Action2

Introduction

Defining graphics set IDs.

Action 2 is used to group sets of sprites from the previous action 1 together, and make them accessible by a variational or random action2 (chain) or an action3.

Syntax

In general, the data looks as follows:

<Sprite-number> * <Length> 02 <feature> <set-id> <num-ent1> <num-ent2> <entries...>

Element	Size	Description
<Sprite-number>	dec	A sequential sprite number
<length>	dec	The total number of bytes used in this action
02	B	Defines action 02
<feature>	B	For what type of feature should the following sprites be used?
<set-id>	B	What set-ID this action 2 defines
<num-ent1>	B	First number of entries, depends on feature
<num-ent2>	B	Second number of entries, depends on feature
<entries...>	W	Entry numbers, depends on the feature

Descriptions

Sprite-number

This is just the number you are at.

Length

Count the number of bytes in this action.

feature

This sets the type of feature that you wish to change. Set it to:

Value	Feature
00	trains
01	road vehicles
02	ships
03	planes
04	stations
05	canals/rivers
06	bridges
07	houses
09	industry tiles
0A	industries
0B	cargos
0D	airports (OpenTTD r19204)
0F	objects
10	rail types (OpenTTD r19056)
11	airport tiles (OpenTTD r19204)

set-id

This defines the ID of the current action 2. This ID will later be referred to by action 3, or a variational/random action 2.

You can reuse action 2 IDs, and there's no restriction on the order in which they are defined.

num-ent1, num-ent2

Each feature has two different graphics ranges, but their exact meaning differs from feature to feature. For example, for vehicles, the first set is used while moving, and the second while loading/unloading in a station.

entries

This is the list of action 1 sets to use, first num-ent1 for the first range, then num-ent2 entries for the second range.

Notes

Do not skip an action 2 using action 9 (unless it skips the whole file). Action 2 must not be skipped by action 9 or the patch will most likely crash. Skip or modify action 3 instead. Skipping an action 2 with an action 7 has no effect.

Feature specific formats

Some features and/or num-ent1 values have a special format. These are detailed on their separate pages (see main menu)