Hello Huihong, On Tue, 2011-09-06 at 10:25 -0700, Huihong Luo wrote: > I noted that Windows additions (vboxmouse.sys and VBoxMouseNT.sys) > doesn't perform any conversion from this 0-FFFF percentange > coordinates, however X11 additions convert them to screen resolution. > Does Windows happen to use the same measurement of 0-0xFFFF ? Yes, since we originally only supported Windows as a guest the Additions and Host-to-Guest protocol were originally designed to work comfortably with Windows. Note that X.Org has evolved/improved quite a bit over the years - if you look at vboxmouse_15.c, which supports a range of different "vintages" of X.Org, you will see that the older ones require us to manually convert the values we read to pixel offsets, whereas the newest let us specify the range of values we return and take care of all the conversion for us. (With an off-by-half pixel error unfortunately which we have to work around in the host code, but such is life.) > Another thing is that the cursor shape at pointer disppears when > moving out of vm guest window, does virtualbox perform some special > task to make the curson not to appear? or the host simply reports some > out of range positions to the guest. I was curious how this is > handled. When mouse integration is enabled the software guest cursor is hidden, and instead the host cursor tracks the shape that the guest cursor would have. From the point of view of the Additions we are providing a hardware cursor (most graphics cards provide a hardware sprite for this purpose), and it is telling us where it should be and what shape it should be. And obviously when the host pointer is not above the guest window it simply takes on the shape requested by whatever other host application it moves over next.
Of course, since we don't let the guest move the host cursor this only works if the guest wants it to be where it is already, but since our input driver is providing the position data this usually works. Regards, Michael > --- On Fri, 9/2/11, Michael Thayer <[email protected]> wrote: > > > From: Michael Thayer <[email protected]> > Subject: Re: [vbox-dev] mouse integration concept level overview? > To: "Huihong Luo" <[email protected]> > Cc: [email protected] > Date: Friday, September 2, 2011, 1:47 PM > > > Hello Huihong, > > On Thu, 2011-09-01 at 20:56 -0700, Huihong Luo wrote: > > I need to know a bit more about the mouse integration. Can someone explain > > in big picture on what happened when a mouse pointer is moving from host to > > the guest? once the mouse inside the guest window, host informs the guest > > about the mouse positions? etc. > > > > I need to get some ideas on this in order to implement the drag-and-drop > > feature for vbox. Right now, it's stuck when the mouse is dragged from host > > to vm, how the guest side knows about that. I need to press a key for now > > to tell the guest side, so the dnd isn't smooth yet. A good understanding > > on mouse integration would be very helpful. > > _______________________________________________ vbox-dev mailing list > > [email protected] http://vbox.innotek.de/mailman/listinfo/vbox-dev > > I'm afraid that this will be a quick-ish explanation for now. When > absolute pointer reporting is enabled (see the VMMDevReq_GetMouseStatus > VMM device request) the current pointer position can be requested with > the VMMDevReqMousePointer request. This is reported as a percentage of > the width and height (respectively) of the guest screen - expressed as a > value from 0 to 0xFFFF - or of the virtual desktop for multi-monitor > guests. The host works out what percentage values correspond to the > position of the host pointer relative to the host window the machine is > running in, and the Additions report the position back to the guest in a > way that the guest OS can convert to the correct pixel offset. The host > sends a VMM device event (basically an interrupt and a data word) when > absolute reporting is enabled or disabled and when new position data is > available. > > Hope that helps a bit. > > Regards, > > Michael -- ORACLE Deutschland B.V. & Co. KG Michael Thayer Werkstrasse 24 VirtualBox engineering 71384 Weinstadt, Germany mailto:[email protected] Hauptverwaltung: Riesstr. 25, D-80992 München Registergericht: Amtsgericht München, HRA 95603 Komplementärin: ORACLE Deutschland Verwaltung B.V. Hertogswetering 163/167, 3543 AS Utrecht, Niederlande Handelsregister der Handelskammer Midden-Niederlande, Nr. 30143697 Geschäftsführer: Jürgen Kunz, Marcel van de Molen, Alexander van der Ven _______________________________________________ vbox-dev mailing list [email protected] http://vbox.innotek.de/mailman/listinfo/vbox-dev
