1 files changed, 205 insertions, 0 deletions
diff --git a/NorthstarDLL/filesystem.cpp b/NorthstarDLL/filesystem.cpp
new file mode 100644
index 00000000..c17d813f
--- /dev/null
+++ b/NorthstarDLL/filesystem.cpp
@@ -0,0 +1,205 @@
+#include "pch.h"
+#include "filesystem.h"
+#include "hooks.h"
+#include "hookutils.h"
+#include "sourceinterface.h"
+#include "modmanager.h"
+
+#include <iostream>
+#include <sstream>
+
+// hook forward declares
+typedef FileHandle_t (*ReadFileFromVPKType)(VPKData* vpkInfo, __int64* b, char* filename);
+ReadFileFromVPKType readFileFromVPK;
+FileHandle_t ReadFileFromVPKHook(VPKData* vpkInfo, __int64* b, char* filename);
+
+typedef bool (*ReadFromCacheType)(IFileSystem* filesystem, char* path, void* result);
+ReadFromCacheType readFromCache;
+bool ReadFromCacheHook(IFileSystem* filesystem, char* path, void* result);
+
+typedef void (*AddSearchPathType)(IFileSystem* fileSystem, const char* pPath, const char* pathID, SearchPathAdd_t addType);
+AddSearchPathType addSearchPathOriginal;
+void AddSearchPathHook(IFileSystem* fileSystem, const char* pPath, const char* pathID, SearchPathAdd_t addType);
+
+typedef FileHandle_t (*ReadFileFromFilesystemType)(
+	IFileSystem* filesystem, const char* pPath, const char* pOptions, int64_t a4, uint32_t a5);
+ReadFileFromFilesystemType readFileFromFilesystem;
+FileHandle_t ReadFileFromFilesystemHook(IFileSystem* filesystem, const char* pPath, const char* pOptions, int64_t a4, uint32_t a5);
+
+typedef VPKData* (*MountVPKType)(IFileSystem* fileSystem, const char* vpkPath);
+MountVPKType mountVPK;
+VPKData* MountVPKHook(IFileSystem* fileSystem, const char* vpkPath);
+
+bool readingOriginalFile;
+std::string currentModPath;
+SourceInterface<IFileSystem>* g_Filesystem;
+
+void InitialiseFilesystem(HMODULE baseAddress)
+{
+	g_Filesystem = new SourceInterface<IFileSystem>("filesystem_stdio.dll", "VFileSystem017");
+
+	// create hooks
+	HookEnabler hook;
+	ENABLER_CREATEHOOK(hook, (char*)baseAddress + 0x5CBA0, &ReadFileFromVPKHook, reinterpret_cast<LPVOID*>(&readFileFromVPK));
+	ENABLER_CREATEHOOK(
+		hook,
+		reinterpret_cast<void*>((*g_Filesystem)->m_vtable->ReadFromCache),
+		&ReadFromCacheHook,
+		reinterpret_cast<LPVOID*>(&readFromCache));
+	ENABLER_CREATEHOOK(
+		hook,
+		reinterpret_cast<void*>((*g_Filesystem)->m_vtable->AddSearchPath),
+		&AddSearchPathHook,
+		reinterpret_cast<LPVOID*>(&addSearchPathOriginal));
+	ENABLER_CREATEHOOK(hook, (char*)baseAddress + 0x15F20, &ReadFileFromFilesystemHook, reinterpret_cast<LPVOID*>(&readFileFromFilesystem));
+	ENABLER_CREATEHOOK(
+		hook, reinterpret_cast<void*>((*g_Filesystem)->m_vtable->MountVPK), &MountVPKHook, reinterpret_cast<LPVOID*>(&mountVPK));
+}
+
+std::string ReadVPKFile(const char* path)
+{
+	// read scripts.rson file, todo: check if this can be overwritten
+	FileHandle_t fileHandle = (*g_Filesystem)->m_vtable2->Open(&(*g_Filesystem)->m_vtable2, path, "rb", "GAME", 0);
+
+	std::stringstream fileStream;
+	int bytesRead = 0;
+	char data[4096];
+	do
+	{
+		bytesRead = (*g_Filesystem)->m_vtable2->Read(&(*g_Filesystem)->m_vtable2, data, (int)std::size(data), fileHandle);
+		fileStream.write(data, bytesRead);
+	} while (bytesRead == std::size(data));
+
+	(*g_Filesystem)->m_vtable2->Close(*g_Filesystem, fileHandle);
+
+	return fileStream.str();
+}
+
+std::string ReadVPKOriginalFile(const char* path)
+{
+	readingOriginalFile = true;
+	std::string ret = ReadVPKFile(path);
+	readingOriginalFile = false;
+
+	return ret;
+}
+
+void SetNewModSearchPaths(Mod* mod)
+{
+	// put our new path to the head if we need to read from a different mod path
+	// in the future we could also determine whether the file we're setting paths for needs a mod dir, or compiled assets
+	if (mod != nullptr)
+	{
+		if ((fs::absolute(mod->ModDirectory) / MOD_OVERRIDE_DIR).string().compare(currentModPath))
+		{
+			spdlog::info("changing mod search path from {} to {}", currentModPath, mod->ModDirectory.string());
+
+			addSearchPathOriginal(
+				&*(*g_Filesystem), (fs::absolute(mod->ModDirectory) / MOD_OVERRIDE_DIR).string().c_str(), "GAME", PATH_ADD_TO_HEAD);
+			currentModPath = (fs::absolute(mod->ModDirectory) / MOD_OVERRIDE_DIR).string();
+		}
+	}
+	else // push compiled to head
+		addSearchPathOriginal(&*(*g_Filesystem), fs::absolute(GetCompiledAssetsPath()).string().c_str(), "GAME", PATH_ADD_TO_HEAD);
+}
+
+bool TryReplaceFile(char* path, bool shouldCompile)
+{
+	if (readingOriginalFile)
+		return false;
+
+	if (shouldCompile)
+		(*g_ModManager).CompileAssetsForFile(path);
+
+	// idk how efficient the lexically normal check is
+	// can't just set all /s in path to \, since some paths aren't in writeable memory
+	auto file = g_ModManager->m_modFiles.find(fs::path(path).lexically_normal().string());
+	if (file != g_ModManager->m_modFiles.end())
+	{
+		SetNewModSearchPaths(file->second.owningMod);
+		return true;
+	}
+
+	return false;
+}
+
+FileHandle_t ReadFileFromVPKHook(VPKData* vpkInfo, __int64* b, char* filename)
+{
+	// move this to a convar at some point when we can read them in native
+	// spdlog::info("ReadFileFromVPKHook {} {}", filename, vpkInfo->path);
+
+	// there is literally never any reason to compile here, since we'll always compile in ReadFileFromFilesystemHook in the same codepath
+	// this is called
+	if (TryReplaceFile(filename, false))
+	{
+		*b = -1;
+		return b;
+	}
+
+	return readFileFromVPK(vpkInfo, b, filename);
+}
+
+bool ReadFromCacheHook(IFileSystem* filesystem, char* path, void* result)
+{
+	// move this to a convar at some point when we can read them in native
+	// spdlog::info("ReadFromCacheHook {}", path);
+
+	if (TryReplaceFile(path, true))
+		return false;
+
+	return readFromCache(filesystem, path, result);
+}
+
+void AddSearchPathHook(IFileSystem* fileSystem, const char* pPath, const char* pathID, SearchPathAdd_t addType)
+{
+	addSearchPathOriginal(fileSystem, pPath, pathID, addType);
+
+	// make sure current mod paths are at head
+	if (!strcmp(pathID, "GAME") && currentModPath.compare(pPath) && addType == PATH_ADD_TO_HEAD)
+	{
+		addSearchPathOriginal(fileSystem, currentModPath.c_str(), "GAME", PATH_ADD_TO_HEAD);
+		addSearchPathOriginal(fileSystem, GetCompiledAssetsPath().string().c_str(), "GAME", PATH_ADD_TO_HEAD);
+	}
+}
+
+FileHandle_t ReadFileFromFilesystemHook(IFileSystem* filesystem, const char* pPath, const char* pOptions, int64_t a4, uint32_t a5)
+{
+	// this isn't super efficient, but it's necessary, since calling addsearchpath in readfilefromvpk doesn't work, possibly refactor later
+	// it also might be possible to hook functions that are called later, idk look into callstack for ReadFileFromVPK
+	if (!readingOriginalFile)
+		TryReplaceFile((char*)pPath, true);
+
+	return readFileFromFilesystem(filesystem, pPath, pOptions, a4, a5);
+}
+
+VPKData* MountVPKHook(IFileSystem* fileSystem, const char* vpkPath)
+{
+	spdlog::info("MountVPK {}", vpkPath);
+	VPKData* ret = mountVPK(fileSystem, vpkPath);
+
+	for (Mod mod : g_ModManager->m_loadedMods)
+	{
+		if (!mod.Enabled)
+			continue;
+
+		for (ModVPKEntry& vpkEntry : mod.Vpks)
+		{
+			// if we're autoloading, just load no matter what
+			if (!vpkEntry.m_bAutoLoad)
+			{
+				// resolve vpk name and try to load one with the same name
+				// todo: we should be unloading these on map unload manually
+				std::string mapName(fs::path(vpkPath).filename().string());
+				std::string modMapName(fs::path(vpkEntry.m_sVpkPath.c_str()).filename().string());
+				if (mapName.compare(modMapName))
+					continue;
+			}
+
+			VPKData* loaded = mountVPK(fileSystem, vpkEntry.m_sVpkPath.c_str());
+			if (!ret) // this is primarily for map vpks and stuff, so the map's vpk is what gets returned from here
+				ret = loaded;
+		}
+	}
+
+	return ret;
+}