Added new HOOK_ONEXPLOSION and a new mode "set_explosion_max_targets" to metarule2_explosions (from Mr.Stalin) (#35)

artifacts/scripting/headers/sfall.h

@@ -57,6 +57,7 @@
 #define HOOK_EXPLOSIVETIMER   (33)
 #define HOOK_DESCRIPTIONOBJ   (34)
 #define HOOK_USESKILLON       (35)
+#define HOOK_ONEXPLOSION      (36)
 
 //Valid arguments to list_begin
 #define LIST_CRITTERS    (0)
@@ -148,6 +149,7 @@
 #define get_explosion_damage(itemPid)         metarule2_explosions(6, itemPid, 0)
 #define set_dynamite_damage(minDmg, maxDmg)   metarule2_explosions(7, minDmg, maxDmg)
 #define set_plastic_damage(minDmg, maxDmg)    metarule2_explosions(8, minDmg, maxDmg)
+#define set_explosion_max_targets(x)          metarule2_explosions(9, x, 0)
 
 
 #define GAME_MSG_COMBAT      (0)

artifacts/scripting/hookscripts.txt

@@ -561,3 +561,20 @@ int     arg3 - skill being used
 
 int     ret1 - a new critter to override the user critter. Pass -1 to cancel the skill use, pass 0 to skip this return value
 int     ret2 - pass 1 to allow the skill being used in combat (only for dude_obj or critter being controlled by the player)
+
+-------------------------------------------
+
+HOOK_ONEXPLOSION (hs_onexplosion.int)
+
+Runs when an explosion occurs and Fallout is checking all the tiles within the explosion radius for targets.
+The tile checking will be interrupted when 6 additional targets (critters) are received.
+
+int     arg1 - event type: 1 - when the explosion is from an explosive item, 0 - otherwise
+Critter arg2 - The attacker
+int     arg3 - The tile on which the explosion occurs
+int     arg4 - checked tile within the explosion radius
+Obj     arg5 - first found object on the checked tile as an additional target
+Critter arg6 - The target critter, may be 0 or equal to the attacker
+int     arg7 - 1 when using throwing weapons (e.g. grenades), 0 otherwise
+
+int     ret1 - overrides the found object on the checked tile, pass 0 to skip the object

artifacts/scripting/sfall function notes.txt

@@ -246,6 +246,9 @@ was made as a dirty easy hack to allow dynamically change some explosion paramet
 - sets the minimum and maximum damage for Plastic Explosives.
 - changed damage will be reset each time the player reloads the game.
 
+> void set_explosion_max_targets(x)
+- sets the maximum number of additional targets for an explosion, valid range: 1..6 (default is 6)
+
 
 Some utility/math functions are available:
 

sfall/Modules/Explosions.cpp

@@ -48,6 +48,7 @@ static bool onlyOnce = false;
 static bool lightingEnabled = false;
 static bool explosionsMetaruleReset = false;
 static bool explosionsDamageReset = false;
+static bool explosionMaxTargetReset = false;
 
 static const DWORD ranged_attack_lighting_fix_back = 0x4118F8;
 
@@ -363,7 +364,8 @@ enum MetaruleExplosionsMode {
 	EXPL_STATIC_EXPLOSION_RADIUS = 5,
 	EXPL_GET_EXPLOSION_DAMAGE = 6,
 	EXPL_SET_DYNAMITE_EXPLOSION_DAMAGE = 7,
-	EXPL_SET_PLASTIC_EXPLOSION_DAMAGE = 8
+	EXPL_SET_PLASTIC_EXPLOSION_DAMAGE = 8,
+	EXPL_SET_EXPLOSION_MAX_TARGET = 9,
 };
 
 static void SetExplosionRadius(int arg1, int arg2) {
@@ -444,6 +446,14 @@ int _stdcall ExplosionsMetaruleFunc(int mode, int arg1, int arg2) {
 		case EXPL_SET_PLASTIC_EXPLOSION_DAMAGE:
 			SetExplosionDamage(fo::ProtoId::PID_PLASTIC_EXPLOSIVES, arg1, arg2);
 			return 0;
+		case EXPL_SET_EXPLOSION_MAX_TARGET:
+			if (arg1 > 0 && arg1 < 7) {
+				SafeWrite8(0x423C93, arg1);
+				explosionMaxTargetReset = true;
+			} else {
+				return 0;
+			}
+			break;
 		default:
 			return -1;
 	}
@@ -466,6 +476,11 @@ void ResetExplosionSettings() {
 	for (int i = 0; i < numDmgChecks; i++) {
 		SafeWrite8(explosion_dmg_check_adr[i], fo::DamageType::DMG_explosion);
 	}
+	// explosion max target count
+	if (explosionMaxTargetReset) {
+		SafeWrite8(0x423C93, 6);
+		explosionMaxTargetReset = false;
+	}
 	explosionsMetaruleReset = false;
 }
 

sfall/Modules/HookScripts.cpp

@@ -80,6 +80,7 @@ static HooksInjectInfo injectHooks[] = {
 	{HOOK_EXPLOSIVETIMER,   Inject_ExplosiveTimerHook,   false},
 	{HOOK_DESCRIPTIONOBJ,   Inject_DescriptionObjHook,   false},
 	{HOOK_USESKILLON,       Inject_UseSkillOnHook,       false},
+	{HOOK_ONEXPLOSION,      Inject_OnExplosionHook,      false},
 };
 
 bool HookScripts::injectAllHooks;

sfall/Modules/HookScripts.h

@@ -62,6 +62,7 @@ enum HookType
 	HOOK_EXPLOSIVETIMER   = 33,
 	HOOK_DESCRIPTIONOBJ   = 34,
 	HOOK_USESKILLON       = 35,
+	HOOK_ONEXPLOSION      = 36,
 	HOOK_COUNT
 };
 

sfall/Modules/HookScripts/CombatHs.cpp

@@ -40,7 +40,6 @@ static void __declspec(naked) ToHitHook() {
 }
 
 static void __fastcall AfterHitRollHook_Script(fo::ComputeAttackResult &ctd, DWORD hitChance, DWORD hit) {
-
 	BeginHook();
 	argCount = 5;
 
@@ -125,7 +124,6 @@ static void __declspec(naked) CalcApCostHook2() {
 }
 
 static void __fastcall ComputeDamageHook_Script(fo::ComputeAttackResult &ctd, DWORD rounds, DWORD multiply) {
-
 	BeginHook();
 	argCount = 12;
 
@@ -168,7 +166,7 @@ static void __declspec(naked) ComputeDamageHook() {
 		push eax;         // store ctd
 		call fo::funcoffs::compute_damage_;
 		pop  ecx;         // restore ctd (eax)
-		pop  edx;         // restore num rounds                  
+		pop  edx;         // restore num rounds
 		call ComputeDamageHook_Script;
 		pop  ecx;
 		retn;
@@ -176,7 +174,6 @@ static void __declspec(naked) ComputeDamageHook() {
 }
 
 static void __fastcall FindTargetHook_Script(DWORD* target, DWORD attacker) {
-
 	BeginHook();
 	argCount = 5;
 
@@ -281,7 +278,7 @@ static void __declspec(naked) AmmoCostHook() {
 		cmp dword ptr [esp + 0x1C + 4], ANIM_fire_continuous;
 		jg skip;
 		mov  ecx, 3;               // hook type burst
-skip:		
+skip:
 		xchg eax, edx;
 		push eax;                  // rounds in attack
 		call AmmoCostHook_Script;  // edx - weapon
@@ -344,6 +341,51 @@ normalTurn:
 	}
 }
 
+fo::GameObject* __fastcall ComputeExplosionOnExtrasHook_Script(fo::GameObject* object, DWORD checkTile, fo::ComputeAttackResult* ctdSource, DWORD isCheck, DWORD isThrowing, fo::GameObject* who) {
+	fo::GameObject* result = object;
+
+	BeginHook();
+	argCount = 7;
+
+	args[0] = isCheck;
+	args[1] = (DWORD)ctdSource->attacker;
+	args[2] = ctdSource->targetTile;
+	args[3] = checkTile;
+	args[4] = (DWORD)object;
+	args[5] = (DWORD)who;
+	args[6] = isThrowing;
+
+	RunHookScript(HOOK_ONEXPLOSION);
+
+	if (cRet > 0) result = (fo::GameObject*)rets[0]; // override object
+
+	EndHook();
+	return result;
+}
+
+static void _declspec(naked) ComputeExplosionOnExtrasHook() {
+	__asm {
+		cmp  dword ptr [esp + 0x34 + 4], 0x429533;  // skip hook when AI assesses the situation in choosing the best weapon
+		jz   end;
+		cmp  dword ptr [esp + 0x34 + 4], 0x4296BC;
+		jnz  hook;
+end:
+		jmp  fo::funcoffs::obj_blocking_at_;
+hook:
+		push ecx;
+		push eax;                                   // who (target/source)
+		call fo::funcoffs::obj_blocking_at_;
+		push [esp + 0x34 - 0x24 + 12];              // isThrowing
+		push [esp + 0x34 - 0x34 + 16];              // isCheck (bypass damage)
+		push esi;                                   // source ctd
+		mov  ecx, eax;                              // object
+		mov  edx, edi;                              // check tile
+		call ComputeExplosionOnExtrasHook_Script;
+		pop  ecx;
+		retn;
+	}
+}
+
 void Inject_ToHitHook() {
 	HookCalls(ToHitHook, {
 		0x421686, // combat_safety_invalidate_weapon_func_
@@ -407,8 +449,11 @@ void Inject_CombatTurnHook() {
 	HookCalls(CombatTurnHook, { 0x422D87, 0x422E20 });
 }
 
-void InitCombatHookScripts() {
+void Inject_OnExplosionHook() {
+	HookCall(0x423D70, ComputeExplosionOnExtrasHook);
+}
 
+void InitCombatHookScripts() {
 	LoadHookScript("hs_tohit", HOOK_TOHIT);
 	LoadHookScript("hs_afterhitroll", HOOK_AFTERHITROLL);
 	LoadHookScript("hs_calcapcost", HOOK_CALCAPCOST);
@@ -417,7 +462,7 @@ void InitCombatHookScripts() {
 	LoadHookScript("hs_itemdamage", HOOK_ITEMDAMAGE);
 	LoadHookScript("hs_ammocost", HOOK_AMMOCOST);
 	LoadHookScript("hs_combatturn", HOOK_COMBATTURN);
-
+	LoadHookScript("hs_onexplosion", HOOK_ONEXPLOSION);
 }
 
 }

sfall/Modules/HookScripts/CombatHs.h

@@ -15,5 +15,6 @@ void Inject_FindTargetHook();
 void Inject_ItemDamageHook();
 void Inject_AmmoCostHook();
 void Inject_CombatTurnHook();
+void Inject_OnExplosionHook();
 
 }