On Wed, Feb 22, 2012 at 03:09:09PM +0100, Gerd Hoffmann wrote:
> On 02/22/12 13:28, Alon Levy wrote:
> > On Wed, Feb 22, 2012 at 12:18:50PM +0100, Gerd Hoffmann wrote:
> >> Hi,
> >>
> >> It's not obvious to me how the non-flipped case (qxl_stride > 0) is
> >> handled now. Have you tested this with both windows+linux guests?
> >
> > It isn't handled. The simplest way is just to if on the stride and do a
> > single memcpy instead of individual line memcpy.
>
> Single memcpy works only for full scanlines. qxl_flip can be extended
> to handle both cases (and should probably also renamed then).
>
> > This of course means we
> > are doing a redundant copy,
>
> No. You can wrap the qxl_flip call into ...
>
> if (is_shared_buffer()) { ... }.
>
> ... to skip the copy if it isn't needed.
>
> > since using our own DisplayAllocator or just
> > the existing deallocate + our own allocate of ds->surface->data removes
> > one copy.
>
> I would just do
>
> if (qxl_stride > 0) {
> qemu_free_displaysurface
> qemu_create_displaysurface_from
> } else {
> qemu_resize_displaysurface
> }
>
Ok, this all works fine, thanks, just one note - linux qxl also uses
negative stride, so actually there is no user for positive stride (and
hence that code path is untested).
> cheers,
> Gerd
>
