Added local file for loading DLL mods and added some checks and printouts to help users.

README.md

@@ -4,7 +4,17 @@ Launches Elden Ring without Easy Anti-Cheat. By default the game will not connec
 
 Intended for convenience, and may be useful as launchers to inject dlls in order to run offline mods.
 
-The "launch_modded_eldenring.exe" launcher must be in the ELDENRING/Game directory (where eldenring.exe is located)
+Users can inject dlls by creating a `eldenring_mods.txt` file and putting the name of each dll you want to load into the file on a new line.  
+
+The "launch_modded_eldenring.exe" launcher must be in the `ELDEN RING/Game` directory (where eldenring.exe is located)
+
+You can prefix a mod with a folder name, and organize your mods, if you'd like. Example:
+
+```
+dllmods/elden_ring_seamless_coop.dll
+```
+
+this will look for `elden_ring_seamless_coop.dll` in the `ELDEN RING/Game/dllmods` folder.
 
 Please don't attempt to play online without Easy Anti-Cheat.
 

launch_modded_eldenring/launch_modded_eldenring.cpp

@@ -7,15 +7,26 @@ int main() {
 }
 
 void LaunchModdedEldenRing::Run() {
-
     using namespace std::chrono_literals;
 
+    if (!CheckConditions()) {
+        should_run = false;
+        system("PAUSE");
+        return;
+    };
+
     if (!LaunchGame()) {
         should_run = false;
         system("PAUSE");
         return;
     };
 
+    if (!InjectDLLMods()) {
+        should_run = false;
+        system("PAUSE");
+        return;
+    };
+
     // Replace with anything else you'd like to do
     // doesn't have to be a dll injection
     /*
@@ -35,8 +46,29 @@ void LaunchModdedEldenRing::Run() {
     return;
 };
 
-bool LaunchModdedEldenRing::LaunchGame() {
+bool LaunchModdedEldenRing::CheckConditions() {
+    if (FileNotFound(L"eldenring.exe")) {
+        printf_s("Failed to find: \"eldenring.exe\". Make sure you put the mod files inside your \"ELDEN RING\\Game\\\" folder!\n");
+        return false;
+    }
+
+    std::string exe_path = GetExePath() + "eldenring.exe";
+    if (exe_path.length() > MAX_PATH) {
+        printf_s("Cannot load path! Path is too long! %llu\\%d \n\"%s\"\n", exe_path.length(), MAX_PATH, exe_path.c_str());
+        return false;
+    }
+
+    //Warnings - These do not cause failure.  
+    if (!FileNotFound(L"dinput8.dll")) {
+        printf_s("Warning: You are launching seamless with the launcher and there is a dinput8.dll.\n"
+            "If this dinput8.dll is a mod loader, it is recommended you use the dll mod loader included with this launcher\n"
+            "Check the README for details on how to add dll mods to the launcher via \"eldenring_mods.txt\"\n");
+    }
 
+    return true;
+}
+
+bool LaunchModdedEldenRing::LaunchGame() {
     OFSTRUCT file_struct = {};
     HFILE elden_ring_exe_handle = OpenFile("eldenring.exe", &file_struct, OF_EXIST);
     if (elden_ring_exe_handle == HFILE_ERROR) {
@@ -52,23 +84,39 @@ bool LaunchModdedEldenRing::LaunchGame() {
     STARTUPINFOA startup_info = {};
     PROCESS_INFORMATION process_info = {};
     if (!CreateProcessA("eldenring.exe", nullptr, nullptr, nullptr,
-        false, 0, nullptr, nullptr, &startup_info, &process_info)) {
+                        false, 0, nullptr, nullptr, &startup_info, &process_info)) {
         printf_s("Failed to launch \"eldenring.exe\"\n");
         return false;
     };
 
     elden_ring_thread = process_info.hThread;
     elden_ring_handle = process_info.hProcess;
 
+    return true;
+}
+
+bool LaunchModdedEldenRing::InjectDLLMods() {
+    std::ifstream file("eldenring_mods.txt");
+    if (file.is_open()) {
+        std::string line;
+        while (std::getline(file, line)) {
+            printf_s("Loading %s...\n", line.c_str());
+            if (!InjectMod(line.c_str())) {
+                printf_s("Failed to load %s...\n", line.c_str());
+                return false;
+            };
+        }
+        file.close();
+    }
     return true;
 };
 
 bool LaunchModdedEldenRing::InjectMod(const char* mod_name) {
-
     OFSTRUCT file_struct = {};
     HFILE elden_ring_exe_handle = OpenFile(mod_name, &file_struct, OF_EXIST);
     if (elden_ring_exe_handle == HFILE_ERROR) {
-        printf_s("Failed to find \"%s\"\n", mod_name);
+        std::string mod_path = GetExePath() + "eldenring.exe";
+        printf_s("Failed to find: (%llu)\n\"%s\"\n", mod_path.length(), mod_path.c_str());
         return false;
     };
 
@@ -87,15 +135,17 @@ bool LaunchModdedEldenRing::InjectMod(const char* mod_name) {
 
     FARPROC load_library_a = GetProcAddress(GetModuleHandleA("Kernel32.dll"), "LoadLibraryA");
     if (!load_library_a) {
-        printf_s("Unable to load mod dll\n");
+        printf_s("Unable to load Kernel32.dll. Cannot call \"LoadLibraryA\" to load dll mods!\n");
         return false;
     };
 
     WriteProcessMemory(elden_ring_handle, dll_path, mod_name, memory_alloc, nullptr);
 
-    HANDLE dll_load_thread = CreateRemoteThread(elden_ring_handle, 0, 0, (LPTHREAD_START_ROUTINE)load_library_a, dll_path, 0, 0);
+    HANDLE dll_load_thread = CreateRemoteThread(elden_ring_handle, 0, 0, (LPTHREAD_START_ROUTINE)load_library_a,
+                                                dll_path, 0, 0);
     if (!dll_load_thread) {
-        printf_s("Unable to inject mod dll\n");
+        std::string modPath = GetExePath() + mod_name;
+        printf_s("Unable to inject dll mod: (%llu)\n\"%s\"\n", modPath.length(), modPath.c_str());
         return false;
     };
 
@@ -107,4 +157,25 @@ bool LaunchModdedEldenRing::InjectMod(const char* mod_name) {
 
     CloseHandle(elden_ring_handle_open);
     return true;
-};
+};
+
+bool LaunchModdedEldenRing::FileNotFound(const std::wstring& name) {
+    return INVALID_FILE_ATTRIBUTES == GetFileAttributes(name.c_str()) && GetLastError() == ERROR_FILE_NOT_FOUND;
+}
+
+std::string LaunchModdedEldenRing::GetExePath() {
+    char module_dir[MAX_PATH + 1];
+    HMODULE mod;
+    GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |
+        GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
+        (LPCWSTR)&"", &mod);
+    GetModuleFileNameA(mod, module_dir, sizeof(module_dir));
+    char* module_file_path_point = strrchr(module_dir, '\\');
+    if (!module_file_path_point) {
+        MessageBoxA(0, "Failed to parse filepath string", "Item Randomiser Mod - Error", MB_ICONERROR);
+        throw std::runtime_error("Failed to parse filepath string");
+    };
+    *module_file_path_point = '\\\0'; //add slash and null terminator
+    return std::string(module_dir);
+}
+

launch_modded_eldenring/launch_modded_eldenring.h

@@ -1,12 +1,18 @@
 #include <windows.h>
 #include <chrono>
 #include <thread>
+#include <fstream>
+#include <string>
 
 class LaunchModdedEldenRing {
 public:
 	void Run();
 	bool LaunchGame();
+	bool InjectDLLMods();
 	bool InjectMod(const char* mod_name);
+	bool FileNotFound(const std::wstring& name);
+	bool CheckConditions();
+	std::string GetExePath();
 
 	LaunchModdedEldenRing() {
 		should_run = true;