Thread: Problem Going to Fullscreen

I tried implementing GameTutorials' method of going to fullscreen mode in my program and it doesn't work. Here is the code. Can someone please tell me how to fix it?

Code:

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
					LPSTR iCmdLine, int iCmdShow)

{
    HWND hWnd;
    MSG msg;
    WNDCLASSEX wc;

    wc.hInstance = hInstance;
    wc.lpszClassName = szClassName;
    wc.lpfnWndProc = WndProc;
    wc.style = CS_DBLCLKS;
    wc.cbSize = sizeof (WNDCLASSEX);
    wc.hIcon = (HICON)LoadImage(hInstance,MAKEINTRESOURCE(IDI_ICON1),IMAGE_ICON,0,0,LR_DEFAULTSIZE);
    wc.hIconSm = (HICON)LoadImage(hInstance,MAKEINTRESOURCE(IDI_ICON1),IMAGE_ICON,0,0,LR_DEFAULTSIZE);
    wc.hCursor = LoadCursor (NULL, IDC_ARROW);
    wc.lpszMenuName = NULL;
    wc.cbClsExtra = 0;
	wc.cbWndExtra = 0;
    wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);

    if (!RegisterClassEx (&wc))
	{
		MessageBox(0,"Failed To Register Windows Class.","Error", MB_OK | MB_ICONERROR);
        return 0;
	}

	ChangeToFullScreen(SCREEN_WIDTH, SCREEN_HEIGHT);

    hWnd = CreateWindowEx (
           0, szClassName, szTitle, WS_CLIPSIBLINGS | WS_CLIPCHILDREN,
		   50, 50, 907, 687, NULL, NULL, hInstance, NULL);

    ShowWindow (hWnd, iCmdShow);

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

    return (int)msg.wParam;
}

ChangeToFullScreen() Function:

Code:

void ChangeToFullScreen(int width, int height)
{
	DEVMODE dmSettings;	
	memset(&dmSettings,0,sizeof(dmSettings));

	if(!EnumDisplaySettings(NULL,ENUM_CURRENT_SETTINGS,&dmSettings))
	{
		MessageBox(NULL, "Could Not Enum Settings.", "Error", MB_OK | MB_ICONERROR);
		return;
	}

	dmSettings.dmPelsWidth	= width;
	dmSettings.dmPelsHeight	= height;
	dmSettings.dmFields = DM_PELSWIDTH | DM_PELSHEIGHT;
	
	int result = ChangeDisplaySettings(&dmSettings,CDS_FULLSCREEN);	

	if(result != DISP_CHANGE_SUCCESSFUL)
	{
		MessageBox(NULL, "Display Mode Not Compatible", "Error", MB_OK | MB_ICONERROR);
		PostQuitMessage(0);
	}
}

You also need to fill the size of the DEVMODE structure.

Code:

dmSettings.dmSize=sizeof(dmSettings);

Also, check the return value of ChangeDisplaySettings(), and make sure it equals DISP_CHANGE_SUCCESSFUL.

Neither of those seemed to work. When I run it I still get the "Display Mode Not Compatible" message which means result != DISP_CHANGE_SUCCESSFUL. Anything else you can think of?

ChangeToFullScreen probably doesn't like the values you're passing as width and height.

To go to full screen, usually you have to choose a common display setting, such as 640x480 or 800x600. Then your window's dimensions should also be 640x480 or 800x600 to fill the screen.

That was it. Thanks for the help.