Re: Support for applications using different video resolutions

[Billy Biggs <vektor dumbterm net>]

Matthias Clasen (maclas gmx de):

> > It is XFree specific only if other X implementations do not provide
> > for you to set the modeline, and then there isn't much you can do..
> > 
> > It is hardware oriented only in that it lets you set the modeline,
> > which is what applications need if they are to control not only the
> > screen size, but also the other aspects of the display such as the
> > refresh rate. That applications can control them is very important.
> 
> But maybe it should be defined in a somewhat more abstract terms than
> directly in terms of the XFree86-specific vidmode extension
> terminology. Ie offer to change the refresh rate, not some cryptic
> NVSCAN or DBLSCAN parameters which (at least I) don't understand at
> all.

  Ideally you only need to understand them if you need to use them.  I
kinda liked the idea of a spec where you only have to set the values you
care about.

  The issue is that some applications ideally would have fine-grained
control over the modeline for selecting specific refresh rates for
video.

> > Perhaps, but it is for window manager - client interaction, which is
> > what EWMH is all about.
> 
> It is, but it has a scope, which is explained in the introduction.
> Certain aspects of wm-client interaction are explicitly declared as
> out of scope for the EWMH. The question I have is whether this vidmode
> changing is too specific for the EWMH, since only very few clients
> need it.

  Are you worried about WMs not implementing it or clients or what?  I'm
confused here.  This seems like exactly something that EWMH should
handle: handling mode changes when multiple applications want specific
refresh rates or resolutions when they are focused.

> > > c) explain the interaction with RandR 
> > 
> > I don't think there should be any interaction with RandR. RandR is
> > meant for long-term changes to your desktop geometry, not for
> > zooming to a new vidmod e.  With RandR, your desktop is actually
> > resized. Your panels should not be resized, and apps moved around,
> > etc, every time you change resolutions to watch a movie.
> 
> If there is no interaction, than this should be explained. The
> paragraph you just wrote may be a good start for this explanation.

  Perhaps there will be an interaction.  If I request a 1024x768 mode,
and then later RandR changes the root to a max size of 800x600, can I
still use my 1024x768 modeline?

  Unfortunately, I'm worried that we may experience some pain as I don't
think the RandR folks considered VidMode in their design.

  -Billy