add Hooking

src/Hooking.cpp

@@ -0,0 +1,22 @@
+#include "Hooking.hpp"
+
+std::map<std::string, IHook *> IHook::hooks;
+
+bool IHook::Exists(const std::string &name) {
+    return hooks.find(name) != hooks.end();
+}
+
+void IHook::Register(IHook *hook) {
+    hooks[hook->name] = hook;
+}
+
+void IHook::Unregister(IHook *hook) {
+    hooks.erase(hook->name);
+}
+
+void IHook::DestroyAll() {
+    for (auto &hook : hooks) {
+        hook.second->Destroy();
+    }
+    hooks.clear();
+}

src/Hooking.hpp

@@ -0,0 +1,66 @@
+// Refer to https://github.com/pushrax/OpenVR-SpaceCalibrator/blob/master/OpenVR-SpaceCalibratorDriver/Hooking.h
+
+#pragma once
+
+#include <MinHook.h>
+#include <map>
+#include <string>
+
+class IHook {
+public:
+    const std::string name;
+
+    IHook(const std::string &name) : name(name) { }
+    virtual ~IHook() { }
+
+    virtual void Destroy() = 0;
+
+    static bool Exists(const std::string &name);
+    static void Register(IHook *hook);
+    static void Unregister(IHook *hook);
+    static void DestroyAll();
+
+private:
+    static std::map<std::string, IHook *> hooks;
+};
+
+template<class FuncType> class Hook : public IHook {
+public:
+    FuncType originalFunc = nullptr;
+    Hook(const std::string &name) : IHook(name) { }
+
+    bool CreateHookInObjectVTable(void *object, int vtableOffset, void *detourFunction) {
+        void **vtable = *((void ***)object);
+
+        targetFunc = vtable[vtableOffset];
+
+        auto err = MH_CreateHook(targetFunc, detourFunction, (LPVOID *)&originalFunc);
+
+        if (err != MH_OK) {
+            vr::VRDriverLog()->Log("Failed to create hook.".c_str());
+            return false;
+        }
+
+        err = MH_EnableHook(targetFunc);
+        if (err != MH_OK) {
+            vr::VRDriverLog()->Log("Failed to enable hook.".c_str());
+            MH_RemoveHook(targetFunc);
+            return false;
+        }
+
+        vr::VRDriverLog()->Log("Hook enabled.".c_str());
+        enabled = true;
+        return true;
+    }
+
+    void Destroy() {
+        if (enabled) {
+            MH_RemoveHook(targetFunc);
+            enabled = false;
+        }
+    }
+
+private:
+    bool enabled = false;
+    void* targetFunc = nullptr;
+};