Production Booster

Production Booster is an OpenTTD GameScript that adjusts primary industry production based on transport efficiency. Well-served industries grow; neglected industries shrink.

Requires OpenTTD 15.0 or later and GameScript API v15.

How It Works

The script tracks raw industries that produce freight cargo and processes them in round-robin batches.

• If last month's average transported percentage is at least increase_threshold, production increases by step_size.
• If it is below decrease_threshold, production decreases by step_size after the grace period.
• Production remains within min_level and max_level.
• Industries without nearby stations are skipped.
• Industries with no output for two or more consecutive economy years are skipped in calendar mode.
• New industries are registered immediately; closed industries are removed safely.

The script takes control of tracked industry production with INDCTL_EXTERNAL_PROD_LEVEL and suppresses the game's random production changes and closures.

Settings

Settings can be changed in-game from the GameScript Parameters window.

Setting	Default	Range	Description
increase_threshold	80	50–100	Transport percentage required to increase production
decrease_threshold	60	0–95	Transport percentage below which production decreases
step_size	4	1–16	Production level change per adjustment
min_level	8	4–64	Minimum production level
max_level	128	4–128	Maximum production level
grace_period_months	3	0–12	Time after opening before production may decrease
batch_divisor	30	5–100	Controls wake frequency; higher values reduce CPU overhead but slow reaction time
log_level	3	1–4	1 = errors, 2 = warnings, 3 = info, 4 = debug

If increase_threshold is less than or equal to decrease_threshold, production changes are suspended and a warning is logged.

Compatibility

OpenTTD	15.0 or later
GameScript API	v15
Industry sets	Vanilla and NewGRF
Timekeeping	Calendar and wallclock modes
Multiplayer	Supported

In wallclock mode, dormancy and grace-period checks are disabled because construction dates and production years use calendar coordinates.

Installation

BaNaNaS

Search for Production Booster in the in-game Game Scripts content browser.

Manual

1. Create <OpenTTD data dir>/game/Production_Booster/.
2. Copy info.nut, main.nut, and version.nut into that directory.
3. Start a game and select Production Booster in GameScript Settings.

Typical OpenTTD data directories:

OS	Path
Windows	Documents\OpenTTD\
macOS	~/Documents/OpenTTD/
Linux	~/.openttd/

Files

File	Purpose
info.nut	Metadata and in-game settings
main.nut	Runtime controller and industry processing
version.nut	Shared script version constant

Performance

Production Booster avoids a full-map industry scan in one tick.

At the default batch_divisor of 30, each wake processes approximately tracked industries / 30. The batch size is anchored to REFERENCE_DIVISOR, while batch_divisor scales the sleep interval. This keeps the per-wake batch size stable and changes how often the script wakes.

• Lower batch_divisor: more frequent processing and faster reaction, with more wake overhead.
• Higher batch_divisor: fewer wake-ups and lower overhead, with slower reaction.
• GetOpsTillSuspend() is checked every 10 industries and the script yields with Sleep() when the reserve is low.
• Freight cargo IDs are cached as plain integer arrays.
• Production commands run synchronously so their return values are meaningful.
• Startup control flags are applied in one asynchronous batch.
• New industries are appended to the current scan without restarting the round-robin pass.
• Duplicate pending scan entries are prevented with an O(1) pending-ID table.
• Stale-industry validation runs every four completed passes; normal open/close events handle routine tracking.

Save and Load

The script saves plain values only: industry IDs, cached cargo-ID arrays, and production capability flags. Scan order and pending scan state are rebuilt after loading.

Older saved data may be migrated when OpenTTD provides it to the new script. If OpenTTD considers an older GameScript version incompatible, it may discard the old script state; v10 then rebuilds its industry tracking from the current map.

License

GNU General Public License v2

Created by nelbin4