OS X, dual monitors: Game in fullscreen, secondary display untouched?

April 1, 2006 11:25 AM

Is there any way, on an Intel iMac with two displays, to make apps like World of Warcraft or Unreal Tournament leave the secondary display alone?

I like to take the occasional game break during the day, but I also like to keep one eye on IM during those sessions. With both the games mentioned, unless I run them in windowed mode, the secondary display, where I keep iChat and my inbox showing, goes blank. Is there any way to change this? Both have a windowed mode, but that causes some oddness with the mouse and it seems to hurt their performance a little.

posted by mph to Technology (8 answers total)

Power down the second monitor when you play? :)
posted by smallerdemon at 11:34 AM on April 1, 2006

OSX uses a "cover window" for full-screen applications. The application developer decides when creating this window whether it will fill one or both screens. As far as I can tell, the decision is arbitrary. Although perhaps it signifies to the operating system that the application is taking over all user input.

It is *possible* you can open the NIB file and change this, although I am betting heavily against (ie, its probably not declarative in the NIB, but procedural in the game's startup routine).

I usually run in Windowed mode, in any event. OSX is a much less "full-screen-oriented' operating system than Windows XP (irony?), and I almost never have problems with games played in non-fullscreen windows. What are the problems you are having with WoW?
posted by clord at 2:52 PM on April 1, 2006

Unfortunately, CGDisplayCapture() is a very efficient member of the Quartz API. It hijacks the specified displays, and there's no way any other app gets them back without quitting the executable that locked them.

Running nm on the WoW executable, I can see they do call CGDisplayCapture, and they must call it on all connected displays. They might have a Very Good Reason™ for this, or they might just assume that's how they have to do it, porting from the Windows environment (see clord's notes on XP being much more fullscreen-centric). Try filing a bug with them and see where it goes. Quote the API I linked above.

All this being said, it's been a while since I used that API, but I believe CGDisplayCapture grants all input rights to the app that called it, which means even if they stopped capturing your secondary display, you'd be able to see your IMs but may not be able to interact with them. I don't quite remember. But do try filing a bug with them, they are pretty responsive over thar at teh Blizzx0r.
posted by symphonik at 3:19 PM on April 1, 2006

Best answer: Oh, and FWIW, I play WoW in windowed mode often with no noticeable performance hit. If it helps, set a macro like this one and you can toggle back and forth between windowed and fullscreen mode whenever you hear iChat's distinctive sound. ;)
posted by symphonik at 4:10 PM on April 1, 2006

I dunno how powerful your machine is, but on mine (G4 PowerBook, 1.25GHz, 512MB RAM) switching between fullscreen and windowed was "non-trivial," as they say. In a crowded WoW area it could take 30 seconds or more to finish drawing all the windows. If you have a computer like mine, I'd lean towards avoiding fullscreen mode rather than toggling.
posted by danb at 5:20 PM on April 1, 2006

Response by poster: I had no idea macros could do stuff like that. Well ... vague idea, but not something I'd explored. Part of me is thrilled and part of me is thinking "yet another thing my scripting compulsion is going to run wild over."
posted by mph at 7:38 PM on April 1, 2006

Best answer: You don't need a macro to toggle WoW windowed mode. Splat-M is the default keybinding and it works just fine.
posted by majick at 7:52 PM on April 1, 2006

Response by poster: Well, WoW seems pretty manageable (at least ... "hear the distinctive IM tone, splat-M, check, deal, go back to gaming" seems doable that way).

The bigger problem child is UT2004 -- In windowed mode, it does some weird stuff with the mouse. The motion of the mouse in the game window is sort of mismapped, to the extent that some menu items will remain just out of reach ... when I try to reach them with the mouse, it sort of warps to the opposite edge. It clears up if I move the mouse off one of the edges then try again, but it's annoying.
posted by mph at 9:52 AM on April 2, 2006