   directdraw and bitmap data
  Hi, i got bitmap data from hardware 60 frame per second, i used StretchDIBits and directdraw, like thisBOOL WINAPI CBFunc(BITMAPINFOHEADER  *pbih,BYTE *pData){HDC hDC;lpDDSPrimary->GetDC(&hDC);StretchDIBits(hDC, 0, 0, 1024, 768, 0, 0, pbih->biWidth, pbih->iHeight, pData,(BITMAPINFO*)pbih, DIB_RGB_COLORS, SRCCOPY);lpDDSPrimary->ReleaseDC(hDC);return TRUE;}but the graphic is not very smooth, how can i do it use directdraw?   