Added opengl hook

overlay_experimental/OpenGL_Hook.cpp

@@ -0,0 +1,144 @@
+#include "../dll/base.h"
+#include "OpenGL_Hook.h"
+#include "Hook_Manager.h"
+
+#include <imgui.h>
+#include <impls/imgui_impl_win32.h>
+#include <impls/imgui_impl_opengl3.h>
+
+#include <GL/glew.h>
+
+#pragma comment(lib, "opengl32")
+#pragma comment(lib, "glew32s")
+
+
+// This is created by OpenGL_Hook::Create, and deleted by the Hook_Manager if not used
+static OpenGL_Hook* hook;
+
+void OpenGL_Hook::hook_ogl()
+{
+    if (!_hooked)
+    {
+        PRINT_DEBUG("Hooked OpenGL\n");
+        _hooked = true;
+        Hook_Manager::Inst().FoundHook(this);
+
+        GLenum err = glewInit();
+        if (GLEW_OK != err)
+        {
+            /* Problem: glewInit failed, something is seriously wrong. */
+            PRINT_DEBUG("Error: %s\n", glewGetErrorString(err));
+        }
+
+        UnhookAll();
+        BeginHook();
+        HookFuncs(
+            std::make_pair<void**, void*>(&(PVOID&)wglSwapBuffers, &OpenGL_Hook::MywglSwapBuffers)
+        );
+        EndHook();
+    }
+}
+
+void OpenGL_Hook::resetRenderState()
+{
+    if (initialized)
+    {
+        ImGui_ImplOpenGL3_Shutdown();
+        ImGui_ImplWin32_Shutdown();
+        ImGui::DestroyContext();
+
+        initialized = false;
+    }
+}
+
+void OpenGL_Hook::prepareForOverlay(HDC hDC)
+{
+    HWND hWnd = WindowFromDC(hDC);
+    RECT rect;
+
+    GetClientRect(hWnd, &rect);
+
+    if (!initialized)
+    {
+        ImGui::CreateContext();
+        ImGuiIO& io = ImGui::GetIO();
+        io.IniFilename = NULL;
+
+        Hook_Manager::Inst().ChangeGameWindow(hWnd);
+
+        ImGui_ImplWin32_Init(hWnd);
+        ImGui_ImplOpenGL3_Init();
+
+        initialized = true;
+    }
+    ImGui_ImplOpenGL3_NewFrame();
+    ImGui_ImplWin32_NewFrame();
+
+    ImGui::NewFrame();
+
+    Hook_Manager::Inst().CallOverlayProc(rect.right, rect.bottom);
+
+    ImGui::EndFrame();
+
+    ImGui::Render();
+
+    ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+}
+
+/////////////////////////////////////////////////////////////////////////////////////
+// OpenGL Initialization functions
+BOOL WINAPI OpenGL_Hook::MywglMakeCurrent(HDC hDC, HGLRC hGLRC)
+{
+    auto res = hook->wglMakeCurrent(hDC, hGLRC);
+    hook->hook_ogl();
+    return res;
+}
+
+/////////////////////////////////////////////////////////////////////////////////////
+BOOL WINAPI OpenGL_Hook::MywglSwapBuffers(HDC hDC)
+{
+    hook->prepareForOverlay(hDC);
+    return hook->wglSwapBuffers(hDC);
+}
+
+OpenGL_Hook::OpenGL_Hook():
+    initialized(false),
+    wglSwapBuffers(nullptr)
+{
+    _dll = GetModuleHandle(DLL_NAME);
+    _hooked = false;
+    // Hook to wglMakeCurrent so we know when it gets called.
+    // If its called, then OpenGL will be used to render the overlay.
+    wglMakeCurrent = (decltype(wglMakeCurrent))GetProcAddress(_dll, "wglMakeCurrent");
+    wglSwapBuffers = (decltype(wglSwapBuffers))GetProcAddress(_dll, "wglSwapBuffers");
+
+    BeginHook();
+    HookFuncs(
+        std::make_pair<void**, void*>(&(PVOID&)wglMakeCurrent, &OpenGL_Hook::MywglMakeCurrent)
+    );
+    EndHook();
+}
+
+OpenGL_Hook::~OpenGL_Hook()
+{
+    PRINT_DEBUG("OpenGL Hook removed\n");
+
+    if (_hooked)
+    {
+        ImGui_ImplOpenGL3_Shutdown();
+        ImGui_ImplWin32_Shutdown();
+        ImGui::DestroyContext();
+    }
+
+    hook = nullptr;
+}
+
+void OpenGL_Hook::Create()
+{
+    if (hook == nullptr)
+    {
+        hook = new OpenGL_Hook;
+        // Register the hook to the Hook Manager
+        Hook_Manager::Inst().AddHook(hook);
+    }
+}