Merge pull request #537 from sfall-team/feature/barter-auto-calc-money

Added ItemCounterAutoCaps that would pre-fill money count box with "correct" amount when in barter.

artifacts/ddraw.ini

@@ -662,6 +662,9 @@ ReloadReserve=-1
 ;Set to 1 to change the counter in the 'Move Items' window to start with maximum number, except in the barter screen
 ItemCounterDefaultMax=0
 
+;Set to 1 to enable caps auto-balancing: when dragging caps between tables in the barter screen, 'Move Items' window will be shown with correct number pre-filled that balances the tables
+ItemCounterAutoCaps=0
+
 ;Set to 1 to leave the music playing in dialogue with talking heads
 EnableMusicInDialogue=0
 

sfall/FalloutEngine/Fallout2.h

@@ -23,6 +23,7 @@
  */
 
 #include "Enums.h"
+#include "GamePids.h"
 #include "FunctionOffsets.h"
 #include "Structs.h"
 #include "EngineUtils.h"

sfall/FalloutEngine/Variables_def.h

@@ -16,7 +16,7 @@ VAR_(bckgnd,                     BYTE*)
 VAR_(black_palette,              DWORD)
 VAR_(BlueColor,                  BYTE)
 VAR_(bottom_line,                DWORD)
-VAR_(btable,                     DWORD)
+VAR_(btable,                     fo::GameObject*)
 VAR_(btncnt,                     DWORD)
 VAR_(buf_length_2,               long)
 VARD(cap,                        fo::AIcap) // dynamic array
@@ -198,7 +198,7 @@ VARA(procTableStrs,              const char*, (int)fo::Scripts::ScriptProc::coun
 VAR_(proto_main_msg_file,        fo::MessageList)
 VARA(proto_msg_files,            fo::MessageList, 6)  // array of 6 elements
 VARA(protoLists,                 fo::ProtoList, 11)
-VAR_(ptable,                     DWORD)
+VAR_(ptable,                     fo::GameObject*)
 VAR_(pud,                        DWORD)
 VAR_(queue,                      fo::Queue*)
 VAR_(quick_done,                 DWORD)
@@ -222,7 +222,7 @@ VAR_(speech_volume,              DWORD)
 VARA(square,                     DWORD*, 3) // use (square && 0xFFF) to get ground fid, and ((square >> 16) && 0xFFF) to get roof
 VAR_(square_rect,                fo::SquareRect) // _square_y
 VAR_(squares,                    DWORD*)
-VARA(stack,                      DWORD, 10)
+VARA(stack,                      fo::GameObject*, 10)
 VARA(stack_offset,               DWORD, 10)
 VARA(stat_data,                  fo::StatInfo, fo::STAT_real_max_stat)
 VAR_(stat_flag,                  DWORD)
@@ -232,7 +232,7 @@ VAR_(Tag_,                       DWORD)
 VAR_(tag_skill,                  DWORD)
 VAR_(target_curr_stack,          DWORD)
 VAR_(target_pud,                 DWORD*)
-VARA(target_stack,               DWORD, 10)
+VARA(target_stack,               fo::GameObject*, 10)
 VARA(target_stack_offset,        DWORD, 10)
 VAR_(target_str,                 DWORD)
 VAR_(target_xpos,                DWORD)

sfall/Modules/HookScripts/MiscHs.cpp

@@ -9,6 +9,9 @@
 
 namespace sfall
 {
+
+static DWORD lastTableCostPC; // keep last cost for pc
+static DWORD lastTableCostNPC;
 
 // The hook is executed twice when entering the barter screen and after transaction: the first time is for the player; the second time is for NPC
 static DWORD __fastcall BarterPriceHook_Script(fo::GameObject* source, fo::GameObject* target, DWORD callAddr) {
@@ -22,12 +25,12 @@ static DWORD __fastcall BarterPriceHook_Script(fo::GameObject* source, fo::GameO
 	args[1] = (DWORD)target;
 	args[2] = !barterIsParty ? computeCost : 0;
 
-	fo::GameObject* bTable = (fo::GameObject*)fo::var::btable;
+	fo::GameObject* bTable = fo::var::btable;
 	args[3] = (DWORD)bTable;
 	args[4] = fo::func::item_caps_total(bTable);
 	args[5] = fo::func::item_total_cost(bTable);
 
-	fo::GameObject* pTable = (fo::GameObject*)fo::var::ptable;
+	fo::GameObject* pTable = fo::var::ptable;
 	args[6] = (DWORD)pTable;
 
 	long pcCost = 0;
@@ -52,6 +55,11 @@ static DWORD __fastcall BarterPriceHook_Script(fo::GameObject* source, fo::GameO
 			cost = rets[0];                   // new cost for npc
 		}
 	}
+	if (isPCHook) {
+		lastTableCostPC = cost;
+	} else {
+		lastTableCostNPC = cost;
+	}
 	EndHook();
 	return cost;
 }
@@ -70,7 +78,6 @@ static void __declspec(naked) BarterPriceHook() {
 	}
 }
 
-static DWORD offersGoodsCost; // keep last cost for pc
 static void __declspec(naked) PC_BarterPriceHook() {
 	__asm {
 		push edx;
@@ -82,18 +89,27 @@ static void __declspec(naked) PC_BarterPriceHook() {
 		call BarterPriceHook_Script;
 		pop  ecx;
 		pop  edx;
-		mov  offersGoodsCost, eax;
 		retn;
 	}
 }
 
 static void __declspec(naked) OverrideCost_BarterPriceHook() {
 	__asm {
-		mov eax, offersGoodsCost;
+		mov eax, lastTableCostPC;
 		retn;
 	}
 }
 
+void BarterPriceHook_GetLastCosts(long& outPcTableCost, long& outNpcTableCost) {
+	if (!HookScripts::HookHasScript(HOOK_BARTERPRICE)) {
+		outPcTableCost = fo::func::item_total_cost(fo::var::ptable);
+		outNpcTableCost = fo::func::barter_compute_value(fo::var::obj_dude, fo::var::target_stack[0]);
+		return;
+	}
+	outPcTableCost = lastTableCostPC;
+	outNpcTableCost = lastTableCostNPC;
+}
+
 static fo::GameObject* sourceSkillOn = nullptr;
 void SourceUseSkillOnInit() { sourceSkillOn = fo::var::obj_dude; }
 

sfall/Modules/HookScripts/MiscHs.h

@@ -21,4 +21,6 @@ void Inject_RollCheckHook();
 
 long PerceptionRangeHook_Invoke(fo::GameObject* watcher, fo::GameObject* target, long type, long result);
 
+void BarterPriceHook_GetLastCosts(long& outPcTableCost, long& outNpcTableCost);
+
 }

sfall/Modules/Inventory.cpp

@@ -22,6 +22,7 @@
 #include "..\Translate.h"
 
 #include "LoadGameHook.h"
+#include "HookScripts\MiscHs.h"
 
 #include "..\Game\inventory.h"
 #include "..\Game\items.h"
@@ -618,12 +619,67 @@ static void __declspec(naked) do_move_timer_hook() {
 	}
 }
 
+static long CalculateSuggestedMoveCount(fo::GameObject* item, long maxQuantity, bool fromPlayer, bool fromInventory) {
+	// This is an exact copy of logic from https://github.com/alexbatalov/fallout2-ce/pull/311
+    if (item->protoId == fo::PID_BOTTLE_CAPS && !fo::var::dialog_target_is_party) {
+        // Calculate change money automatically
+        long totalCostPlayer;
+        long totalCostNpc;
+		BarterPriceHook_GetLastCosts(totalCostPlayer, totalCostNpc);
+        // Actor's balance: negative - the actor must add money to balance the tables and vice versa
+        long balance = fromPlayer ? totalCostPlayer - totalCostNpc : totalCostNpc - totalCostPlayer;
+        if ((balance < 0 && fromInventory) || (balance > 0 && !fromInventory)) {
+            return min(std::abs(balance), maxQuantity);
+        }
+    }
+	return 1;
+}
+
+static bool itemCounterDefaultMax;
+static bool itemCounterAutoCaps;
+static long __fastcall CalculateDefaultMoveCount(DWORD maybeItem, DWORD retAddr, DWORD maxValue) {
+	maxValue = min(maxValue, 99999); // capped like in vanilla
+	if ((GetLoopFlags() & BARTER) != 0) {
+		if (itemCounterAutoCaps && maxValue > 1) {
+			bool fromPlayer;
+			bool fromInventory;
+			switch (retAddr) {
+			case 0x474F96: // barter_move_inventory
+				fromPlayer = true;
+				fromInventory = true;
+				break;
+			case 0x475015: // barter_move_inventory
+				fromPlayer = false;
+				fromInventory = true;
+				break;
+			case 0x475261: // barter_move_from_table_inventory
+				fromPlayer = true;
+				fromInventory = false;
+				break;
+			case 0x4752DE: // barter_move_from_table_inventory
+				fromPlayer = false;
+				fromInventory = false;
+				break;
+			default:
+				return 1;
+			}
+			// maybeItem may not contain object pointer in all cases, but it does in all 4 from above.
+			return CalculateSuggestedMoveCount((fo::GameObject*)maybeItem, maxValue, fromPlayer, fromInventory);
+		}
+		return 1;
+	}
+	return itemCounterDefaultMax ? maxValue : 1;
+}
+
 static void __declspec(naked) do_move_timer_hack() {
 	__asm {
-		mov  ebx, 1;
-		call GetLoopFlags;
-		test eax, BARTER;
-		cmovz ebx, ebp; // set max when not in barter
+		push ecx;
+		push ebp; // max
+		mov edx, dword ptr[esp + 32]; // return address
+		mov ecx, dword ptr[esp + 20]; // item, potentially
+		call CalculateDefaultMoveCount;
+		mov  ebx, eax;
+		pop ecx;
 		retn;
 	}
 }
@@ -755,7 +811,9 @@ void Inventory::init() {
 		skipFromContainer = IniReader::GetConfigInt("Input", "FastMoveFromContainer", 0);
 	}
 
-	if (IniReader::GetConfigInt("Misc", "ItemCounterDefaultMax", 0)) {
+	itemCounterDefaultMax = IniReader::GetConfigInt("Misc", "ItemCounterDefaultMax", 0);
+	itemCounterAutoCaps = IniReader::GetConfigInt("Misc", "ItemCounterAutoCaps", 0);
+	if (itemCounterDefaultMax || itemCounterAutoCaps) {
 		MakeCall(0x4768A3, do_move_timer_hack);
 	}