In an email exchange from May 2006 (quoted below) a question was asked about primary surfaces, and a response given that I would like to clarify.
The question gave three ways to create a 'primary surface' and the response accepted these. But I think that only one does create a primary Surface - the other two are just getting the Surface of a primary Layer, which is not at all the same thing. Method (1) does create a primary Surface: > DFBSurfaceDescription dsc; > IDirectFBSurface *primary; > IDirectFB *dfb; > > dsc.flags = DSDESC_CAPS; > dsc.caps = DSCAPS_PRIMARY | DSCAPS_FLIPPING; > dfb->CreateSurface( dfb, &dsc, &primary ) but surely method (2) does not: > IDirectFB *dfb; > IDirectFBDisplayLayer *layer; > IDirectFBSurface *primary; > IDirectFBWindow *window; > > DFBWindowDescription wind_desc; > > dfb->GetDisplayLayer (dfb, DLID_PRIMARY, &layer); > layer->CreateWindow(layer, &wind_desc, &window); > window->GetSurface(window, &primary); and nor does method (3: IDirectFB *dfb; IDirectFBDisplayLayer *layer; IDirectFBSurface *primary; DFBDisplayLayerConfig config; dfb->GetDisplayLayer (dfb, DLID_PRIMARY, &layer); layer->SetCooperativeLevel(layer, DLSCL_EXCLUSIVE); layer->SetConfiguration(layer, &config); layer->GetSurface(layer, &primary); I think a primary Surface is an abstraction. It refers to the Surface that the application is using (and has an implication that this Surface will be displayed). If IDirectFB:CooperativeLevel is FULLSCREEN or EXCLUSIVE then the 'primary Surface' will be the Surface of the primary DisplayLayer. But if IDirectFB:CooperativeLevel is NORMAL then the primary Surface will be the Surface of a Window of the primary Layer (that Window being created implicitly) - so this is not the Surface of the primary Layer. Method (1) creates a primary Surface, which happens to be the Surface of the primary Layer. Method (2) gets a Surface of a Window of the primary Layer. Method (3) gets a Surface of the primary Layer. I think in this dialog the term 'primary Surface' and the meaning 'Surface of a primary Layer' have been unintentionally confused. It seems to me that such confusion is common. But I would like to confirm that my interpretation is correct so that I do not teach incorrectly. I'd value any clarification or contradiction. Thanks, Chris ======================== Chris Bore BORES Signal Processing [EMAIL PROTECTED] www.bores.com Tel: +44 1483 740138 Mobile: +44 7921 153 219 [directfb-users] Creating primary surface Denis Oliver Kropp dok at directfb.org Fri May 19 02:54:23 CEST 2006 Previous message: [directfb-users] Creating primary surface Next message: [directfb-users] DirectFB-0.9.25.1 and MPlayer Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] ---------------------------------------------------------------------------- ---- Sergio LSI wrote: > Hi, > > I am a newbie and I would like to know the difference between > the following ways to create a primary surface > > 1) > DFBSurfaceDescription dsc; > IDirectFBSurface *primary; > IDirectFB *dfb; > > dsc.flags = DSDESC_CAPS; > dsc.caps = DSCAPS_PRIMARY | DSCAPS_FLIPPING; > dfb->CreateSurface( dfb, &dsc, &primary ) pros - adding one call to dfb->SetCooperativeLevel() makes it behave like 3) - user can use options like: "force-windowed", "force-desktop", "pixelformat", "mode" (also window size) - has an autograb mode for the mouse cursor (type or click in window) cons - no control over implicitly created window, like position - no events from the window, only raw input events available > 2) > IDirectFB *dfb; > IDirectFBDisplayLayer *layer; > IDirectFBSurface *primary; > IDirectFBWindow *window; > > DFBWindowDescription wind_desc; > > dfb->GetDisplayLayer (dfb, DLID_PRIMARY, &layer); > layer->CreateWindow(layer, &wind_desc, &window); > window->GetSurface(window, &primary); pros - can have more than one window - direct window creation - window control - window events 3) IDirectFB *dfb; IDirectFBDisplayLayer *layer; IDirectFBSurface *primary; DFBDisplayLayerConfig config; dfb->GetDisplayLayer (dfb, DLID_PRIMARY, &layer); layer->SetCooperativeLevel(layer, DLSCL_EXCLUSIVE); layer->SetConfiguration(layer, &config); layer->GetSurface(layer, &primary); pros - direct layer configuration - layer control -- Best regards, Denis Oliver Kropp .------------------------------------------. | DirectFB - Hardware accelerated graphics | | http://www.directfb.org/ | "------------------------------------------" _______________________________________________ directfb-users mailing list directfb-users@directfb.org http://mail.directfb.org/cgi-bin/mailman/listinfo/directfb-users
