Merge pull request #3530 from myk002/myk_item_value

fix item prices and algorithm

docs/changelog.txt

@@ -45,12 +45,16 @@ changelog.txt uses a syntax similar to RST, with a few special sequences:
 
 ## API
 - ``Units::getUnitByNobleRole``, ``Units::getUnitsByNobleRole``: unit lookup API by role
+- ``Items::markForTrade()``, ``Items::isRequestedTradeGood()``, ``Items::getValue``: see Lua notes below
 
 ## Internals
+- Price calculations fixed for many item types
 
 ## Lua
-- ``dfhack.items.markForTrade``: new API for marking items for trade
 - ``dfhack.units.getUnitByNobleRole``, ``dfhack.units.getUnitsByNobleRole``: unit lookup API by role
+- ``dfhack.items.markForTrade``: mark items for trade
+- ``dfhack.items.isRequestedTradeGood``: discover whether an item is named in a trade agreement with an active caravan
+- ``dfhack.items.getValue``: gained optional ``caravan`` and ``caravan_buying`` parameters for prices that take trader races and agreements into account
 
 ## Removed
 

docs/dev/Lua API.rst

@@ -1768,9 +1768,20 @@ Items module
 
   Calculates the base value for an item of the specified type and material.
 
-* ``dfhack.items.getValue(item)``
+* ``dfhack.items.getValue(item[, caravan_state, caravan_buying])``
 
-  Calculates the Basic Value of an item, as seen in the View Item screen.
+  Calculates the value of an item. If a ``df.caravan_state`` object is given
+  (from ``df.global.plotinfo.caravans`` or
+  ``df.global.main_interface.trade.mer``), then the value is modified by civ
+  properties and any trade agreements that might be in effect. In this case,
+  specify ``caravan_buying`` as ``true`` to get the price the caravan will pay
+  for the item and ``false`` to get the price that the caravan will sell the
+  item for.
+
+* ``dfhack.items.isRequestedTradeGood(item[, caravan_state])``
+
+  Returns whether a caravan will pay extra for the given item. If caravan_state
+  is not given, checks all active caravans.
 
 * ``dfhack.items.createItem(item_type, item_subtype, mat_type, mat_index, unit)``
 

library/LuaApi.cpp

@@ -2020,6 +2020,7 @@ static const LuaWrapper::FunctionReg dfhack_items_module[] = {
     WRAPM(Items, getSubtypeDef),
     WRAPM(Items, getItemBaseValue),
     WRAPM(Items, getValue),
+    WRAPM(Items, isRequestedTradeGood),
     WRAPM(Items, createItem),
     WRAPM(Items, checkMandates),
     WRAPM(Items, canTrade),

library/include/modules/Items.h

@@ -34,6 +34,7 @@ distribution.
 
 #include "DataDefs.h"
 #include "df/building_tradedepotst.h"
+#include "df/caravan_state.h"
 #include "df/item.h"
 #include "df/item_type.h"
 #include "df/general_ref.h"
@@ -189,8 +190,8 @@ DFHACK_EXPORT df::proj_itemst *makeProjectile(MapExtras::MapCache &mc, df::item
 /// Gets value of base-quality item with specified type and material
 DFHACK_EXPORT int getItemBaseValue(int16_t item_type, int16_t item_subtype, int16_t mat_type, int32_t mat_subtype);
 
-/// Gets the value of a specific item, ignoring civ values and trade agreements
-DFHACK_EXPORT int getValue(df::item *item);
+/// Gets the value of a specific item, taking into account civ values and trade agreements if a caravan is given
+DFHACK_EXPORT int getValue(df::item *item, df::caravan_state *caravan = NULL, bool caravan_buying = false);
 
 DFHACK_EXPORT int32_t createItem(df::item_type type, int16_t item_subtype, int16_t mat_type, int32_t mat_index, df::unit* creator);
 
@@ -202,6 +203,8 @@ DFHACK_EXPORT bool canTrade(df::item *item);
 DFHACK_EXPORT bool canTradeWithContents(df::item *item);
 /// marks the given item for trade at the given depot
 DFHACK_EXPORT bool markForTrade(df::item *item, df::building_tradedepotst *depot);
+/// Returns true if an active caravan will pay extra for the given item
+DFHACK_EXPORT bool isRequestedTradeGood(df::item *item, df::caravan_state *caravan = NULL);
 
 /// Checks whether the item is an assigned hauling vehicle
 DFHACK_EXPORT bool isRouteVehicle(df::item *item);