Home › Dev CE (experimental) › CityGrowth

Experimental: needs Dev CE (fork of the Community Extension, release zip and source). A GameCore that adds these Lua methods by calling engine functions directly. Not part of the upstream Community Extension, single-player testing only. Descriptions on these pages were written by an AI assistant from decompiled code and are marked inferred unless a test result confirms them.

CityGrowth

14 methods (Dev CE test build). this is found with the game's own ICityGrowth instance resolver (plain).

Method	Signature	Purpose (AI-written, inferred)	Tested	Engine function	Current
AddGrowth	`CityGrowth:AddGrowth(xGrowth: number (fixed point, 1/256 steps))`	Adds food growth to a city; grows population when it crosses the threshold and shrinks it when stored food goes negative.	plumbing ✓ this ✓ (oracle)	City::Growth::AddGrowth	`0x123160`
ChangeFeatureAppealModifier	`CityGrowth:ChangeFeatureAppealModifier(eFeature: integer, iChange: integer)`	Adds a delta to the appeal modifier a city gets for a specific feature type, creating the entry if missing and removing it if the total returns to zero.	plumbing ✓ ran ±1, reversible ✓, no visible effect this ✓ (oracle)	City::Growth::ChangeFeatureAppealModifier	`0x123370`
DoCityGrowth	`CityGrowth:DoCityGrowth()`	Per-turn city growth step: computes food surplus (food yield minus consumption), applies growth modifier, adds it via AddGrowth, and sends starvation, stagnation, housing and amenity notifications (each throttled to once per 10 turns).	plumbing ✓ this ✓ (oracle)	—	`0x123460`
GetAmenitiesLostFromWarWeariness	`CityGrowth:GetAmenitiesLostFromWarWeariness() → number`	Returns amenities this city loses to war weariness, from the owner's diplomacy state.	plumbing ✓ this ✓ (oracle)	—	`0x123fb0`
GetAmenitiesNeeded	`CityGrowth:GetAmenitiesNeeded() → number`	Returns amenities the city needs for its population from the economic rules.	plumbing ✓ this ✓ (oracle)	—	`0x123fe0`
GetFeatureAppealModifier	`CityGrowth:GetFeatureAppealModifier(eFeature: integer) → number`	Looks up the city's stored appeal modifier for a feature type; 0 if none.	plumbing ✓ this ✓ (oracle)	—	`0x124010`
GetHappinessGrowthModifier	`CityGrowth:GetHappinessGrowthModifier() → number`	Growth modifier from happiness: amenity surplus mapped to a happiness level then to a growth modifier.	plumbing ✓ this ✓ (oracle)	—	`0x124110`
GetHousingGrowthModifier	`CityGrowth:GetHousingGrowthModifier() → number`	Growth modifier from housing: housing from water, buildings, improvements and districts passed to the surplus-reduction rule.	plumbing ✓ this ✓ (oracle)	—	`0x1245e0`
GetLoyaltyGrowthModifier	`CityGrowth:GetLoyaltyGrowthModifier() → number`	Growth modifier from the city's loyalty level, read from the loyalty level definition; 1.0 (0x100) if no level.	plumbing ✓ this ✓ (oracle)	—	`0x124660`
GetOccupationGrowthModifier	`CityGrowth:GetOccupationGrowthModifier() → number`	Returns the global occupation growth modifier parameter converted to fixed point.	plumbing ✓ this ✓ (oracle)	—	`0x1246f0`
GetOtherGrowthModifier	`CityGrowth:GetOtherGrowthModifier() → number`	Other growth modifier: player growth-rate setting times 0.01 plus the city's own extra modifier field at 0x84.	plumbing ✓ this ✓ (oracle)	—	`0x124750`
GetTurnsUntilStarvation	`CityGrowth:GetTurnsUntilStarvation() → number`	Turns until the city's stored food runs out given a negative surplus; -1 if not starving or population is 1 or less, 1 if no stored food.	plumbing ✓ this ✓ (oracle)	—	`0x124a80`
HasDroughtPrevention	`CityGrowth:HasDroughtPrevention() → boolean`	Checks whether the city has a district or a worked improvement (flagged in XP2 definitions) that prevents drought.	plumbing ✓ this ✓ (oracle)	—	`0x124c70`
RemoveFeatureAppealModifier	`CityGrowth:RemoveFeatureAppealModifier(eFeature: integer)`	Removes the city's appeal modifier entry for a feature by swapping in the last entry.	plumbing ✓ this ✓ (oracle)	—	`0x124e10`

Details

AddGrowth

Arguments: xGrowth — food amount to add (raw/256)

Writes - stored growth at this+0x80 - city population via ChangePopulation(+1/-1)

Side effects - City::Instance::ChangePopulation

Input checks: Negative stored food with population greater than 1 starves one pop and resets; population 1 clamps to 0. Excess after growth is capped just below the threshold.

Preconditions - valid city - game thread

Multiplayer: safe-deterministic. Risk: medium (changes population). Confidence of the reading: high.

Verified from the code - adds param to stored food - growth when stored >= threshold*256: subtract threshold, +1 pop, cap - negative path: -1 pop if pop>1, reset to threshold plus amount floored at 0

Inferred - field at +0x80 is stored food in FixedPoint

ChangeFeatureAppealModifier

Arguments: eFeature — feature type; iChange — amount to add to the modifier

Writes - vector of (feature, modifier) pairs at this+0x8 (size at +0x18, capacity at +0x10): append, update, or remove entry

Side effects - calls RemoveFeatureAppealModifier when the sum would be zero - may grow the vector (allocation)

Input checks: None on the feature id; any value is stored. No recalculation of appeal is triggered here.

Preconditions - game thread

Multiplayer: safe-deterministic. Risk: low (Small list update; no appeal refresh visible.). Confidence of the reading: medium.

Verified from the code - Linear search of an 8-byte (feature,int) pair list - If not found: appends new pair (growing vector if full) - If found and existing value equals -iChange: calls RemoveFeatureAppealModifier - Otherwise adds iChange to the stored value

Inferred - Entries are used to modify per-feature appeal calculation in the city

Open questions - Who recomputes appeal after this change

DoCityGrowth

Writes - Growth food accumulator (via AddGrowth) - Last-notification turn fields at 0x88, 0x8c, 0x90, 0x94

Side effects - Reporting::Notification::Send for starving, no-growth, housing and amenity warnings

Input checks: No argument validation; notification throttled by game turn.

Multiplayer: may-desync, changes city population food. Risk: high (drives population growth and sends notifications). Confidence of the reading: medium.

GetAmenitiesLostFromWarWeariness

Input checks: None; assumes valid owner.

Multiplayer: read-only, reads city/district state only. Risk: low (pure getter). Confidence of the reading: high.

GetAmenitiesNeeded

Input checks: None.

Multiplayer: read-only, reads city/district state only. Risk: low (pure getter). Confidence of the reading: high.

GetFeatureAppealModifier

Arguments: eFeature — feature type to look up

Input checks: No range check; linear search.

Multiplayer: read-only, reads city/district state only. Risk: low (pure getter). Confidence of the reading: high.