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implement crouch walk game logic
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@cipherxof
cipherxof committed Nov 15, 2023
1 parent c5bc27b commit ec02add
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Showing 4 changed files with 176 additions and 20 deletions.
1 change: 1 addition & 0 deletions MGS3CrouchWalk/MGS3CrouchWalk.vcxproj
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Expand Up @@ -155,6 +155,7 @@
<ClInclude Include="ini.h" />
<ClInclude Include="Memory.h" />
<ClInclude Include="MinHook.h" />
<ClInclude Include="types.h" />
</ItemGroup>
<ItemGroup>
<ClCompile Include="dllmain.cpp" />
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3 changes: 3 additions & 0 deletions MGS3CrouchWalk/MGS3CrouchWalk.vcxproj.filters
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Expand Up @@ -27,6 +27,9 @@
<ClInclude Include="ini.h">
<Filter>Header Files</Filter>
</ClInclude>
<ClInclude Include="types.h">
<Filter>Header Files</Filter>
</ClInclude>
</ItemGroup>
<ItemGroup>
<ClCompile Include="dllmain.cpp">
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115 changes: 95 additions & 20 deletions MGS3CrouchWalk/dllmain.cpp
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Expand Up @@ -2,38 +2,102 @@
#include "Memory.h"
#include "MinHook.h"
#include "ini.h"
#include "types.h"

HMODULE GameModule = GetModuleHandleA("METAL GEAR SOLID3.exe");
uintptr_t GameBase = (uintptr_t)GameModule;
uintptr_t* CamoIndexData = NULL;
uintptr_t ActSquatStillOffset = 0;
MovementWork* plWorkGlobal = NULL;
float CamoIndexModifier = 1.0f;
int CamoIndexValue = 0;
bool CrouchWalkEnabled = false;
bool CrouchMoving = false;
mINI::INIStructure Config;

typedef uintptr_t* __fastcall InitializeCamoIndexDelegate(uintptr_t a1, int a2);
InitializeCamoIndexDelegate* InitializeCamoIndex;

typedef uintptr_t __fastcall CalculateCamoIndexDelegate(uintptr_t a1, int a2);
CalculateCamoIndexDelegate* CalculateCamoIndex;
uintptr_t __fastcall CalculateCamoIndexHook(uintptr_t a1, int a2)
ActionSquatStillDelegate* ActionSquatStill;
PlayerSetMotionDelegate* PlayerSetMotionInternal;
SetMotionDataDelegate* SetMotionData;
PlayerStatusCheckDelegate* PlayerStatusCheck;
ActMovementDelegate* ActMovement;

uintptr_t PlayerSetMotion(__int64 work, PlayerMotion motion)
{
int motionIndex = (int)motion;

if (motionIndex > 0)
{
motionIndex--;
}

return PlayerSetMotionInternal(work, (PlayerMotion)motionIndex);
}

int* __fastcall ActionSquatStillHook(__int64 work, MovementWork* plWork, __int64 a3, __int64 a4)
{
uintptr_t result = CalculateCamoIndex(a1, a2);
// we store this here so we don't have to hardcode another address that
// needs to be updated with each new game patch
plWorkGlobal = plWork;

if (CamoIndexData != NULL)
int* result = ActionSquatStill(work, plWork, a3, a4);
int16_t padForce = *(int16_t*)(work + 2016);

CrouchMoving = padForce > plWork->padForceLimit;

// 0xDE seems to make sure we aren't in first person mode
if (CrouchMoving && !PlayerStatusCheck(0xDE))
{
if (!CrouchWalkEnabled)
plWork->motion = PlayerSetMotion(work, PlayerMotion::RunUpwards); // we must set the motion to something unusable on the first run, otherwise the anim won't reset properly
else
plWork->motion = PlayerSetMotion(work, PlayerMotion::StandMoveStalk); // hijack the stalking motion

CrouchWalkEnabled = true;
}

if (CrouchWalkEnabled && (plWork->flag & MovementFlag::FlagStand) != 0)
CrouchWalkEnabled = false;

return result;
}

void __fastcall SetMotionDataHook(int* m_ctrl, int layer, PlayerMotion motion, int time, __int64 a5)
{
if (motion == PlayerMotion::StandMoveStalk && CrouchWalkEnabled)
motion = PlayerMotion::SquatMove;

SetMotionData(m_ctrl, layer, motion, time, a5);
}

__int64 __fastcall ActMovementHook(MovementWork* plWork, __int64 work, int flag)
{
if (plWorkGlobal != NULL && plWorkGlobal->action != ActSquatStillOffset)
CrouchWalkEnabled = false;

return ActMovement(plWork, work, flag);
}

int* __fastcall CalculateCamoIndexHook(int* a1, int a2)
{
int* result = CalculateCamoIndex(a1, a2);

if (CamoIndexData != NULL && CrouchWalkEnabled)
{
int index = a2 << 7;
auto camoIndex = (int*)((char*)&CamoIndexData[4] + index + 4);
auto movementState = (int*)((char*)&CamoIndexData[4] + index + 8);

if (*camoIndex >= 1000) // ignore if stealth is equipped
if (*camoIndex >= 1000) // ignore if stealth is equipped (todo: properly check item for ezgun and spider camo)
{
return result;
}

if (*movementState == 0x6002)
if (CrouchMoving)
{
*camoIndex = *camoIndex < 0 ? *camoIndex / CamoIndexModifier : *camoIndex * CamoIndexModifier;
*camoIndex += CamoIndexValue;
*camoIndex = *camoIndex < 0 ? *camoIndex / CamoIndexModifier : *camoIndex * CamoIndexModifier;
*camoIndex -= CamoIndexValue;

if (*camoIndex > 950) *camoIndex = 950;
if (*camoIndex < -1000) *camoIndex = -1000;
Expand All @@ -42,18 +106,30 @@ uintptr_t __fastcall CalculateCamoIndexHook(uintptr_t a1, int a2)

return result;
}

void InstallHooks()
void InstallHooks()
{
int status = MH_Initialize();

uintptr_t actMovementOffset = (uintptr_t)Memory::PatternScan(GameModule, "40 53 56 57 48 81 EC F0 00 00 00 48 8B 05 96 ?? ?? 00 48 33 C4 48 89 84 24 B0 00 00 00 48 8B F9");
uintptr_t setMotionDataOffset = (uintptr_t)Memory::PatternScan(GameModule, "48 85 C9 0F 84 42 03 00 00 4C 8B DC 55 53 56 41");
uintptr_t calcuateCamoIndexOffset = (uintptr_t)Memory::PatternScan(GameModule, "48 83 EC 30 0F 29 74 24 20 48 8B F9 48 63 F2 E8") - 0x10;
uintptr_t initializeCamoIndexOffset = (uintptr_t)Memory::PatternScan(GameModule, "85 D2 75 33 0F 57 C0 48 63 C2 48 C1 E0 07 48 8D");
uint8_t* disableCrouchProneOffset = Memory::PatternScan(GameModule, "00 00 7E 19 83 4F 68 10");

ActSquatStillOffset = (uintptr_t)Memory::PatternScan(GameModule, "4C 8B DC 55 57 41 56 49 8D 6B A1 48 81 EC 00 01");
InitializeCamoIndex = (InitializeCamoIndexDelegate*)Memory::PatternScan(GameModule, "85 D2 75 33 0F 57 C0 48 63 C2 48 C1 E0 07 48 8D");
PlayerSetMotionInternal = (PlayerSetMotionDelegate*)(Memory::PatternScan(GameModule, "B9 0F 01 00 00 E8 ?? 36 FF FF 85 C0 74 2A BA FF") - 0x10);
PlayerStatusCheck = (PlayerStatusCheckDelegate*)Memory::PatternScan(GameModule, "8B D1 B8 01 00 00 00 83 E1 1F D3 E0 8B CA 48 C1");

Memory::DetourFunction(actMovementOffset, (LPVOID)ActMovementHook, (LPVOID*)&ActMovement);
Memory::DetourFunction(setMotionDataOffset, (LPVOID)SetMotionDataHook, (LPVOID*)&SetMotionData);
Memory::DetourFunction(calcuateCamoIndexOffset, (LPVOID)CalculateCamoIndexHook, (LPVOID*)&CalculateCamoIndex);
Memory::DetourFunction(ActSquatStillOffset, (LPVOID)ActionSquatStillHook, (LPVOID*)&ActionSquatStill);

InitializeCamoIndex = (InitializeCamoIndexDelegate*)initializeCamoIndexOffset;
CamoIndexData = InitializeCamoIndex(0, 0);

DWORD oldProtect;
VirtualProtect((LPVOID)disableCrouchProneOffset, 8, PAGE_EXECUTE_READWRITE, &oldProtect);
disableCrouchProneOffset[7] = 0x00;
}

void ReadConfig()
Expand All @@ -71,20 +147,19 @@ DWORD WINAPI MainThread(LPVOID lpParam)
WCHAR* filename = PathFindFileName(exePath);

if (wcsncmp(filename, L"launcher.exe", 13) == 0)
{
return true;
}

Sleep(3000); // delay, just in case
ReadConfig();
InstallHooks();

return true;
}

BOOL APIENTRY DllMain( HMODULE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
BOOL APIENTRY DllMain(HMODULE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
switch (ul_reason_for_call)
{
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77 changes: 77 additions & 0 deletions MGS3CrouchWalk/types.h
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#pragma once

#include <cstdint>

const enum PlayerMotion
{
Stand = 0,
Squat = 2,
StandMoveSlow = 3,
StandMoveStalk = 4,
Run = 5,
RunUpwards = 6,
Ground = 9,
GroundMove = 10,
RunToRolling = 21,
RollingToStand = 22,
RollingToGround = 23,
StandCover = 97,
SquatCover = 98,
SquatMove = 199
};

const enum MovementFlag
{
FlagWalk = 0x20u,
FlagSquatToGround = 0x30u,
FlagStand = 0x40u,
};

struct MovementWork
{
uint32_t field00;
uint32_t field04;
uint32_t field08;
uint32_t field0C;
uint32_t field10;
uint32_t field14;
uint32_t field18;
uint32_t field1C;
uint32_t field20;
uint32_t field24;
uint32_t field28;
uint32_t field2C;
uint32_t field30;
uint32_t field34;
uint32_t field38;
uint32_t field3C;
uint32_t field40;
uint32_t field44;
uint32_t field48;
uint32_t field4C;
uint32_t field50;
uint32_t field54;
uintptr_t action;
uint32_t motion;
uint32_t field64;
uint32_t flag;
uint16_t padCount;
uint16_t field6C;
uint16_t turnDir;
uint32_t field70;
uint32_t field74;
uint32_t field78;
uint32_t field7C;
uint32_t field80;
uint32_t field84;
uint32_t field88;
uint32_t padForceLimit;
};

typedef uintptr_t* __fastcall InitializeCamoIndexDelegate(int* a1, int a2);
typedef int* __fastcall CalculateCamoIndexDelegate(int* a1, int a2);
typedef int* __fastcall ActionSquatStillDelegate(__int64 work, MovementWork* plWork, __int64 a3, __int64 a4);
typedef uint32_t __fastcall PlayerSetMotionDelegate(__int64 work, PlayerMotion motion);
typedef void __fastcall SetMotionDataDelegate(int* m_ctrl, int layer, int motion, int time, __int64 a5);
typedef __int64 __fastcall PlayerStatusCheckDelegate(unsigned int a1);
typedef __int64 __fastcall ActMovementDelegate(MovementWork* plWork, __int64 work, int flag);

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