[RFC xserver v3 13/14] present: Send a PresentWindowCrtcNotify event appropriately

[Michel Dänzer]

On 27/09/17 07:19 AM, Louis-Francis Ratté-Boulianne wrote:
> When the window has changed CRTC, send the event.

This doesn't make sense to me I'm afraid.

With the current present implementation, which CRTC is used for
synchronization shouldn't have any cottelation with which modifiers are
optimal for the pixmap being presented. (The window may still be visible
on the same set of CRTCs as before we switched the CRTC for synchronization)

What does matter for the modifiers is whether or not page flipping can
be used. So I'd suggest:

* Name the event something along the lines of "drawable specific
  modifiers might have changed" instead of "synchronization CRTC has
  changed"
* Send the event when
  a) The window is currently not flipping, but its geometry changed such
     that it might be able to use flipping (e.g. from
     present_config_notify)
  b) The window was flipping but no longer can (e.g. from
     present_unflip)


Or maybe it would be sufficient for clients to simply re-query the
modifiers in response to PresentConfigureNotify events?


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer