XGL + Compiz

I've been experimenting with XGL and Compiz on my two Linux systems for some time, and thought I'd share with everyone and see how other people have experienced it. Many of you are probably wondering what XGL and Compiz are: I could say that XGL is a fully OpenGL accellerated X server, and that Compiz is a window & composite manager that runs on top of XGL, but since a picture is worth a thousand words and a video is a thousand pictures, the Novell demonstration of XGL/Compiz should do a much better job than I. For those too lazy to watch an eleven minute video, a few screenshots of my system will have to suffice.




OK, now that you've seen the video, you're probably wondering how to get it working under your system. First of all, a Linux system is required; *BSD might work, but I have no clue about that. It would be best to run a 32bit x86 version of Linux; 64bit and PPC versions have problems of their own. The three distributions that currently seem to run (relatively) well with it are Ubuntu Dapper (possibly Breezy as well), Gentoo, and Suse. Gentoo apparently has a LiveCD available, but I don't know much about that option; Ubuntu Dapper is probably the easiest of the three and is what most of my experience is on.

First a word of warning: XGL and Compiz are still considered alpha (if not pre-alpha) software packages, and as such should not be installed lightly. Do not blame me if your computer needs a reinstall, blows up, makes long distance phone calls, or spawn into a self-aware being that launches the US nuclear arsenal at Russia in an attempt to star a War of the Machines. That said, I've run into relatively few problems with them once I got them working, and they shouldn't do any damage to your system; at most a couple of config files will have to be changed back to default. Anyways, read through the official UbuntuForums thread on XGL/Compiz for installation instructions under Dapper; for the most part that should work. I use two custom package repositories, by Quinnstorm and Reggaemanu, which seem much easier to use, feature-rich, and stabler. They can be found at Quinnstorm's Compiz forums: to use them, add the following to /etc/apt/sources.list

deb http://www.beerorkid.com/compiz/ dapper main
deb http://xgl.compiz.info/ dapper main

On my two systems, I've gotten one to work perfectly and one...well, that one is having problems. The working one has the specs:
32bit AMD 2800+, GeForce 5600, 1GB PC333, 19" monitor @ 1280x1024
while the second
64bit AMD ML37, ATI X700 Go, 1GB PC333, 15.4" monitor @ 1680x1050
I don't know if its the 64bit, ATI, or a combination that's giving me the problem, bit I'll be trying a 32bit install on it some time this week so I'll know more then.

On the working system, stability is remarkable for alpha software; I've noticed problems only when switching an app from fullscreen to window mode repeatedly, and restarting the app solves he problem. There isn't much slowdown; some videos play somewhat slowly, but that could just be my computer being too slow to handle the h264 codec or 1080p quicktime files.

Anyways, that's all I have time for right now. I'd like to hear other people's experiences with it, and non-Linux users impressions.

First-hand impressions have me loving this.

First of all, at the very basic, it gives some GUI eye-candy that's on-par (and beyond that of,) Windows XP and Mac OS X.

Secondly, it gives way to have some nice, useful functionality. In the Novell video, they showed what was very much like their own Expose function (which I find even better than Alt+tab,) and I think we could see even more useful things like that.

I'd love to try it, but I a) don't have the time to yet, b) would have to clear out some space on my computer to get a Linux partition on it and c) the other computer I would try it with I fear would be far too underpowered for it (700MHz, 128MB RAM, NVidia TNT2.) I even think my own computer would be underpowered, but I'm not nearly as worried about it not working.

Maybe if I work enough over the summer and can get a laptop, I'll get Ubuntu on it and try this bugger out.

It certainly has more eye-candy than OS X... but I'm not sure it's so much more usable. Multiple desktops obviously appeal to the Linux crowd, where it's been a well-established thing for many years... but I wouldn't want to try to manage multiple desktops myself, ESPECIALLY if I had two monitors.

Ripping off Exposé was obvious, and no wonder, it's an awesome feature (though, without the complement of spring-loaded folders, I'd find it less useful). The whole wobbly/warpy windows bit seems a bit pointless though, the kind of thing that's just to show off that yes, it's 3D. At least the genie effect for minimizing on OS X has a purpose—to help guide the user to where their window went, physically.

Also, I notice XGL seems to make a lot of the same mistakes OS X made in its first iterations and Vista is making now—that is to say "a lot of transparency everywhere." Yes, obviously 3D compositing makes translucent windows possible. But it's WAY easy to get slap-happy about that shit and not think about readability and usability. That's why translucency in OS X has been SERIOUSLY toned down since 10.0/10.1.

My philosophy is that compositing windows in 3D should be about improving UI speed and smoothness, plus allowing for useful window transformations, a la Exposé, not useless eye-candy like blurry glass window borders (Vista) or warpy/wobbly windows (XGL). There definitely are some good ideas in here, but I think that both XGL and Vista could learn from Apple's mistakes instead of repeating them.

Originally Posted by Cless

My philosophy is that compositing windows in 3D should be about improving UI speed and smoothness, plus allowing for useful window transformations [...] not useless eye-candy

I agree with you on that, but I don't believe that XGL is already on the wrong track. Those demos and early implementations already floating around are of course loaded with eye candy but as part of the regular distros to come or respectively their desktop environments, it'll be up to the user wether those new capabilities are employed solely for fancy special effects or time saving usability features. When the time comes, both kinds will be available in abundance (open source does that to software ). It's like those virtual desktops you mentioned, some don't use them, some got eight. I use two, by the way.

Originally Posted by Cless

Also, I notice XGL seems to make a lot of the same mistakes OS X made in its first iterations and Vista is making now—that is to say "a lot of transparency everywhere."

I don't remember any transparency before Expose. Where was it? I think the only time I ever activated transparency in OS X was to get a neat-looking terminal window.

How fast does XGL/Compiz run compared to a normal environment? I've found the Composite X extension allows for some nice transparency and shadows KDE 3.5, but in other cases it simply caused problems. Also, for some bizarre reason the simple OpenGL programs I'm writing for class would show content from other windows when they were focused.

Oh yeah, and can XGL/Compiz be installed alongside x.org or would I be better off testing it on a separate install?

As far as the whole benefit of eyecandy debate goes, yes I know alot of it has no usability benefits. Then again, things like the Exposè feature, the 8x zoom are extremely useful. Lots of Linux users do use the multiple desktops they get by default, and the cube rotation is good in that it gives a visual cue that one is changing desktops. I've also used the transparency to good use; running a program behind my web browser, I can still see its status. The live Vista-like switcher is useful, especially when using multiple desktops, as it helps you pick which window you want to move the focus to. Even the wobbly is somewhat useful; true, its pretty much just eyecandy the way they showed it (when moving the windows), but it also can make windows wobble when they receive focus, which is a good way to show the user which window is currently active. And as Cyrus said, because compiz is based on plugins so the user will have full control of what features are used and what features aren't used. Plus you could always just not install XGL/Compiz at all, for those with slower computers.

In terms of speed, XGL doesn't seem to affect normal operations much, if at all. I haven't tried anything intensive yet with OpenGL, but glxgears runs fine and mplayer runs with gl2 output. Compiz has a setting to disable most effects when an app goes fullscreen, so that should cut down on problems. The only slowdown I've noticed was when playing 1080p quicktime files and h264 matroska files. I'm pretty sure that its not Compiz or XGL causing those problems though; my computer is probably just too slow to handle 1080p video and the new h264 codec is more computationally intense than, say, xvid.

As far as trying it on your own, XGL actually needs X.org, and runs on top of it (I currently have Xgl and Xorg in my process list). Its fairly easy to disable XGL, all I have to do is comment out a few lines in my /etc/gdm/gdm.conf. Compiz is even easier to disable; just take it out of you Sessions list in Gnome or whatever you use to autostart it. The way I'm set up, my default X server is XGL without compiz., and I have a button in my panel that replaces the default window manager with compiz.

Or you could always try the Live CD I mentioned earlier. Actually, I know at least of one other, a quick google search should turn up others if this one doesn't work for you.

I realized Xgl was an x.org extension, but unfortunately for me it's for 7.0 which is still in testing on Gentoo and I really fucked up when I tried to install it. I may, however, see if I can put up an experimental environment on my other hard drive. At least then I won't have to worry about screwing up my main system.

Originally Posted by Magic

I don't remember any transparency before Expose. Where was it? I think the only time I ever activated transparency in OS X was to get a neat-looking terminal window.

Menus used to me much more transparent than they are now. Additionally, title-bars on out-of-focus windows used to be semi-transparent. Combined with the much more intense pinstripes in earlier revisions, it made readability somewhat nightmarish.

A terminal window I can SORT of understand, if you're just doing terminal-like things that don't fill up the whole terminal with text. But for any window that's full of text/graphics? I don't want to be able to see through that shit—I want to be able to READ it. If I was running irssi in a terminal, I wouldn't want to see through that either. It impedes readability and hence functionality.

That's why I feel that way about Vista's glass title-bars. Yeah, it LOOKS neat, it's a nice tech demo, but A) with different blurred colors coming through, reading text can be hard, and B) it's difficult as fuck to figure out which window is in focus.

As long as the user can control transparency it shouldn't be a problem, although then everybody gets to complain about what is/isn't enabled by default. Also, in the video they were able to enable/disable transparency through a menu which is definitely a good idea (how about titlebar buttons?).

Originally Posted by Magic

As long as the user can control transparency it shouldn't be a problem, although then everybody gets to complain about what is/isn't enabled by default. Also, in the video they were able to enable/disable transparency through a menu which is definitely a good idea (how about titlebar buttons?).

See, I'm of the opinion that a real UI designer knows better than the user does, and ought to do their best to save them from themselves, not encourage stupid shit.

But yes, for the Linux crowd (which overall seems to be much more into "tweaking" than "usability") obviously the option is a good thing... even if it's a stupid thing.

I've been doing more experimenting, and the OpenGL situation seems worse than I originally thought. I've tried two games; Enemy Territory runs incredibly slowly and with alot of visual glitches, while Doom 3 doesn't run at all. Both run fine when I login without XGL, but not when I log in with XGL and without Compiz, so it seems its more an XGL problem than a Compiz problem. Fortunately its not terribly difficult to turn XGL on/off, merely a few commented out lines in /etc/gdm/gdm.conf-custom (and would be an even easier option in the Sessions menu of gdm if I ever set that up), so for now I'll just have to know when I login whether I want games or eyecandy.

Magic: Actually, the current implementation I'm using (the Quinnstorm patches to Compiz) uses a simple alt+mousewheel action to control the transparency, with a menu option to reset the transparency to 0 (or opacity to 100, which is how it is internally I think). There's also a way to set the default opacity for selected applications using the transset plugin.

Cless: My thoughts are that while the average user, indeed, doesn't really know what they want in a UI design, more advanced users are capable of that decision. Which is why the important thing is to provide sensible defaults; the defaults should be optimized for the standard user who doesn't know anything about tweaking, while the ability left open for an advanced user to customize everything to his/her taste. But then again I'm a Linux user, and that seems to be what most Linux users think.

Originally Posted by OnlyJedi

My thoughts are that while the average user, indeed, doesn't really know what they want in a UI design, more advanced users are capable of that decision. Which is why the important thing is to provide sensible defaults; the defaults should be optimized for the standard user who doesn't know anything about tweaking, while the ability left open for an advanced user to customize everything to his/her taste. But then again I'm a Linux user, and that seems to be what most Linux users think.

Yes, that's the way it should be and probably already is on the big Linux desktops. Reasonable default settings coupled with lots of well placed options for customization.
And while I don't want to start an OS war and personally never used a Mac (and I'd love to, just to broaden my horizon), quite a few people, especially experienced users told me that they felt somewhat belittled and patronized by OS X's overall look and feel, due to a lack of options in some areas.

True. But I've also heard from experienced users who got used to having less un-needed options and came to realize how much silly crap they fiddled with that they didn't need to. Granted, there should be options for all kinds of stuff, but they should not be used by most.

I'd love to see the wobbly windows and snap-to options added to OS X 10.5. And this reminds me that I really hope to see an expose knockoff on Vista.

This is probably a stupid question, but can XGL be used with KDE?

I'm running Kubuntu 5.10 and I'd like to give this a shot.

Just found this today (was searching for topics on Quake, which is why it's highlighted). Apparently it's a LiveCD equipped with XGL. I'm currently torrenting it, but if I can get it to work I'll let people know.

BurningRanger:

Found this on the web. Does this answer your question? The thread on UbuntuForums, XGL/Compiz at KDE startup, should contain details. You can try searching for more threads there, but be warned; in the last few weeks they changed it so only registered users can use the search function.

Let us know how it turns out.

@ BurningRanger
At this point you can get it to sorta run with KDE but only with the Gnome extension for Compiz. So no QT window decorations for now. Personally, I'll wait until someone integrates the XGL features directly into KWin.

@ Magic
OnlyJedi already mentioned that live CD in the inital post ... and indeed it's pretty cool. You'll probably like it.

Originally Posted by Cyrus XIII

@ Magic
OnlyJedi already mentioned that live CD in the inital post ... and indeed it's pretty cool. You'll probably like it.

Oops, I'm really good at doing that.