Amar M. Balutkar schrieb: > Hi, > > Does DirectFB have support for virtual display? By virtual display i > mean to have a display larger then the screen and allow me to pan around.
The FBDev implementation doesn't implement this, but in general a layer can have a big surface, while it's showing only a portion of that on the screen. In the public API it's IDirectFBDisplayLayer::SetSourceRectangle() for "panning" and SetConfiguration() to choose the surface size. But currently this also defines the display mode in the FBDev implementation which needs to be fixed before SetSourceRectangle() can be supported. > The obvious advantage of having this is that in case of multiple > applications i can render these applications on the virtual display > (virtual display > actual display) and just change the viewport (to show > the next application) on some event like an Alt+Tab. This i think would > be a faster way to navigate between applications then to blit them to > the primary surface. Sure, that's nice if you don't have a fast hardware blitter. You could also use the new IDirectFBDisplayLayer::SwitchContext() with each application having its own exclusive context to the layer. That way nothing is blitted as each layer context has its own surface which is being displayed. But switching layer contexts causes the whole configuration to be reprogrammed. In the FBDev case it involves setting the (probably same) screen timings and other values again, which in some cases (hw/driver) can cause artifacts or even blackouts. -- Best regards, Denis Oliver Kropp .------------------------------------------. | DirectFB - Hardware accelerated graphics | | http://www.directfb.org/ | "------------------------------------------" _______________________________________________ directfb-dev mailing list [email protected] http://mail.directfb.org/cgi-bin/mailman/listinfo/directfb-dev
