Added new HOOK_USESKILLON and PartyMemberSkillFix option (#191)

artifacts/ddraw.ini

@@ -75,7 +75,8 @@ Use32BitHeadGraphics=0
 ;Requires graphics mode 4 or 5
 AllowDShowMovies=0
 
-;Fade effect time length percentage modifier
+;Fade effect time percentage modifier
+;Default is 100. Decrease/increase this value to speed up/slow down fade effects
 FadeMultiplier=100
 
 ;XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
@@ -631,6 +632,13 @@ DisplaySwiftLearnerExp=1
 ;Set to 1 to display party member's current level/AC/addict flag on the combat control panel
 PartyMemberExtraInfo=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 apply his/her skills when you use First Aid/Doctor skills 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
+
 ;Set to 1 to skip loading game settings from a saved game, except for the game/combat difficulty settings
 ;Set to 2 to also skip loading the game/combat difficulty settings
 SkipLoadingGameSettings=0

artifacts/scripting/headers/sfall.h

@@ -55,6 +55,8 @@
 #define HOOK_GAMEMODECHANGE   (31)
 #define HOOK_USEANIMOBJ       (32)
 #define HOOK_EXPLOSIVETIMER   (33)
+#define HOOK_DESCRIPTIONOBJ   (34)
+#define HOOK_USESKILLON       (35)
 
 //Valid arguments to list_begin
 #define LIST_CRITTERS    (0)

artifacts/scripting/hookscripts.txt

@@ -544,3 +544,17 @@ An example usage would be to add an additional description to the item based on
 Obj     arg1 - the item
 
 int     ret1 - a pointer to the new text received by using "get_string_pointer" function
+
+-------------------------------------------
+
+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 arg1 - The user critter (usually dude_obj)
+Obj     arg2 - the target object/critter
+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)

sfall/Modules/HookScripts.cpp

@@ -79,6 +79,7 @@ static HooksInjectInfo injectHooks[] = {
 	{HOOK_USEANIMOBJ,       Inject_UseAnimateObjHook,    false},
 	{HOOK_EXPLOSIVETIMER,   Inject_ExplosiveTimerHook,   false},
 	{HOOK_DESCRIPTIONOBJ,   Inject_DescriptionObjHook,   false},
+	{HOOK_USESKILLON,       Inject_UseSkillOnHook,       false},
 };
 
 bool HookScripts::injectAllHooks;
@@ -227,6 +228,7 @@ void HookScripts::init() {
 	OnKeyPressed() += KeyPressHook;
 	OnMouseClick() += MouseClickHook;
 	LoadGameHook::OnGameModeChange() += GameModeChangeHook;
+	LoadGameHook::OnAfterGameStarted() += SourceUseSkillOnInit;
 
 	HookScripts::injectAllHooks = (isDebug && (GetConfigInt("Debugging", "InjectAllGameHooks", 0) != 0));
 }

sfall/Modules/HookScripts.h

@@ -61,6 +61,7 @@ enum HookType
 	HOOK_USEANIMOBJ       = 32,
 	HOOK_EXPLOSIVETIMER   = 33,
 	HOOK_DESCRIPTIONOBJ   = 34,
+	HOOK_USESKILLON       = 35,
 	HOOK_COUNT
 };
 

sfall/Modules/HookScripts/MiscHs.cpp

@@ -392,6 +392,85 @@ end:
 	}
 }
 
+static fo::GameObject* sourceSkillOn = nullptr;
+void SourceUseSkillOnInit() { sourceSkillOn = fo::var::obj_dude; }
+
+static char resultSkillOn;
+static long bakupCombatState;
+static void __cdecl 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::var::obj_dude;
+	resultSkillOn = 0;
+	bakupCombatState = -1;
+
+	RunHookScript(HOOK_USESKILLON);
+	EndHook();
+
+	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::var::combat_state;
+			fo::var::combat_state = 0;
+		}
+	}
+}
+
+static void __declspec(naked) UseSkillOnHook() {
+	__asm {
+		push ecx;
+		push ebx;                    // skill id
+		push edx;                    // target
+		push eax;                    // user
+		call UseSkillOnHook_Script;
+		pop  eax;
+		pop  edx;
+		add  esp, 4; // ebx
+		pop  ecx;
+		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;
+		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;
+	}
+}
+
 void Inject_BarterPriceHook() {
 	HookCalls(BarterPriceHook, {
 		0x474D4C,
@@ -440,6 +519,16 @@ void Inject_ExplosiveTimerHook() {
 	HookCall(0x49BDC4, ExplosiveTimerHook);
 }
 
+void Inject_UseSkillOnHook() {
+	HookCalls(UseSkillOnHook, { 0x44C3CA, 0x44C81C });
+	MakeCall(0x4127BA, UseSkillOnHack);
+	SafeWrite8(0x4127BF, 0x90);
+	MakeCalls(skill_use_hack, {0x4AB05D, 0x4AB558, 0x4ABA60}); // fix checking obj_dude's target
+	// replace source skill user
+	SafeWriteBatch<DWORD>((DWORD)&sourceSkillOn, {0x4AAF47, 0x4AB051, 0x4AB3FB, 0x4AB550, 0x4AB8FA, 0x4ABA54});
+	SafeWriteBatch<DWORD>((DWORD)&sourceSkillOn, {0x4AB0EF, 0x4AB5C0, 0x4ABAF2}); // fix for time
+}
+
 void InitMiscHookScripts() {
 
 	LoadHookScript("hs_barterprice", HOOK_BARTERPRICE);
@@ -450,6 +539,7 @@ void InitMiscHookScripts() {
 	LoadHookScript("hs_setglobalvar", HOOK_SETGLOBALVAR);
 	LoadHookScript("hs_resttimer", HOOK_RESTTIMER);
 	LoadHookScript("hs_explosivetimer", HOOK_EXPLOSIVETIMER);
+	LoadHookScript("hs_useskillon", HOOK_USESKILLON);
 }
 
 }

sfall/Modules/HookScripts/MiscHs.h

@@ -3,6 +3,7 @@
 namespace sfall
 {
 	void InitMiscHookScripts();
+	void SourceUseSkillOnInit();
 
 	void Inject_BarterPriceHook();
 	void Inject_UseSkillHook();
@@ -12,4 +13,5 @@ namespace sfall
 	void Inject_SetGlobalVarHook();
 	void Inject_RestTimerHook();
 	void Inject_ExplosiveTimerHook();
+	void Inject_UseSkillOnHook();
 }

sfall/Modules/MiscPatches.cpp

@@ -448,6 +448,24 @@ 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 const DWORD EncounterTableSize[] = {
 	0x4BD1A3, 0x4BD1D9, 0x4BD270, 0x4BD604, 0x4BDA14, 0x4BDA44, 0x4BE707,
 	0x4C0815, 0x4C0D4A, 0x4C0FD4,
@@ -855,6 +873,21 @@ void KeepWeaponSelectModePatch() {
 	}
 }
 
+void PartyMemberSkillPatch() {
+	// Fixed getting distance from source to target when using skills
+	// Note: this will cause the party member to apply his/her skill when you use First Aid/Doctor skill 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 (GetConfigInt("Misc", "PartyMemberSkillFix", 0) != 0) {
+		dlog("Applying party member using First Aid/Doctor skill patch.", 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
+}
+
 void SkipLoadingGameSettingsPatch() {
 	int skipLoading = GetConfigInt("Misc", "SkipLoadingGameSettings", 0);
 	if (skipLoading) {
@@ -969,6 +1002,8 @@ void MiscPatches::init() {
 	DisplaySecondWeaponRangePatch();
 	KeepWeaponSelectModePatch();
 
+	PartyMemberSkillPatch();
+
 	SkipLoadingGameSettingsPatch();
 	InterfaceDontMoveOnTopPatch();
 }

sfall/main.cpp

@@ -279,7 +279,7 @@ static bool LoadOriginalDll(DWORD dwReason) {
 	switch (dwReason) {
 		case DLL_PROCESS_ATTACH:
 			char path[MAX_PATH];
-			CopyMemory(path + GetSystemDirectory(path , MAX_PATH - 10), "\\ddraw.dll", 11); // path to original dll
+			CopyMemory(path + GetSystemDirectoryA(path , MAX_PATH - 10), "\\ddraw.dll", 11); // path to original dll
 			ddraw.dll = LoadLibrary(path);
 			if (!ddraw.dll || ddraw.dll == INVALID_HANDLE_VALUE) {
 				MessageBox(0, "Cannot load the original ddraw.dll library.", "sfall", MB_ICONERROR);