Add ability to enable/disable vehicle model hierarchy typo fixes

Client/mods/deathmatch/logic/luadefs/CLuaEngineDefs.cpp

@@ -10,6 +10,7 @@
  *****************************************************************************/
 
 #include "StdInc.h"
+#include <multiplayer/CMultiplayer.h>
 #include <game/CColPoint.h>
 #include <game/CObjectGroupPhysicalProperties.h>
 #include <game/CStreaming.h>
@@ -83,6 +84,17 @@ size_t EngineStreamingGetBufferSize()
     return g_pGame->GetStreaming()->GetStreamingBufferSize();
 }
 
+// Opt-in SilentPatch-style fixes for stock vehicle.dff hierarchy typos (wheel_lm_dummy vs wheel_lm, etc.).
+void EngineSetVehicleHierarchyTypoFixesEnabled(bool enabled)
+{
+    g_pCore->GetMultiplayer()->SetVehicleHierarchyTypoFixesEnabled(enabled);
+}
+
+bool EngineGetVehicleHierarchyTypoFixesEnabled()
+{
+    return g_pCore->GetMultiplayer()->GetVehicleHierarchyTypoFixesEnabled();
+}
+
 void CLuaEngineDefs::LoadFunctions()
 {
     constexpr static const std::pair<const char*, lua_CFunction> functions[]{
@@ -163,6 +175,8 @@ void CLuaEngineDefs::LoadFunctions()
         {"enginePreloadWorldArea", ArgumentParser<EnginePreloadWorldArea>},
         {"engineRestreamModel", ArgumentParser<EngineRestreamModel>},
         {"engineRestream", ArgumentParser<EngineRestream>},
+        {"engineSetVehicleHierarchyTypoFixesEnabled", ArgumentParser<EngineSetVehicleHierarchyTypoFixesEnabled>},
+        {"engineGetVehicleHierarchyTypoFixesEnabled", ArgumentParser<EngineGetVehicleHierarchyTypoFixesEnabled>},
 
         // CLuaCFunctions::AddFunction ( "engineReplaceMatchingAtomics", EngineReplaceMatchingAtomics );
         // CLuaCFunctions::AddFunction ( "engineReplaceWheelAtomics", EngineReplaceWheelAtomics );
@@ -212,6 +226,9 @@ void CLuaEngineDefs::AddClass(lua_State* luaVM)
     lua_classfunction(luaVM, "setModelTXDID", "engineSetModelTXDID");
     lua_classfunction(luaVM, "resetModelTXDID", "engineResetModelTXDID");
 
+    lua_classfunction(luaVM, "setVehicleHierarchyTypoFixesEnabled", "engineSetVehicleHierarchyTypoFixesEnabled");
+    lua_classfunction(luaVM, "getVehicleHierarchyTypoFixesEnabled", "engineGetVehicleHierarchyTypoFixesEnabled");
+
     lua_registerstaticclass(luaVM, "Engine");
 
     // `EngineStreaming` class

Client/multiplayer_sa/CMultiplayerSA.h

@@ -356,6 +356,9 @@ class CMultiplayerSA : public CMultiplayer
     void SetBoatWaterSplashEnabled(bool bEnabled);
     void SetTyreSmokeEnabled(bool bEnabled);
 
+    void SetVehicleHierarchyTypoFixesEnabled(bool bEnabled) override;
+    bool GetVehicleHierarchyTypoFixesEnabled() const override;
+
     void SetLastStaticAnimationPlayed(eAnimGroup dwGroupID, eAnimID dwAnimID, DWORD dwAnimArrayAddress)
     {
         m_dwLastStaticAnimGroupID = dwGroupID;

Client/multiplayer_sa/CMultiplayerSA_VehicleHierarchyTypoFixes.cpp

@@ -0,0 +1,82 @@
+/*****************************************************************************
+ *
+ *  PROJECT:     Multi Theft Auto
+ *  LICENSE:     See LICENSE in the top level directory
+ *  FILE:        multiplayer_sa/CMultiplayerSA_VehicleHierarchyTypoFixes.cpp
+ *  PURPOSE:     Optional CVehicleModelInfo hierarchy compare hook (matches SilentPatch SA)
+ *
+ *  GTA matches IDE/handling component names to frame names via _stricmp inside
+ *  CVehicleModelInfo setup. Stock models use inconsistent spellings; SilentPatch
+ *  wraps that call to accept both canonical and typo names. We expose the same
+ *  behaviour only when enabled so servers can keep fully vanilla visuals.
+ *
+ *****************************************************************************/
+
+#include "StdInc.h"
+#include "CMultiplayerSA.h"
+
+#include <utility>
+
+namespace
+{
+    // Off by default (matches stock GTA SA without SilentPatch).
+    bool g_bVehicleHierarchyTypoFixesEnabled = false;
+
+    int(__cdecl* g_pfnOrgStricmp)(const char*, const char*) = nullptr;
+
+    // Pairs are { correct name, name as in shipping .dff }. Must be sorted by the second string.
+    static constexpr std::pair<const char*, const char*> typosAndFixes[] = {
+        {"boat_moving_hi", "boat_moving"},
+        {"elevator_r", "elevator"},
+        {"misc_a", "misca"},
+        {"misc_b", "miscb"},
+        {"taillights", "tailights"},
+        {"taillights2", "tailights2"},
+        {"transmission_f", "transmision_f"},
+        {"transmission_r", "transmision_r"},
+        {"wheel_lm_dummy", "wheel_lm"},
+    };
+
+    int __cdecl Hooked_VehicleHierarchy_Stricmp(const char* dataName, const char* nodeName)
+    {
+        if (!g_bVehicleHierarchyTypoFixesEnabled)
+            return g_pfnOrgStricmp(dataName, nodeName);
+
+        const int origComp = g_pfnOrgStricmp(dataName, nodeName);
+        if (origComp == 0)
+            return 0;
+
+        for (const auto& typo : typosAndFixes)
+        {
+            const int nodeComp = _stricmp(typo.second, nodeName);
+            if (nodeComp > 0)
+                break;
+
+            if (nodeComp == 0 && _stricmp(typo.first, dataName) == 0)
+                return 0;
+        }
+
+        return origComp;
+    }
+}  // namespace
+
+void InitVehicleHierarchyTypoFixesHook()
+{
+    // SA 1.0 US: indirect call to _stricmp while CVehicleModelInfo binds handling/IDE component names to clump frames.
+    // Same site hooked by SilentPatch (`InterceptCall(0x4C5311, ...)`).
+    constexpr DWORD CALLSITE = 0x4C5311;
+    HookCheckOriginalByte(CALLSITE, 0xE8);
+    const DWORD rel = *reinterpret_cast<DWORD*>(CALLSITE + 1);
+    g_pfnOrgStricmp = reinterpret_cast<decltype(g_pfnOrgStricmp)>(CALLSITE + 5 + rel);
+    HookInstallCall(CALLSITE, reinterpret_cast<DWORD>(&Hooked_VehicleHierarchy_Stricmp));
+}
+
+void CMultiplayerSA::SetVehicleHierarchyTypoFixesEnabled(bool bEnabled)
+{
+    g_bVehicleHierarchyTypoFixesEnabled = bEnabled;
+}
+
+bool CMultiplayerSA::GetVehicleHierarchyTypoFixesEnabled() const
+{
+    return g_bVehicleHierarchyTypoFixesEnabled;
+}

Client/multiplayer_sa/CMultiplayerSA_VehicleHierarchyTypoFixes.h

@@ -0,0 +1,12 @@
+/*****************************************************************************
+ *
+ *  PROJECT:     Multi Theft Auto
+ *  LICENSE:     See LICENSE in the top level directory
+ *  FILE:        multiplayer_sa/CMultiplayerSA_VehicleHierarchyTypoFixes.h
+ *  PURPOSE:     Init for optional vehicle.dff hierarchy typo matching (SilentPatch-style)
+ *
+ *****************************************************************************/
+
+#pragma once
+
+void InitVehicleHierarchyTypoFixesHook();

Client/multiplayer_sa/CMultiplayerSA_Vehicles.cpp

@@ -9,6 +9,7 @@
  *****************************************************************************/
 
 #include "StdInc.h"
+#include "CMultiplayerSA_VehicleHierarchyTypoFixes.h"
 
 static bool __fastcall AreVehicleDoorsUndamageable(CVehicleSAInterface* vehicle)
 {
@@ -72,4 +73,7 @@ static void __declspec(naked) HOOK_CDamageManager__ProgressDoorDamage()
 void CMultiplayerSA::InitHooks_Vehicles()
 {
     EZHookInstall(CDamageManager__ProgressDoorDamage);
+
+    // SilentPatch-style optional matching for typo'd vehicle component frame names (see CMultiplayerSA_VehicleHierarchyTypoFixes.cpp).
+    InitVehicleHierarchyTypoFixesHook();
 }

Client/sdk/multiplayer/CMultiplayer.h

@@ -463,6 +463,11 @@ class CMultiplayer
     virtual void SetBoatWaterSplashEnabled(bool bEnabled) = 0;
     virtual void SetTyreSmokeEnabled(bool bEnabled) = 0;
 
+    // When enabled, matches canonical vehicle component names to the typo'd hierarchy nodes in stock GTA SA models
+    // (SilentPatch-style fix). Off by default so behaviour stays vanilla unless a script opts in.
+    virtual void SetVehicleHierarchyTypoFixesEnabled(bool bEnabled) = 0;
+    virtual bool GetVehicleHierarchyTypoFixesEnabled() const = 0;
+
     virtual eAnimGroup GetLastStaticAnimationGroupID() = 0;
     virtual eAnimID    GetLastStaticAnimationID() = 0;
     virtual DWORD      GetLastAnimArrayAddress() = 0;