Direct Draw back buffer problem

[Rouslan]

I am new at using directX and am clueless as to why my GetAttachedSurface returns an error. This program works just fine with only one surface. I have included my WinMain function.

int APIENTRY WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,
					 LPSTR lpCmdLine, int nCmdShow)
{
	DDSURFACEDESC2 ddsd;
	HRESULT hRet;

	MSG msg;
	HWND hWnd;
	WNDCLASS wc;

	LONGLONG cur_time;
	DWORD time_count;
	LONGLONG perf_cnt;
	bool perf_flag=false;
	LONGLONG next_time=0;
	LONGLONG last_time=0;
	double time_elapsed;
	double time_scale;

	wc.style		=CS_HREDRAW|CS_VREDRAW;
	wc.lpfnWndProc	=(WNDPROC)WindowProc;
	wc.cbClsExtra	=0;
	wc.cbWndExtra	=0;
	wc.hInstance	=hInstance;
	wc.hIcon		=LoadIcon(hInstance,"Rouslan");
	wc.hCursor		=LoadCursor(NULL,IDC_ARROW);
	wc.hbrBackground=(HBRUSH)(COLOR_WINDOW+1);
	wc.lpszMenuName	=MAKEINTRESOURCE(IDR_MENU1);
	wc.lpszClassName="Rouslan";
	if(!RegisterClass(&wc))return false;

	if(QueryPerformanceFrequency((LARGE_INTEGER*)&perf_cnt))
	{
		perf_flag=true;
		time_count=perf_cnt/30;
		QueryPerformanceCounter((LARGE_INTEGER*)&next_time);
		time_scale=1.0/perf_cnt;
	}else{
		next_time=timeGetTime();
		time_scale=0.001;
		time_count=33;
	}
	last_time=next_time;

	hInst=hInstance;

	hWnd = CreateWindow(lpszAppName,lpszTitle,WS_POPUP,0,0,
		GetSystemMetrics(SM_CXSCREEN),GetSystemMetrics(SM_CYSCREEN),NULL,NULL,hInstance,NULL);

	if(!hWnd)return false;

	ShowWindow(hWnd,nCmdShow);
	UpdateWindow(hWnd);

	hRet=DirectDrawCreateEx(NULL,(LPVOID*)&lpDD,IID_IDirectDraw7,NULL);
	if(hRet != DD_OK)return false;

	hRet = lpDD->SetCooperativeLevel(hWnd,DDSCL_FULLSCREEN|DDSCL_EXCLUSIVE);
	if(hRet != DD_OK)return false;

	hRet = lpDD->SetDisplayMode(640,480,16,0,0);

	/*hRet=lpDD->CreateClipper(NULL,&lpClip,NULL);
	if(hRet != DD_OK)
	{
		ErrStr=Err_CreateClip;
		return false;
	}
	lpClip->SetHWnd(0,hWnd);*/

	ZeroMemory(&ddsd,sizeof(ddsd));
	ddsd.dwSize = sizeof(ddsd);
	ddsd.dwFlags = DDSD_CAPS|DDSD_BACKBUFFERCOUNT;
	ddsd.dwBackBufferCount=1;
	ddsd.ddsCaps.dwCaps = DDSCAPS_PRIMARYSURFACE|DDSCAPS_FLIP|DDSCAPS_COMPLEX;
	hRet=lpDD->CreateSurface(&ddsd, &lpDDSPrimary, NULL);
	if(hRet != DD_OK)return false;

	/////////GOOD UP TO HERE///////////

	DDSCAPS2 ddscaps;
	ddscaps.dwCaps=DDSCAPS_BACKBUFFER;
	hRet=lpDDSPrimary->GetAttachedSurface(&ddscaps,&lpDDSBack);
	if(hRet!=DD_OK)
	{
		MessageBox(hWnd,"This message gets called","Hmm",MB_OK);
		return false;
	}

	/////////BREAK DOWN HERE///////////
	

	//lpDDSPrimary->SetClipper(lpClip);
	bInit=true;

	GAME.SetWndData(&hWnd,&hInst);

	while(true)
	{
		if(PeekMessage(&msg,NULL,0,0,PM_NOREMOVE))
		{
			if(!GetMessage(&msg,NULL,0,0))return msg.wParam;
			TranslateMessage(&msg);
			DispatchMessage(&msg);
		}else{
			if(perf_flag)QueryPerformanceCounter((LARGE_INTEGER*)&cur_time);
			else cur_time=timeGetTime();

			if(cur_time>next_time)
			{
				time_elapsed=(cur_time-last_time)*time_scale;
				last_time=cur_time;
				GAME.Action();
				SCREEN.DrawScreen(&GAME,&hWnd);
				next_time=cur_time+time_count;
			}
		}
	}
	return(msg.wParam);
}

 

[apatterno]

Well I'm not really sure, this is just a gues:

Three lines after [tt]/////////GOOD UP TO HERE///////////[/tt], try inserting

[tt]ddsCaps.dwCaps2 = 0;[/tt]

The DDSCAPS structure actually has 4 members, (only [tt]dwCaps[/tt] and [tt]dwCaps2[/tt] are used, though.) Since [tt]dwCaps2[/tt] wasn't getting initialized, it probably had a random value like [tt]0xCCCCCCCC[/tt], which could cause [tt]GetAttachedSurface[/tt] to fail when it tries to get a back buffer with a whole bunch of capabilities declared in [tt]dwCaps2[/tt].

Sorry if it doesn't work, this is just my guess-- I've actually been off the DirectDraw7 scene since DirectX 8 came out, so I'm a bit rusty in that subject.

Happy gaming

 

[Rouslan]

Thanks for trying but that didn't help. Anyways when I checked which error message it turned out to be DDERR_NOTFOUND. That seems strange to me.

 

[Rouslan]

Never mind. I just switched to Direct X 8 and couldn't be happier.