Question

I am currently learning DirectX so I am a starter and I am stuck at one code. I am studying from a book and I have written this code. It should draw a bitmap on the window but its giving me a blank screen. Moreover when I click esc button it gives an error but if I move or stretch the window before pressing esc, it doesnt give an error. Any help appreciated. I am using Visual Studio 2010 and C++. I have one assumption that the error might be at D3DXCreateSurfaceFromFile. Here is the code;

//Header files to include
#include <d3d9.h>
#include <time.h>
#include <d3dx9.h>

//Application title
#define APPTITLE L"Load_Bitmap"

//Screen Resolution
#define WIDTH 640
#define HEIGHT 480

//Forward Declarations
LRESULT WINAPI WinProc( HWND, UINT, WPARAM, LPARAM);
ATOM MyRegisterClass( HINSTANCE);
int GameInit(HWND);
void GameRun(HWND);
void GameEnd(HWND);

//Direct3d objects
LPDIRECT3D9 d3d = NULL;
LPDIRECT3DDEVICE9 d3ddev = NULL;
LPDIRECT3DSURFACE9 backbuffer = NULL;
LPDIRECT3DSURFACE9  surface = NULL;

//Macros to read the keyboard asynchronously
#define KEY_DOWN(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0)
#define KEY_UP(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0)


//Window Event Callback Function
LRESULT WINAPI WinProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch(msg)
    {
        case WM_DESTROY:
            GameEnd( hWnd);
            PostQuitMessage(0);
            return 0;
    }

    return DefWindowProc( hWnd, msg, wParam, lParam);
}

//Helper function to set up the window properties
ATOM MyRegisterClass( HINSTANCE hInstance)
{
    WNDCLASSEX wc;

    wc.cbSize = sizeof( WNDCLASSEX);
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = (WNDPROC)WinProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = hInstance;
    wc.hIcon = NULL;
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wc.lpszMenuName = NULL;
    wc.lpszClassName = APPTITLE;
    wc.hIconSm = NULL;

    //Set up the window with the class info
    return RegisterClassEx(&wc);



}

//Entry point for a windows program
int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstancem, LPSTR lpCmdLine, int nCmdShow)
{
    //Declare variables
    MSG msg;

    //Register the class
    MyRegisterClass( hInstance);

    //Initialize Application
    HWND hWnd;

    //Create new Window
    hWnd = CreateWindow( APPTITLE, APPTITLE, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, WIDTH, HEIGHT, NULL, NULL, hInstance, NULL);

    if( !hWnd)
        return FALSE;

    //Display the Window
    ShowWindow( hWnd, nCmdShow);
    UpdateWindow( hWnd);

    //Initialize the Game
    if( !GameInit( hWnd))
        return FALSE;

    //Main Message Loop
    int done = 0;
    while(!done)
    {
        if(PeekMessage( &msg, hWnd, 0, 0, PM_REMOVE))
        {
            //Look for quit message
            if( msg.message == WM_QUIT)
                done = 1;

            //Decode and pass messages on to WndProc
            TranslateMessage( &msg);
            DispatchMessage( &msg);
        }
        else
            //Process game loop( else prevents running after window is closed)
            GameRun(hWnd);
    }

    return msg.wParam;
}

int GameInit( HWND hWnd)
{
    HRESULT result;

    //Initialize Direct3d
    d3d = Direct3DCreate9(D3D_SDK_VERSION);
    if( d3d == NULL)
    {
        MessageBox( hWnd, L"Error initializing Direct3d", L"Error", MB_OK);
        return 0;
    }

    //Set Direct3D presentation parameters
    D3DPRESENT_PARAMETERS d3dpp;
    ZeroMemory( &d3dpp, sizeof(d3dpp));

    d3dpp.Windowed = TRUE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3dpp.BackBufferFormat = D3DFMT_X8R8G8B8;
    d3dpp.BackBufferCount = 1;
    d3dpp.BackBufferWidth = WIDTH;
    d3dpp.BackBufferHeight = HEIGHT;
    d3dpp.hDeviceWindow = hWnd;

    //Create Direct3D device
    d3d->CreateDevice( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd, D3DCREATE_SOFTWARE_VERTEXPROCESSING, &d3dpp, &d3ddev);

    if( d3ddev == NULL)
    {
        MessageBox( hWnd, L"Error creating Direct3d device", L"Error", MB_OK);
        return 0;
    }

    //Set Random number seed
    //srand( time(NULL));

    //Clear the backbuffer to black
    d3ddev->Clear( 0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB( 0,0,0), 1.0f, 0);

    //Create pointer to the back buffer
    d3ddev->GetBackBuffer(0, 0, D3DBACKBUFFER_TYPE_MONO, &backbuffer);

    //Create surface
    result = d3ddev->CreateOffscreenPlainSurface( 640, 480, D3DFMT_X8R8G8B8, 
                                                D3DPOOL_DEFAULT, &surface, NULL);

    if( result != D3D_OK)
        return 1;

    //load surface from file
    result = D3DXLoadSurfaceFromFile(
        surface, NULL, NULL, L"c.bmp", NULL, D3DX_DEFAULT, 0, NULL);

    //Make sure file was loaded okay
    if( result != D3D_OK)
        return 1;

    d3ddev->StretchRect( surface, NULL, backbuffer, NULL, D3DTEXF_NONE);

    //Return okay
    return 1;
}

void GameRun(HWND hWnd)
{

    //Make Sure the Direct3d device is valid
    if( d3ddev == NULL)
        return;

    //Start Rendering
    if( d3ddev->BeginScene())
    {
        //Create pointer to the back buffer
        d3ddev->GetBackBuffer( 0, 0, D3DBACKBUFFER_TYPE_MONO, &backbuffer);

        //Draw surface to the backbuffer
        d3ddev->StretchRect( surface, NULL, backbuffer, NULL, D3DTEXF_NONE);
        //StopRendering
        d3ddev->EndScene();
    }

    //Display the back buffer on the screen
    d3ddev->Present( NULL, NULL, NULL, NULL);

    //Check for escape key( to exit program)
    if( KEY_DOWN(VK_ESCAPE))
        PostMessage(hWnd, WM_DESTROY, 0, 0);
}

void GameEnd(HWND hWnd)
{
    //free the surface
    if( surface != NULL)
        surface->Release();

    //Release the Direct3D device
    if( d3ddev != NULL)
        d3ddev->Release();

    if( d3d != NULL)
        d3d->Release();
}

Answer 1

Post WM_QUIT instead of WM_DESTROY when you check the escape key. As it stands now the message-loop will never quit since it depends on WM_QUIT being posted, and it will keep calling GameRun even after the surfaces are deleted.