BitBlt med synkronisering (Slippa flimmer) ??

Hej!

Jag använder mig av tekniken att använda dubbel buffring - dock uppstår ett flimmer med jämna mellanrum. I Direct X så inväntar man en s.k. V-sync innan man blittar backbuffer till frontbuffer. Hur skall man göra i "vanlig" WIN32 miljö?

Tacksam för svar... :)

Nedan följer ett kodexempel:

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	HDC		hdc;
	PAINTSTRUCT           ps;
	static HINSTANCE	hInstance;
	static HBITMAP	hBitmapGubbe, hBitmapBuff;
	static HDC	hdcGubbe, hdcBuff;	
	static POINT	ptGubbePos;
	

	

	switch(message)
	{
	case WM_CREATE:
		{
			hInstance = (HINSTANCE) GetWindowLong(hwnd, GWL_HINSTANCE);

			hdc = GetDC(hwnd);
			hBitmapGubbe = (HBITMAP) LoadImage(hInstance, TEXT("gubbe.bmp"), IMAGE_BITMAP, 
				0, 0, LR_LOADFROMFILE | LR_CREATEDIBSECTION);

			hBitmapBuff = (HBITMAP) CreateCompatibleBitmap(hdc, 400, 200);

			ReleaseDC(hwnd, hdc);
			
			SetTimer(hwnd, 1, 50, NULL);
			
			return 0;
		}

	case WM_TIMER:
		{
			switch(wParam)
			{
			case 1:
				{
					if(ptGubbePos.x < 360)
					ptGubbePos.x += 1;

					if(ptGubbePos.x >= 360)
						ptGubbePos.x = 0;
						

					InvalidateRect(hwnd, NULL, TRUE);
				}
			}
			
			return 0;
		}
	
	case WM_PAINT:
		{
			
			hdc = BeginPaint(hwnd, &ps);

			hdcGubbe = CreateCompatibleDC(hdc);
			SelectObject(hdcGubbe, hBitmapGubbe);

			hdcBuff = CreateCompatibleDC(hdc);
			SelectObject(hdcBuff, hBitmapBuff);
			Rectangle(hdcBuff, -1, -1, 400, 200);

			BitBlt(hdcBuff, ptGubbePos.x, 0, 66, 77, hdcGubbe, 0, 0, SRCCOPY); 
			
			
			//	Visa gubbe:
			BitBlt(hdc, 0, 0, 400, 200, hdcBuff, 0, 0, SRCCOPY);
			

			DeleteDC(hdcGubbe);
			DeleteDC(hdcBuff);
			
			EndPaint(hwnd, &ps);
			return 0;
		}

	case WM_DESTROY:
		{
			PostQuitMessage(0);
			return 0;
		}
	}
	return DefWindowProc(hwnd, message, wParam, lParam);
}