Added a fixed implementation of ai_check_drugs_ function

* which has all fixes/hook built-in.

Disabled old fixes for vanilla ai_check_drugs_ in AI.cpp/BugFixes.cpp.

sfall/FalloutEngine/Functions_def.h

@@ -23,6 +23,7 @@ WRAP_WATCOM_FFUNC4(fo::GameObject*, ai_best_weapon, fo::GameObject*, source, fo:
 WRAP_WATCOM_FFUNC3(bool, ai_can_use_weapon, fo::GameObject*, critter, fo::GameObject*, item, DWORD, hitMode)
 WRAP_WATCOM_FFUNC3(long, ai_have_ammo, fo::GameObject*, critter, fo::GameObject*, item, fo::GameObject**, outAmmo)
 WRAP_WATCOM_FFUNC3(long, ai_pick_hit_mode, fo::GameObject*, source, fo::GameObject*, item, fo::GameObject*, target)
+WRAP_WATCOM_FFUNC3(long, ai_magic_hands, fo::GameObject*, source, fo::GameObject*, object, long, msgNumber)
 WRAP_WATCOM_FFUNC3(fo::GameObject*, ai_search_inven_weap, fo::GameObject*, source, long, apCheck, fo::GameObject*, target)
 WRAP_WATCOM_FFUNC3(void, check_for_death, fo::GameObject*, critter, long, amountDamage, long*, flags)
 WRAP_WATCOM_FFUNC6(long, combat_safety_invalidate_weapon_func, fo::GameObject*, source, fo::GameObject*, weapon, long, hitMode, fo::GameObject*, targetA, DWORD*, outSafeRange, fo::GameObject*, targetB)
@@ -37,7 +38,7 @@ WRAP_WATCOM_FFUNC3(void, intface_update_items, long, animate, long, modeLeft, lo
 WRAP_WATCOM_FFUNC3(fo::GameObject*, inven_find_type, fo::GameObject*, critter, long, itemType, DWORD*, slot)
 WRAP_WATCOM_FFUNC3(long, inven_wield, fo::GameObject*, critter, fo::GameObject*, item, long, slot)
 WRAP_WATCOM_FFUNC3(long, item_add_force, fo::GameObject*, critter, fo::GameObject*, item, long, count)
-WRAP_WATCOM_FFUNC3(long, item_mp_cost, fo::GameObject*, source, long, hitMode, long, isCalled)
+WRAP_WATCOM_FFUNC3(long, item_remove_mult, fo::GameObject*, critter, fo::GameObject*, item, long, count) // WARNING: HOOK_REMOVEINVENOBJ uses the return address in this function
 WRAP_WATCOM_FFUNC3(long, item_w_mp_cost, fo::GameObject*, source, long, hitMode, long, isCalled)
 // Calculates path and returns it's length
 WRAP_WATCOM_FFUNC6(long, make_path_func, fo::GameObject*, objectFrom, long, tileFrom, long, tileTo, char*, pathDataBuffer, long, checkTileTo, void*, blockingFunc)
@@ -46,6 +47,7 @@ WRAP_WATCOM_FFUNC3(long, message_find, DWORD*, msgFile, long, msgNumber, DWORD*,
 WRAP_WATCOM_FFUNC4(long, mouse_click_in, long, x, long, y, long, x_offs, long, y_offs)
 WRAP_WATCOM_FFUNC4(long, mouse_in, long, x, long, y, long, x_offs, long, y_offs)
 WRAP_WATCOM_FFUNC3(fo::GameObject*, obj_blocking_at, fo::GameObject*, object, long, tile, long, elevation)
+WRAP_WATCOM_FFUNC4(long, obj_connect, fo::GameObject*, object, long, tile, long, elevation, RECT*, rect)
 WRAP_WATCOM_FFUNC4(long, obj_dist_with_tile, fo::GameObject*, source, long, sourceTile, fo::GameObject*, target, long, targetTile)
 WRAP_WATCOM_FFUNC4(long, obj_move_to_tile, fo::GameObject*, object, long, tile, long, elevation, RECT*, rect)
 WRAP_WATCOM_FFUNC3(long, obj_new_sid_inst, fo::GameObject*, object, long, sType, long, scriptIndex)
@@ -71,6 +73,8 @@ WRAP_WATCOM_FFUNC3(const char*, interpretGetString, fo::Program*, scriptPtr, DWO
 /* stdcall */
 WRAP_WATCOM_FUNC1(fo::AIcap*, ai_cap, fo::GameObject*, critter)
 WRAP_WATCOM_FUNC2(void, ai_print_msg, fo::GameObject*, object, long, mode)
+WRAP_WATCOM_FUNC2(fo::GameObject*, ai_retrieve_object, fo::GameObject*, critter, fo::GameObject*, item)
+WRAP_WATCOM_FUNC2(fo::GameObject*, ai_search_environ, fo::GameObject*, critter, long, itemType)
 WRAP_WATCOM_FUNC1(fo::Program*, allocateProgram, const char*, filePath)
 WRAP_WATCOM_FUNC2(long, anim_can_use_door, fo::GameObject*, source, fo::GameObject*, object)
 WRAP_WATCOM_FUNC1(bool, art_exists, long, artFid)
@@ -136,6 +140,7 @@ WRAP_WATCOM_FUNC2(long, is_within_perception, fo::GameObject*, source, fo::GameO
 WRAP_WATCOM_FUNC1(long, isPartyMember, fo::GameObject*, obj)
 WRAP_WATCOM_FUNC1(long, item_c_curr_size, fo::GameObject*, critter)
 WRAP_WATCOM_FUNC1(long, item_caps_total, fo::GameObject*, object)
+WRAP_WATCOM_FUNC2(long, item_d_take_drug, fo::GameObject*, source, fo::GameObject*, item)
 WRAP_WATCOM_FUNC1(long, item_get_type, fo::GameObject*, item)
 WRAP_WATCOM_FUNC2(fo::GameObject*, item_hit_with, fo::GameObject*, critter, long, hitMode)
 WRAP_WATCOM_FUNC1(long, item_m_dec_charges, fo::GameObject*, item) // Returns 0 on success, -1 if the item has no charges

sfall/Game/combatAI.cpp

@@ -4,11 +4,13 @@
  *
  */
 
-//#include "..\main.h"
+#include "..\main.h"
 #include "..\FalloutEngine\Fallout2.h"
 
 #include "..\Modules\HookScripts\CombatHs.h"
 
+#include "items.h"
+
 #include "combatAI.h"
 
 namespace game
@@ -22,7 +24,184 @@ bool CombatAI::ai_can_use_weapon(fo::GameObject* source, fo::GameObject* weapon,
 	return sf::CanUseWeaponHook_Invoke(result, source, weapon, hitMode);
 }
 
-void CombatAI::init() { // TODO: add to main.cpp
+static const long aiUseItemAPCost = 2;
+static std::vector<long> healingItemPids = {fo::PID_STIMPAK, fo::PID_SUPER_STIMPAK, fo::PID_HEALING_POWDER};
+
+static bool CheckHealingItems(fo::GameObject* item) {
+	return (std::find(healingItemPids.cbegin(), healingItemPids.cend(), item->protoId) != healingItemPids.cend());
+}
+
+// True - use failed
+static bool UseItemDrugFunc(fo::GameObject* source, fo::GameObject* item) {
+	bool result = (game::Items::item_d_take_drug(source, item) == -1);
+	if (result) {
+		fo::func::item_add_force(source, item, 1);
+	} else {
+		fo::func::ai_magic_hands(source, item, 5000);
+		fo::func::obj_connect(item, source->tile, source->elevation, 0);
+		fo::func::obj_destroy(item);
+	}
+	return result;
+}
+
+static long drugUsePerfFixMode;
+
+void __stdcall CombatAI::ai_check_drugs(fo::GameObject* source) {
+	if (fo::func::critter_body_type(source)) return; // Robotic/Quadruped cannot use drugs
+
+	DWORD slot = -1;
+	long noInvenDrug = 0;
+	bool drugWasUsed = false;
+
+	fo::GameObject* lastItem = nullptr; // combatAIInfoGetLastItem_(source); unused function, always returns 0
+	if (!lastItem) {
+		fo::AIcap* cap = fo::func::ai_cap(source);
+		if (!cap) return;
+
+		long hpPercent = 50;
+		long chance = 0;
+
+		switch ((fo::AIpref::chem_use_mode)cap->chem_use) {
+		case fo::AIpref::chem_use_mode::stims_when_hurt_little: // use only healing drugs
+			hpPercent = 60;
+			break;
+		case fo::AIpref::chem_use_mode::stims_when_hurt_lots:   // use only healing drugs
+			hpPercent = 30;
+			break;
+		case fo::AIpref::chem_use_mode::sometimes:
+			if (!(fo::var::combatNumTurns % 3)) chance = 25; // every three turns
+			//hpPercent = 50;
+			break;
+		case fo::AIpref::chem_use_mode::anytime:
+			if (!(fo::var::combatNumTurns % 3)) chance = 75; // every three turns
+			//hpPercent = 50;
+			break;
+		case fo::AIpref::chem_use_mode::always:
+			chance = 100; // 99%
+			break;
+		case fo::AIpref::chem_use_mode::clean:
+			return; // exit: don't use drugs
+		}
+
+		long minHP = (hpPercent * fo::func::stat_level(source, fo::Stat::STAT_max_hit_points)) / 100;
+
+		// [FIX] for AI not checking minimum hp properly for using stimpaks (prevents premature fleeing)
+		if (cap->min_hp > minHP) minHP = cap->min_hp;
+
+		while (fo::func::stat_level(source, fo::Stat::STAT_current_hp) < minHP && source->critter.movePoints >= aiUseItemAPCost) {
+			fo::GameObject* itemFind = fo::func::inven_find_type(source, fo::ItemType::item_type_drug, &slot);
+			if (!itemFind) {
+				noInvenDrug = 2; // healing drugs were not found in the inventory (was 1)
+				break;
+			}
+
+			if (CheckHealingItems(itemFind) && !fo::func::item_remove_mult(source, itemFind, 1)) {
+				if (!UseItemDrugFunc(source, itemFind)) {
+					drugWasUsed = true;
+				}
+
+				if (source->critter.movePoints < aiUseItemAPCost) {
+					source->critter.movePoints = 0;
+				} else {
+					source->critter.movePoints -= aiUseItemAPCost;
+				}
+				slot = -1;
+			}
+		}
+
+		// use any drug (except healing drugs) if there is a chance of using it
+		if (!drugWasUsed && chance > 0 && fo::func::roll_random(0, 100) < chance) {
+			long usedCount = 0;
+			while (source->critter.movePoints >= aiUseItemAPCost) {
+				fo::GameObject* item = fo::func::inven_find_type(source, fo::ItemType::item_type_drug, &slot);
+				if (!item) {
+					noInvenDrug = 1;
+					break;
+				}
+
+				long counter = 0;
+
+				if (drugUsePerfFixMode > 0) {
+					fo::GameObject* firstFoundDrug = item;
+					do {
+						// [FIX] Allow using only the drugs listed in chem_primary_desire and healing drugs (AIDrugUsePerfFix == 2)
+						while (item->protoId != cap->chem_primary_desire[counter]) if (++counter > 2) break;
+						if (counter <= 2) break; // there is a match
+
+						// [FIX] for AI not taking chem_primary_desire in AI.txt as a preference when using drugs in the inventory
+						if (drugUsePerfFixMode == 1) {
+							item = fo::func::inven_find_type(source, fo::ItemType::item_type_drug, &slot);
+							if (!item) {
+								item = firstFoundDrug;
+								break;
+							}
+							counter = 0;
+						}
+					} while (counter < 3);
+				} else {
+					// if the durg is equal to the first item of preference, then check the next two (vanilla behavior)
+					while (item->protoId == cap->chem_primary_desire[counter]) if (++counter > 2) break;
+				}
+
+				// if the preference counter is less than 3, then AI can use the drug
+				if (counter < 3) {
+					// if the item is NOT a healing drug
+					if (!CheckHealingItems(item) && !fo::func::item_remove_mult(source, item, 1)) {
+						if (!UseItemDrugFunc(source, item)) {
+							drugWasUsed = true;
+							usedCount++;
+						}
+
+						if (source->critter.movePoints < aiUseItemAPCost) {
+							source->critter.movePoints = 0;
+						} else {
+							source->critter.movePoints -= aiUseItemAPCost;
+						}
+						slot = -1;
+
+						fo::AIpref::chem_use_mode chemUse = (fo::AIpref::chem_use_mode)cap->chem_use;
+						if (chemUse == fo::AIpref::chem_use_mode::sometimes ||
+						    (chemUse == fo::AIpref::chem_use_mode::anytime && usedCount >= 2))
+						{
+							break;
+						}
+					}
+				}
+			}
+		}
+	}
+	// search for drugs on the map
+	if (lastItem || (!drugWasUsed /*&& noInvenDrug*/)) {
+		do {
+			if (!lastItem) lastItem = fo::func::ai_search_environ(source, fo::ItemType::item_type_drug);
+			if (!lastItem) lastItem = fo::func::ai_search_environ(source, fo::ItemType::item_type_misc_item);
+			if (lastItem) lastItem = fo::func::ai_retrieve_object(source, lastItem);
+
+			// [FIX] Prevent the use of healing drugs when not necessary
+			// noInvenDrug: is set to 2 that healing is required
+			if (lastItem && noInvenDrug != 2 && CheckHealingItems(lastItem)) {
+				long maxHP = fo::func::stat_level(source, fo::Stat::STAT_max_hit_points);
+				if (10 + source->critter.health >= maxHP) { // quick check current HP
+					return; // exit: don't use healing item
+				}
+			}
+
+			if (lastItem && !fo::func::item_remove_mult(source, lastItem, 1)) {
+				if (!UseItemDrugFunc(source, lastItem)) lastItem = nullptr;
+
+				if (source->critter.movePoints < aiUseItemAPCost) {
+					source->critter.movePoints = 0;
+				} else {
+					source->critter.movePoints -= aiUseItemAPCost;
+				}
+			}
+		} while (lastItem && source->critter.movePoints >= aiUseItemAPCost);
+	}
+}
+
+void CombatAI::init() {
+	drugUsePerfFixMode = sf::IniReader::GetConfigInt("Misc", "AIDrugUsePerfFix", 0);
+	if (drugUsePerfFixMode > 0) sf::dlogr("Applying AI drug use preference fix.", DL_FIX);
 }
 
 }

sfall/Game/combatAI.h

@@ -9,11 +9,15 @@
 namespace game
 {
 
+#include "..\FalloutEngine\Fallout2.h"
+
 class CombatAI {
 public:
 	static void init();
 
 	static bool ai_can_use_weapon(fo::GameObject* source, fo::GameObject* weapon, long hitMode);
+
+	static void __stdcall ai_check_drugs(fo::GameObject* source);
 };
 
 }

sfall/Game/items.cpp

@@ -8,6 +8,7 @@
 #include "..\FalloutEngine\Fallout2.h"
 
 #include "..\Modules\HookScripts\CombatHs.h"
+#include "..\Modules\HookScripts\ObjectHs.h"
 #include "..\Modules\Perks.h"
 
 #include "..\Game\stats.h"
@@ -21,6 +22,12 @@ namespace sf = sfall;
 
 static constexpr int reloadCostAP = 2; // engine default reload AP cost
 
+// Implementation of item_d_take_ engine function with the HOOK_USEOBJON hook
+long Items::item_d_take_drug(fo::GameObject* source, fo::GameObject* item) {
+	if (sf::UseObjOnHook_Invoke(source, item, source) == -1) return -1;
+	return fo::func::item_d_take_drug(source, item);
+}
+
 long Items::item_count(fo::GameObject* who, fo::GameObject* item) {
 	for (int i = 0; i < who->invenSize; i++) {
 		auto tableItem = &who->invenTable[i];

sfall/Game/items.h

@@ -13,6 +13,9 @@ class Items {
 public:
 	static void init();
 
+	// Implementation of item_d_take_ engine function with the HOOK_USEOBJON hook
+	static long item_d_take_drug(fo::GameObject* source, fo::GameObject* item);
+
 	static long item_count(fo::GameObject* who, fo::GameObject* item);
 
 	static long item_weapon_range(fo::GameObject* source, fo::GameObject* weapon, long hitMode);

sfall/Modules/AI.cpp

@@ -22,6 +22,7 @@
 #include "..\FalloutEngine\Fallout2.h"
 #include "LoadGameHook.h"
 
+#include "..\Game\combatAI.h"
 #include "..\Game\items.h"
 
 #include "AI.h"
@@ -112,8 +113,10 @@ end:
 		add  esp, 4;
 		jmp  combat_ai_hack_Ret;
 tryHeal:
-		mov  eax, esi;
-		call fo::funcoffs::ai_check_drugs_;
+		push ecx;
+		push esi;                            // mov  eax, esi;
+		call game::CombatAI::ai_check_drugs; // call fo::funcoffs::ai_check_drugs_;
+		pop  ecx;
 		cmp  [esi + health], edx; // edx - minimum hp, below which NPC will run away
 		jge  end;
 		retn; // flee
@@ -126,7 +129,7 @@ static void __declspec(naked) ai_check_drugs_hook() {
 		mov  edx, dword ptr [esp + 0x34 - 0x1C + 4]; // ai cap
 		mov  edx, [edx + 0x10];                      // min_hp
 		cmp  eax, edx;                               // curr_hp < cap.min_hp
-		cmovl edi, edx;
+		cmovl edi, edx;                              // min_hp <- cap.min_hp
 		retn;
 	}
 }
@@ -663,12 +666,12 @@ void AI::init() {
 	// Fix to allow fleeing NPC to use drugs
 	MakeCall(0x42B1DC, combat_ai_hack);
 	// Fix for AI not checking minimum hp properly for using stimpaks (prevents premature fleeing)
-	HookCall(0x428579, ai_check_drugs_hook);
+	//HookCall(0x428579, ai_check_drugs_hook);
 
 	// Fix to prevent the use of healing drugs when not necessary
-	HookCall(0x4287D7, ai_check_drugs_hook_healing);
-	SafeWrite8(0x4285A8, 2);    // set noInvenItem = 2
-	SafeWrite8(0x4287A0, 0x8C); // jnz > jl (noInvenItem < 1)
+	//HookCall(0x4287D7, ai_check_drugs_hook_healing);
+	//SafeWrite8(0x4285A8, 2);    // set noInvenItem = 2
+	//SafeWrite8(0x4287A0, 0x8C); // jnz > jl (noInvenItem < 1)
 
 	// Fix for NPC stuck in fleeing mode when the hit chance of a target was too low
 	HookCall(0x42B1E3, combat_ai_hook_FleeFix);

sfall/Modules/BugFixes.cpp

@@ -3641,20 +3641,20 @@ void BugFixes::init()
 	// Display a pop-up message box about death from radiation
 	HookCall(0x42D733, process_rads_hook_msg);
 
-	int drugUsePerfFix = IniReader::GetConfigInt("Misc", "AIDrugUsePerfFix", 0);
-	if (drugUsePerfFix > 0) {
-		dlog("Applying AI drug use preference fix.", DL_FIX);
-		if (drugUsePerfFix == 1) {
-			// Fix for AI not taking chem_primary_desire in AI.txt as drug use preference when using drugs in their inventory
-			MakeCall(0x42869D, ai_check_drugs_hack_break);
-			MakeCall(0x4286AB, ai_check_drugs_hack_check, 1);
-			MakeCall(0x4286C7, ai_check_drugs_hack_use);
-		}
-		// Fix to allow using only the drugs listed in chem_primary_desire and healing drugs (stimpaks and healing powder)
-		SafeWrite8(0x4286B1, CodeType::JumpZ);  // jnz > jz (ai_check_drugs_)
-		SafeWrite8(0x4286C5, CodeType::JumpNZ); // jz > jnz (ai_check_drugs_)
-		dlogr(" Done", DL_FIX);
-	}
+	//int drugUsePerfFix = IniReader::GetConfigInt("Misc", "AIDrugUsePerfFix", 0);
+	//if (drugUsePerfFix > 0) {
+	//	dlog("Applying AI drug use preference fix.", DL_FIX);
+	//	if (drugUsePerfFix == 1) {
+	//		// Fix for AI not taking chem_primary_desire in AI.txt as drug use preference when using drugs in their inventory
+	//		MakeCall(0x42869D, ai_check_drugs_hack_break);
+	//		MakeCall(0x4286AB, ai_check_drugs_hack_check, 1);
+	//		MakeCall(0x4286C7, ai_check_drugs_hack_use);
+	//	}
+	//	// Fix to allow using only the drugs listed in chem_primary_desire and healing drugs (stimpaks and healing powder)
+	//	SafeWrite8(0x4286B1, CodeType::JumpZ);  // jnz > jz (ai_check_drugs_)
+	//	SafeWrite8(0x4286C5, CodeType::JumpNZ); // jz > jnz (ai_check_drugs_)
+	//	dlogr(" Done", DL_FIX);
+	//}
 
 	// Fix for chem_primary_desire values in party member AI packets not being saved correctly
 	HookCall(0x42803E, cai_cap_save_hook);

sfall/Modules/HookScripts/ObjectHs.cpp

@@ -10,6 +10,27 @@
 namespace sfall
 {
 
+static long UseObjOnHook_Script(fo::GameObject* source, fo::GameObject* item, fo::GameObject* target) {
+	BeginHook();
+	argCount = 3;
+
+	args[0] = (DWORD)target; // target
+	args[1] = (DWORD)source; // user
+	args[2] = (DWORD)item;   // item
+
+	RunHookScript(HOOK_USEOBJON);
+
+	long result = (cRet > 0) ? rets[0] : -1;
+	EndHook();
+
+	return result; // -1 - default handler
+}
+
+long UseObjOnHook_Invoke(fo::GameObject* source, fo::GameObject* item, fo::GameObject* target) {
+	if (!HookScripts::HookHasScript(HOOK_USEOBJON)) return -1;
+	return UseObjOnHook_Script(source, item, target);
+}
+
 static void __declspec(naked) UseObjOnHook() {
 	__asm {
 		HookBegin;
@@ -369,9 +390,9 @@ void Inject_UseObjOnHook() {
 
 	// the following hooks allows to catch drug use of AI and from action cursor
 	HookCalls(Drug_UseObjOnHook, {
-		0x4285DF, // ai_check_drugs
-		0x4286F8, // ai_check_drugs
-		0x4287F8, // ai_check_drugs
+		//0x4285DF, // ai_check_drugs
+		//0x4286F8, // ai_check_drugs
+		//0x4287F8, // ai_check_drugs
 		0x473573  // inven_action_cursor
 	});
 }

sfall/Modules/HookScripts/ObjectHs.h

@@ -13,4 +13,6 @@ namespace sfall
 	void Inject_ScriptProcedureHook2();
 	void Inject_AdjustPoisonHook();
 	void Inject_AdjustRadsHook();
+
+	long UseObjOnHook_Invoke(fo::GameObject* source, fo::GameObject* item, fo::GameObject* target);
 }

sfall/ReplacementFuncs.h

@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include "Game\combatAI.h"
 #include "Game\inventory.h"
 #include "Game\items.h"
 #include "Game\render.h"

sfall/main.cpp

@@ -102,6 +102,7 @@ DWORD HRPAddress(DWORD addr) {
 char falloutConfigName[65] = {0};
 
 void InitReplacementHacks() {
+	game::CombatAI::init();
 	game::Inventory::init();
 	game::Items::init();
 	game::Render::init();