Bloodstained RotN dialogue/menu resolution fix

dllmain.cpp

// This code requires some files from my Arise-SDK project:
// https://github.com/emoose/Arise-SDK/tree/b73c7ea9fceea2c494cbb8ebc74c6b3d1d35cbf6

#include "pch.h"
#include <cstdio>

#define SDK_VERSION "0.1.25"

HMODULE DllHModule;
HMODULE GameHModule;
uintptr_t mBaseAddress;

bool InitGame()
{
  printf("\nBloodstainedFix " SDK_VERSION " - https://github.com/emoose\n");

  GameHModule = GetModuleHandleA(NULL);

  if (!GameHModule)
  {
    MessageBoxA(0, "Failed to get module handle for game, unloading ResolutionFix...", "ResolutionFix", 0);
    return false;
  }
  mBaseAddress = reinterpret_cast<uintptr_t>(GameHModule);

  return true;
}

bool inited = false;

uint32_t Addr_UTextureRenderTarget2D__PostLoad = 0x1E7A100; // steam addr, as of 30th sept 2021
typedef void*(*UTextureRenderTarget2D__PostLoad_Fn)(uint8_t* thisptr);
UTextureRenderTarget2D__PostLoad_Fn UTextureRenderTarget2D__PostLoad_Orig;

void* UTextureRenderTarget2D__PostLoad_Hook(uint8_t* thisptr)
{
  void* ret = UTextureRenderTarget2D__PostLoad_Orig(thisptr);

  uint32_t* SizeX = (uint32_t*)(thisptr + 0xD0);
  uint32_t* SizeY = (uint32_t*)(thisptr + 0xD4);

  // TODO: two different PostLoad calls use 1920x1080, which one actually needs the fix?
  if (*SizeX == 1920 && *SizeY == 1080)
  {
    *SizeX = 3840;
    *SizeY = 2160;
  }

  return ret;
}

void InitPlugin()
{
  inited = false;
  MH_Initialize();

  MODULEINFO modInfo;
  if (GetModuleInformation(GetCurrentProcess(), GameHModule, &modInfo, sizeof(MODULEINFO)))
  {
    auto* funcSignature = "\x3B\xC2\x44\x8B\x81\xD4\x00\x00\x00";
    auto* funcMask = "xxxxxxxxx";

    uint8_t* UTextureRenderTarget2D__PostLoad = FindSignature((void*)mBaseAddress, modInfo.SizeOfImage, funcSignature, funcMask);
    if (UTextureRenderTarget2D__PostLoad)
    {
      UTextureRenderTarget2D__PostLoad -= 0xC;
      Addr_UTextureRenderTarget2D__PostLoad = (uint32_t)(UTextureRenderTarget2D__PostLoad - mBaseAddress);
    }
  }

  auto* funcExpectedBytes = "\x8B\x81\xD0\x00\x00\x00"; // mov eax, [rcx+0D0h]
  if (memcmp(funcExpectedBytes, (void*)(mBaseAddress + Addr_UTextureRenderTarget2D__PostLoad), 6))
  {
    MessageBoxA(0, "Failed to locate UTextureRenderTarget2D::PostLoad inside 'BloodstainedRotN-Win64-Shipping.exe', unloading ResolutionFix...", "ResolutionFix", 0);
    return;
  }

  // Hook UTextureRenderTarget2D::PostLoad so we can adjust RT width/height after it's been loaded in
  MH_GameHook(UTextureRenderTarget2D__PostLoad);

  MH_EnableHook(MH_ALL_HOOKS);
  inited = true;
}

BOOL APIENTRY DllMain( HMODULE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
                     )
{
    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
      DllHModule = hModule;

      bool Proxy_Attach(); // proxy.cpp
      Proxy_Attach();

      if (InitGame())
        Proxy_InitSteamStub();

      break;
    case DLL_THREAD_ATTACH:
    case DLL_THREAD_DETACH:
      break;
    case DLL_PROCESS_DETACH:
      void Proxy_Detach();
      Proxy_Detach();
      break;
    }
    return TRUE;
}