From 41fd1e349584466c07a4093baff2f9f14b42897f Mon Sep 17 00:00:00 2001
From: NovaRain <novarain@gmail.com>
Date: Sun, 15 Mar 2026 07:55:23 +0800
Subject: [PATCH] Fixed +/- not updating brightness slider when used on the
 Pref screen

(ref. fallout2-ce/fallout2-ce#298)
---
 sfall/FalloutEngine/VariableOffsets.h |  2 ++
 sfall/Modules/Interface.cpp           | 39 ++++++++++++++++++++++++++-
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/sfall/FalloutEngine/VariableOffsets.h b/sfall/FalloutEngine/VariableOffsets.h
index 3074f105..f504a06a 100644
--- a/sfall/FalloutEngine/VariableOffsets.h
+++ b/sfall/FalloutEngine/VariableOffsets.h
@@ -41,6 +41,7 @@
 #define FO_VAR_carCurrentArea             0x672E68
 #define FO_VAR_carGasAmount               0x672E6C
 #define FO_VAR_card_old_fid1              0x5709EC
+#define FO_VAR_changed                    0x6639A8 // used in the Preferences screen
 #define FO_VAR_character_points           0x518538
 #define FO_VAR_cmap                       0x51DF34
 #define FO_VAR_colorTable                 0x6A38D0
@@ -287,6 +288,7 @@
 #define FO_VAR_pip_win                    0x6644C4
 #define FO_VAR_pipboy_message_file        0x664348
 #define FO_VAR_pipmesg                    0x664338
+#define FO_VAR_prfwin                     0x663904
 #define FO_VAR_preload_list_index         0x519640
 #define FO_VAR_procTableStrs              0x51C758  // table of procId (from define.h) => procName map
 #define FO_VAR_proto_main_msg_file        0x6647FC
diff --git a/sfall/Modules/Interface.cpp b/sfall/Modules/Interface.cpp
index e51697b9..2a6d1712 100644
--- a/sfall/Modules/Interface.cpp
+++ b/sfall/Modules/Interface.cpp
@@ -781,7 +781,7 @@ static void __fastcall wmDetectHotspotHover(long wmMouseX, long wmMouseY) {
 
 static __declspec(naked) void wmWorldMap_hack() {
 	__asm {
-		cmp  ds:[FO_VAR_In_WorldMap], 1; // player is moving
+		cmp  dword ptr ds:[FO_VAR_In_WorldMap], 1; // player is moving
 		jne  checkHover;
 		mov  eax, dword ptr ds:[FO_VAR_wmWorldOffsetY]; // overwritten code
 		retn;
@@ -1084,6 +1084,39 @@ skip:
 	}
 }
 
+static __declspec(naked) void IncDecGamma_hack0() {
+	__asm {
+		call GetLoopFlags;
+		test eax, OPTIONS;
+		jnz  inPref;
+		mov  ebx, 0x3FF00000; // overwritten engine code
+		retn;
+inPref:
+		pop  ebx;
+		add  ebx, 39; // offset to next section (0x492916, 0x4929FA)
+		jmp  ebx;
+	}
+}
+
+static __declspec(naked) void IncDecGamma_hack1() {
+	__asm {
+		call GetLoopFlags;
+		test eax, OPTIONS;
+		jnz  inPref;
+		mov  eax, ds:[0x6638D4]; // overwritten engine code
+		retn;
+inPref:
+		mov  eax, 17; // Brightness slider
+		call fo::funcoffs::UpdateThing_;
+		mov  eax, ds:[FO_VAR_prfwin];
+		call fo::funcoffs::win_draw_; // redraw the Preferences screen
+		mov  dword ptr ds:[FO_VAR_changed], 1;
+		pop  edx;
+		add  edx, 52; // offset to next section (0x4929BE, 0x492A9E)
+		jmp  edx;
+	}
+}
+
 static __declspec(naked) void display_body_hook() {
 	__asm {
 		mov  ebx, [esp + 0x60 - 0x28 + 8];
@@ -1444,6 +1477,10 @@ void Interface::init() {
 	MakeCalls(gdCustomSelect_hack_buttons, {0x44A100, 0x44A151});
 	MakeCall(0x44A47D, gdCustomSelect_hack_keyretn);
 
+	// Fix the +/- keys not updating the brightness slider when used on the Preferences screen
+	MakeCalls(IncDecGamma_hack0, {0x4928EA, 0x4929CE});
+	MakeCalls(IncDecGamma_hack1, {0x492985, 0x492A65});
+
 	LoadGameHook::OnGameInit() += []() {
 		// Needs to be invoked in OnGameInit when screen height is already known and db is initialized.
 		ExpandedBarterPatch();