// ImGui - standalone example application for DirectX 11

#include <imgui.h>
#include "imgui_impl_dx11.h"
#include <d3d11.h>
#include <d3dcompiler.h>
#define DIRECTINPUT_VERSION 0x0800
#include <dinput.h>

// Data
static ID3D11Device*            g_pd3dDevice = NULL;
static ID3D11DeviceContext*     g_pd3dDeviceContext = NULL;
static IDXGISwapChain*          g_pSwapChain = NULL;
static ID3D11RenderTargetView*  g_mainRenderTargetView = NULL;

void CreateRenderTarget()
{
    DXGI_SWAP_CHAIN_DESC sd;
    g_pSwapChain->GetDesc(&sd);

    // Create the render target
    ID3D11Texture2D* pBackBuffer;               
    D3D11_RENDER_TARGET_VIEW_DESC render_target_view_desc;
    ZeroMemory(&render_target_view_desc, sizeof(render_target_view_desc));
    render_target_view_desc.Format = sd.BufferDesc.Format;
    render_target_view_desc.ViewDimension = D3D11_RTV_DIMENSION_TEXTURE2D;
    g_pSwapChain->GetBuffer(0, __uuidof(ID3D11Texture2D), (LPVOID*)&pBackBuffer);
    g_pd3dDevice->CreateRenderTargetView(pBackBuffer, &render_target_view_desc, &g_mainRenderTargetView);
    g_pd3dDeviceContext->OMSetRenderTargets(1, &g_mainRenderTargetView, NULL);
    pBackBuffer->Release();
}

void CleanupRenderTarget()
{
    if (g_mainRenderTargetView) { g_mainRenderTargetView->Release(); g_mainRenderTargetView = NULL; }
}

HRESULT CreateDeviceD3D(HWND hWnd)
{
    // Setup swap chain
    DXGI_SWAP_CHAIN_DESC sd;
    {
        ZeroMemory(&sd, sizeof(sd));
        sd.BufferCount = 2;
        sd.BufferDesc.Width = 0;
        sd.BufferDesc.Height = 0;
        sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
        sd.BufferDesc.RefreshRate.Numerator = 60;
        sd.BufferDesc.RefreshRate.Denominator = 1;
        sd.Flags = DXGI_SWAP_CHAIN_FLAG_ALLOW_MODE_SWITCH;
        sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
        sd.OutputWindow = hWnd;
        sd.SampleDesc.Count = 1;
        sd.SampleDesc.Quality = 0;
        sd.Windowed = TRUE;
        sd.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;
    }

    UINT createDeviceFlags = 0;
#ifdef _DEBUG
    createDeviceFlags |= D3D11_CREATE_DEVICE_DEBUG;
#endif
    D3D_FEATURE_LEVEL featureLevel;
    const D3D_FEATURE_LEVEL featureLevelArray[1] = { D3D_FEATURE_LEVEL_11_0, };
    if (D3D11CreateDeviceAndSwapChain(NULL, D3D_DRIVER_TYPE_HARDWARE, NULL, createDeviceFlags, featureLevelArray, 1, D3D11_SDK_VERSION, &sd, &g_pSwapChain, &g_pd3dDevice, &featureLevel, &g_pd3dDeviceContext) != S_OK)
        return E_FAIL;

    // Setup rasterizer
    {
        D3D11_RASTERIZER_DESC RSDesc;
        memset(&RSDesc, 0, sizeof(D3D11_RASTERIZER_DESC));
        RSDesc.FillMode = D3D11_FILL_SOLID;
        RSDesc.CullMode = D3D11_CULL_NONE;
        RSDesc.FrontCounterClockwise = FALSE;
        RSDesc.DepthBias = 0;
        RSDesc.SlopeScaledDepthBias = 0.0f;
        RSDesc.DepthBiasClamp = 0;
        RSDesc.DepthClipEnable = TRUE;
        RSDesc.ScissorEnable = TRUE;
        RSDesc.AntialiasedLineEnable = FALSE;
        RSDesc.MultisampleEnable = (sd.SampleDesc.Count > 1) ? TRUE : FALSE;

        ID3D11RasterizerState* pRState = NULL;
        g_pd3dDevice->CreateRasterizerState(&RSDesc, &pRState);
        g_pd3dDeviceContext->RSSetState(pRState);
        pRState->Release();
    }

    CreateRenderTarget();

    return S_OK;
}

void CleanupDeviceD3D()
{
    CleanupRenderTarget();
    if (g_pSwapChain) { g_pSwapChain->Release(); g_pSwapChain = NULL; }
    if (g_pd3dDeviceContext) { g_pd3dDeviceContext->Release(); g_pd3dDeviceContext = NULL; }
    if (g_pd3dDevice) { g_pd3dDevice->Release(); g_pd3dDevice = NULL; }
}

extern LRESULT ImGui_ImplDX11_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    if (ImGui_ImplDX11_WndProcHandler(hWnd, msg, wParam, lParam))
        return true;

    switch (msg)
    {
    case WM_SIZE:
        if (g_pd3dDevice != NULL && wParam != SIZE_MINIMIZED)
        {
            ImGui_ImplDX11_InvalidateDeviceObjects();
            CleanupRenderTarget();
            g_pSwapChain->ResizeBuffers(0, (UINT)LOWORD(lParam), (UINT)HIWORD(lParam), DXGI_FORMAT_UNKNOWN, 0);
            CreateRenderTarget();
            ImGui_ImplDX11_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);
}

int main(int, char**)
{
    // Create application window
    WNDCLASSEX wc = { sizeof(WNDCLASSEX), CS_CLASSDC, WndProc, 0L, 0L, GetModuleHandle(NULL), NULL, LoadCursor(NULL, IDC_ARROW), NULL, NULL, L"ImGui Example", NULL };
    RegisterClassEx(&wc);
    HWND hwnd = CreateWindow(L"ImGui Example", L"ImGui DirectX11 Example", WS_OVERLAPPEDWINDOW, 100, 100, 1280, 800, NULL, NULL, wc.hInstance, NULL);

    // Initialize Direct3D
    if (CreateDeviceD3D(hwnd) < 0)
    {
        CleanupDeviceD3D();
        UnregisterClass(L"ImGui Example", wc.hInstance);
        return 1;
    }

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

    // Setup ImGui binding
    ImGui_ImplDX11_Init(hwnd, g_pd3dDevice, g_pd3dDeviceContext);

    // Load Fonts
    // (see extra_fonts/README.txt for more details)
    //ImGuiIO& io = ImGui::GetIO();
    //io.Fonts->AddFontDefault();
    //io.Fonts->AddFontFromFileTTF("../../extra_fonts/Cousine-Regular.ttf", 15.0f);
    //io.Fonts->AddFontFromFileTTF("../../extra_fonts/DroidSans.ttf", 16.0f);
    //io.Fonts->AddFontFromFileTTF("../../extra_fonts/ProggyClean.ttf", 13.0f);
    //io.Fonts->AddFontFromFileTTF("../../extra_fonts/ProggyTiny.ttf", 10.0f);
    //io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());

    // Merge glyphs from multiple fonts into one (e.g. combine default font with another with Chinese glyphs, or add icons)
    //ImWchar icons_ranges[] = { 0xf000, 0xf3ff, 0 };
    //ImFontConfig icons_config; icons_config.MergeMode = true; icons_config.PixelSnapH = true;
    //io.Fonts->AddFontFromFileTTF("../../extra_fonts/DroidSans.ttf", 18.0f);
    //io.Fonts->AddFontFromFileTTF("../../extra_fonts/fontawesome-webfont.ttf", 18.0f, &icons_config, icons_ranges);

    bool show_test_window = true;
    bool show_another_window = false;
    ImVec4 clear_col = ImColor(114, 144, 154);

    // Main loop
    MSG msg;
    ZeroMemory(&msg, sizeof(msg));
    while (msg.message != WM_QUIT)
    {
        if (PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
            continue;
        }
        ImGui_ImplDX11_NewFrame();

        // 1. Show a simple window
        // Tip: if we don't call ImGui::Begin()/ImGui::End() the widgets appears in a window automatically called "Debug"
        {
            static float f = 0.0f;
            ImGui::Text("Hello, world!");
            ImGui::SliderFloat("float", &f, 0.0f, 1.0f);
            ImGui::ColorEdit3("clear color", (float*)&clear_col);
            if (ImGui::Button("Test Window")) show_test_window ^= 1;
            if (ImGui::Button("Another Window")) show_another_window ^= 1;
            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
        }

        // 2. Show another simple window, this time using an explicit Begin/End pair
        if (show_another_window)
        {
            ImGui::SetNextWindowSize(ImVec2(200,100), ImGuiSetCond_FirstUseEver);
            ImGui::Begin("Another Window", &show_another_window);
            ImGui::Text("Hello");
            ImGui::End();
        }

        // 3. Show the ImGui test window. Most of the sample code is in ImGui::ShowTestWindow()
        if (show_test_window)
        {
            ImGui::SetNextWindowPos(ImVec2(650, 20), ImGuiSetCond_FirstUseEver);     // Normally user code doesn't need/want to call it because positions are saved in .ini file anyway. Here we just want to make the demo initial state a bit more friendly!
            ImGui::ShowTestWindow(&show_test_window);
        }

        // Rendering
        g_pd3dDeviceContext->ClearRenderTargetView(g_mainRenderTargetView, (float*)&clear_col);
        ImGui::Render();
        g_pSwapChain->Present(0, 0);
    }

    ImGui_ImplDX11_Shutdown();
    CleanupDeviceD3D();
    UnregisterClass(L"ImGui Example", wc.hInstance);

    return 0;
}
