Added script bindings for manipulating the characters experience.

6 files changed, 120 insertions, 5 deletions

diff --git a/ChangeLog b/ChangeLog
index 002010fd..0584405a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2008-11-01  Philipp Sehmisch  <tmw@crushnet.org>
+
+	* src/game-server/character.hpp, src/game-server/scripting/lua.cpp: Added
+	script bindings for manipulating the characters experience.
+	* src/game-server/character.cpp: Catched a potential integer underflow in
+	experience calculation.
+	* data/scripts/lib/test.lua: added constants for character skills.
+	* data/scripts/test.lua: Added example script for manipulating character
+	experience.
+
 2008-10-31  David Athay  <ko2fan@gmail.com>
 
 	* src/utils/string.cpp, src/utils/string.hpp, src/Makefile.am,
diff --git a/data/scripts/libs/libtmw.lua b/data/scripts/libs/libtmw.lua
index 251e20a0..d1e397e4 100644
--- a/data/scripts/libs/libtmw.lua
+++ b/data/scripts/libs/libtmw.lua
@@ -52,6 +52,17 @@ ATTR_DEXTERITY = 18
 ATTR_VITALITY = 19
 ATTR_INTELLIGENCE = 20
 ATTR_WILLPOWER = 21
+SKILL_WEAPON_NONE = 22
+SKILL_WEAPON_KNIFE = 23
+SKILL_WEAPON_SWORD = 24
+SKILL_WEAPON_POLEARM = 25
+SKILL_WEAPON_STAFF = 26
+SKILL_WEAPON_WHIP = 27
+SKILL_WEAPON_BOW = 28
+SKILL_WEAPON_SHOOTING = 29
+SKILL_WEAPON_MACE = 30
+SKILL_WEAPON_AXE = 31
+SKILL_WEAPON_THROWN = 32
 
 TILESIZE = 32
 HOURS = 3600
diff --git a/data/scripts/test.lua b/data/scripts/test.lua
index 7f96a61e..98892951 100644
--- a/data/scripts/test.lua
+++ b/data/scripts/test.lua
@@ -25,6 +25,7 @@ atinit(function()
   create_npc("Fire Demon", 202, 58 * TILESIZE + 16, 35 * TILESIZE + 16, firedemon_talk, firedemon_update)
   create_npc("Post Box", 158, 45 * TILESIZE + 16, 22 * TILESIZE + 16, post_talk)
   create_npc("Fireworker", 158, 43 * TILESIZE, 23 * TILESIZE, fireworker_talk, npclib.walkaround_small)
+  create_npc("Axe Trainer", 126, 65 * TILESIZE, 18 * TILESIZE, axetrainer_talk, nil)
 
   tmw.trigger_create(56 * TILESIZE, 32 * TILESIZE, 64, 64, "patrol_waypoint", 1, true)
   tmw.trigger_create(63 * TILESIZE, 32 * TILESIZE, 64, 64, "patrol_waypoint", 2, true)
@@ -213,3 +214,21 @@ function fireworker_talk(npc, ch)
       end
   end
 end
+
+function axetrainer_talk(npc, ch)
+  do_message(npc, ch, "I am the axe trainer. Do you want to get better at using axes?")
+  local answer = do_choice(npc, ch, "Please train me, master.", "I am good enough with axes.")
+  if answer == 1 then
+    local newexp = tmw.chr_get_exp(ch, SKILL_WEAPON_AXE) + 100
+    local nextlevel = tmw.exp_for_level(tmw.being_get_attribute(ch, SKILL_WEAPON_AXE) + 1)
+    tmw.chr_give_exp(ch, SKILL_WEAPON_AXE, 100)
+    local message = "I gave you 100 axe exp."
+    if newexp > nextlevel then
+      message = message.." This should be enough to reach the next level."
+    else
+      message = message.." You will still need "..tostring(nextlevel - newexp).." exp to reach the next level."
+    end
+    message = message.." I should really stop doing this when the server goes live."
+    do_message(npc, ch, message);
+  end
+end
diff --git a/src/game-server/character.cpp b/src/game-server/character.cpp
index 8758b64e..bf8355cd 100644
--- a/src/game-server/character.cpp
+++ b/src/game-server/character.cpp
@@ -322,6 +322,7 @@ void Character::receiveExperience(size_t skill, int experience)
         // add exp
         long int newExp = mExperience.at(skill - CHAR_SKILL_BEGIN) + experience;
         if (newExp > INT_MAX) newExp = INT_MAX; // avoid integer overflow.
+        if (newExp < 0) newExp = 0; // avoid integer underflow/negative exp
         mExperience.at(skill - CHAR_SKILL_BEGIN) = newExp;
         mModifiedExperience.insert(skill - CHAR_SKILL_BEGIN);
 
diff --git a/src/game-server/character.hpp b/src/game-server/character.hpp
index 30914344..03006712 100644
--- a/src/game-server/character.hpp
+++ b/src/game-server/character.hpp
@@ -248,6 +248,11 @@ class Character : public Being
         { mExperience[skill] = 0; receiveExperience(skill + CHAR_SKILL_BEGIN , value) ; }
 
         /**
+         * Returns the exp needed to reach a specific skill level
+         */
+        static int expForLevel(int level);
+
+        /**
          * Tries to use a character point to increase a
          * basic attribute
          */
@@ -301,11 +306,6 @@ class Character : public Being
         void flagAttribute(int);
 
         /**
-         * Returns the exp needed to reach a specific skill level
-         */
-        static int expForLevel(int level);
-
-        /**
          * Returns the exp needed for next skill levelup
          */
         int getExpNeeded(size_t skill);
diff --git a/src/scripting/lua.cpp b/src/scripting/lua.cpp
index c0c7a95c..34e66427 100644
--- a/src/scripting/lua.cpp
+++ b/src/scripting/lua.cpp
@@ -902,6 +902,77 @@ static int LuaEffect_Create(lua_State *s)
     return 0;
 }
 
+/**
+ * Gets the exp total in a skill of a specific character
+ * tmw.chr_get_exp (being, skill)
+ */
+static int LuaChr_GetExp(lua_State *s)
+{
+    Character *c = getCharacter(s, 1);
+    if (!c)
+    {
+        raiseScriptError(s, "luaChr_GetExp called for nonexistent character.");
+        return 0;
+    }
+
+    int skill = lua_tointeger(s, 2);
+    if (skill < CHAR_SKILL_BEGIN || skill >= CHAR_SKILL_END)
+    {
+        raiseScriptError(s, "luaChr_GetExp called for nonexistent skill number %d.", skill);
+        return 0;
+    }
+
+    int exp = c->getExperience(skill - CHAR_SKILL_BEGIN);
+
+    lua_pushinteger(s, exp);
+    return 1;
+}
+
+
+/**
+ * Gives the character a certain amount of experience points
+ * in a skill. Can also be used to reduce the exp amount when
+ * desired.
+ * tmw.chr_give_exp (being, skill, amount)
+ */
+static int LuaChr_GiveExp(lua_State *s)
+{
+    Character *c = getCharacter(s, 1);
+    if (!c)
+    {
+        raiseScriptError(s, "luaChr_GiveExp called for nonexistent character.");
+        return 0;
+    }
+
+    int skill = lua_tointeger(s, 2);
+    if (skill < CHAR_SKILL_BEGIN || skill >= CHAR_SKILL_END)
+    {
+        raiseScriptError(s, "luaChr_GiveExp called for nonexistent skill number %d.", skill);
+        return 0;
+    }
+
+    int exp = lua_tointeger(s, 3);
+
+    c->receiveExperience(skill, exp);
+
+    return 0;
+}
+
+
+/**
+ * Returns the exp total necessary to reach a specific skill level.
+ * tmw.exp_for_level (level)
+ */
+static int LuaExpForLevel(lua_State *s)
+{
+    int level = lua_tointeger(s, 1);
+
+    int exp = Character::expForLevel(level);
+
+    lua_pushinteger(s, exp);
+    return 1;
+}
+
 
 LuaScript::LuaScript():
     nbArgs(-1)
@@ -923,6 +994,9 @@ LuaScript::LuaScript():
         { "chr_get_quest",          &LuaChr_GetQuest      },
         { "chr_set_quest",          &LuaChr_SetQuest      },
         { "chr_get_post",           &LuaChr_GetPost       },
+        { "chr_get_exp",            &LuaChr_GetExp        },
+        { "chr_give_exp",           &LuaChr_GiveExp       },
+        { "exp_for_level",          &LuaExpForLevel       },
         { "monster_create",         &LuaMonster_Create    },
         { "being_walk",             &LuaBeing_Walk        },
         { "being_say",              &LuaBeing_Say         },