Fixed the check of the ammo cost for a shot in CheckWeaponAmmoCost (#360)

artifacts/scripting/hookscripts.txt

@@ -349,6 +349,7 @@ int     arg2 - Ammo cost calculated by original function (this is basically 2 fo
 int     arg3 - Type of hook (0 - when subtracting ammo after single shot attack, 1 - when checking for "out of ammo" before attack, 2 - when calculating number of burst rounds, 3 - when subtracting ammo after burst attack)
 
 int     ret0 - new ammo cost value (set to 0 for unlimited ammo)
+               NOTE: for hook type 2, you should return the new cost value based on the original ammo cost instead of the number of bullets
 
 -------------------------------------------
 

sfall/Modules/AI.cpp

@@ -346,14 +346,14 @@ static long tempReloadCost;
 
 static long __fastcall item_weapon_reload_cost_fix(fo::GameObject* source, fo::GameObject* weapon, fo::GameObject** outAmmo) {
 	long reloadCost = game::Items::item_weapon_mp_cost(source, weapon, fo::AttackType::ATKTYPE_RWEAPON_RELOAD, 0);
-	if (reloadCost > source->critter.movePoints) return -1; // no action points
+	if (reloadCost > source->critter.movePoints) return -1; // not enough action points
 	tempReloadCost = reloadCost;
 
 	return fo::func::ai_have_ammo(source, weapon, outAmmo); // 0 - no ammo
 }
 
 static void __declspec(naked) ai_try_attack_hook_cost_reload() {
-	static const DWORD ai_try_attack_hook_unwield_Ret = 0x42AACD;
+	static const DWORD ai_try_attack_hook_goNext_Ret = 0x42A9F2;
 	__asm {
 		push ebx;      // ammoObj ref
 		mov  ecx, eax; // source
@@ -361,9 +361,10 @@ static void __declspec(naked) ai_try_attack_hook_cost_reload() {
 		cmp  eax, -1;
 		je   noAPs;
 		retn;
-noAPs:
+noAPs:  // not enough action points
 		add  esp, 4; // destroy ret
-		jmp  ai_try_attack_hook_unwield_Ret; // unwield weapon (default)
+		mov  edi, 10;
+		jmp  ai_try_attack_hook_goNext_Ret; // end ai_try_attack_
 	}
 }
 

sfall/Modules/Combat.cpp

@@ -89,26 +89,31 @@ static bool hookedAimedShot;
 static std::vector<DWORD> disabledAS;
 static std::vector<DWORD> forcedAS;
 
-DWORD __fastcall Combat::check_item_ammo_cost(fo::GameObject* weapon, DWORD hitMode) {
-	DWORD rounds = 1;
+static bool checkWeaponAmmoCost;
 
-	long anim = fo::func::item_w_anim_weap(weapon, (fo::AttackType)hitMode);
+// Compares the cost (required count of rounds) for one shot with the current amount of ammo to make an attack or other checks
+long __fastcall Combat::check_item_ammo_cost(fo::GameObject* weapon, fo::AttackType hitMode) {
+	long currAmmo = fo::func::item_w_curr_ammo(weapon);
+	if (!checkWeaponAmmoCost || currAmmo <= 0) return currAmmo;
+
+	long rounds = 1; // default ammo for single shot
+
+	long anim = fo::func::item_w_anim_weap(weapon, hitMode);
 	if (anim == fo::Animation::ANIM_fire_burst || anim == fo::Animation::ANIM_fire_continuous) {
 		rounds = fo::func::item_w_rounds(weapon); // ammo in burst
 	}
-	if (HookScripts::IsInjectHook(HOOK_AMMOCOST)) {
-		AmmoCostHook_Script(1, weapon, rounds);   // get rounds cost from hook
-	} else if (rounds == 1) {
-		fo::func::item_w_compute_ammo_cost(weapon, &rounds);
-	}
-	long currAmmo = fo::func::item_w_curr_ammo(weapon);
 
-	long cost = 1; // default cost
-	if (currAmmo > 0) {
-		cost = rounds / currAmmo;
-		if (rounds % currAmmo) cost++; // round up
+	DWORD newRounds = rounds;
+
+	if (HookScripts::IsInjectHook(HOOK_AMMOCOST)) {
+		AmmoCostHook_Script(1, weapon, newRounds); // newRounds returns the new "ammo" value multiplied by the cost
+	} else if (rounds == 1) { // NOTE: it doesn't make sense to call item_w_compute_ammo_cost for rounds greater than one
+		fo::func::item_w_compute_ammo_cost(weapon, &newRounds);
 	}
-	return (cost > currAmmo) ? 0 : 1;  // 0 - this will force "Out of ammo", 1 - this will force success (enough ammo)
+
+	// calculate the cost
+	long cost = (newRounds != rounds) ? newRounds / rounds : 1; // 1 - default cost
+	return (cost > currAmmo) ? 0 : currAmmo; // 0 - this will force "Not Enough Ammo"
 }
 
 // adds check for weapons which require more than 1 ammo for single shot (super cattle prod & mega power fist) and burst rounds
@@ -129,8 +134,8 @@ static void __declspec(naked) ai_search_inven_weap_hook() {
 	using namespace fo;
 	__asm {
 		push ecx;
-		mov  ecx, eax;                      // weapon
 		mov  edx, ATKTYPE_RWEAPON_PRIMARY; // hitMode
+		mov  ecx, eax;                     // weapon
 		call Combat::check_item_ammo_cost; // enough ammo?
 		pop  ecx;
 		retn;
@@ -160,34 +165,36 @@ tryAttack:
 	}
 }
 
-static DWORD __fastcall divide_burst_rounds_by_ammo_cost(fo::GameObject* weapon, register DWORD currAmmo, DWORD burstRounds) {
-	DWORD rounds = 1; // default multiply
+/*** The return value should set the correct count of rounds for the burst calculated based on the cost ***/
+static long __fastcall divide_burst_rounds_by_ammo_cost(long currAmmo, fo::GameObject* weapon, long burstRounds) {
+	DWORD roundsCost = 1; // default burst cost
 
 	if (HookScripts::IsInjectHook(HOOK_AMMOCOST)) {
-		rounds = burstRounds;             // rounds in burst
-		AmmoCostHook_Script(2, weapon, rounds);
+		roundsCost = burstRounds;                   // rounds in burst (the number of rounds fired in the burst)
+		AmmoCostHook_Script(2, weapon, roundsCost); // roundsCost returns the new cost
 	}
 
-	DWORD cost = burstRounds * rounds;    // so much ammo is required for this burst
+	long cost = burstRounds * roundsCost; // amount of ammo required for this burst (multiplied by 1 or by the value returned from HOOK_AMMOCOST)
 	if (cost > currAmmo) cost = currAmmo; // if cost ammo more than current ammo, set it to current
 
-	return (cost / rounds);               // divide back to get proper number of rounds for damage calculations
+	return (cost / roundsCost);           // divide back to get proper number of rounds for damage calculations
 }
 
 static void __declspec(naked) compute_spray_hack() {
-	__asm {
-		push edx;         // weapon
-		push ecx;         // current ammo in weapon
-		xchg ecx, edx;
-		push eax;         // eax - rounds in burst attack, need to set ebp
+	__asm { // ebp = current ammo
+//		push edx;      // weapon
+//		push ecx;      // current ammo in weapon
+		push eax;      // rounds in burst attack, need to set ebp
 		call divide_burst_rounds_by_ammo_cost;
 		mov  ebp, eax; // overwriten code
-		pop  ecx;
-		pop  edx;
+//		pop  ecx;
+//		pop  edx;
 		retn;
 	}
 }
 
+////////////////////////////////////////////////////////////////////////////////
+
 static double ApplyModifiers(std::vector<KnockbackModifier>* mods, fo::GameObject* object, double val) {
 	for (size_t i = 0; i < mods->size(); i++) {
 		KnockbackModifier* mod = &(*mods)[i];
@@ -271,11 +278,12 @@ bool Combat::IsBurstDisabled(fo::GameObject* critter) {
 }
 
 static long __fastcall CheckDisableBurst(fo::GameObject* critter, fo::GameObject* weapon) {
-	if (fo::func::item_w_anim_weap(weapon, fo::AttackType::ATKTYPE_RWEAPON_SECONDARY) == fo::Animation::ANIM_fire_burst &&
-		Combat::IsBurstDisabled(critter))
-	{
+	if (Combat::IsBurstDisabled(critter)) {
+		long anim = fo::func::item_w_anim_weap(weapon, fo::AttackType::ATKTYPE_RWEAPON_SECONDARY);
+		if (anim == fo::Animation::ANIM_fire_burst || anim == fo::Animation::ANIM_fire_continuous) {
 			return 10; // Disable Burst (area_attack_mode - non-existent value)
 		}
+	}
 	return 0;
 }
 
@@ -520,10 +528,11 @@ void Combat::init() {
 	// Disables secondary burst attacks for the critter
 	MakeCall(0x429E44, ai_pick_hit_mode_hack_noBurst, 1);
 
-	if (GetConfigInt("Misc", "CheckWeaponAmmoCost", 0)) {
+	checkWeaponAmmoCost = (GetConfigInt("Misc", "CheckWeaponAmmoCost", 0) != 0);
+	if (checkWeaponAmmoCost) {
 		MakeCall(0x4234B3, compute_spray_hack, 1);
 		HookCall(0x4266E9, combat_check_bad_shot_hook);
-		HookCall(0x429A37, ai_search_inven_weap_hook);
+		HookCall(0x429A37, ai_search_inven_weap_hook); // check if there is enough ammo to shoot
 		HookCall(0x42A95D, ai_try_attack_hook); // jz func
 	}
 

sfall/Modules/Combat.h

@@ -49,7 +49,7 @@ public:
 
 	static long determineHitChance;
 
-	static DWORD __fastcall check_item_ammo_cost(fo::GameObject* weapon, DWORD hitMode);
+	static long __fastcall check_item_ammo_cost(fo::GameObject* weapon, fo::AttackType hitMode);
 
 	static bool IsBurstDisabled(fo::GameObject* critter);
 };

sfall/Modules/HookScripts/CombatHs.cpp

@@ -343,7 +343,7 @@ int __fastcall AmmoCostHook_Script(DWORD hookType, fo::GameObject* weapon, DWORD
 		rounds = 1;             // set default multiply for check burst attack
 	} else {
 		result = fo::func::item_w_compute_ammo_cost(weapon, &rounds);
-		if (result == -1) goto failed; // failed computed
+		if (result == -1) goto failed; // computation failed
 	}
 	args[2] = rounds;           // rounds as computed by game (cost)
 
@@ -367,7 +367,7 @@ static void __declspec(naked) AmmoCostHook() {
 		mov  ecx, 3;               // hook type burst
 skip:
 		xchg eax, edx;
-		push eax;                  // rounds in attack
+		push eax;                  // rounds in attack ref
 		call AmmoCostHook_Script;  // edx - weapon
 		retn;
 	}
@@ -634,7 +634,7 @@ void Inject_ItemDamageHook() {
 }
 
 void Inject_AmmoCostHook() {
-	HookCall(0x423A7C, AmmoCostHook);
+	HookCall(0x423A7C, AmmoCostHook); // compute_attack_
 }
 
 void Inject_CombatTurnHook() {