Re: [Qemu-devel] console muti-head some more design input

[Dave Airlie]

>> Have a look the virtio-gpu branch in my repo (don't look at the
>> history, its ugly, just the final state), you'll see code in sdl2.c to
>> do input translation from window coordinates to the overall screen
>> space. So we need at least the x,y offset in the ui code, and I think
>> we need to communicate that via the console.
>>
>
> One of the patches I will be submitting as part of this includes 
> bi-directional calls to set the orientation. A HwOp, and a 
> DisplayChangeListenerOp. This allows you to move the display orientation 
> around in the guest (if your driver and backend support it), or to move the 
> orientation around by dragging windows... Either way you have the data you 
> need to get absolute coordinates right, even if you are scaling the guest 
> display in your windows. Whether the orientation offsets end up stored in the 
> QemuConsole or not becomes an implementation detail if you get notifications.

Okay I just hacked up something similar with the bidirectional ops,
and ran into the fact that DisplayChangeListeners are stored per
DisplayState, so when my GPU drivers tries to callback for console
number 1, the dcls for both consoles gets called, this doesn't seem so
optimal.

Dave.