[Openicc] XICC specification draft

[Michael R Sweet]

Ross Burton wrote:
> On Sun, 2005-06-26 at 22:18 +1000, David Burren wrote:
> 
>>Which profile should be used in multi-head configs?  In a traditional  
>>multi-head X11 system, each screen can be accessed via a different  
>>$DISPLAY (e.g. machine:0.[screen-number]).  But with this system  
>>there's no facility to move windows between screens or have them  
>>spanning screens.  So systems like Xcinerama establish a single  
>>virtual screen covering the entire multi-head area.  And this is what  
>>can happen with Apple's Xquartz. 
> 
> 
> I was wondering how long it would take for someone else to notice that
> the _ICC_PROFILE spec partially breaks on Xinerama.  As Sven points out,
> the Xinerama concept itself is broken, but I think it's fair to say that
> people with Xinerama either have:

Actually, I disagree that Xinerama is broken.  The previous "standard"
for multi-head displays (:0.0, :0.1, etc.) was completely unusable
for a lot of reasons (I won't waste bandwidth here on that), and
while the current Xinerama spec may be lacking in some ways, it
would be more productive to address its deficiencies than to bash
it.

> 1) a single main display and a number of "utility" displays, which are
> not used for the work (but hold toolbars, documentation, etc).  In this
> case the work display is a superior display, the utility displays might
> be smaller LCDs.
> 
> 2) a number of identical monitors, and a desktop which truely spans them
> all.  In this case as the monitors are identical, the same display
> profile should work.

Even for this case, each monitor will deviate slightly from the
other, so color management power users will want to install a
separate profile for each screen.

I think you can just add additional properties to track each display
by rectangle index - use _ICC_PROFILE for the first (0th) rectangle,
and _ICC_PROFILEn for each additional display.  An app can then
figure out which screen the window is on and get the proper profile.

-- 
______________________________________________________________________
Michael Sweet, Easy Software Products           mike at easysw dot com
Internet Printing and Publishing Software        http://www.easysw.com