r5sdk/r5launcher/main.cpp

#include <stdio.h>

#include <Windows.h>
#include <detours.h>

void PrintLastError()
{
    //Get the error message, if any.
    DWORD errorMessageID = ::GetLastError();
    if (errorMessageID == 0)
        return;

    LPSTR messageBuffer = nullptr;
    size_t size = FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
        NULL, errorMessageID, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPSTR)&messageBuffer, 0, NULL);

    printf("ERROR: %s\n", messageBuffer);
    LocalFree(messageBuffer);
}

bool LaunchR5Apex()
{
    FILE* sLaunchParams;
    CHAR sArgumentSize[1024];
    CHAR sCommandDirectory[MAX_PATH];
    LPSTR sCommandLine = sCommandDirectory;

#pragma warning(suppress : 4996)
    sLaunchParams = fopen("launchparams.txt", "r"); // "+exec autoexec -dev -fnf -noplatform"

    BOOL result;

    CHAR sDevDll[MAX_PATH];
    CHAR sGameExe[MAX_PATH];
    CHAR sGameDirectory[MAX_PATH];

    STARTUPINFO StartupInfo = { 0 };
    PROCESS_INFORMATION ProcInfo = { 0 };

    // Initialize the startup info structure.
    StartupInfo.cb = sizeof(STARTUPINFO);

    // Load command line arguments from a file on the disk.
    if (sLaunchParams)
    {
        while (fgets(sArgumentSize, sizeof(sArgumentSize), sLaunchParams) != NULL)
            fclose(sLaunchParams);
    }

    // Format the file paths for the game exe and dll.
    GetCurrentDirectory(MAX_PATH, sGameDirectory);
    snprintf(sGameExe, sizeof(sGameExe), "%s\\r5apex.exe", sGameDirectory);
    snprintf(sDevDll, sizeof(sDevDll), "%s\\r5dev.dll", sGameDirectory);
    snprintf(sCommandLine, sizeof(sCommandDirectory), "%s\\r5apex.exe %s", sGameDirectory, sArgumentSize);

    printf("Launching Apex Dev...\n");
    printf(" - CWD: %s\n", sGameDirectory);
    printf(" - EXE: %s\n", sGameExe);
    printf(" - DLL: %s\n", sDevDll);
    printf(" - CLI: %s\n", sCommandLine);

    // Build our list of dlls to inject.
    LPCSTR DllsToInject[1] =
    {
        sDevDll
    };

    // Create the game process in a suspended state with our dll.
    result = DetourCreateProcessWithDllsA(
        sGameExe,                 // lpApplicationName
        sCommandLine,             // lpCommandLine
        NULL,                     // lpProcessAttributes
        NULL,                     // lpThreadAttributes
        FALSE,                    // bInheritHandles
        CREATE_SUSPENDED,         // dwCreationFlags
        NULL,                     // lpEnvironment
        sGameDirectory,           // lpCurrentDirectory
        &StartupInfo,             // lpStartupInfo
        &ProcInfo,                // lpProcessInformation
        1,                        // nDlls
        DllsToInject,             // rlpDlls
        NULL                      // pfCreateProcessA
    );

    // Failed to create the game process.
    if (!result)
    {
        PrintLastError();
        return false;
    }

    // Resume the process.
    ResumeThread(ProcInfo.hThread);

    // Close the process and thread handles.
    CloseHandle(ProcInfo.hProcess);
    CloseHandle(ProcInfo.hThread);

    return true;
}

int main(int argc, char* argv[], char* envp[])
{
    LaunchR5Apex();
    Sleep(1000);
    return 0;
}