Added DirectX hooks

Warning: DX9 doesn't support resizing (TODO), DX12 has not beed tested and is not finished.
No OpenGL support for now.

overlay_experimental/DX12_Hook.h

@@ -0,0 +1,49 @@
+#ifndef __INCLUDED_DX12_HOOK_H__
+#define __INCLUDED_DX12_HOOK_H__
+
+#include <d3d12.h>
+#include "DirectX_VTables.h"
+#include "Base_Hook.h"
+
+class DX12_Hook : public Base_Hook
+{
+public:
+    static constexpr const char DLL_NAME[] = "d3d12.dll";
+
+private:
+    // Variables
+    bool initialized;
+    ID3D12CommandAllocator* pCmdAlloc;
+    ID3D12GraphicsCommandList* pCmdList;
+    ID3D12DescriptorHeap* pDescriptorHeap;
+    D3D12_CPU_DESCRIPTOR_HANDLE mainRenderTargetDescriptor;
+
+    // Functions
+    DX12_Hook();
+    virtual ~DX12_Hook();
+
+    void hook_dx12(D3D_FEATURE_LEVEL MinimumFeatureLevel);
+    void resetRenderState();
+    void prepareForOverlay(IDXGISwapChain* pSwapChain);
+
+    // Hook to render functions
+    static HRESULT STDMETHODCALLTYPE MyPresent(IDXGISwapChain* _this, UINT SyncInterval, UINT Flags);
+    static HRESULT STDMETHODCALLTYPE MyResizeTarget(IDXGISwapChain* _this, const DXGI_MODE_DESC* pNewTargetParameters);
+    static HRESULT STDMETHODCALLTYPE MyResizeBuffers(IDXGISwapChain* _this, UINT BufferCount, UINT Width, UINT Height, DXGI_FORMAT NewFormat, UINT SwapChainFlags);
+
+    decltype(&IDXGISwapChain::Present)       Present;
+    decltype(&IDXGISwapChain::ResizeBuffers) ResizeBuffers;
+    decltype(&IDXGISwapChain::ResizeTarget)  ResizeTarget;
+
+    // Hook functions so we know we use DX11
+    static decltype(D3D12CreateDevice) MyD3D12CreateDevice;
+
+    decltype(D3D12CreateDevice)* D3D12CreateDevice;
+
+public:
+    static void Create(); // Initialize DX11 Hook.
+    
+    void loadFunctions(ID3D12Device *pDevice, IDXGISwapChain *pSwapChain);
+};
+
+#endif//__INCLUDED_DX12_HOOK_H__