Backported three more hooks from 4.1:

* USESKILLON, ONEXPLOSION, SETLIGHTING.

Backported PartyMemberSkillFix option from 4.1.
Updated documents.

artifacts/ddraw.ini

@@ -762,6 +762,13 @@ AIBestWeaponFix=1
 ;chem_primary_desire also works as a priority list of drug items the NPC will try to pick up in combat when they are on the ground
 AIDrugUsePerfFix=0
 
+;Set to 1 to fix the bug of using First Aid/Doctor skills when using them on the player
+;This will cause the party member to perform First Aid/Doctor skills when you use them on the player, but only if
+;the player is standing next to the party member
+;Note that because the related engine function is not fully implemented, enabling this option without a global script
+;that overrides First Aid/Doctor functions has very limited usefulness
+PartyMemberSkillFix=0
+
 ;Overrides the global variable number used to show the special death message of the Modoc toilet explosion
 ;Set to -1 to disable the special death message when the global variable is set
 SpecialDeathGVAR=491

artifacts/scripting/headers/sfall.h

@@ -60,6 +60,10 @@
 #define HOOK_USEANIMOBJ       (32)
 #define HOOK_EXPLOSIVETIMER   (33)
 #define HOOK_DESCRIPTIONOBJ   (34)
+#define HOOK_USESKILLON       (35)
+#define HOOK_ONEXPLOSION      (36)
+//#define HOOK_SUBCOMBATDAMAGE  (37) // unimplemented
+#define HOOK_SETLIGHTING      (38)
 #define HOOK_SNEAK            (39)
 #define HOOK_STDPROCEDURE     (40)
 #define HOOK_STDPROCEDURE_END (41)

artifacts/scripting/hookscripts.md

@@ -679,6 +679,57 @@ int     ret0 - a pointer to the new text received by using the get_string_pointe
 
 -------------------------------------------
 
+#### `HOOK_USESKILLON (hs_useskillon.int)`
+
+Runs before using any skill on any object. Lets you override the critter that uses the skill.
+
+__NOTE:__ The user critter can't be overridden when using Steal skill.
+
+```
+Critter arg0 - the user critter (usually dude_obj)
+Obj     arg1 - the target object/critter
+int     arg2 - skill being used
+
+int     ret0 - a new critter to override the user critter. Pass -1 to cancel the skill use, pass 0 to skip this return value
+int     ret1 - pass 1 to allow the skill to be used in combat (only for dude_obj or critter being controlled by the player)
+```
+
+-------------------------------------------
+
+#### `HOOK_ONEXPLOSION (hs_onexplosion.int)`
+
+Runs when Fallout is checking all the tiles within the explosion radius for targets before an explosion occurs.\
+The tile checking will be interrupted when 6 additional targets (critters) are received.
+
+```
+int     arg0 - event type: 1 - when checking objects within the explosion radius without causing damage (e.g. the player drops an active explosive), 0 - otherwise
+Critter arg1 - the attacker
+int     arg2 - the tile on which the explosion occurs
+int     arg3 - checked tile within the explosion radius
+Obj     arg4 - first found object on the checked tile as an additional target
+Critter arg5 - the target critter, may be 0 or equal to the attacker
+int     arg6 - 1 when using throwing weapons (e.g. grenades), 0 otherwise
+
+int     ret0 - overrides the found object on the checked tile, pass 0 to skip the object
+```
+
+-------------------------------------------
+
+#### `HOOK_SETLIGHTING (hs_setlighting.int)`
+
+Runs before setting the light level for an object or a map. You can override the result.
+
+```
+Obj     arg0 - the object being set, or -1 when setting the light level for a map
+int     arg1 - the light intensity
+int     arg2 - the light radius, or -1 when setting the light level for a map
+
+int     ret0 - overrides the light intensity. Intensity range is from 0 to 65536
+int     ret1 - overrides the light radius. Radius range is from 0 to 8 (works only for the object)
+```
+
+-------------------------------------------
+
 #### `HOOK_SNEAK (hs_sneak.int)`
 
 Runs when the Sneak skill is activated, or when the game rolls another Sneak check after the duration for the current one is over.\

sfall/FalloutEngine/FunctionOffsets_def.h

@@ -42,6 +42,7 @@ FUNC(_word_wrap_,                     0x4BC6F0)
 FUNC(action_get_an_object_,           0x412134)
 FUNC(action_loot_container_,          0x4123E8)
 FUNC(action_use_an_item_on_object_,   0x411F2C)
+FUNC(action_use_skill_on_,            0x41255C)
 FUNC(add_bar_box_,                    0x4616F0)
 FUNC(adjust_ac_,                      0x4715F8)
 FUNC(adjust_fid_,                     0x4716E8)

sfall/Modules/HookScripts.cpp

@@ -97,10 +97,10 @@ static HooksInjectInfo injectHooks[] = {
 	{HOOK_USEANIMOBJ,       Inject_UseAnimateObjHook,    false},
 	{HOOK_EXPLOSIVETIMER,   Inject_ExplosiveTimerHook,   false},
 	{HOOK_DESCRIPTIONOBJ,   Inject_DescriptionObjHook,   false},
+	{HOOK_USESKILLON,       Inject_UseSkillOnHook,       false},
+	{HOOK_ONEXPLOSION,      Inject_OnExplosionHook,      false},
 	{-1,                    nullptr,                     false}, // dummy
-	{-1,                    nullptr,                     false}, // dummy
-	{-1,                    nullptr,                     false}, // dummy
-	{-1,                    nullptr,                     false}, // dummy
+	{HOOK_SETLIGHTING,      Inject_SetLightingHook,      false},
 	{HOOK_SNEAK,            Inject_SneakCheckHook,       false},
 	{HOOK_STDPROCEDURE,     Inject_ScriptProcedureHook,  false},
 	{HOOK_STDPROCEDURE_END, Inject_ScriptProcedureHook2, false},

sfall/Modules/HookScripts.h

@@ -52,7 +52,7 @@ enum HookType
 	HOOK_INVENTORYMOVE    = 24,
 	HOOK_INVENWIELD       = 25,
 	HOOK_ADJUSTFID        = 26,
-	HOOK_COMBATTURN       = 27, // unimplemented
+//	HOOK_COMBATTURN       = 27, // unimplemented
 	HOOK_CARTRAVEL        = 28,
 	HOOK_SETGLOBALVAR     = 29,
 	HOOK_RESTTIMER        = 30,
@@ -60,6 +60,10 @@ enum HookType
 	HOOK_USEANIMOBJ       = 32,
 	HOOK_EXPLOSIVETIMER   = 33,
 	HOOK_DESCRIPTIONOBJ   = 34,
+	HOOK_USESKILLON       = 35,
+	HOOK_ONEXPLOSION      = 36,
+//	HOOK_SUBCOMBATDAMAGE  = 37, // unimplemented
+	HOOK_SETLIGHTING      = 38,
 	HOOK_SNEAK            = 39,
 	HOOK_STDPROCEDURE     = 40,
 	HOOK_STDPROCEDURE_END = 41,

sfall/Modules/HookScripts/CombatHs.cpp

@@ -317,6 +317,55 @@ skip:
 	}
 }
 
+fo::GameObject* __fastcall ComputeExplosionOnExtrasHook_Script(fo::GameObject* object, DWORD isCheck, DWORD checkTile, fo::ComputeAttackResult* ctdSource, 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
+		xor  edx, edx;
+		cmp  dword ptr [esp + 0x34 + 16], 0x412F11; // check called from action_explode_
+		jz   skip;
+		mov  edx, [esp + 0x34 - 0x34 + 16];         // isCheck (bypass damage)
+skip:
+		push esi;                                   // source ctd
+		push edi;                                   // check tile
+		mov  ecx, eax;                              // object
+		call ComputeExplosionOnExtrasHook_Script;   // edx - isCheck
+		pop  ecx;
+		retn;
+	}
+}
+
 static DWORD targetRet = 0;
 static bool targetObjHookHasRet = false;
 
@@ -441,6 +490,10 @@ void Inject_AmmoCostHook() {
 	HookCall(0x423A7C, AmmoCostHook); // compute_attack_
 }
 
+void Inject_OnExplosionHook() {
+	HookCall(0x423D70, ComputeExplosionOnExtrasHook);
+}
+
 void Inject_TargetObjectHook() {
 	MakeCall(0x44BB16, gmouse_bk_process_hook, 1);
 	SafeWrite8(0x44BB00, 0x15);
@@ -457,6 +510,7 @@ void InitCombatHookScripts() {
 	HookScripts::LoadHookScript("hs_findtarget", HOOK_FINDTARGET);
 	HookScripts::LoadHookScript("hs_itemdamage", HOOK_ITEMDAMAGE);
 	HookScripts::LoadHookScript("hs_ammocost", HOOK_AMMOCOST);
+	HookScripts::LoadHookScript("hs_onexplosion", HOOK_ONEXPLOSION);
 	HookScripts::LoadHookScript("hs_targetobject", HOOK_TARGETOBJECT);
 }
 

sfall/Modules/HookScripts/CombatHs.h

@@ -14,6 +14,7 @@ void Inject_CombatDamageHook();
 void Inject_FindTargetHook();
 void Inject_ItemDamageHook();
 void Inject_AmmoCostHook();
+void Inject_OnExplosionHook();
 void Inject_TargetObjectHook();
 
 int __fastcall AmmoCostHook_Script(DWORD hookType, fo::GameObject* weapon, DWORD &rounds);

sfall/Modules/HookScripts/Common.cpp

@@ -67,7 +67,7 @@ static bool CheckRecursiveHooks(DWORD hook) {
 	if (hook == currentRunHook) {
 		switch (hook) {
 		case HOOK_SETGLOBALVAR:
-//		case HOOK_SETLIGHTING:
+		case HOOK_SETLIGHTING:
 			return true;
 		default:
 			if (isDebug) fo::func::debug_printf("\nWARNING: A recursive hook with ID %d was running.", hook);

sfall/Modules/HookScripts/MiscHs.cpp

@@ -94,6 +94,86 @@ static void __declspec(naked) OverrideCost_BarterPriceHook() {
 	}
 }
 
+static fo::GameObject* sourceSkillOn = nullptr;
+void SourceUseSkillOnInit() { sourceSkillOn = *fo::ptr::obj_dude; }
+
+static char resultSkillOn; // -1 - cancel handler, 1 - replace user
+static long bakupCombatState;
+
+static void __fastcall UseSkillOnHook_Script(DWORD source, DWORD target, register DWORD skillId) {
+	BeginHook();
+	argCount = 3;
+
+	args[0] = source;  // user
+	args[1] = target;  // target
+	args[2] = skillId; // skill id
+
+	sourceSkillOn = *fo::ptr::obj_dude;
+	resultSkillOn = 0;
+	bakupCombatState = -1;
+
+	RunHookScript(HOOK_USESKILLON);
+
+	if (skillId != fo::Skill::SKILL_STEAL && cRet > 0) { // not work for steal skill
+		if (rets[0] != 0) {
+			resultSkillOn = (rets[0] == -1) ? -1 : 1;
+			if (resultSkillOn == 1) {
+				sourceSkillOn = (fo::GameObject*)rets[0];
+			}
+		}
+		if (resultSkillOn != -1 && cRet > 1 && rets[1] == 1) {
+			bakupCombatState = *fo::ptr::combat_state;
+			*fo::ptr::combat_state = 0;
+		}
+	}
+	EndHook();
+}
+
+static void __declspec(naked) UseSkillOnHook() {
+	__asm {
+		push eax;
+		push ecx;
+		push edx;
+		push ebx;                    // skill id
+		mov  ecx, eax;               // user
+		call UseSkillOnHook_Script;  // edx - target
+		pop  edx;
+		pop  ecx;
+		pop  eax;
+		cmp  resultSkillOn, -1;      // skip handler
+		jnz  handler;
+		retn;
+handler:
+		jmp  fo::funcoffs::action_use_skill_on_;
+	}
+}
+
+static void __declspec(naked) UseSkillOnHack() {
+	__asm {
+		cmp bakupCombatState, -1;
+		jz  skip;
+		mov ebp, bakupCombatState;
+		mov dword ptr ds:[FO_VAR_combat_state], ebp;
+skip:
+		cmp resultSkillOn, 0;
+		jz  default;
+		mov edi, sourceSkillOn; // skill user (override from hook)
+		retn;  // flag ZF = 0
+default:
+		// engine code
+		cmp eax, dword ptr ds:[FO_VAR_obj_dude];
+		retn;
+	}
+}
+
+static void __declspec(naked) skill_use_hack() {
+	__asm {
+		cmp   ebp, dword ptr ds:[FO_VAR_obj_dude];
+		setnz al;
+		retn;
+	}
+}
+
 static void __declspec(naked) UseSkillHook() {
 	__asm {
 		HookBegin;
@@ -610,6 +690,21 @@ void Inject_ExplosiveTimerHook() {
 	HookCall(0x49BDC4, ExplosiveTimerHook);
 }
 
+void Inject_UseSkillOnHook() {
+	const DWORD useSkillOnHkAddr[] = {0x44C3CA, 0x44C81C};
+	HookCalls(UseSkillOnHook, useSkillOnHkAddr);
+	MakeCall(0x4127BA, UseSkillOnHack, 1);
+	const DWORD skillUseTgtAddr[] = {0x4AB05D, 0x4AB558, 0x4ABA60};
+	MakeCalls(skill_use_hack, skillUseTgtAddr); // fix checking obj_dude's target
+
+	// replace _obj_dude with source skill user (skill_use_ function)
+	const DWORD skillUseSrcAddr[] = {
+		0x4AAF47, 0x4AB051, 0x4AB3FB, 0x4AB550, 0x4AB8FA, 0x4ABA54,
+		0x4AB0EF, 0x4AB5C0, 0x4ABAF2 // fix for time increment
+	};
+	SafeWriteBatch<DWORD>((DWORD)&sourceSkillOn, skillUseSrcAddr);
+}
+
 void Inject_EncounterHook() {
 	HookCall(0x4C02AF, wmWorldMap_hook);
 	HookCall(0x4C095C, wmRndEncounterOccurred_hook);
@@ -617,6 +712,7 @@ void Inject_EncounterHook() {
 
 void InitMiscHookScripts() {
 	HookScripts::LoadHookScript("hs_barterprice", HOOK_BARTERPRICE);
+	HookScripts::LoadHookScript("hs_useskillon", HOOK_USESKILLON);
 	HookScripts::LoadHookScript("hs_useskill", HOOK_USESKILL);
 	HookScripts::LoadHookScript("hs_steal", HOOK_STEAL);
 	HookScripts::LoadHookScript("hs_sneak", HOOK_SNEAK);

sfall/Modules/HookScripts/MiscHs.h

@@ -4,8 +4,10 @@ namespace sfall
 {
 
 void InitMiscHookScripts();
+void SourceUseSkillOnInit();
 
 void Inject_BarterPriceHook();
+void Inject_UseSkillOnHook();
 void Inject_UseSkillHook();
 void Inject_StealCheckHook();
 void Inject_SneakCheckHook();

sfall/Modules/HookScripts/ObjectHs.cpp

@@ -185,6 +185,72 @@ skip:
 	}
 }
 
+static bool __fastcall SetLightingHook_Script(DWORD &intensity, DWORD &radius, DWORD object) {
+	BeginHook();
+	argCount = 3;
+
+	args[0] = object;
+	args[1] = intensity;
+	args[2] = radius;
+	RunHookScript(HOOK_SETLIGHTING);
+
+	bool result = false;
+	if (cRet > 0) {
+		int light = rets[0];
+		if (light < 0) light = 0;
+		intensity = light;
+		if (cRet > 1 && object != -1) {
+			int dist = rets[1];
+			if (dist < 0) dist = 0;
+			radius = dist;
+		}
+		result = true;
+	}
+	EndHook();
+	return result;
+}
+
+static void __declspec(naked) SetObjectLightHook() {
+	__asm {
+		pushadc;
+		push ebp;
+		mov  edx, esp;  // &radius
+		push ebx;
+		mov  ecx, esp;  // &intensity
+		push esi;       // object
+		call SetLightingHook_Script;
+		test al, al;
+		jz   skip;
+		pop  ebx;       // return intensity value
+		pop  ebp;       // return radius value
+		jmp  end;
+skip:
+		add  esp, 8;
+end:
+		popadc;
+		jmp  fo::funcoffs::obj_turn_off_light_;
+	}
+}
+
+static void __declspec(naked) SetMapLightHook() {
+	__asm {
+		push ecx;
+		push ebx;
+		mov  ecx, esp;  // &intensity
+		push -1;        // no object (it's a map)
+		mov  edx, esp;  // no radius
+		call SetLightingHook_Script;
+		add  esp, 4;
+		test al, al;
+		jz   skip;
+		mov  ebx, [esp - 4]; // return intensity value
+skip:
+		pop  ecx;
+		cmp  ebx, dword ptr ds:[0x47A93D]; // get miminal ambient light intensity (16384)
+		retn;
+	}
+}
+
 static DWORD __fastcall StdProcedureHook_Script(long numHandler, fo::ScriptInstance* script, DWORD procTable) {
 	BeginHook();
 	argCount = 4;
@@ -282,6 +348,11 @@ void Inject_DescriptionObjHook() {
 	HookCall(0x49AE28, DescriptionObjHook);
 }
 
+void Inject_SetLightingHook() {
+	HookCall(0x48ACA0, SetObjectLightHook);
+	MakeCall(0x47A934, SetMapLightHook, 1);
+}
+
 void Inject_ScriptProcedureHook() {
 	MakeCall(0x4A491F, ScriptStdProcedureHook);
 }
@@ -293,7 +364,9 @@ void Inject_ScriptProcedureHook2() {
 void InitObjectHookScripts() {
 	HookScripts::LoadHookScript("hs_useobjon", HOOK_USEOBJON);
 	HookScripts::LoadHookScript("hs_useobj", HOOK_USEOBJ);
+	HookScripts::LoadHookScript("hs_useanimobj", HOOK_USEANIMOBJ);
 	HookScripts::LoadHookScript("hs_descriptionobj", HOOK_DESCRIPTIONOBJ);
+	HookScripts::LoadHookScript("hs_setlighting", HOOK_SETLIGHTING);
 	HookScripts::LoadHookScript("hs_stdprocedure", HOOK_STDPROCEDURE); // combo hook
 	HookScripts::LoadHookScript("hs_stdprocedure", HOOK_STDPROCEDURE_END);
 }

sfall/Modules/HookScripts/ObjectHs.h

@@ -9,6 +9,7 @@ void Inject_UseObjOnHook();
 void Inject_UseObjHook();
 void Inject_UseAnimateObjHook();
 void Inject_DescriptionObjHook();
+void Inject_SetLightingHook();
 void Inject_ScriptProcedureHook();
 void Inject_ScriptProcedureHook2();
 

sfall/Modules/LoadGameHook.cpp

@@ -36,6 +36,7 @@
 #include "Graphics.h"
 #include "HeroAppearance.h"
 #include "HookScripts\Common.h"
+#include "HookScripts\MiscHs.h"
 #include "Interface.h"
 #include "Inventory.h"
 #include "LoadOrder.h"
@@ -141,6 +142,7 @@ static void __stdcall RunOnBeforeGameStart() {
 static void __stdcall RunOnAfterGameStarted() {
 	if (femaleMsgs) CheckPlayerGender();
 	if (disableHorrigan) *fo::ptr::Meet_Frank_Horrigan = true;
+	SourceUseSkillOnInit();
 	InitGlobalScripts(); // running sfall scripts
 }
 

sfall/Modules/MiscPatches.cpp

@@ -261,8 +261,8 @@ static void __fastcall SwapHandSlots(fo::GameObject* item, fo::GameObject* &toSl
 	} else { // swap slots
 		fo::ItemButtonItem hands[2];
 		std::memcpy(hands, fo::ptr::itemButtonItems, sizeof(fo::ItemButtonItem) * 2);
-		hands[fo::HandSlot::Left].primaryAttack   = fo::AttackType::ATKTYPE_RWEAPON_PRIMARY;
-		hands[fo::HandSlot::Left].secondaryAttack = fo::AttackType::ATKTYPE_RWEAPON_SECONDARY;
+		hands[fo::HandSlot::Left].primaryAttack    = fo::AttackType::ATKTYPE_RWEAPON_PRIMARY;
+		hands[fo::HandSlot::Left].secondaryAttack  = fo::AttackType::ATKTYPE_RWEAPON_SECONDARY;
 		hands[fo::HandSlot::Right].primaryAttack   = fo::AttackType::ATKTYPE_LWEAPON_PRIMARY;
 		hands[fo::HandSlot::Right].secondaryAttack = fo::AttackType::ATKTYPE_LWEAPON_SECONDARY;
 
@@ -332,6 +332,24 @@ static void __declspec(naked) intface_update_items_hack_end() {
 	}
 }
 
+static void __declspec(naked) action_use_skill_on_hook() {
+	__asm { // eax = dude_obj, edx = target, ebp = party_member
+		cmp  eax, edx;
+		jnz  end;                     // jump if target != dude_obj
+		mov  edx, ebp;
+		call fo::funcoffs::obj_dist_; // check distance between dude_obj and party_member
+		cmp  eax, 1;                  // if the distance is greater than 1, then reset the register
+		jg   skip;
+		inc  eax;
+		retn;
+skip:
+		xor  eax, eax;
+		retn;
+end:
+		jmp  fo::funcoffs::obj_dist_;
+	}
+}
+
 static void __declspec(naked) endgame_movie_hook() {
 	__asm {
 		cmp  [esp + 16], 0x45C563; // call from op_endgame_movie_
@@ -714,6 +732,21 @@ static void KeepSelectModePatch() {
 	//}
 }
 
+static void PartyMemberSkillPatch() {
+	// Fix getting distance from source to target when using skills
+	// Note: this will cause the party member to perform First Aid/Doctor skills when you use them on the player, but only if
+	// the player is standing next to the party member. Because the related engine function is not fully implemented, enabling
+	// this option without a global script that overrides First Aid/Doctor functions has very limited usefulness
+	if (IniReader::GetConfigInt("Misc", "PartyMemberSkillFix", 0)) {
+		dlog("Applying First Aid/Doctor skill use patch for party members.", DL_INIT);
+		HookCall(0x412836, action_use_skill_on_hook);
+		dlogr(" Done", DL_INIT);
+	}
+	// Small code patch for HOOK_USESKILLON (change obj_dude to source)
+	SafeWrite32(0x4128F3, 0x90909090);
+	SafeWrite16(0x4128F7, 0xFE39); // cmp esi, _obj_dude -> cmp esi, edi
+}
+
 #pragma pack(push, 1)
 struct CodeData {
 	DWORD dd;
@@ -1085,6 +1118,8 @@ void MiscPatches::init() {
 	DisplaySecondWeaponRangePatch();
 	KeepSelectModePatch();
 
+	PartyMemberSkillPatch();
+
 	SkipLoadingGameSettingsPatch();
 
 	UseWalkDistancePatch();