Capture Screen

void CaptureScreen(LPDIRECT3DDEVICE9 pDevice, TCHAR szFileName)
{
	if (!pDevice || !szFileName)
		return;

	DWORD tickStart = GetTickCount();
	
	// There is 2 Methods 
	// 1. Capture Front Buffer
	// 2. Capture Back Buffer (Faster)
	bool isBackBuffer = true;
	
	RECT rectWindow = {0};
	RECT rectDesktop = {0};
	GetClientRect(g_hMainWnd, &rectWindow);
	GetClientRect(GetDesktopWindow(), &rectDesktop);

	IDirect3DSurface9* pSurface = NULL;
	HRESULT hResult = S_OK;

	if (isBackBuffer)
	{
		hResult = pDevice->GetBackBuffer(0, 0, D3DBACKBUFFER_TYPE_MONO, &pSurface);
	}
	else
	{
		/*
		For windowed mode, the size of the destination surface 
		should be the size of the desktop. For full-screen mode, 
		the size of the destination surface should be the screen size. 
		*/

		bool isFullScreen = IsFullScreenMode(); 
		int nWidth	= isFullScreen ? rectWindow.right - rectWindow.left 
					: rectDesktop.right - rectDesktop.left;
		int nHeight	= isFullScreen ? rectWindow.bottom - rectWindow.top 
					: rectDesktop.bottom - rectDesktop.top;

		hResult = pDevice->CreateOffscreenPlainSurface(nWidth, nHeight, D3DFMT_A8R8G8B8, D3DPOOL_SCRATCH, &pSurface, NULL);
		hResult = pDevice->GetFrontBufferData(0, pSurface);
	}

	if (pSurface)
	{
		hResult = D3DXSaveSurfaceToFile(szFileName, D3DXIFF_JPG, pSurface, NULL, &rectWindow);
		pSurface->Release();  
	}

	tickDiff = GetTickCount() - tickStart;
}

Back Buffer를 Capture하는 것이 더 빠르다.
- Back Buffer : 500~600ms
- Front Buffer : 1300~1400ms

Test 환경
- CPU : Core2 Duo E650 @ 2.33GHz
- RAM : 1024MB
- VGA : NVIDIA GeForce 8500 GT (512MB)
- Window 크기 : 1024 * 768