Split grenade collision from weapon collision (PR #2716)

Author: Merlin

Client/multiplayer_sa/CMultiplayerSA.cpp

@@ -1572,6 +1572,7 @@ void CMultiplayerSA::InitHooks()
 
     InitHooks_Streaming();
     InitHooks_FrameRateFixes();
+    InitHooks_ProjectileCollisionFix();
     InitHooks_ObjectStreamerOptimization();
 }
 

Client/multiplayer_sa/CMultiplayerSA.h

@@ -77,6 +77,7 @@ class CMultiplayerSA : public CMultiplayer
     void                InitHooks_FixLineOfSightArgs();
     void                InitHooks_Streaming();
     void                InitHooks_FrameRateFixes();
+    void                InitHooks_ProjectileCollisionFix();
     void                InitHooks_ObjectStreamerOptimization();
     CRemoteDataStorage* CreateRemoteDataStorage();
     void                DestroyRemoteDataStorage(CRemoteDataStorage* pData);

Client/multiplayer_sa/CMultiplayerSA_ProjectileCollisionFix.cpp

@@ -0,0 +1,84 @@
+/*****************************************************************************
+ *
+ *  PROJECT:     Multi Theft Auto
+ *  LICENSE:     See LICENSE in the top level directory
+ *  FILE:        multiplayer_sa/CMultiplayerSA_ProjectileCollisionFix.cpp
+ *
+ *  Multi Theft Auto is available from https://www.multitheftauto.com/
+ *
+ *****************************************************************************/
+
+#include "StdInc.h"
+#include "../game_sa/CColModelSA.h"
+
+static CColModelSAInterface colModelGrenade;
+
+static void InitializeGrenadeColModel()
+{
+    // CColModel::CColModel
+    ((CColModelSAInterface*(__thiscall*)(CColModelSAInterface*))(0x40FB60))(&colModelGrenade);
+
+    colModelGrenade.m_bounds.m_vecMin = CVector(-0.25f, -0.25f, -0.25f);
+    colModelGrenade.m_bounds.m_vecMax = CVector(0.25f, 0.25f, 0.25f);
+
+    colModelGrenade.m_sphere.m_center = CVector(0, 0, 0);
+    colModelGrenade.m_sphere.m_radius = 0.25f;
+
+    // CColModel::AllocateData
+    ((void(__thiscall*)(CColModelSAInterface*, int, int, int, int, int, int))(0x40F870))(&colModelGrenade, 1, 0, 0, 0, 0, 0);
+
+    // CColSphere::Set
+    ((void(__thiscall*)(CColSphereSA*, float, CVector&, unsigned char, char, unsigned char))(0x40FD10))(
+        &colModelGrenade.m_data->m_spheres[0],
+        colModelGrenade.m_sphere.m_radius * 0.75f,
+        colModelGrenade.m_sphere.m_center,
+        56, 0, 255);
+}
+
+#define HOOKPOS_CTempColModels__Initialise 0x5BB87D
+#define HOOKSIZE_CTempColModels__Initialise 0x6
+static const unsigned int RETURN_CTempColModels__Initialise = 0x5BB883;
+static void _declspec(naked) HOOK_CTempColModels__Initialise()
+{
+    _asm {
+        mov ds:[0x968FE4], edx
+
+        call InitializeGrenadeColModel
+
+        jmp RETURN_CTempColModels__Initialise
+    }
+}
+
+#define HOOKPOS_CFileLoader__LoadWeaponObject 0x5B401E
+#define HOOKSIZE_CFileLoader__LoadWeaponObject 0x5
+static const unsigned int RETURN_CFileLoader__LoadWeaponObject = 0x5B4023;
+static void _declspec(naked) HOOK_CFileLoader__LoadWeaponObject()
+{
+    _asm {
+        mov eax, [esp+0x8]
+        cmp eax, 342
+        je grenade
+        cmp eax, 343
+        je grenade
+        cmp eax, 344
+        je grenade
+        cmp eax, 363
+        je grenade
+
+        push 0x968FD0
+        jmp RETURN_CFileLoader__LoadWeaponObject
+
+    grenade:
+        push offset colModelGrenade
+        jmp RETURN_CFileLoader__LoadWeaponObject
+    }
+}
+
+void CMultiplayerSA::InitHooks_ProjectileCollisionFix()
+{
+    EZHookInstall(CTempColModels__Initialise);
+    EZHookInstall(CFileLoader__LoadWeaponObject);
+
+    MemCpy((void*)0x7383FF, "\xE9\x5E\x01\x00\x00", 5);
+    MemSet((void*)0x738404, 0x90, 0x9C);
+}