examples/example_win32_directx12/main.cpp - external/github.com/ocornut/imgui - Git at Google

 // dear imgui: standalone example application for DirectX 12
 // If you are new to dear imgui, see examples/README.txt and documentation at the top of imgui.cpp.
 // FIXME: 64-bit only for now! (Because sizeof(ImTextureId) == sizeof(void*))

 #include "imgui.h"
 #include "imgui_impl_win32.h"
 #include "imgui_impl_dx12.h"
 #include <d3d12.h>
 #include <dxgi1_4.h>
 #include <tchar.h>

 #define DX12_ENABLE_DEBUG_LAYER     0

 struct FrameContext
 {
     ID3D12CommandAllocator* CommandAllocator;
     UINT64                  FenceValue;
 };

 // Data
 static int const                    NUM_FRAMES_IN_FLIGHT = 3;
 static FrameContext                 g_frameContext[NUM_FRAMES_IN_FLIGHT] = {};
 static UINT                         g_frameIndex = 0;

 static int const                    NUM_BACK_BUFFERS = 3;
 static ID3D12Device*                g_pd3dDevice = NULL;
 static ID3D12DescriptorHeap*        g_pd3dRtvDescHeap = NULL;
 static ID3D12DescriptorHeap*        g_pd3dSrvDescHeap = NULL;
 static ID3D12CommandQueue*          g_pd3dCommandQueue = NULL;
 static ID3D12GraphicsCommandList*   g_pd3dCommandList = NULL;
 static ID3D12Fence*                 g_fence = NULL;
 static HANDLE                       g_fenceEvent = NULL;
 static UINT64                       g_fenceLastSignaledValue = 0;
 static IDXGISwapChain3*             g_pSwapChain = NULL;
 static HANDLE                       g_hSwapChainWaitableObject = NULL;
 static ID3D12Resource*              g_mainRenderTargetResource[NUM_BACK_BUFFERS] = {};
 static D3D12_CPU_DESCRIPTOR_HANDLE  g_mainRenderTargetDescriptor[NUM_BACK_BUFFERS] = {};

 // Forward declarations of helper functions
 bool CreateDeviceD3D(HWND hWnd);
 void CleanupDeviceD3D();
 void CreateRenderTarget();
 void CleanupRenderTarget();
 void WaitForLastSubmittedFrame();
 FrameContext* WaitForNextFrameResources();
 void ResizeSwapChain(HWND hWnd, int width, int height);
 LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);

 // Main code
 int main(int, char**)
 {
     // Create application window
     WNDCLASSEX wc = { sizeof(WNDCLASSEX), CS_CLASSDC, WndProc, 0L, 0L, GetModuleHandle(NULL), NULL, NULL, NULL, NULL, _T("ImGui Example"), NULL };
     ::RegisterClassEx(&wc);
     HWND hwnd = ::CreateWindow(wc.lpszClassName, _T("Dear ImGui DirectX12 Example"), WS_OVERLAPPEDWINDOW, 100, 100, 1280, 800, NULL, NULL, wc.hInstance, NULL);

     // Initialize Direct3D
     if (!CreateDeviceD3D(hwnd))
     {
         CleanupDeviceD3D();
         ::UnregisterClass(wc.lpszClassName, wc.hInstance);
         return 1;
     }

     // Show the window
     ::ShowWindow(hwnd, SW_SHOWDEFAULT);
     ::UpdateWindow(hwnd);

     // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls

     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();

     // Setup Platform/Renderer bindings
     ImGui_ImplWin32_Init(hwnd);
     ImGui_ImplDX12_Init(g_pd3dDevice, NUM_FRAMES_IN_FLIGHT,
         DXGI_FORMAT_R8G8B8A8_UNORM,
         g_pd3dSrvDescHeap->GetCPUDescriptorHandleForHeapStart(),
         g_pd3dSrvDescHeap->GetGPUDescriptorHandleForHeapStart());

     // Load Fonts
     // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return NULL. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which ImGui_ImplXXXX_NewFrame below will call.
     // - Read 'misc/fonts/README.txt' for more instructions and details.
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //io.Fonts->AddFontDefault();
     //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
     //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
     //io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
     //io.Fonts->AddFontFromFileTTF("../../misc/fonts/ProggyTiny.ttf", 10.0f);
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != NULL);

     // Our state
     bool show_demo_window = true;
     bool show_another_window = false;
     ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);

     // Main loop
     MSG msg;
     ZeroMemory(&msg, sizeof(msg));
     while (msg.message != WM_QUIT)
     {
         // Poll and handle messages (inputs, window resize, etc.)
         // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
         // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application.
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
         if (::PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
         {
             ::TranslateMessage(&msg);
             ::DispatchMessage(&msg);
             continue;
         }

         // Start the Dear ImGui frame
         ImGui_ImplDX12_NewFrame();
         ImGui_ImplWin32_NewFrame();
         ImGui::NewFrame();

         // 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
         if (show_demo_window)
             ImGui::ShowDemoWindow(&show_demo_window);

         // 2. Show a simple window that we create ourselves. We use a Begin/End pair to created a named window.
         {
             static float f = 0.0f;
             static int counter = 0;

             ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.

             ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
             ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
             ImGui::Checkbox("Another Window", &show_another_window);

             ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
             ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color

             if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
                 counter++;
             ImGui::SameLine();
             ImGui::Text("counter = %d", counter);

             ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
             ImGui::End();
         }

         // 3. Show another simple window.
         if (show_another_window)
         {
             ImGui::Begin("Another Window", &show_another_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
             ImGui::Text("Hello from another window!");
             if (ImGui::Button("Close Me"))
                 show_another_window = false;
             ImGui::End();
         }

         // Rendering
         FrameContext* frameCtxt = WaitForNextFrameResources();
         UINT backBufferIdx = g_pSwapChain->GetCurrentBackBufferIndex();
         frameCtxt->CommandAllocator->Reset();

         D3D12_RESOURCE_BARRIER barrier = {};
         barrier.Type                   = D3D12_RESOURCE_BARRIER_TYPE_TRANSITION;
         barrier.Flags                  = D3D12_RESOURCE_BARRIER_FLAG_NONE;
         barrier.Transition.pResource   = g_mainRenderTargetResource[backBufferIdx];
         barrier.Transition.Subresource = D3D12_RESOURCE_BARRIER_ALL_SUBRESOURCES;
         barrier.Transition.StateBefore = D3D12_RESOURCE_STATE_PRESENT;
         barrier.Transition.StateAfter  = D3D12_RESOURCE_STATE_RENDER_TARGET;

         g_pd3dCommandList->Reset(frameCtxt->CommandAllocator, NULL);
         g_pd3dCommandList->ResourceBarrier(1, &barrier);
         g_pd3dCommandList->ClearRenderTargetView(g_mainRenderTargetDescriptor[backBufferIdx], (float*)&clear_color, 0, NULL);
         g_pd3dCommandList->OMSetRenderTargets(1, &g_mainRenderTargetDescriptor[backBufferIdx], FALSE, NULL);
         g_pd3dCommandList->SetDescriptorHeaps(1, &g_pd3dSrvDescHeap);
         ImGui::Render();
         ImGui_ImplDX12_RenderDrawData(ImGui::GetDrawData(), g_pd3dCommandList);
         barrier.Transition.StateBefore = D3D12_RESOURCE_STATE_RENDER_TARGET;
         barrier.Transition.StateAfter  = D3D12_RESOURCE_STATE_PRESENT;
         g_pd3dCommandList->ResourceBarrier(1, &barrier);
         g_pd3dCommandList->Close();

         g_pd3dCommandQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*)&g_pd3dCommandList);

         g_pSwapChain->Present(1, 0); // Present with vsync
         //g_pSwapChain->Present(0, 0); // Present without vsync

         UINT64 fenceValue = g_fenceLastSignaledValue + 1;
         g_pd3dCommandQueue->Signal(g_fence, fenceValue);
         g_fenceLastSignaledValue = fenceValue;
         frameCtxt->FenceValue = fenceValue;
     }

     WaitForLastSubmittedFrame();
     ImGui_ImplDX12_Shutdown();
     ImGui_ImplWin32_Shutdown();
     ImGui::DestroyContext();

     CleanupDeviceD3D();
     ::DestroyWindow(hwnd);
     ::UnregisterClass(wc.lpszClassName, wc.hInstance);

     return 0;
 }

 // Helper functions

 bool CreateDeviceD3D(HWND hWnd)
 {
     // Setup swap chain
     DXGI_SWAP_CHAIN_DESC1 sd;
     {
         ZeroMemory(&sd, sizeof(sd));
         sd.BufferCount = NUM_BACK_BUFFERS;
         sd.Width = 0;
         sd.Height = 0;
         sd.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
         sd.Flags = DXGI_SWAP_CHAIN_FLAG_FRAME_LATENCY_WAITABLE_OBJECT;
         sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
         sd.SampleDesc.Count = 1;
         sd.SampleDesc.Quality = 0;
         sd.SwapEffect = DXGI_SWAP_EFFECT_FLIP_DISCARD;
         sd.AlphaMode = DXGI_ALPHA_MODE_UNSPECIFIED;
         sd.Scaling = DXGI_SCALING_STRETCH;
         sd.Stereo = FALSE;
     }

     if (DX12_ENABLE_DEBUG_LAYER)
     {
         ID3D12Debug* dx12Debug = NULL;
         if (SUCCEEDED(D3D12GetDebugInterface(IID_PPV_ARGS(&dx12Debug))))
         {
             dx12Debug->EnableDebugLayer();
             dx12Debug->Release();
         }
     }

     D3D_FEATURE_LEVEL featureLevel = D3D_FEATURE_LEVEL_11_0;
     if (D3D12CreateDevice(NULL, featureLevel, IID_PPV_ARGS(&g_pd3dDevice)) != S_OK)
         return false;

     {
         D3D12_DESCRIPTOR_HEAP_DESC desc = {};
         desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_RTV;
         desc.NumDescriptors = NUM_BACK_BUFFERS;
         desc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_NONE;
         desc.NodeMask = 1;
         if (g_pd3dDevice->CreateDescriptorHeap(&desc, IID_PPV_ARGS(&g_pd3dRtvDescHeap)) != S_OK)
             return false;

         SIZE_T rtvDescriptorSize = g_pd3dDevice->GetDescriptorHandleIncrementSize(D3D12_DESCRIPTOR_HEAP_TYPE_RTV);
         D3D12_CPU_DESCRIPTOR_HANDLE rtvHandle = g_pd3dRtvDescHeap->GetCPUDescriptorHandleForHeapStart();
         for (UINT i = 0; i < NUM_BACK_BUFFERS; i++)
         {
             g_mainRenderTargetDescriptor[i] = rtvHandle;
             rtvHandle.ptr += rtvDescriptorSize;
         }
     }

     {
         D3D12_DESCRIPTOR_HEAP_DESC desc = {};
         desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV;
         desc.NumDescriptors = 1;
         desc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE;
         if (g_pd3dDevice->CreateDescriptorHeap(&desc, IID_PPV_ARGS(&g_pd3dSrvDescHeap)) != S_OK)
             return false;
     }

     {
         D3D12_COMMAND_QUEUE_DESC desc = {};
         desc.Type = D3D12_COMMAND_LIST_TYPE_DIRECT;
         desc.Flags = D3D12_COMMAND_QUEUE_FLAG_NONE;
         desc.NodeMask = 1;
         if (g_pd3dDevice->CreateCommandQueue(&desc, IID_PPV_ARGS(&g_pd3dCommandQueue)) != S_OK)
             return false;
     }

     for (UINT i = 0; i < NUM_FRAMES_IN_FLIGHT; i++)
         if (g_pd3dDevice->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT, IID_PPV_ARGS(&g_frameContext[i].CommandAllocator)) != S_OK)
             return false;

     if (g_pd3dDevice->CreateCommandList(0, D3D12_COMMAND_LIST_TYPE_DIRECT, g_frameContext[0].CommandAllocator, NULL, IID_PPV_ARGS(&g_pd3dCommandList)) != S_OK ||
         g_pd3dCommandList->Close() != S_OK)
         return false;

     if (g_pd3dDevice->CreateFence(0, D3D12_FENCE_FLAG_NONE, IID_PPV_ARGS(&g_fence)) != S_OK)
         return false;

     g_fenceEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
     if (g_fenceEvent == NULL)
         return false;

     {
         IDXGIFactory4* dxgiFactory = NULL;
         IDXGISwapChain1* swapChain1 = NULL;
         if (CreateDXGIFactory1(IID_PPV_ARGS(&dxgiFactory)) != S_OK ||
             dxgiFactory->CreateSwapChainForHwnd(g_pd3dCommandQueue, hWnd, &sd, NULL, NULL, &swapChain1) != S_OK ||
             swapChain1->QueryInterface(IID_PPV_ARGS(&g_pSwapChain)) != S_OK)
             return false;
         swapChain1->Release();
         dxgiFactory->Release();
         g_pSwapChain->SetMaximumFrameLatency(NUM_BACK_BUFFERS);
         g_hSwapChainWaitableObject = g_pSwapChain->GetFrameLatencyWaitableObject();
     }

     CreateRenderTarget();
     return true;
 }

 void CleanupDeviceD3D()
 {
     CleanupRenderTarget();
     if (g_pSwapChain) { g_pSwapChain->Release(); g_pSwapChain = NULL; }
     if (g_hSwapChainWaitableObject != NULL) { CloseHandle(g_hSwapChainWaitableObject); }
     for (UINT i = 0; i < NUM_FRAMES_IN_FLIGHT; i++)
         if (g_frameContext[i].CommandAllocator) { g_frameContext[i].CommandAllocator->Release(); g_frameContext[i].CommandAllocator = NULL; }
     if (g_pd3dCommandQueue) { g_pd3dCommandQueue->Release(); g_pd3dCommandQueue = NULL; }
     if (g_pd3dCommandList) { g_pd3dCommandList->Release(); g_pd3dCommandList = NULL; }
     if (g_pd3dRtvDescHeap) { g_pd3dRtvDescHeap->Release(); g_pd3dRtvDescHeap = NULL; }
     if (g_pd3dSrvDescHeap) { g_pd3dSrvDescHeap->Release(); g_pd3dSrvDescHeap = NULL; }
     if (g_fence) { g_fence->Release(); g_fence = NULL; }
     if (g_fenceEvent) { CloseHandle(g_fenceEvent); g_fenceEvent = NULL; }
     if (g_pd3dDevice) { g_pd3dDevice->Release(); g_pd3dDevice = NULL; }
 }

 void CreateRenderTarget()
 {
     for (UINT i = 0; i < NUM_BACK_BUFFERS; i++)
     {
         ID3D12Resource* pBackBuffer = NULL;
         g_pSwapChain->GetBuffer(i, IID_PPV_ARGS(&pBackBuffer));
         g_pd3dDevice->CreateRenderTargetView(pBackBuffer, NULL, g_mainRenderTargetDescriptor[i]);
         g_mainRenderTargetResource[i] = pBackBuffer;
     }
 }

 void CleanupRenderTarget()
 {
     WaitForLastSubmittedFrame();

     for (UINT i = 0; i < NUM_BACK_BUFFERS; i++)
         if (g_mainRenderTargetResource[i]) { g_mainRenderTargetResource[i]->Release(); g_mainRenderTargetResource[i] = NULL; }
 }

 void WaitForLastSubmittedFrame()
 {
     FrameContext* frameCtxt = &g_frameContext[g_frameIndex % NUM_FRAMES_IN_FLIGHT];

     UINT64 fenceValue = frameCtxt->FenceValue;
     if (fenceValue == 0)
         return; // No fence was signaled

     frameCtxt->FenceValue = 0;
     if (g_fence->GetCompletedValue() >= fenceValue)
         return;

     g_fence->SetEventOnCompletion(fenceValue, g_fenceEvent);
     WaitForSingleObject(g_fenceEvent, INFINITE);
 }

 FrameContext* WaitForNextFrameResources()
 {
     UINT nextFrameIndex = g_frameIndex + 1;
     g_frameIndex = nextFrameIndex;

     HANDLE waitableObjects[] = { g_hSwapChainWaitableObject, NULL };
     DWORD numWaitableObjects = 1;

     FrameContext* frameCtxt = &g_frameContext[nextFrameIndex % NUM_FRAMES_IN_FLIGHT];
     UINT64 fenceValue = frameCtxt->FenceValue;
     if (fenceValue != 0) // means no fence was signaled
     {
         frameCtxt->FenceValue = 0;
         g_fence->SetEventOnCompletion(fenceValue, g_fenceEvent);
         waitableObjects[1] = g_fenceEvent;
         numWaitableObjects = 2;
     }

     WaitForMultipleObjects(numWaitableObjects, waitableObjects, TRUE, INFINITE);

     return frameCtxt;
 }

 void ResizeSwapChain(HWND hWnd, int width, int height)
 {
     DXGI_SWAP_CHAIN_DESC1 sd;
     g_pSwapChain->GetDesc1(&sd);
     sd.Width = width;
     sd.Height = height;

     IDXGIFactory4* dxgiFactory = NULL;
     g_pSwapChain->GetParent(IID_PPV_ARGS(&dxgiFactory));

     g_pSwapChain->Release();
     CloseHandle(g_hSwapChainWaitableObject);

     IDXGISwapChain1* swapChain1 = NULL;
     dxgiFactory->CreateSwapChainForHwnd(g_pd3dCommandQueue, hWnd, &sd, NULL, NULL, &swapChain1);
     swapChain1->QueryInterface(IID_PPV_ARGS(&g_pSwapChain));
     swapChain1->Release();
     dxgiFactory->Release();

     g_pSwapChain->SetMaximumFrameLatency(NUM_BACK_BUFFERS);

     g_hSwapChainWaitableObject = g_pSwapChain->GetFrameLatencyWaitableObject();
     assert(g_hSwapChainWaitableObject != NULL);
 }

 // Win32 message handler
 extern LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
 LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
 {
     if (ImGui_ImplWin32_WndProcHandler(hWnd, msg, wParam, lParam))
         return true;

     switch (msg)
     {
     case WM_SIZE:
         if (g_pd3dDevice != NULL && wParam != SIZE_MINIMIZED)
         {
             ImGui_ImplDX12_InvalidateDeviceObjects();
             CleanupRenderTarget();
             ResizeSwapChain(hWnd, (UINT)LOWORD(lParam), (UINT)HIWORD(lParam));
             CreateRenderTarget();
             ImGui_ImplDX12_CreateDeviceObjects();
         }
         return 0;
     case WM_SYSCOMMAND:
         if ((wParam & 0xfff0) == SC_KEYMENU) // Disable ALT application menu
             return 0;
         break;
     case WM_DESTROY:
         ::PostQuitMessage(0);
         return 0;
     }
     return ::DefWindowProc(hWnd, msg, wParam, lParam);
 }
	// dear imgui: standalone example application for DirectX 12
	// If you are new to dear imgui, see examples/README.txt and documentation at the top of imgui.cpp.
	// FIXME: 64-bit only for now! (Because sizeof(ImTextureId) == sizeof(void*))

	#include "imgui.h"
	#include "imgui_impl_win32.h"
	#include "imgui_impl_dx12.h"
	#include <d3d12.h>
	#include <dxgi1_4.h>
	#include <tchar.h>

	#define DX12_ENABLE_DEBUG_LAYER 0

	struct FrameContext
	{
	ID3D12CommandAllocator* CommandAllocator;
	UINT64 FenceValue;
	};

	// Data
	static int const NUM_FRAMES_IN_FLIGHT = 3;
	static FrameContext g_frameContext[NUM_FRAMES_IN_FLIGHT] = {};
	static UINT g_frameIndex = 0;

	static int const NUM_BACK_BUFFERS = 3;
	static ID3D12Device* g_pd3dDevice = NULL;
	static ID3D12DescriptorHeap* g_pd3dRtvDescHeap = NULL;
	static ID3D12DescriptorHeap* g_pd3dSrvDescHeap = NULL;
	static ID3D12CommandQueue* g_pd3dCommandQueue = NULL;
	static ID3D12GraphicsCommandList* g_pd3dCommandList = NULL;
	static ID3D12Fence* g_fence = NULL;
	static HANDLE g_fenceEvent = NULL;
	static UINT64 g_fenceLastSignaledValue = 0;
	static IDXGISwapChain3* g_pSwapChain = NULL;
	static HANDLE g_hSwapChainWaitableObject = NULL;
	static ID3D12Resource* g_mainRenderTargetResource[NUM_BACK_BUFFERS] = {};
	static D3D12_CPU_DESCRIPTOR_HANDLE g_mainRenderTargetDescriptor[NUM_BACK_BUFFERS] = {};

	// Forward declarations of helper functions
	bool CreateDeviceD3D(HWND hWnd);
	void CleanupDeviceD3D();
	void CreateRenderTarget();
	void CleanupRenderTarget();
	void WaitForLastSubmittedFrame();
	FrameContext* WaitForNextFrameResources();
	void ResizeSwapChain(HWND hWnd, int width, int height);
	LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);

	// Main code
	int main(int, char**)
	{
	// Create application window
	WNDCLASSEX wc = { sizeof(WNDCLASSEX), CS_CLASSDC, WndProc, 0L, 0L, GetModuleHandle(NULL), NULL, NULL, NULL, NULL, _T("ImGui Example"), NULL };
	::RegisterClassEx(&wc);
	HWND hwnd = ::CreateWindow(wc.lpszClassName, _T("Dear ImGui DirectX12 Example"), WS_OVERLAPPEDWINDOW, 100, 100, 1280, 800, NULL, NULL, wc.hInstance, NULL);

	// Initialize Direct3D
	if (!CreateDeviceD3D(hwnd))
	{
	CleanupDeviceD3D();
	::UnregisterClass(wc.lpszClassName, wc.hInstance);
	return 1;
	}

	// Show the window
	::ShowWindow(hwnd, SW_SHOWDEFAULT);
	::UpdateWindow(hwnd);

	// Setup Dear ImGui context
	IMGUI_CHECKVERSION();
	ImGui::CreateContext();
	ImGuiIO& io = ImGui::GetIO(); (void)io;
	//io.ConfigFlags \|= ImGuiConfigFlags_NavEnableKeyboard; // Enable Keyboard Controls
	//io.ConfigFlags \|= ImGuiConfigFlags_NavEnableGamepad; // Enable Gamepad Controls

	// Setup Dear ImGui style
	ImGui::StyleColorsDark();
	//ImGui::StyleColorsClassic();

	// Setup Platform/Renderer bindings
	ImGui_ImplWin32_Init(hwnd);
	ImGui_ImplDX12_Init(g_pd3dDevice, NUM_FRAMES_IN_FLIGHT,
	DXGI_FORMAT_R8G8B8A8_UNORM,
	g_pd3dSrvDescHeap->GetCPUDescriptorHandleForHeapStart(),
	g_pd3dSrvDescHeap->GetGPUDescriptorHandleForHeapStart());

	// Load Fonts
	// - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
	// - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
	// - If the file cannot be loaded, the function will return NULL. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
	// - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which ImGui_ImplXXXX_NewFrame below will call.
	// - Read 'misc/fonts/README.txt' for more instructions and details.
	// - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
	//io.Fonts->AddFontDefault();
	//io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
	//io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
	//io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
	//io.Fonts->AddFontFromFileTTF("../../misc/fonts/ProggyTiny.ttf", 10.0f);
	//ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
	//IM_ASSERT(font != NULL);

	// Our state
	bool show_demo_window = true;
	bool show_another_window = false;
	ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);

	// Main loop
	MSG msg;
	ZeroMemory(&msg, sizeof(msg));
	while (msg.message != WM_QUIT)
	{
	// Poll and handle messages (inputs, window resize, etc.)
	// You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
	// - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application.
	// - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.
	// Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
	if (::PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
	{
	::TranslateMessage(&msg);
	::DispatchMessage(&msg);
	continue;
	}

	// Start the Dear ImGui frame
	ImGui_ImplDX12_NewFrame();
	ImGui_ImplWin32_NewFrame();
	ImGui::NewFrame();

	// 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
	if (show_demo_window)
	ImGui::ShowDemoWindow(&show_demo_window);

	// 2. Show a simple window that we create ourselves. We use a Begin/End pair to created a named window.
	{
	static float f = 0.0f;
	static int counter = 0;

	ImGui::Begin("Hello, world!"); // Create a window called "Hello, world!" and append into it.

	ImGui::Text("This is some useful text."); // Display some text (you can use a format strings too)
	ImGui::Checkbox("Demo Window", &show_demo_window); // Edit bools storing our window open/close state
	ImGui::Checkbox("Another Window", &show_another_window);

	ImGui::SliderFloat("float", &f, 0.0f, 1.0f); // Edit 1 float using a slider from 0.0f to 1.0f
	ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color

	if (ImGui::Button("Button")) // Buttons return true when clicked (most widgets return true when edited/activated)
	counter++;
	ImGui::SameLine();
	ImGui::Text("counter = %d", counter);

	ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
	ImGui::End();
	}

	// 3. Show another simple window.
	if (show_another_window)
	{
	ImGui::Begin("Another Window", &show_another_window); // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
	ImGui::Text("Hello from another window!");
	if (ImGui::Button("Close Me"))
	show_another_window = false;
	ImGui::End();
	}

	// Rendering
	FrameContext* frameCtxt = WaitForNextFrameResources();
	UINT backBufferIdx = g_pSwapChain->GetCurrentBackBufferIndex();
	frameCtxt->CommandAllocator->Reset();

	D3D12_RESOURCE_BARRIER barrier = {};
	barrier.Type = D3D12_RESOURCE_BARRIER_TYPE_TRANSITION;
	barrier.Flags = D3D12_RESOURCE_BARRIER_FLAG_NONE;
	barrier.Transition.pResource = g_mainRenderTargetResource[backBufferIdx];
	barrier.Transition.Subresource = D3D12_RESOURCE_BARRIER_ALL_SUBRESOURCES;
	barrier.Transition.StateBefore = D3D12_RESOURCE_STATE_PRESENT;
	barrier.Transition.StateAfter = D3D12_RESOURCE_STATE_RENDER_TARGET;

	g_pd3dCommandList->Reset(frameCtxt->CommandAllocator, NULL);
	g_pd3dCommandList->ResourceBarrier(1, &barrier);
	g_pd3dCommandList->ClearRenderTargetView(g_mainRenderTargetDescriptor[backBufferIdx], (float*)&clear_color, 0, NULL);
	g_pd3dCommandList->OMSetRenderTargets(1, &g_mainRenderTargetDescriptor[backBufferIdx], FALSE, NULL);
	g_pd3dCommandList->SetDescriptorHeaps(1, &g_pd3dSrvDescHeap);
	ImGui::Render();
	ImGui_ImplDX12_RenderDrawData(ImGui::GetDrawData(), g_pd3dCommandList);
	barrier.Transition.StateBefore = D3D12_RESOURCE_STATE_RENDER_TARGET;
	barrier.Transition.StateAfter = D3D12_RESOURCE_STATE_PRESENT;
	g_pd3dCommandList->ResourceBarrier(1, &barrier);
	g_pd3dCommandList->Close();

	g_pd3dCommandQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*)&g_pd3dCommandList);

	g_pSwapChain->Present(1, 0); // Present with vsync
	//g_pSwapChain->Present(0, 0); // Present without vsync

	UINT64 fenceValue = g_fenceLastSignaledValue + 1;
	g_pd3dCommandQueue->Signal(g_fence, fenceValue);
	g_fenceLastSignaledValue = fenceValue;
	frameCtxt->FenceValue = fenceValue;
	}

	WaitForLastSubmittedFrame();
	ImGui_ImplDX12_Shutdown();
	ImGui_ImplWin32_Shutdown();
	ImGui::DestroyContext();

	CleanupDeviceD3D();
	::DestroyWindow(hwnd);
	::UnregisterClass(wc.lpszClassName, wc.hInstance);

	return 0;
	}

	// Helper functions

	bool CreateDeviceD3D(HWND hWnd)
	{
	// Setup swap chain
	DXGI_SWAP_CHAIN_DESC1 sd;
	{
	ZeroMemory(&sd, sizeof(sd));
	sd.BufferCount = NUM_BACK_BUFFERS;
	sd.Width = 0;
	sd.Height = 0;
	sd.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
	sd.Flags = DXGI_SWAP_CHAIN_FLAG_FRAME_LATENCY_WAITABLE_OBJECT;
	sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
	sd.SampleDesc.Count = 1;
	sd.SampleDesc.Quality = 0;
	sd.SwapEffect = DXGI_SWAP_EFFECT_FLIP_DISCARD;
	sd.AlphaMode = DXGI_ALPHA_MODE_UNSPECIFIED;
	sd.Scaling = DXGI_SCALING_STRETCH;
	sd.Stereo = FALSE;
	}

	if (DX12_ENABLE_DEBUG_LAYER)
	{
	ID3D12Debug* dx12Debug = NULL;
	if (SUCCEEDED(D3D12GetDebugInterface(IID_PPV_ARGS(&dx12Debug))))
	{
	dx12Debug->EnableDebugLayer();
	dx12Debug->Release();
	}
	}

	D3D_FEATURE_LEVEL featureLevel = D3D_FEATURE_LEVEL_11_0;
	if (D3D12CreateDevice(NULL, featureLevel, IID_PPV_ARGS(&g_pd3dDevice)) != S_OK)
	return false;

	{
	D3D12_DESCRIPTOR_HEAP_DESC desc = {};
	desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_RTV;
	desc.NumDescriptors = NUM_BACK_BUFFERS;
	desc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_NONE;
	desc.NodeMask = 1;
	if (g_pd3dDevice->CreateDescriptorHeap(&desc, IID_PPV_ARGS(&g_pd3dRtvDescHeap)) != S_OK)
	return false;

	SIZE_T rtvDescriptorSize = g_pd3dDevice->GetDescriptorHandleIncrementSize(D3D12_DESCRIPTOR_HEAP_TYPE_RTV);
	D3D12_CPU_DESCRIPTOR_HANDLE rtvHandle = g_pd3dRtvDescHeap->GetCPUDescriptorHandleForHeapStart();
	for (UINT i = 0; i < NUM_BACK_BUFFERS; i++)
	{
	g_mainRenderTargetDescriptor[i] = rtvHandle;
	rtvHandle.ptr += rtvDescriptorSize;
	}
	}

	{
	D3D12_DESCRIPTOR_HEAP_DESC desc = {};
	desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV;
	desc.NumDescriptors = 1;
	desc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE;
	if (g_pd3dDevice->CreateDescriptorHeap(&desc, IID_PPV_ARGS(&g_pd3dSrvDescHeap)) != S_OK)
	return false;
	}

	{
	D3D12_COMMAND_QUEUE_DESC desc = {};
	desc.Type = D3D12_COMMAND_LIST_TYPE_DIRECT;
	desc.Flags = D3D12_COMMAND_QUEUE_FLAG_NONE;
	desc.NodeMask = 1;
	if (g_pd3dDevice->CreateCommandQueue(&desc, IID_PPV_ARGS(&g_pd3dCommandQueue)) != S_OK)
	return false;
	}

	for (UINT i = 0; i < NUM_FRAMES_IN_FLIGHT; i++)
	if (g_pd3dDevice->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT, IID_PPV_ARGS(&g_frameContext[i].CommandAllocator)) != S_OK)
	return false;

	if (g_pd3dDevice->CreateCommandList(0, D3D12_COMMAND_LIST_TYPE_DIRECT, g_frameContext[0].CommandAllocator, NULL, IID_PPV_ARGS(&g_pd3dCommandList)) != S_OK \|\|
	g_pd3dCommandList->Close() != S_OK)
	return false;

	if (g_pd3dDevice->CreateFence(0, D3D12_FENCE_FLAG_NONE, IID_PPV_ARGS(&g_fence)) != S_OK)
	return false;

	g_fenceEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
	if (g_fenceEvent == NULL)
	return false;

	{
	IDXGIFactory4* dxgiFactory = NULL;
	IDXGISwapChain1* swapChain1 = NULL;
	if (CreateDXGIFactory1(IID_PPV_ARGS(&dxgiFactory)) != S_OK \|\|
	dxgiFactory->CreateSwapChainForHwnd(g_pd3dCommandQueue, hWnd, &sd, NULL, NULL, &swapChain1) != S_OK \|\|
	swapChain1->QueryInterface(IID_PPV_ARGS(&g_pSwapChain)) != S_OK)
	return false;
	swapChain1->Release();
	dxgiFactory->Release();
	g_pSwapChain->SetMaximumFrameLatency(NUM_BACK_BUFFERS);
	g_hSwapChainWaitableObject = g_pSwapChain->GetFrameLatencyWaitableObject();
	}

	CreateRenderTarget();
	return true;
	}

	void CleanupDeviceD3D()
	{
	CleanupRenderTarget();
	if (g_pSwapChain) { g_pSwapChain->Release(); g_pSwapChain = NULL; }
	if (g_hSwapChainWaitableObject != NULL) { CloseHandle(g_hSwapChainWaitableObject); }
	for (UINT i = 0; i < NUM_FRAMES_IN_FLIGHT; i++)
	if (g_frameContext[i].CommandAllocator) { g_frameContext[i].CommandAllocator->Release(); g_frameContext[i].CommandAllocator = NULL; }
	if (g_pd3dCommandQueue) { g_pd3dCommandQueue->Release(); g_pd3dCommandQueue = NULL; }
	if (g_pd3dCommandList) { g_pd3dCommandList->Release(); g_pd3dCommandList = NULL; }
	if (g_pd3dRtvDescHeap) { g_pd3dRtvDescHeap->Release(); g_pd3dRtvDescHeap = NULL; }
	if (g_pd3dSrvDescHeap) { g_pd3dSrvDescHeap->Release(); g_pd3dSrvDescHeap = NULL; }
	if (g_fence) { g_fence->Release(); g_fence = NULL; }
	if (g_fenceEvent) { CloseHandle(g_fenceEvent); g_fenceEvent = NULL; }
	if (g_pd3dDevice) { g_pd3dDevice->Release(); g_pd3dDevice = NULL; }
	}

	void CreateRenderTarget()
	{
	for (UINT i = 0; i < NUM_BACK_BUFFERS; i++)
	{
	ID3D12Resource* pBackBuffer = NULL;
	g_pSwapChain->GetBuffer(i, IID_PPV_ARGS(&pBackBuffer));
	g_pd3dDevice->CreateRenderTargetView(pBackBuffer, NULL, g_mainRenderTargetDescriptor[i]);
	g_mainRenderTargetResource[i] = pBackBuffer;
	}
	}

	void CleanupRenderTarget()
	{
	WaitForLastSubmittedFrame();

	for (UINT i = 0; i < NUM_BACK_BUFFERS; i++)
	if (g_mainRenderTargetResource[i]) { g_mainRenderTargetResource[i]->Release(); g_mainRenderTargetResource[i] = NULL; }
	}

	void WaitForLastSubmittedFrame()
	{
	FrameContext* frameCtxt = &g_frameContext[g_frameIndex % NUM_FRAMES_IN_FLIGHT];

	UINT64 fenceValue = frameCtxt->FenceValue;
	if (fenceValue == 0)
	return; // No fence was signaled

	frameCtxt->FenceValue = 0;
	if (g_fence->GetCompletedValue() >= fenceValue)
	return;

	g_fence->SetEventOnCompletion(fenceValue, g_fenceEvent);
	WaitForSingleObject(g_fenceEvent, INFINITE);
	}

	FrameContext* WaitForNextFrameResources()
	{
	UINT nextFrameIndex = g_frameIndex + 1;
	g_frameIndex = nextFrameIndex;

	HANDLE waitableObjects[] = { g_hSwapChainWaitableObject, NULL };
	DWORD numWaitableObjects = 1;

	FrameContext* frameCtxt = &g_frameContext[nextFrameIndex % NUM_FRAMES_IN_FLIGHT];
	UINT64 fenceValue = frameCtxt->FenceValue;
	if (fenceValue != 0) // means no fence was signaled
	{
	frameCtxt->FenceValue = 0;
	g_fence->SetEventOnCompletion(fenceValue, g_fenceEvent);
	waitableObjects[1] = g_fenceEvent;
	numWaitableObjects = 2;
	}

	WaitForMultipleObjects(numWaitableObjects, waitableObjects, TRUE, INFINITE);

	return frameCtxt;
	}

	void ResizeSwapChain(HWND hWnd, int width, int height)
	{
	DXGI_SWAP_CHAIN_DESC1 sd;
	g_pSwapChain->GetDesc1(&sd);
	sd.Width = width;
	sd.Height = height;

	IDXGIFactory4* dxgiFactory = NULL;
	g_pSwapChain->GetParent(IID_PPV_ARGS(&dxgiFactory));

	g_pSwapChain->Release();
	CloseHandle(g_hSwapChainWaitableObject);

	IDXGISwapChain1* swapChain1 = NULL;
	dxgiFactory->CreateSwapChainForHwnd(g_pd3dCommandQueue, hWnd, &sd, NULL, NULL, &swapChain1);
	swapChain1->QueryInterface(IID_PPV_ARGS(&g_pSwapChain));
	swapChain1->Release();
	dxgiFactory->Release();

	g_pSwapChain->SetMaximumFrameLatency(NUM_BACK_BUFFERS);

	g_hSwapChainWaitableObject = g_pSwapChain->GetFrameLatencyWaitableObject();
	assert(g_hSwapChainWaitableObject != NULL);
	}

	// Win32 message handler
	extern LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
	LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
	{
	if (ImGui_ImplWin32_WndProcHandler(hWnd, msg, wParam, lParam))
	return true;

	switch (msg)
	{
	case WM_SIZE:
	if (g_pd3dDevice != NULL && wParam != SIZE_MINIMIZED)
	{
	ImGui_ImplDX12_InvalidateDeviceObjects();
	CleanupRenderTarget();
	ResizeSwapChain(hWnd, (UINT)LOWORD(lParam), (UINT)HIWORD(lParam));
	CreateRenderTarget();
	ImGui_ImplDX12_CreateDeviceObjects();
	}
	return 0;
	case WM_SYSCOMMAND:
	if ((wParam & 0xfff0) == SC_KEYMENU) // Disable ALT application menu
	return 0;
	break;
	case WM_DESTROY:
	::PostQuitMessage(0);
	return 0;
	}
	return ::DefWindowProc(hWnd, msg, wParam, lParam);
	}