VBoxDispDrvEnableDirectDraw

//
// GDI calls the driver's DrvEnableDirectDraw function to obtain pointers to the DirectDraw callbacks that the driver supports.
// 驱动支持DirectDraw的函数
//
// 填充三个回调接口
// DD_CALLBACKS
//   DDHAL_CB32_CREATESURFACE
//   DDHAL_CB32_CANCREATESURFACE
//   DDHAL_CB32_MAPMEMORY

// DD_SURFACECALLBACKS
//   DDHAL_SURFCB32_LOCK
//   DDHAL_SURFCB32_UNLOCK

// DD_PALETTECALLBACKS
// 无
//
// 如果支持硬件加速，则增加DD_SURFACECALLBACKS的回调
//
BOOL APIENTRY
VBoxDispDrvEnableDirectDraw(DHPDEV dhpdev, DD_CALLBACKS *pCallBacks, DD_SURFACECALLBACKS *pSurfaceCallBacks,
                            DD_PALETTECALLBACKS *pPaletteCallBacks)
{
    LOGF_ENTER();

    pCallBacks->dwSize = sizeof(DD_CALLBACKS);
    pCallBacks->CreateSurface = VBoxDispDDCreateSurface;
    pCallBacks->CanCreateSurface = VBoxDispDDCanCreateSurface;
    pCallBacks->MapMemory = VBoxDispDDMapMemory;
    pCallBacks->dwFlags = DDHAL_CB32_CREATESURFACE|DDHAL_CB32_CANCREATESURFACE|DDHAL_CB32_MAPMEMORY;

    pSurfaceCallBacks->dwSize = sizeof(DD_SURFACECALLBACKS);
    pSurfaceCallBacks->Lock = VBoxDispDDLock;
    pSurfaceCallBacks->Unlock = VBoxDispDDUnlock;
    pSurfaceCallBacks->dwFlags = DDHAL_SURFCB32_LOCK|DDHAL_SURFCB32_UNLOCK;

    pPaletteCallBacks->dwSize = sizeof(DD_PALETTECALLBACKS);
    pPaletteCallBacks->dwFlags = 0;

#ifdef VBOX_WITH_VIDEOHWACCEL
    PVBOXDISPDEV pDev = (PVBOXDISPDEV)dhpdev;

    if (pDev->vhwa.bEnabled)
    {
        pSurfaceCallBacks->DestroySurface = VBoxDispDDDestroySurface;
        pSurfaceCallBacks->Flip = VBoxDispDDFlip;
        pSurfaceCallBacks->GetFlipStatus = VBoxDispDDGetFlipStatus;
        pSurfaceCallBacks->Blt = VBoxDispDDBlt;
        pSurfaceCallBacks->GetBltStatus = VBoxDispDDGetBltStatus;
        pSurfaceCallBacks->SetColorKey = VBoxDispDDSetColorKey;
        pSurfaceCallBacks->dwFlags |= DDHAL_SURFCB32_DESTROYSURFACE|
                                      DDHAL_SURFCB32_FLIP|DDHAL_SURFCB32_GETFLIPSTATUS|
                                      DDHAL_SURFCB32_BLT|DDHAL_SURFCB32_GETBLTSTATUS|
                                      DDHAL_SURFCB32_SETCOLORKEY;

        if(pDev->vhwa.caps & VBOXVHWA_CAPS_OVERLAY)
        {
            pSurfaceCallBacks->UpdateOverlay = VBoxDispDDUpdateOverlay;
            pSurfaceCallBacks->SetOverlayPosition = VBoxDispDDSetOverlayPosition;
            pSurfaceCallBacks->dwFlags |= DDHAL_SURFCB32_UPDATEOVERLAY|DDHAL_SURFCB32_SETOVERLAYPOSITION;
        }
    }
#endif

    LOGF_LEAVE();
    return TRUE;
}