✅ Verified in-game — deeper pass: documented the _ShopSelection affordability gate (nCost <= MrxPmc.GetCashQty()) and its MrxPmc.AddCashQty(-nCost, ...) debit path, surfaced tTypeToIcon, cross-linked economy modules, replaced vacuous modder notes; all functions/imports re-confirmed

MrxShop

Module: mrxshop.lua

Overview

The MrxShop module is responsible for managing the in-game store system, including generating and displaying shop lists, handling item purchases, and maintaining persistence of purchased items. It interacts with various other modules like MrxFactionManager, MrxPmc, and WifEquipmentData to determine prices, availability, and player resources.

Inheritance

Inherits from: none
Imports: WifMissionData, MrxSupportData, WifEquipmentData, MrxPmc, MrxUtil, MrxFactionManager, MrxRewardData

Instance pattern

This is a stateless manager/utility module. It does not follow the per-instance pattern (keyed by uGuid). Instead, it maintains global state through _tGlobalShopList and _oVender.

Functions

`Init()`

Initializes the global shop list for each faction by populating _tGlobalShopList with default values.

`Open(oVender, fOnClose, tOnCloseData)`

Opens the shop interface for a given vendor. It sets up the shop UI, applies price scaling, separates items into unlocked and locked categories, sorts them by cost, and handles item selection through _ShopSelection.

`_GetShopList(oVender, sFactionId)`

Generates a list of potential shop items based on the vendor’s faction. It retrieves both support and equipment items that can be sold in the shop.

`_GetPriceScale(oVender)`

Determines the price scale for items in the shop. Returns 1.0 if the vendor has a custom vehicle shop; otherwise, it uses MrxFactionManager.GetPriceScale to get the faction’s PMC price scale.

`_ShopSelection(sId, nAmt)`

The purchase handler wired into Hud.Shop (see Events). Returns false immediately if sId == "Locked". Otherwise it looks the id up in MrxSupportData.tSupportData (or, failing that, WifEquipmentData.GetEquipmentData), computes nCost = base * nPriceScale * nAmt, and applies the affordability gate:

if nCost <= MrxPmc.GetCashQty() then   -- can afford (a $0 item always passes)
  MrxPmc.AddSupportQty(sId, nAmt, false, nCost)   -- or MrxPmc.AddEquipment(sId)
  MrxPmc.AddCashQty(-nCost, nil, "[Generic.ShopItems]")   -- debit, HUD-updating
  return true
end

This single nCost <= MrxPmc.GetCashQty() comparison is the whole “can the player buy this?” check — there is no separate free-item flag. Zeroing an item’s nCashCost/nCost (in MrxSupportData/WifEquipmentData) makes nCost evaluate to 0, which always passes the gate, i.e. makes the item free. Note the debit goes through MrxPmc.AddCashQty (HUD-updating), not Player.SetCash.

`_AddPurchasedSupportItem(sId)`

Adds a support item to the list of purchased items for the vendor’s faction.

`_AddPurchasedEquipmentItem(sId)`

Adds an equipment item to the list of purchased items for the vendor’s faction.

`Close()`

Closes the shop interface for the local player.

`GetIndexedShopList(oVender)`

Generates an indexed list of unlocked status for each item in the shop, used for client-server synchronization.

`SetIndexedShopList(tIndexedList)`

Sets the indexed list of unlocked status for each item in the shop.

`GetTotalNumberOfItems(sFaction)`

Returns the total number of items available in the shop for a given faction.

`GetNumberOfPurchasedItems(sFaction)`

Returns the number of items purchased by players for a given faction.

`GetNumberOfUnlockedItems(sFaction)`

Returns the number of items unlocked for a given faction.

`SaveSingleton()`

Saves the current state of _tGlobalShopList to persistent storage.

`LoadSingleton(tData)`

Loads the saved state of _tGlobalShopList from persistent storage.

Events

No Event.* references appear anywhere in this file. Shop interaction is wired entirely through Hud.Shop callbacks instead of the engine event system:

Hud.Shop:SetCallback({..., fCallback = _ShopSelection, ...}) — routes item purchases to _ShopSelection.
Hud.Shop:SetCloseCallback({..., fCallback = function() ... end, ...}) — an inline anonymous function (not a named module function) that clears _oVender and invokes the caller-supplied fOnClose/tOnCloseData via MrxUtil.CallWithOptionalArgs.

Both callback targets (_ShopSelection, the inline closure) are defined in this file, so there’s no undefined-callback issue here.

Module constants

tTypeToIcon — maps an item’s sType/nType to a HUD icon tag string used as a name prefix, e.g. Airstrike = "[airstrike] ", Light = "[vehmlight] ", Heavy = "[vehmheavy] ", Boat = "[vehboat] ", Heli = "[vehheli] ", and [WifEquipmentData.knTypeFuelTank] = "[fuelsilo] ". Change these to reswap the shop-row icons.

Notes for modders

Make an item free / change its price without touching this file — prices come from the source data tables, not from MrxShop. Support prices are tSupport.nCashCost in MrxSupportData; equipment prices are tEquipmentData.nCost in WifEquipmentData. The faction/vendor multiplier is nPriceScale from _GetPriceScale (via MrxFactionManager.GetPriceScale); a vendor with HasCustomVehicleShop() forces scale 1.0.
The affordability check is nCost <= MrxPmc.GetCashQty() in _ShopSelection — a $0 item always passes. There is no separate “unlock = free” path here; a locked item is filtered out earlier (its sId becomes "Locked", which _ShopSelection rejects).
Item availability (which ids appear at all) is driven by MrxRewardData.GetAllPotentialShopItems(sFactionId) inside _GetShopList, and per-item unlock state by MrxSupportData.IsItemUnlocked / WifEquipmentData.IsItemUnlocked.
On clients (Net.IsClient()), unlock status is read from a synced _tIndexedShopList (set via SetIndexedShopList) rather than recomputed locally, and grappling hooks are suppressed from the client list. Keep that in mind if you mod shop contents in co-op.