lua: add UnitPreDamaged callin.

it's similar to UnitDamaged, but it's synced only and it can (should) return new damage value.
spring · Apr 11, 2009 · 535cff5 · 535cff5
1 parent c49d916
commit 535cff5
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diff --git a/installer/builddata/springcontent/LuaGadgets/gadgets.lua b/installer/builddata/springcontent/LuaGadgets/gadgets.lua
@@ -108,6 +108,7 @@ local callInLists = {
   'UnitExperience',
   'UnitIdle',
   'UnitCmdDone',
+  'UnitPreDamaged',
   'UnitDamaged',
   'UnitTaken',
   'UnitGiven',
@@ -1257,6 +1258,19 @@ function gadgetHandler:UnitCmdDone(unitID, unitDefID, unitTeam, cmdID, cmdTag)
 end
 
 
+function gadgetHandler:UnitPreDamaged(unitID, unitDefID, unitTeam,
+                                   damage, paralyzer, weaponID,
+                                   attackerID, attackerDefID, attackerTeam)
+  local dam = damage
+  for _,g in ipairs(self.UnitPreDamagedList) do
+    dam = g:UnitPreDamaged(unitID, unitDefID, unitTeam,
+                  dam, paralyzer, weaponID,
+                  attackerID, attackerDefID, attackerTeam)
+  end
+  return dam
+end
+
+
 function gadgetHandler:UnitDamaged(unitID, unitDefID, unitTeam,
                                    damage, paralyzer, weaponID,
                                    attackerID, attackerDefID, attackerTeam)

diff --git a/rts/Lua/LuaRules.cpp b/rts/Lua/LuaRules.cpp
@@ -127,6 +127,7 @@ CLuaRules::CLuaRules()
 	haveTerraformComplete      = HasCallIn("TerraformComplete");
 	haveDrawUnit               = HasCallIn("DrawUnit");
 	haveAICallIn               = HasCallIn("AICallIn");
+	haveUnitPreDamaged         = HasCallIn("UnitPreDamaged");
 
 	SetupUnsyncedFunction("DrawUnit");
 	SetupUnsyncedFunction("AICallIn");
@@ -811,6 +812,69 @@ bool CLuaRules::TerraformComplete(const CUnit* unit, const CUnit* build)
 }
 
 
+/**
+ * called after every damage modification (even HitByWeaponId)
+ * but before the damage is applied
+ *
+ * expects a number returned by lua code; it is stored under *newDamage if
+ * newDamage != NULL.
+ */
+bool CLuaRules::UnitPreDamaged(const CUnit* unit, const CUnit* attacker,
+                             float damage, int weaponID, bool paralyzer,
+                             float* newDamage)
+{
+	if (!haveUnitPreDamaged) {
+		return false;
+	}
+
+	LUA_CALL_IN_CHECK(L);
+	lua_checkstack(L, 11);
+
+	int errfunc = SetupTraceback();
+
+	static const LuaHashString cmdStr("UnitPreDamaged");
+	if (!cmdStr.GetGlobalFunc(L)) {
+		// remove error handler
+		if (errfunc) lua_pop(L, 1);
+		return false; // the call is not defined
+	}
+
+	int argCount = 5;
+	lua_pushnumber(L, unit->id);
+	lua_pushnumber(L, unit->unitDef->id);
+	lua_pushnumber(L, unit->team);
+	lua_pushnumber(L, damage);
+	lua_pushboolean(L, paralyzer);
+	if (fullRead) {
+		lua_pushnumber(L, weaponID);
+		argCount += 1;
+		if (attacker != NULL) {
+			lua_pushnumber(L, attacker->id);
+			lua_pushnumber(L, attacker->unitDef->id);
+			lua_pushnumber(L, attacker->team);
+			argCount += 3;
+		}
+	}
+
+	// call the routine
+	RunCallInTraceback(cmdStr, argCount, 1, errfunc);
+
+	// get the results
+	if (!lua_isnumber(L, -1)) {
+		logOutput.Print("%s() bad return value, expected number\n", cmdStr.GetString().c_str());
+		lua_pop(L, 1);
+		return false;
+	}
+
+	const float retval = lua_tonumber(L, -1);
+	lua_pop(L, 1);
+	if (newDamage) {
+		*newDamage = retval;
+	}
+	return true;
+}
+
+
 /******************************************************************************/
 
 bool CLuaRules::DrawUnit(int unitID)

diff --git a/rts/Lua/LuaRules.h b/rts/Lua/LuaRules.h
@@ -66,6 +66,10 @@ class CLuaRules : public CLuaHandleSynced
 		void Cob2Lua(const LuaHashString& funcName, const CUnit* unit,
 		             int& argsCount, int args[MAX_LUA_COB_ARGS]);
 
+		bool UnitPreDamaged(const CUnit* unit, const CUnit* attacker,
+                             float damage, int weaponID, bool paralyzer,
+                             float* newDamage);
+
 		// unsynced
 		bool DrawUnit(int unitID);
 		const char* AICallIn(const char* data, int inSize, int* outSize);
@@ -122,6 +126,7 @@ class CLuaRules : public CLuaHandleSynced
 		bool haveTerraformComplete;
 		bool haveDrawUnit;
 		bool haveAICallIn;
+		bool haveUnitPreDamaged;
 
 		map<string, string> infoMap;
 

diff --git a/rts/Sim/Units/Unit.cpp b/rts/Sim/Units/Unit.cpp
@@ -1008,6 +1008,12 @@ void CUnit::DoDamage(const DamageArray& damages, CUnit *attacker,const float3& i
 	float experienceMod = expMultiplier;
 
 	const int paralyzeTime = damages.paralyzeDamageTime;
+	float newDamage = damage;
+
+	if (luaRules && luaRules->UnitPreDamaged(this, attacker, damage, weaponId,
+			!!damages.paralyzeDamageTime, &newDamage))
+		damage = newDamage;
+
 
 	if (paralyzeTime == 0) { // real damage
 		if (damage > 0.0f) {

diff --git a/rts/System/EventHandler.cpp b/rts/System/EventHandler.cpp
@@ -134,6 +134,7 @@ CEventHandler::CEventHandler()
 	SetupEvent("AllowStartPosition",     NULL, CONTROL_BIT);
 	SetupEvent("TerraformComplete",      NULL, CONTROL_BIT);
 	SetupEvent("MoveCtrlNotify",         NULL, CONTROL_BIT);
+	SetupEvent("UnitPreDamaged",         NULL, CONTROL_BIT);
 }