The nfo/grf Technical Reference

Action 0 - Properties for industry tiles

Defining properties of industry tiles



Introduction

Industry tiles work similarly to town buildings, except that they are not stand-alone. This means an industry tile can't stand alone, it's always part of an industry.

Defining industry tiles follows the same schema as houses do: to start using an ID, you first need to define it by setting property 8 for it. If you try to reference an ID (either via action0 or via action3) that isn't defined, your request is ignored, but not reported as an error, either. This means that if you want to conditionally define an ID, all you need to do is skipping the action0 that sets property8, and everything else gets skipped automatically.

Industry tile IDs are unique within each grf file. In total, TTDPatch can have up to 256 new industry tile IDs (i.e. old tile types don't count). OpenTTD can have 512 IDs for all active grf files, but that includes non-overridden original tiles. The per-GRF ID is specified as a byte, which means no GRF can define more than 256 tile IDs. You should use your industry tile IDs sparingly. Variational action 2 variable 43 for industry tiles can help you limiting tile consumption to 2 or 3 per industry. Try to avoid using tile FFh, so it can be turned into an extended byte (in Action 3) in the distant future without breaking your NewGRF.


Properties

NumberVersionSizeDescription
082.0.1 a43BSubstitute building type
09BIndustry tile override
0A, 0B, 0CWTile acceptance
0D2.0.1 a49BLand shape flags
0E2.0.1 a54BCallback flags
0FWAnimation information
10BAnimation speed.
11BTriggers for callback 25
122.5 beta 2BSpecial flags


Description

Substitute tile type (08)


This tile type will be used instead of your new one if your definition isn't available for any reason. Valid values are 00h-AEh. Assigning this property copies the properties of the old type just like it does with houses.
If this tile's action 3 appears before this property is set, the action 3 will have no effect.

Industry tile override (09)


Works like the house override property for houses.

Tile acceptance (0A, 0B, 0C)


These three words define what cargoes the tile accepts, and how much of them. The low byte defines the type of the cargo according to the current climate, while the high byte defines the degree of acceptance in 1/8 units. If you don't need all three cargo types, just zero out the high byte of the extra properties.

From GRF version 7 and above, the meaning of the low byte changes: instead of a climate-dependent cargo slot number, you have to give a climate-independent cargo ID. If your GRF has a cargo translation table, then this ID is the index in that table; otherwise, it's the cargo bit. Acceptance of cargoes not currently present will automatically be disabled.

Land shape flags (0D)


This property defines which slopes the tile can be built on.

BitValueMeaning
01NW edge cannot be lowered
12NE edge cannot be lowered
24SW edge cannot be lowered
38SE edge cannot be lowered
410Can only be built on flat land
520The tile is allowed on both land and water (only from alpha 58)

Industry tiles are never built on steep slopes unless callback 2F is enabled, but bits 0..4 are ignored in that case.

Bit 5 can be used to allow tiles of land industries built on water or vice versa. It effectively disables the land/water check code for the tile. If you need to customize the behavior further, you can use callback 2F to decide what kind of water/land is allowed.

Note:

Be careful when setting this property. If you fail to set it correctly, your industry may end up building on a hillside, which is probably not what you want. The easiest way is to set bit 4 for middle tiles, bit 0 for the tiles along the SE edge, bit 1 for those along the SW edge and so on.

Callback flags (0E)


BitValueMeaning
01use callback 26 to decide the next animation frame
12use callback 27 to decide animation speed
24use callback 2B to decide amount of acceptance (only from 2.0.1 a55 vcs 3)
38use callback 2C to decide accepted types (only from 2.0.1 a55 vcs 3)
410use callback 2F to check if a slope is suitable
520use callback 30 to decide if default foundations need to be drawn
640use callback 3C to allow or deny autosloping below the tile (only from 2.5 beta 3)

Please note that callback 25 doesn't have a bit here. To use callback 25, simply set the wanted bits in property 11 and it will work as intended.

Animation information (0F)


The low BYTE specifies the number of animation frames minus one, so 00 means 1 frame, 01 means 2 frames etc. The maximum number of frames is 256, although you can have some problems if your animation exceeds FD (253) frames. The high BYTE must be 0 for non-looping animations and 01 for looping animations. Every other value is reserved for future use. In addition, if the whole WORD contains FFFF, animation is turned off for this tile (this is the default value).

Animation speed (10)


The meaning is the same as for house property 1B, but the lower limit is 0 instead of 2, so the fastest possible animation changes frames every game tick (27ms). The default value is 2.

Triggers for callback 25 (11)


Call callback 25 when:

BitValueMeaning
01the construction state changes
12the tile is processed in the periodic processing loop
24the industry of the tile is processed in the periodic processing loop (synchronized animation)
38the industry of the tile receives input cargo from a station
410the industry distributes its output cargo to one of the stations nearby (from beta 2)


Special flags (12)


BitValueMeaning
01Callback 26 needs random bits