desert
m6 bits 4..2: type of hedge on NW border of the tile
`1` | Railway tracks
- | m1 bits 4..0: owner of the tile m2: see signals m3 bits 7..4: see signals m3 bits 3..0 = track type:
  `0` | conventional railway
  `1` | electrified railway
  `2` | monorail
  `3` | maglev
- m4 bits 7..4: see signals m4 bits 3..0: Ground type (values with fences are not valid for depots and checkpoints)
  `0` | on bare land
  `1` | on grass, no fences
  `2` | fence on the NW side
  `3` | fence on the SE side
  `4` | fences on the NW and SE sides
  `5` | fence on the NE side
  `6` | fence on the SW side
  `7` | fences on the NE and SW sides
  `8` | fence on the E side (track in the W corner)
  `9` | fence on the W side (track in the E corner)
  `A` | fence on the S side (track in the N corner)
  `B` | fence on the N side (track in the S corner)
  `C` | on snow or desert
  `D` | on grass with fence and shore or water on the free halftile
  `E` | higher part on foundation with snow, lower without snow
- - m5 bit 7 clear: railway track m5 bits 5..0: track layout: bit set = track present:
    bit 0: | in the X direction
    bit 1: | in the Y direction
    bit 2: | in the north corner (direction W-E)
    bit 3: | in the south corner (direction W-E)
    bit 4: | in the west corner (direction N-S)
    bit 5: | in the east corner (direction N-S)
  - m5 bit 6 set = with signals: There are at most 4 signals on a tile. The signals 0..3 belong to the directions:
    | Track `0` (X) | Track `1` (Y) | Track `2` (north) | Track `3` (south) | Track `4` (west) | Track `5` (east)
    Signal `0` |  |  |  | west |  | south
    Signal `1` |  |  |  | east |  | north
    Signal `2` | south-west | north-west | west |  | south |
    Signal `3` | north-east | south-east | east |  | north |
    - m2 bit 7: Signal 0 and 1: set = semaphore signals, clear = light signals m2 bit 3: Signal 2 and 3: set = semaphore signals, clear = light signals m2 bits 6..4: type of signal 0 and 1 (same values as m2 bits 2..0) m2 bits 2..0: type of signal 2 and 3
      `000`: | normal signals
      `001`: | pre-signals
      `010`: | exit-signals
      `011`: | combo-signals
      `100`: | pbs signals
      `101`: | no-entry signals
  - m3 bits 7..4: bit set = signal 3..0 present m4 bits 7..4: bit clear = signal 3..0 shows red m2 bits 8..10: track reserved for pbs
    `0` | not reserved
    `1` | X direction
    `2` | Y direction
    `3` | north corner (W-E)
    `4` | south corner (W-E)
    `5` | west corner (N-S)
    `6` | east corner (N-S)
- - m2 bit 11: opposite track is reserved, too m5 bit 7 set, bit 6 set: railway depot m2: Depot index m5 bits 1..0: exit towards
    `0` | NE
    `1` | SE
    `2` | SW
    `3` | NW
m5 bit 4: pbs reservation state
`2` | Roads
- | m2: Index into the array of towns (owning town for town roads; closest town otherwise, INVALID_TOWN if there is no town or we are creating a town) m7 bit 5 set = on snow or desert m7 bits 7..6: present road types
  bit 0 | normal road
  bit 1 | tram
- - m3 bits 7..4: owner of road type 1 (tram); OWNER_NONE (`10`) is stored as OWNER_TOWN (`0F`) m5 bits 7 clear: road or level-crossing m6 bits 5..3:
    `0` | on bare land
    `1` | on grass
    `2` | paved
    `3` | with streetlights
    `5` | tree-lined
    `6` | on grass with road works
    `7` | paved with road works
  - - m5 bit 6 clear: road m1 bits 4..0: owner of the road type 0 (normal road) m7 bits 3..0: counter for the roadworks m5 bits 3..0: road layout road type 0 (normal road): bit set = road piece present:
      bit 0: | NW piece
      bit 1: | SW piece
      bit 2: | SE piece
      bit 3: | NE piece
    - m3 bits 0..3: road layout road type 1 (tram) m5 bits 5..4: bits to disallow vehicles to go a specific direction
      bit 0: | set = disallow driving in south-west or south-east direction
      bit 1: | set = disallow driving in north-west or north-east direction
  - - m5 bit 6 set: level crossing m1 bits 4..0: owner of the railway track m3 bits 3..0: railway track type m5 bit 0: direction
      `0` | road in the X direction, rail in Y
      `1` | road in the Y direction, rail in X
- - m5 bit 5: set if crossing lights are on m7 bits 4..0: owner of the road type 0 (normal road) m5 bit 4: pbs reservation state m5 bit 7 set, bit 6 clear: road depot m1 bits 4..0: owner of the depot m2: Depot index m5 bits 1..0: exit towards:
    `0` | NE
    `1` | SE
    `2` | SW
    `3` | NW
m7 bits 4..0: owner of the road type 0 (normal road)
`3` | Town building
| m1 : Random bits (newhouses) m2 : index into the array of towns m3 bit 7 : set : House is complete m5 : Age of house in years, clamped at 255 clear : House is in construction m5 bits 7..5 : free m5 bits 4..3 : construction stage m5 bits 2..0 : construction counter m3 bit 6 : bit 8 of house type (m4), allowing 512 different types. m3 bit 5 : free m3 bits 4..0 : triggers activated (newhouses) m4 : town building type (with m3[6] bit) m5 : see m3 bit 7 m6 : If newhouses is activated bits 7..2 : Periodic processing time remaining Standard behaviour bits 7..2 : lift position (for houses type 04 and 05) m7 : If newhouses is activated Current animation frame Standard behaviour (only for houses type 04 and 05) bits 7..4 : free bits 3..1 : lift destination. Values can be 0..6, except 1. So the building has 6 effective floors. This is due to the fact that the first floor is 2 'normal' floors high. One 'normal' floor has a height of 6 lift positions. bit 0 : Lift has destination when set Newhouses is the name englobing a newGRF feature developped by TTDPatch devs (mainly Csaboka). It allows the replacement of the properties as well as the graphics of houses in the game. To distinguish between the standard behaviour and the newGRF one, HouseID (m4 + m3[6]) is tested for anything above 110. 110 is the count of standard houses. So above 110 means there is a new definition of at least one house
`4` | Trees
- | m1 bits 4..0: owner (normally `10`) m2 bits 8..6: ground
  `0` | on grass
  `1` | on rough land (density must be 3)
  `2` | on snow or desert
  `3` | on shore (density must be 3)
  `4` | on snow with rough land underneed
- m2 bits 5..4: ground density m2 bits 3..0: update counter, incremented on every periodic processing. on wraparound the growth status is updated (or, if it's `3`, a random action is taken) m3 bits 7..0: type of trees:
  `00`..`0B` | temperate climate trees
  `0C`..`13` | sub-arctic climate trees
  `14`..`1A` | rainforest trees
  `1B` | cactus plants
  `1C`..`1F` | sub-tropical climate, non-rainforest, non-desert trees
  `20`..`28` | toyland trees
- Note: the actually displayed set of trees depends on both type and number of trees m5 bits 7..6: number of trees minus one m5 bits 2..0: growth status:
  `0`..`2` | one of trees is growing
  `3` | all trees are fully grown
  `4`..`6` | one of trees is withering
`5` | Station tiles
- | m1 bits 6..5: water class for buoys, water part of docks and for airport tiles m1 bits 4..0: owner of the station m2: index into the array of stations m3 bits 7..4: persistent random data for railway stations/waypoints and airports) m3 bits 7..4: owner of tram tracks (road stop) m3 bits 3..0: track type for railway stations/waypoints m4: custom station id; 0 means standard graphics m5: graphics index (range from 0..255 for each station type):
  `00`..`07` | railway station
  `00`..`01` | open platform
  `02`..`03` | open platform with station building
  `04`....`07` | roofed platform
  bit 0: clear = in X direction, set = in Y direction
  `00`..`01` | waypoints
  `00` | in X direction
  `01` | in Y direction
  `00`..`FF` | all airports
  `00`..`05` | road stops
  `00` | exit towards NE
  `01` | exit towards SE
  `02` | exit towards SW
  `03` | exit towards NW
  `04` | drive through X
  `05` | drive through Y
  `00`..`05` | ship dock
  `00` | SW coast part
  `01` | NW coast part
  `02` | NE coast part
  `03` | SE coast part
  `04` | X direction water part
  `05` | Y direction water part
m6 bits 5..3: the station type (rail, airport, truck, bus, oilrig, dock, buoy, waypoint) m6 bit 2: pbs reservation state for railway stations/waypoints m7 bits 4..0: owner of road (road stops) m7 bits 7..6: present road types (road stops) m7: animation frame (railway stations/waypoints, airports)
`6` | Water
- | m1 bits 6..5 : Water class (sea, canal or river) m1 bits 4..0: owner (for sea, rivers, and coasts normally `11`) m2: Depot index (for depots only) m4: Random data for canal or river tiles m5: tile type:
  `00` | water, canal or river
  `01` | coast or riverbank
  `10`..`1B` | canal locks
  `10` | middle part, (SW-NE direction)
  `11` | middle part, (NW-SE direction)
  `12` | middle part, (NE-SW direction)
  `13` | middle part, (SE-NW direction)
  `14` | lower part, (SW-NE direction)
  `15` | lower part, (NW-SE direction)
  `16` | lower part, (NE-SW direction)
  `17` | lower part, (SE-NW direction)
  `18` | upper part, (SW-NE direction)
  `19` | upper part, (NW-SE direction)
  `1A` | upper part, (NE-SW direction)
  `1B` | upper part, (SE-NW direction)
  `80`..`83` | ship depots
  `80` | ship depot, NE part (X direction)
  `81` | ship depot, SW part (X direction)
  `82` | ship depot, NW part (Y direction)
  `83` | ship depot, SE part (Y direction)
`7` | Void
| Tiles of this class form an invisible, one tile wide border at the south (bottom) edges of the map, so as to protect several algorithms from the consequences of a wraparound at the edges.
`8` | Industries
- | m1 bit 7: clear = under construction m1 bits 6..5 : Water class (sea, canal, river or land) m1 bits 3..2: construction counter, for buildings under construction incremented on every periodic tile processing m1 bits 1..0: stage of construction (`3` = completed), incremented when the construction counter wraps around the meaning is different for some animated tiles which are never under construction (types `01`, `1E`..`20`, `30`, `58`; see above) m2: index into the array of industries m3: random bits (NewGRF) m4: animation loop m5: type (plus m6 bit 2): (note: this is not the same as the industry type, which is stored in the array of industries)
  `00`..`06` | coal mine
  `00` | wheel tower when not animated
  `01` | wheel tower when animated animation state in m7 bits 5..0; m7 bit 6 set = sound already generated
  `07`..`0A` | power station
  `08` | chimney
  `0A` | transformer; animation progress in m7(valid range `0`..`7`)
  `0B`..`0F` | sawmill
  `10`..`11` | forest
  `11` | trees cut down
  `12`..`17` | oil refinery
  `18`..`1C` | oil rig
  `1D`..`20` | oil wells
  `1D` | not animated
  `1E`..`20` | various stages of animation; progress of animation in m7
  `21`..`26` | farm
  `27`..`2A` | factory (temperate climate)
  `2B`..`2E` | printing works
  `2F`..`33` | copper ore mine
  `2F` | wheel tower when not animated
  `30` | wheel tower when animated; animation state in m7 bits 5..0; m7 bit 6 set = sound already generated
  `31` | chimney
  `34`..`39` | steel mill
  `3A`..`3B` | bank (temperate climate)
  `3C`..`3F` | food processing plant
  `40`..`47` | paper mill
  `48`..`58` | gold mine
  `4F` | wheel tower when not animated
  `58` | wheel tower when animated; animation state in m7 bits 5..0; m7 bit 6 set = sound already generated
  `59`..`5A` | bank (sub-arctic or sub-tropical climate)
  `5B`..`63` | diamond mine
  `64`..`73` | iron ore mine
  `74` | fruit plantation
  `75` | rubber plantation
  `76`..`77` | water supply
  `78` | water tower
  `79`..`7C` | factory (sub-tropical climate)
  `7D`..`80` | lumber mill
  `81`..`82` | candyfloss forest
  `82` | candyfloss 'trees' cut down
  `83`..`86` | sweet factory
  `87`..`88` | battery farm
  `88` | batteries 'reaped'
  `89` | cola wells
  `8A`..`8D` | toy shop
  `8E`..`93` | toy factory
  `8F` | Animated part; animation state in m7 (valid range `00`..`31`) Tile animation is started (m4 zeroed) on the periodic processing. While the animation is in progress, m4 holds the number of animation cycles that have already taken place. when this number reaches 8 the animation is stopped.
  `94`..`9B` | plastic fountains (various stages of cyclic animation)
  `9C`..`9F` | fizzy drink factory
  `A0`..`A3` | bubble generator
  `A1` | generators
  `A2` | bubble capture facility; animation state in m7 (valid range `00`..`27`)
  `A4`..`A6` | toffee quarry
  `A5` | animated part; animation state in m3 (valid range `00`..`45`)
  `A7`..`AE` | sugar mine
  `AE` | animated part; animation state in m3 (valid range `00`..`5F`)
  `AF`..`1FF` | NewGRF industries industry
m6 bits 5..3: random triggers (NewGRF) m6 bit 2: bit 8 of type (see m5) m7: animation frame
`9` | Tunnel / bridge
- - | m1 bits 4..0: owner m3 bits 7..4: owner of tram m3 bits 3..0: track type for railway m5 bit 4: pbs reservation state for railway m5 bits 7 clear: tunnel entrance/exit m5 bit 7 set: bridge ramp m6 bits 5..2: bridge type:
    Type | Max. speed (mph) | Description
    --- | --- | ---
    `0` | 20 | wooden
    `1` | 30 | concrete
    `2` | 40 | girder, steel
    `3` | 50 | suspension, concrete
    `4` | 60 | suspension, steel
    `5` | 70 | suspension, steel
    `6` | 100 | cantilever, steel
    `7` | 130 | cantilever, steel
    `8` | 150 | cantilever, steel
    `9` | 160 | girder, steel
    `A` | 200 | tubular, steel
    `B` | 320 | tubular, steel
    `C` | 380 | tubular, silicon
- m5 bits 3..2: transport type
  `0` | railway
  `1` | road
  `2` | water
- m5 bits 1..0: direction onto the bridge / out of the tunnel
  `0` | NE
  `1` | SE
  `2` | SW
  `3` | NW
m7 bits 4..0: owner of road m7 bit 5 set = on snow or desert m7 bits 7..6: present road types for road
`A` | `Objects`
| m1 bits 6..5 : Water class (sea, canal, river or land) m1 bits 4..0: owner of the object (for lighthouses and transmitters normally `10`) m2: index into the array of objects, bits 0 to 15 (upper bits in m5) m3: random bits m5: index into the array of objects, bits 16 to 23 (lower bits in m2) m7: animation counter
Classes `B` through `F` are reserved. The presence of a tile in one of the reserved classes will crash OTTD.

Original Copyright © 2003 by Marcin Grzegorczyk for TTDLX.
Transport Tycoon and Transport Tycoon Deluxe are Copyright © by Chris Sawyer.
All the other trademarks are the property of their respective owners.