/************************************************************************
 *
 * File: DemoApp.cpp
 *
 * Description: 
 * 
 * 
 *  This file is part of the Microsoft Windows SDK Code Samples.
 * 
 *  Copyright (C) Microsoft Corporation.  All rights reserved.
 * 
 * This source code is intended only as a supplement to Microsoft
 * Development Tools and/or on-line documentation.  See these other
 * materials for detailed information regarding Microsoft code samples.
 * 
 * THIS CODE AND INFORMATION ARE PROVIDED AS IS WITHOUT WARRANTY OF ANY
 * KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
 * PARTICULAR PURPOSE.
 * 
 ************************************************************************/

#include "SimpleHelloWorld.h"


/******************************************************************
*                                                                 *
*  DemoApp::DemoApp constructor                             *
*                                                                 *
*  Initialize member data                                         *
*                                                                 *
******************************************************************/

DemoApp::DemoApp() :
    hwnd_(NULL),
    wszText_(NULL),
    cTextLength_(0),
    pD2DFactory_(NULL),
    pRT_(NULL),
    pBlackBrush_(NULL),
    pDWriteFactory_(NULL),
    pTextFormat_(NULL)
{
}

/******************************************************************
*                                                                 *
*  DemoApp::~DemoApp destructor                             *
*                                                                 *
*  Tear down resources                                            *
*                                                                 *
******************************************************************/

DemoApp::~DemoApp()
{
    SafeRelease(&pD2DFactory_);
    SafeRelease(&pRT_);
    SafeRelease(&pBlackBrush_);
    SafeRelease(&pDWriteFactory_);
    SafeRelease(&pTextFormat_);
}

/******************************************************************
*                                                                 *
*  DemoApp::Initialize                                         *
*                                                                 *
*  Create application window and device-independent resources     *
*                                                                 *
******************************************************************/

HRESULT DemoApp::Initialize()
{
    WNDCLASSEX wcex;

    //get the dpi information
    HDC screen = GetDC(0);
    dpiScaleX_ = GetDeviceCaps(screen, LOGPIXELSX) / 96.0f;
    dpiScaleY_ = GetDeviceCaps(screen, LOGPIXELSY) / 96.0f;
    ReleaseDC(0, screen);
    
    // Return failure unless CreateDeviceIndependentResources returns SUCCEEDED.
    HRESULT hr = S_OK;

    ATOM atom;

    // Register window class.
    wcex.cbSize        = sizeof(WNDCLASSEX);
    wcex.style         = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc   = DemoApp::WndProc;
    wcex.cbClsExtra    = 0;
    wcex.cbWndExtra    = sizeof(LONG_PTR);
    wcex.hInstance     = HINST_THISCOMPONENT;
    wcex.hbrBackground = NULL;
    wcex.lpszMenuName  = NULL;
    wcex.hIcon         = LoadIcon(
                            NULL,
                            IDI_APPLICATION);
    wcex.hCursor       = LoadCursor(
                            NULL,
                            IDC_ARROW);
    wcex.lpszClassName = TEXT("DemoApp");
    wcex.hIconSm       = LoadIcon(
                            NULL,
                            IDI_APPLICATION
                            );

    atom = RegisterClassEx(
        &wcex
        );

    hr = atom ? S_OK : E_FAIL;

    if (SUCCEEDED(hr))
    {
        // Create window.
        hwnd_ = CreateWindow(
            TEXT("DemoApp"),
            TEXT("Simple DirectWrite Hello World"),
            WS_OVERLAPPEDWINDOW,
            CW_USEDEFAULT,
            CW_USEDEFAULT,
            static_cast<int>(640.0f / dpiScaleX_),
            static_cast<int>(480.0f / dpiScaleY_),
            NULL,
            NULL,
            HINST_THISCOMPONENT,
            this
            );
    }
   
    if (SUCCEEDED(hr))
    {
        hr = hwnd_ ? S_OK : E_FAIL;
    }
    
    if (SUCCEEDED(hr))
    {
        hr = CreateDeviceIndependentResources(
            );
    }

    if (SUCCEEDED(hr))
    {
        ShowWindow(
            hwnd_,
            SW_SHOWNORMAL
            );


        UpdateWindow(
            hwnd_
            );
    }

    if (SUCCEEDED(hr))
    {
        hr = DrawD2DContent();
    }

    return hr;
}

/******************************************************************
*                                                                 *
*  DemoApp::CreateDeviceIndependentResources                   *
*                                                                 *
*  This method is used to create resources which are not bound    *
*  to any device. Their lifetime effectively extends for the      *
*  duration of the app. These resources include the Direct2D and  *
*  DirectWrite factories; and a DirectWrite Text Format object    *
*  (used for identifying particular font characteristics) and     *
*  a Direct2D geometry.                                           *
*                                                                 *
******************************************************************/

HRESULT DemoApp::CreateDeviceIndependentResources()
{
    HRESULT hr;

    // Create Direct2D factory.
    hr = D2D1CreateFactory(
        D2D1_FACTORY_TYPE_SINGLE_THREADED,
        &pD2DFactory_
        );

    // Create a shared DirectWrite factory.
    if (SUCCEEDED(hr))
    {
        hr = DWriteCreateFactory(
            DWRITE_FACTORY_TYPE_SHARED,
            __uuidof(IDWriteFactory),
            reinterpret_cast<IUnknown**>(&pDWriteFactory_)
            );
    }

    // The string to display.
    wszText_ = L"Hello World using DirectWrite!";
    cTextLength_ = (UINT32)wcslen(wszText_);

    // Create a text format using Gabriola with a font size of 72.
    // This sets the default font, weight, stretch, style, and locale.
    if (SUCCEEDED(hr))
    {
        hr = pDWriteFactory_->CreateTextFormat(
            L"Gabriola",                // Font family name.
            NULL,                       // Font collection (NULL sets it to use the system font collection).
            DWRITE_FONT_WEIGHT_REGULAR,
            DWRITE_FONT_STYLE_NORMAL,
            DWRITE_FONT_STRETCH_NORMAL,
            72.0f,
            L"en-us",
            &pTextFormat_
            );
    }

    // Center align (horizontally) the text.
    if (SUCCEEDED(hr))
    {
        hr = pTextFormat_->SetTextAlignment(DWRITE_TEXT_ALIGNMENT_CENTER);
    }

    if (SUCCEEDED(hr))
    {
        hr = pTextFormat_->SetParagraphAlignment(DWRITE_PARAGRAPH_ALIGNMENT_CENTER);
    }

    return hr;
}

/******************************************************************
*                                                                 *
*  DemoApp::CreateDeviceResources                              *
*                                                                 *
*  This method creates resources which are bound to a particular  *
*  D3D device. It's all centralized here, in case the resources   *
*  need to be recreated in case of D3D device loss (eg. display   *
*  change, remoting, removal of video card, etc).                 *
*                                                                 *
******************************************************************/

HRESULT DemoApp::CreateDeviceResources()
{
    HRESULT hr = S_OK;

    RECT rc;
    GetClientRect(hwnd_, &rc);

    D2D1_SIZE_U size = D2D1::SizeU(rc.right - rc.left, rc.bottom - rc.top);

    if (!pRT_)
    {
        // Create a Direct2D render target.
        hr = pD2DFactory_->CreateHwndRenderTarget(
                D2D1::RenderTargetProperties(),
                D2D1::HwndRenderTargetProperties(
                    hwnd_,
                    size
                    ),
                &pRT_
                );

        // Create a black brush.
        if (SUCCEEDED(hr))
        {
            hr = pRT_->CreateSolidColorBrush(
                D2D1::ColorF(D2D1::ColorF::Black),
                &pBlackBrush_
                );
        }

    }

    return hr;
}

/******************************************************************
*                                                                 *
*  DemoApp::DiscardDeviceResources                             *
*                                                                 *
*  Discard device-specific resources which need to be recreated   *
*  when a D3D device is lost                                      *
*                                                                 *
******************************************************************/

void DemoApp::DiscardDeviceResources()
{
    SafeRelease(&pRT_);
    SafeRelease(&pBlackBrush_);
}


/******************************************************************
*                                                                 *
*  DemoApp::DrawText                                           *
*                                                                 *
*  This method will draw text using the IDWriteTextFormat         *
*  via the Direct2D render target                                 *
*                                                                 *
******************************************************************/

HRESULT DemoApp::DrawText()
{
    RECT rc;

    GetClientRect(
        hwnd_,
        &rc
        );

    // Create a D2D rect that is the same size as the window.
    D2D1_RECT_F layoutRect = D2D1::RectF(
        static_cast<FLOAT>(rc.top) / dpiScaleY_,
        static_cast<FLOAT>(rc.left) / dpiScaleX_,
        static_cast<FLOAT>(rc.right - rc.left) / dpiScaleX_,
        static_cast<FLOAT>(rc.bottom - rc.top) / dpiScaleY_
        );

    // Use the DrawText method of the D2D render target interface to draw.
    pRT_->DrawText(
        wszText_,        // The string to render.
        cTextLength_,    // The string's length.
        pTextFormat_,    // The text format.
        layoutRect,       // The region of the window where the text will be rendered.
        pBlackBrush_     // The brush used to draw the text.
        );

    return S_OK;
}

/******************************************************************
*                                                                 *
*  DemoApp::DrawD2DContent                                     *
*                                                                 *
*  This method writes "Hello World"                               *
*                                                                 *
*  Note that this function will not render anything if the window *
*  is occluded (eg. obscured by other windows or off monitor).    *
*  Also, this function will automatically discard device-specific *
*  resources if the D3D device disappears during execution, and   *
*  will recreate the resources the next time it's invoked.        *
*                                                                 *
******************************************************************/

HRESULT DemoApp::DrawD2DContent()
{
    HRESULT hr;

    hr = CreateDeviceResources();

    if (!(pRT_->CheckWindowState() & D2D1_WINDOW_STATE_OCCLUDED))
    {
        pRT_->BeginDraw();

        pRT_->SetTransform(D2D1::IdentityMatrix());

        pRT_->Clear(D2D1::ColorF(D2D1::ColorF::White));

        if (SUCCEEDED(hr))
        {
            // Call the DrawText method of this class.
            DrawText();
        }

        if (SUCCEEDED(hr))
        {
            hr = pRT_->EndDraw(
                );
        }
    }

    if (FAILED(hr))
    {
        DiscardDeviceResources();
    }

    return hr;
}


/******************************************************************
*                                                                 *
*  DemoApp::OnResize                                           *
*                                                                 *
*  If the application receives a WM_SIZE message, this method     *
*  resize the render target appropriately.                        *
*                                                                 *
******************************************************************/

void DemoApp::OnResize(UINT width, UINT height)
{
    if (pRT_)
    {
        D2D1_SIZE_U size;
        size.width = width;
        size.height = height;
        pRT_->Resize(size);
    }
}

/******************************************************************
*                                                                 *
*  DemoApp::WndProc                                            *
*                                                                 *
*  Window message handler                                         *
*                                                                 *
******************************************************************/

LRESULT CALLBACK DemoApp::WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    if (message == WM_CREATE)
    {
        LPCREATESTRUCT pcs = (LPCREATESTRUCT)lParam;
        DemoApp *pDemoApp = (DemoApp *)pcs->lpCreateParams;

        ::SetWindowLongPtrW(
            hwnd,
            GWLP_USERDATA,
            PtrToUlong(pDemoApp));

        return 1;
    }

    DemoApp *pDemoApp = reinterpret_cast<DemoApp *>(static_cast<LONG_PTR>(
                ::GetWindowLongPtrW(hwnd, GWLP_USERDATA)));

    if (pDemoApp)
    {
        switch(message)
        {
        case WM_SIZE:
            {
                UINT width = LOWORD(lParam);
                UINT height = HIWORD(lParam);
                pDemoApp->OnResize(width, height);
            }
            return 0;

        case WM_PAINT:
        case WM_DISPLAYCHANGE:
            {
                ValidateRect(hwnd, NULL);
                pDemoApp->DrawD2DContent();
            }
            return 0;

        case WM_DESTROY:
            {
                PostQuitMessage(0);
            }
            return 1;
        }
    }
    return DefWindowProc(
        hwnd,
        message,
        wParam,
        lParam
        );
}