WIP: itype->use elimination.

res/e3a/items.xml

@@ -81,9 +81,7 @@
   </resource>
 
   <resource name="xmastree">
-    <item weight="0">
-      <function name="use" value="lua_useitem"/>
-    </item>
+    <item weight="0" use="yes" />
   </resource>
 
 </resources>

res/eressea/items.xml

@@ -17,21 +17,15 @@
   </resource>
 
   <resource name="snowman">
-    <item notlost="yes" weight="1">
-      <function name="use" value="lua_useitem"/>
-    </item>
+    <item notlost="yes" weight="1" use="yes" />
   </resource>
 
   <resource name="snowglobe">
-    <item notlost="yes" weight="1">
-      <function name="use" value="lua_useitem"/>
-    </item>
+    <item notlost="yes" weight="1" use="yes" />
   </resource>
 
   <resource name="ring_of_levitation" appearance="ring">
-    <item notlost="yes" weight="0" cursed="true">
-      <function name="use" value="lua_useitem"/>
-    </item>
+    <item notlost="yes" weight="0" cursed="true" use="yes" />
   </resource>
 
   <resource name="birthdaycake">
@@ -44,23 +38,17 @@
 
 <!-- ambassador rewards -->
   <resource name="seashell">
-    <item cursed="true" weight="0">
-      <function name="use" value="lua_useitem"/>
-    </item>
+    <item cursed="true" weight="0" use="yes" />
   </resource>
 
 <!-- xmas 2005 -->
   <resource name="stardust" appearance="vial">
-    <item weight="0">
-      <function name="use" value="lua_useitem"/>
-    </item>
+    <item weight="0" use="yes" />
   </resource>
 
 <!-- xmas 2006 -->
   <resource name="xmastree">
-    <item weight="0">
-      <function name="use" value="lua_useitem"/>
-    </item>
+    <item weight="0" use="yes" />
   </resource>
 
 <!-- museum items -->

src/helpers.c

@@ -490,14 +490,18 @@ static int lua_equipmentcallback(const struct equipment *eq, unit * u)
 }
 
 /** callback for an item-use function written in lua. */
-int
-lua_useitem(struct unit *u, const struct item_type *itype, int amount,
+static int
+use_item_lua(struct unit *u, const struct item_type *itype, int amount,
 struct order *ord)
 {
     lua_State *L = (lua_State *)global.vm_state;
     int result = 0;
     char fname[64];
 
+    if (itype->use) {
+        return itype->use(u, itype, amount, ord);
+    }
+
     strlcpy(fname, "use_", sizeof(fname));
     strlcat(fname, itype->rtype->_name, sizeof(fname));
 
@@ -551,7 +555,6 @@ void register_tolua_helpers(void)
     register_function((pf_generic)lua_callspell, TOLUA_CAST "lua_castspell");
     register_function((pf_generic)lua_initfamiliar,
         TOLUA_CAST "lua_initfamiliar");
-    register_item_use(&lua_useitem, TOLUA_CAST "lua_useitem");
     register_function((pf_generic)lua_getresource,
         TOLUA_CAST "lua_getresource");
     register_function((pf_generic)lua_canuse_item,
@@ -565,6 +568,7 @@ void register_tolua_helpers(void)
     register_function((pf_generic)lua_maintenance,
         TOLUA_CAST "lua_maintenance");
 
+    item_use_fun = use_item_lua;
     res_produce_fun = produce_resource_lua;
     res_limit_fun = limit_resource_lua;
     register_item_give(lua_giveitem, TOLUA_CAST "lua_giveitem");

src/kernel/item.h

@@ -107,6 +107,7 @@ extern "C" {
 #define ITF_BIG              0x0008     /* big item, e.g. does not fit in a bag of holding */
 #define ITF_ANIMAL           0x0010     /* an animal */
 #define ITF_VEHICLE          0x0020     /* a vehicle, drawn by two animals */
+#define ITF_CANUSE           0x0040     /* can be used with use_item_fun callout */
 
     /* error codes for item_type::use */
 #define ECUSTOM   -1

src/kernel/resources.c

@@ -213,6 +213,8 @@ struct rawmaterial_type *rmt_create(struct resource_type *rtype)
     return rmtype;
 }
 
+int(*item_use_fun)(struct unit *u, const struct item_type *itype, int amount,
+    struct order *ord);
 int(*res_limit_fun)(const struct region *, const struct resource_type *);
 void(*res_produce_fun)(struct region *, const struct resource_type *, int);
 

src/kernel/resources.h

@@ -74,7 +74,8 @@ extern "C" {
 
     extern int(*res_limit_fun)(const struct region *, const struct resource_type *);
     extern void(*res_produce_fun)(struct region *, const struct resource_type *, int);
-
+    extern int (*item_use_fun)(struct unit *, const struct item_type *, int amount,
+        struct order *ord);
     int limit_resource(const struct region *r, const struct resource_type *rtype);
     void produce_resource(struct region *r, const struct resource_type *rtype, int amount);
 

src/kernel/xmlreader.c

@@ -767,6 +767,8 @@ static item_type *xml_readitem(xmlXPathContextPtr xpath, resource_type * rtype)
 
     if (xml_bvalue(node, "cursed", false))
         flags |= ITF_CURSED;
+    if (xml_bvalue(node, "use", false))
+        flags |= ITF_CANUSE;
     if (xml_bvalue(node, "notlost", false))
         flags |= ITF_NOTLOST;
     if (xml_bvalue(node, "herb", false))
@@ -849,6 +851,7 @@ static item_type *xml_readitem(xmlXPathContextPtr xpath, resource_type * rtype)
             struct order *))fun;
         }
         else if (strcmp((const char *)propValue, "use") == 0) {
+            itype->flags |= ITF_CANUSE;
             itype->use =
                 (int(*)(struct unit *, const struct item_type *, int,
             struct order *))fun;

src/laws.c

@@ -3252,8 +3252,8 @@ static int use_item(unit * u, const item_type * itype, int amount, struct order
         return ENOITEM;
     }
 
-    if (itype->use) {
-        int result = itype->use(u, itype, amount, ord);
+    if (itype->flags & ITF_CANUSE) {
+        int result = item_use_fun(u, itype, amount, ord);
         if (result > 0) {
             use_pooled(u, itype->rtype, GET_DEFAULT, result);
         }