// ImGui - standalone example application for DirectX 9
// If you are new to ImGui, see examples/README.txt and documentation at the top of imgui.cpp.

#include "imgui.h"
#include "imgui_impl_dx9.h"
#include <d3d9.h>
#define DIRECTINPUT_VERSION 0x0800
#include <dinput.h>
#include <tchar.h>

// Data
static LPDIRECT3DDEVICE9        g_pd3dDevice = NULL;
static D3DPRESENT_PARAMETERS    g_d3dpp;

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_ImplDX9_InvalidateDeviceObjects();
            g_d3dpp.BackBufferWidth  = LOWORD(lParam);
            g_d3dpp.BackBufferHeight = HIWORD(lParam);
            HRESULT hr = g_pd3dDevice->Reset(&g_d3dpp);
            if (hr == D3DERR_INVALIDCALL)
                IM_ASSERT(0);
            ImGui_ImplDX9_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, NULL, NULL, NULL, _T("ImGui Example"), NULL };
    RegisterClassEx(&wc);
    HWND hwnd = CreateWindow(_T("ImGui Example"), _T("ImGui DirectX9 Example"), WS_OVERLAPPEDWINDOW, 100, 100, 1280, 800, NULL, NULL, wc.hInstance, NULL);

    // Initialize Direct3D
    LPDIRECT3D9 pD3D;
    if ((pD3D = Direct3DCreate9(D3D_SDK_VERSION)) == NULL)
    {
        UnregisterClass(_T("ImGui Example"), wc.hInstance);
        return 0;
    }
    ZeroMemory(&g_d3dpp, sizeof(g_d3dpp));
    g_d3dpp.Windowed = TRUE;
    g_d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    g_d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;
    g_d3dpp.EnableAutoDepthStencil = TRUE;
    g_d3dpp.AutoDepthStencilFormat = D3DFMT_D16;
    g_d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_ONE; // Present with vsync
    //g_d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_IMMEDIATE; // Present without vsync, maximum unthrottled framerate

    // Create the D3DDevice
    if (pD3D->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hwnd, D3DCREATE_HARDWARE_VERTEXPROCESSING, &g_d3dpp, &g_pd3dDevice) < 0)
    {
        pD3D->Release();
        UnregisterClass(_T("ImGui Example"), wc.hInstance);
        return 0;
    }

    // Setup Dear ImGui binding
    IMGUI_CHECKVERSION();
    ImGui::CreateContext();
    ImGuiIO& io = ImGui::GetIO(); (void)io;
    //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
    ImGui_ImplDX9_Init(hwnd, g_pd3dDevice);

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

    // 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);

    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));
    ShowWindow(hwnd, SW_SHOWDEFAULT);
    UpdateWindow(hwnd);
    while (msg.message != WM_QUIT)
    {
        // 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;
        }
        ImGui_ImplDX9_NewFrame();

        // 1. Show a simple window.
        // Tip: if we don't call ImGui::Begin()/ImGui::End() the widgets automatically appears in a window called "Debug".
        {
            static float f = 0.0f;
            static int counter = 0;
            ImGui::Text("Hello, world!");                           // Display some text (you can use a format string too)
            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

            ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our windows open/close state
            ImGui::Checkbox("Another Window", &show_another_window);

            if (ImGui::Button("Button"))                            // Buttons return true when clicked (NB: 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);
        }

        // 2. Show another simple window. In most cases you will use an explicit Begin/End pair to name your windows.
        if (show_another_window)
        {
            ImGui::Begin("Another Window", &show_another_window);
            ImGui::Text("Hello from another window!");
            if (ImGui::Button("Close Me"))
                show_another_window = false;
            ImGui::End();
        }

        // 3. Show the ImGui demo window. Most of the sample code is in ImGui::ShowDemoWindow(). Read its code to learn more about Dear ImGui!
        if (show_demo_window)
        {
            ImGui::SetNextWindowPos(ImVec2(650, 20), ImGuiCond_FirstUseEver); // Normally user code doesn't need/want to call this because positions are saved in .ini file anyway. Here we just want to make the demo initial state a bit more friendly!
            ImGui::ShowDemoWindow(&show_demo_window);
        }

        // Rendering
        ImGui::EndFrame();
        g_pd3dDevice->SetRenderState(D3DRS_ZENABLE, false);
        g_pd3dDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, false);
        g_pd3dDevice->SetRenderState(D3DRS_SCISSORTESTENABLE, false);
        D3DCOLOR clear_col_dx = D3DCOLOR_RGBA((int)(clear_color.x*255.0f), (int)(clear_color.y*255.0f), (int)(clear_color.z*255.0f), (int)(clear_color.w*255.0f));
        g_pd3dDevice->Clear(0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, clear_col_dx, 1.0f, 0);
        if (g_pd3dDevice->BeginScene() >= 0)
        {
            ImGui::Render();
            ImGui_ImplDX9_RenderDrawData(ImGui::GetDrawData());
            g_pd3dDevice->EndScene();
        }
        HRESULT result = g_pd3dDevice->Present(NULL, NULL, NULL, NULL);

        // Handle loss of D3D9 device
        if (result == D3DERR_DEVICELOST && g_pd3dDevice->TestCooperativeLevel() == D3DERR_DEVICENOTRESET)
        {
            ImGui_ImplDX9_InvalidateDeviceObjects();
            g_pd3dDevice->Reset(&g_d3dpp);
            ImGui_ImplDX9_CreateDeviceObjects();
        }
    }

    ImGui_ImplDX9_Shutdown();
    ImGui::DestroyContext();

    if (g_pd3dDevice) g_pd3dDevice->Release();
    if (pD3D) pD3D->Release();
    DestroyWindow(hwnd);
    UnregisterClass(_T("ImGui Example"), wc.hInstance);

    return 0;
}