//-----------------------------------------------------------------------------
// File: DDEx1.CPP
//
// Desc: Direct Draw example program 1.  Creates a Direct Draw 
//       object and then a primary surface with a back buffer.
//       Slowly flips between the primary surface and the back
//       buffer.  Press F12 to terminate the program.
//
// Copyright (c) 1995-1998 Microsoft Corporation. All rights reserved.
//-----------------------------------------------------------------------------

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
//-----------------------------------------------------------------------------
// Include files
//-----------------------------------------------------------------------------
#include <windows.h>
#include <ddraw.h>
#include <stdio.h>
#include <stdarg.h>
#include "resource.h"

//-----------------------------------------------------------------------------
// Local definitions
//-----------------------------------------------------------------------------
#define NAME                "DDExample1"
#define TITLE               "Direct Draw Example 1"

//-----------------------------------------------------------------------------
// Default settings
//-----------------------------------------------------------------------------
#define TIMER_ID            1
#define TIMER_RATE          500

//-----------------------------------------------------------------------------
// Global data
//-----------------------------------------------------------------------------
LPDIRECTDRAW4               g_pDD = NULL;        // DirectDraw object
LPDIRECTDRAWSURFACE4        g_pDDSPrimary = NULL;// DirectDraw primary surface
LPDIRECTDRAWSURFACE4        g_pDDSBack = NULL;   // DirectDraw back surface
BOOL                        g_bActive = FALSE;   // Is application active?

//-----------------------------------------------------------------------------
// Local data
//-----------------------------------------------------------------------------
static char                 szMsg[] = "Page Flipping Test: Press F12 to exit";
static char                 szFrontMsg[] = "Front buffer (F12 to quit)";
static char                 szBackMsg[] = "Back buffer (F12 to quit)";




//-----------------------------------------------------------------------------
// Name: ReleaseAllObjects()
// Desc: Finished with all objects we use; release them
//-----------------------------------------------------------------------------
static void
ReleaseAllObjects(void)
{
    if (g_pDD != NULL)
    {
        if (g_pDDSPrimary != NULL)
        {
            g_pDDSPrimary->Release();
            g_pDDSPrimary = NULL;
        }
        g_pDD->Release();
        g_pDD = NULL;
    }
}




//-----------------------------------------------------------------------------
// Name: InitFail()
// Desc: This function is called if an initialization function fails
//-----------------------------------------------------------------------------
HRESULT
InitFail(HWND hWnd, HRESULT hRet, LPCTSTR szError,...)
{
    char                        szBuff[128];
    va_list                     vl;

    va_start(vl, szError);
    vsprintf(szBuff, szError, vl);
    ReleaseAllObjects();
    MessageBox(hWnd, szBuff, TITLE, MB_OK);
    DestroyWindow(hWnd);
    va_end(vl);
    return hRet;
}




//-----------------------------------------------------------------------------
// Name: UpdateFrame()
// Desc: Displays the proper text for the page
//-----------------------------------------------------------------------------
static void
UpdateFrame(HWND hWnd)
{
    static BYTE                 phase = 0;
    HDC                         hdc;
    DDBLTFX                     ddbltfx;
    RECT                        rc;
    SIZE                        size;

    // Use the blter to do a color fill to clear the back buffer
    ZeroMemory(&ddbltfx, sizeof(ddbltfx));
    ddbltfx.dwSize = sizeof(ddbltfx);
    ddbltfx.dwFillColor = 0;
    g_pDDSBack->Blt(NULL, NULL, NULL, DDBLT_COLORFILL | DDBLT_WAIT, &ddbltfx);

    if (g_pDDSBack->GetDC(&hdc) == DD_OK)
    {
        SetBkColor(hdc, RGB(0, 0, 255));
        SetTextColor(hdc, RGB(255, 255, 0));
        if (phase)
        {
            GetClientRect(hWnd, &rc);
            GetTextExtentPoint(hdc, szMsg, lstrlen(szMsg), &size);
            TextOut(hdc, (rc.right - size.cx) / 2, (rc.bottom - size.cy) / 2,
                    szMsg, sizeof(szMsg) - 1);
            TextOut(hdc, 0, 0, szFrontMsg, lstrlen(szFrontMsg));
            phase = 0;
        }
        else
        {
            TextOut(hdc, 0, 0, szBackMsg, lstrlen(szBackMsg));
            phase = 1;
        }
        g_pDDSBack->ReleaseDC(hdc);
    }
}




//-----------------------------------------------------------------------------
// Name: WindowProc()
// Desc: The Main Window Procedure
//-----------------------------------------------------------------------------
long FAR PASCAL
WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    HRESULT                     hRet;

    switch (message)
    {
        case WM_ACTIVATEAPP:
            // Pause if minimized or not the top window
            g_bActive = (wParam == WA_ACTIVE) || (wParam == WA_CLICKACTIVE);
            return 0L;

        case WM_DESTROY:
            // Clean up and close the app
            ReleaseAllObjects();
            PostQuitMessage(0);
            return 0L;

        case WM_KEYDOWN:
            // Handle any non-accelerated key commands
            switch (wParam)
            {
                case VK_ESCAPE:
                case VK_F12:
                    PostMessage(hWnd, WM_CLOSE, 0, 0);
                    return 0L;
            }
            break;

        case WM_SETCURSOR:
            // Turn off the cursor since this is a full-screen app
            SetCursor(NULL);
            return TRUE;

        case WM_TIMER:
            // Update and flip surfaces
            if (g_bActive && TIMER_ID == wParam)
            {
                UpdateFrame(hWnd);
                while (TRUE)
                {
                    hRet = g_pDDSPrimary->Flip(NULL, 0);
                    if (hRet == DD_OK)
                        break;
                    if (hRet == DDERR_SURFACELOST)
                    {
                        hRet = g_pDDSPrimary->Restore();
                        if (hRet != DD_OK)
                            break;
                    }
                    if (hRet != DDERR_WASSTILLDRAWING)
                        break;
                }
            }
            break;
    }
    return DefWindowProc(hWnd, message, wParam, lParam);
}




//-----------------------------------------------------------------------------
// Name: InitApp()
// Desc: Do work required for every instance of the application:
//          Create the window, initialize data
//-----------------------------------------------------------------------------
static HRESULT
InitApp(HINSTANCE hInstance, int nCmdShow)
{
    HWND                        hWnd;
    WNDCLASS                    wc;
    DDSURFACEDESC2              ddsd;
    DDSCAPS2                    ddscaps;
    HRESULT                     hRet;
    LPDIRECTDRAW                pDD;

    // Set up and register window class
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = WindowProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = hInstance;
    wc.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_MAIN_ICON));
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH )GetStockObject(BLACK_BRUSH);
    wc.lpszMenuName = NAME;
    wc.lpszClassName = NAME;
    RegisterClass(&wc);

    // Create a window
    hWnd = CreateWindowEx(WS_EX_TOPMOST,
                          NAME,
                          TITLE,
                          WS_POPUP,
                          0,
                          0,
                          GetSystemMetrics(SM_CXSCREEN),
                          GetSystemMetrics(SM_CYSCREEN),
                          NULL,
                          NULL,
                          hInstance,
                          NULL);
    if (!hWnd)
        return FALSE;
    ShowWindow(hWnd, nCmdShow);
    UpdateWindow(hWnd);
    SetFocus(hWnd);

    ///////////////////////////////////////////////////////////////////////////
    // Create the main DirectDraw object
    ///////////////////////////////////////////////////////////////////////////
    hRet = DirectDrawCreate(NULL, &pDD, NULL);
    if (hRet != DD_OK)
        return InitFail(hWnd, hRet, "DirectDrawCreate FAILED");

    // Fetch DirectDraw4 interface
    hRet = pDD->QueryInterface(IID_IDirectDraw4, (LPVOID *) & g_pDD);
    if (hRet != DD_OK)
        return InitFail(hWnd, hRet, "QueryInterface FAILED");

    // Get exclusive mode
    hRet = g_pDD->SetCooperativeLevel(hWnd, DDSCL_EXCLUSIVE | DDSCL_FULLSCREEN);
    if (hRet != DD_OK)
        return InitFail(hWnd, hRet, "SetCooperativeLevel FAILED");

    // Set the video mode to 640x480x8
    hRet = g_pDD->SetDisplayMode(640, 480, 8, 0, 0);
    if (hRet != DD_OK)
        return InitFail(hWnd, hRet, "SetDisplayMode FAILED");

    // Create the primary surface with 1 back buffer
    ZeroMemory(&ddsd, sizeof(ddsd));
    ddsd.dwSize = sizeof(ddsd);
    ddsd.dwFlags = DDSD_CAPS | DDSD_BACKBUFFERCOUNT;
    ddsd.ddsCaps.dwCaps = DDSCAPS_PRIMARYSURFACE |
        DDSCAPS_FLIP |
        DDSCAPS_COMPLEX;
    ddsd.dwBackBufferCount = 1;
    hRet = g_pDD->CreateSurface(&ddsd, &g_pDDSPrimary, NULL);
    if (hRet != DD_OK)
        return InitFail(hWnd, hRet, "CreateSurface FAILED");

    // Get a pointer to the back buffer
    ddscaps.dwCaps = DDSCAPS_BACKBUFFER;
    hRet = g_pDDSPrimary->GetAttachedSurface(&ddscaps, &g_pDDSBack);
    if (hRet != DD_OK)
        return InitFail(hWnd, hRet, "GetAttachedSurface FAILED");

    // Create a timer to flip the pages
    if (TIMER_ID != SetTimer(hWnd, TIMER_ID, TIMER_RATE, NULL))
        return InitFail(hWnd, hRet, "SetTimer FAILED");

    return DD_OK;
}




//-----------------------------------------------------------------------------
// Name: WinMain()
// Desc: Initialization, message loop
//-----------------------------------------------------------------------------
int PASCAL
WinMain(HINSTANCE hInstance,
        HINSTANCE hPrevInstance,
        LPSTR lpCmdLine,
        int nCmdShow)
{
    MSG                         msg;

    if (InitApp(hInstance, nCmdShow) != DD_OK)
        return FALSE;

    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}
