STDMETHODIMP CAggDrawSurface::GetCaps(LPDDSCAPS lpDDSCaps)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->GetCaps(lpDDSCaps);
}


STDMETHODIMP CAggDrawSurface::GetClipper(LPDIRECTDRAWCLIPPER *lplpDDClipper)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->GetClipper(lplpDDClipper);
}


STDMETHODIMP CAggDrawSurface::GetColorKey(DWORD dwFlags,LPDDCOLORKEY lpDDColorKey)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->GetColorKey(dwFlags,lpDDColorKey);
}


STDMETHODIMP CAggDrawSurface::GetDC(HDC *lphDC)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->GetDC(lphDC);
}


STDMETHODIMP CAggDrawSurface::GetFlipStatus(DWORD dwFlags)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->GetFlipStatus(dwFlags);
}


STDMETHODIMP CAggDrawSurface::GetOverlayPosition(LPLONG lpdwX,LPLONG lpdwY)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->GetOverlayPosition(lpdwX,lpdwY);
}


STDMETHODIMP CAggDrawSurface::GetPalette(LPDIRECTDRAWPALETTE *lplpDDPalette)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->GetPalette(lplpDDPalette);
}


STDMETHODIMP CAggDrawSurface::GetPixelFormat(LPDDPIXELFORMAT lpDDPixelFormat)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->GetPixelFormat(lpDDPixelFormat);
}


// A bit of a warning here: Our media samples in DirectShow aggregate on
// IDirectDraw and IDirectDrawSurface (ie are available through IMediaSample
// by QueryInterface). Unfortunately the underlying DirectDraw code cannot
// be aggregated so we have to use these classes. The snag is that when we
// call a different surface and pass in this interface as perhaps the source
// surface the call will fail because DirectDraw dereferences the pointer to
// get at its private data structures. Therefore we supply this workaround to give
// access to the real IDirectDraw surface. A filter can call GetSurfaceDesc
// and we will fill in the lpSurface pointer with the real underlying surface

STDMETHODIMP CAggDrawSurface::GetSurfaceDesc(LPDDSURFACEDESC lpDDSurfaceDesc)
{
    ASSERT(m_pDirectDrawSurface);

    // First call down to the underlying DirectDraw

    HRESULT hr = m_pDirectDrawSurface->GetSurfaceDesc(lpDDSurfaceDesc);
    if (FAILED(hr)) {
        return hr;
    }

    // Store the real DirectDrawSurface interface
    lpDDSurfaceDesc->lpSurface = m_pDirectDrawSurface;
    return hr;
}


STDMETHODIMP CAggDrawSurface::Initialize(LPDIRECTDRAW lpDD,LPDDSURFACEDESC lpDDSurfaceDesc)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->Initialize(lpDD,lpDDSurfaceDesc);
}


STDMETHODIMP CAggDrawSurface::IsLost()
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->IsLost();
}


STDMETHODIMP CAggDrawSurface::Lock(LPRECT lpDestRect,LPDDSURFACEDESC lpDDSurfaceDesc,DWORD dwFlags,HANDLE hEvent)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->Lock(lpDestRect,lpDDSurfaceDesc,dwFlags,hEvent);
}


STDMETHODIMP CAggDrawSurface::ReleaseDC(HDC hDC)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->ReleaseDC(hDC);
}


STDMETHODIMP CAggDrawSurface::Restore()
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->Restore();
}


STDMETHODIMP CAggDrawSurface::SetClipper(LPDIRECTDRAWCLIPPER lpDDClipper)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->SetClipper(lpDDClipper);
}


STDMETHODIMP CAggDrawSurface::SetColorKey(DWORD dwFlags,LPDDCOLORKEY lpDDColorKey)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->SetColorKey(dwFlags,lpDDColorKey);
}


STDMETHODIMP CAggDrawSurface::SetOverlayPosition(LONG dwX,LONG dwY)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->SetOverlayPosition(dwX,dwY);
}


STDMETHODIMP CAggDrawSurface::SetPalette(LPDIRECTDRAWPALETTE lpDDPalette)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->SetPalette(lpDDPalette);
}


STDMETHODIMP CAggDrawSurface::Unlock(LPVOID lpSurfaceData)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->Unlock(lpSurfaceData);
}


STDMETHODIMP CAggDrawSurface::UpdateOverlay(LPRECT lpSrcRect,LPDIRECTDRAWSURFACE lpDDDestSurface,LPRECT lpDestRect,DWORD dwFlags,LPDDOVERLAYFX lpDDOverlayFX)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->UpdateOverlay(lpSrcRect,lpDDDestSurface,lpDestRect,dwFlags,lpDDOverlayFX);
}


STDMETHODIMP CAggDrawSurface::UpdateOverlayDisplay(DWORD dwFlags)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->UpdateOverlayDisplay(dwFlags);
}


STDMETHODIMP CAggDrawSurface::UpdateOverlayZOrder(DWORD dwFlags,LPDIRECTDRAWSURFACE lpDDSReference)
{
    ASSERT(m_pDirectDrawSurface);
    return m_pDirectDrawSurface->UpdateOverlayZOrder(dwFlags,lpDDSReference);
}


// DirectShow must work on multiple platforms.  In particular, it also runs on
// Windows NT 3.51 which does not have DirectDraw capabilities. The filters
// cannot therefore link statically to the DirectDraw library. To make their
// lives that little bit easier we provide this class that manages loading
// and unloading the library and creating the initial IDirectDraw interface

CLoadDirectDraw::CLoadDirectDraw() :
    m_pDirectDraw(NULL),
    m_hDirectDraw(NULL)
{
}


// Destructor forces unload

CLoadDirectDraw::~CLoadDirectDraw()
{
    ReleaseDirectDraw();

    if (m_hDirectDraw) {
        NOTE("Unloading library");
        FreeLibrary(m_hDirectDraw);
    }
}


// We can't be sure that DirectDraw is always available so we can't statically
// link to the library. Therefore we load the library, get the function entry
// point addresses and call them to create the driver objects. We return S_OK
// if we manage to load DirectDraw correctly otherwise we return E_NOINTERFACE
// We initialise a DirectDraw instance by explicitely loading the library and
// calling GetProcAddress on the DirectDrawCreate entry point that it exports

// On a multi monitor system, we can get the DirectDraw object for any
// monitor (device) with the optional szDevice parameter

HRESULT CLoadDirectDraw::LoadDirectDraw(LPSTR szDevice)
{
    PDRAWCREATE pDrawCreate;
    PDRAWENUM pDrawEnum;
    LPDIRECTDRAWENUMERATEEXA pDrawEnumEx;
    HRESULT hr = NOERROR;

    NOTE("Entering DoLoadDirectDraw");

    // Is DirectDraw already loaded

    if (m_pDirectDraw) {
        NOTE("Already loaded");
        ASSERT(m_hDirectDraw);
        return NOERROR;
    }

    // Make sure the library is available

    if(!m_hDirectDraw)
    {
        UINT ErrorMode = SetErrorMode(SEM_NOOPENFILEERRORBOX);
        m_hDirectDraw = LoadLibrary(TEXT("DDRAW.DLL"));
        SetErrorMode(ErrorMode);

        if (m_hDirectDraw == NULL) {
            DbgLog((LOG_ERROR,1,TEXT("Can't load DDRAW.DLL")));
            NOTE("No library");
            return E_NOINTERFACE;
        }
    }

    // Get the DLL address for the creator function

    pDrawCreate = (PDRAWCREATE)GetProcAddress(m_hDirectDraw,"DirectDrawCreate");
    // force ANSI, we assume it
    pDrawEnum = (PDRAWENUM)GetProcAddress(m_hDirectDraw,"DirectDrawEnumerateA");
    pDrawEnumEx = (LPDIRECTDRAWENUMERATEEXA)GetProcAddress(m_hDirectDraw,
						"DirectDrawEnumerateExA");

    // We don't NEED DirectDrawEnumerateEx, that's just for multimon stuff
    if (pDrawCreate == NULL || pDrawEnum == NULL) {
        DbgLog((LOG_ERROR,1,TEXT("Can't get functions: Create=%x Enum=%x"),
			pDrawCreate, pDrawEnum));
        NOTE("No entry point");
        ReleaseDirectDraw();
        return E_NOINTERFACE;
    }

    DbgLog((LOG_TRACE,3,TEXT("Creating DDraw for device %s"),
					szDevice ? szDevice : "<NULL>"));

    // Create a DirectDraw display provider for this device, using the fancy
    // multimon-aware version, if it exists
    if (pDrawEnumEx)
        m_pDirectDraw = DirectDrawCreateFromDeviceEx(szDevice, pDrawCreate,
								pDrawEnumEx);
    else
        m_pDirectDraw = DirectDrawCreateFromDevice(szDevice, pDrawCreate,
								pDrawEnum);

    if (m_pDirectDraw == NULL) {
            DbgLog((LOG_ERROR,1,TEXT("Can't create DDraw")));
            NOTE("No instance");
            ReleaseDirectDraw();
            return E_NOINTERFACE;
    }
    return NOERROR;
}


// Called to release any DirectDraw provider we previously loaded. We may be
// called at any time especially when something goes horribly wrong and when
// we need to clean up before returning so we can't guarantee that all state
// variables are consistent so free only those really allocated allocated
// This should only be called once all reference counts have been released

void CLoadDirectDraw::ReleaseDirectDraw()
{
    NOTE("Releasing DirectDraw driver");

    // Release any DirectDraw provider interface

    if (m_pDirectDraw) {
        NOTE("Releasing instance");
        m_pDirectDraw->Release();
        m_pDirectDraw = NULL;
    }

}


// Return NOERROR (S_OK) if DirectDraw has been loaded by this object

HRESULT CLoadDirectDraw::IsDirectDrawLoaded()
{
    NOTE("Entering IsDirectDrawLoaded");

    if (m_pDirectDraw == NULL) {
        NOTE("DirectDraw not loaded");
        return S_FALSE;
    }
    return NOERROR;
}


// Return the IDirectDraw interface we look after

LPDIRECTDRAW CLoadDirectDraw::GetDirectDraw()
{
    NOTE("Entering GetDirectDraw");

    if (m_pDirectDraw == NULL) {
        NOTE("No DirectDraw");
        return NULL;
    }

    NOTE("Returning DirectDraw");
    m_pDirectDraw->AddRef();
    return m_pDirectDraw;
}


// Are we running on Direct Draw version 1?  We need to find out as
// we rely on specific bug fixes in DirectDraw 2 for fullscreen playback. To
// find out, we simply see if it supports IDirectDraw2.  Only version 2 and
// higher support this.

BOOL CLoadDirectDraw::IsDirectDrawVersion1()
{

    if (m_pDirectDraw == NULL)
	return FALSE;

    IDirectDraw2 *p = NULL;
    HRESULT hr = m_pDirectDraw->QueryInterface(IID_IDirectDraw2, (void **)&p);
    if (p)
	p->Release();
    if (hr == NOERROR) {
        DbgLog((LOG_TRACE,3,TEXT("Direct Draw Version 2 or greater")));
	return FALSE;
    } else {
        DbgLog((LOG_TRACE,3,TEXT("Direct Draw Version 1")));
	return TRUE;
    }
}