Using two screens, want games to just use one

NetRAVEN5000 · 01-14-2009, 04:04 PM

I'm not sure if this is the right place to put this or not. . .
Anyways, basically I'm back at school, and I've got two monitors (both hooked to one card BTW - it's a dual-head ATi 4670 HD vidcard). I've got them working such that I can drag a window across from one to the other in KDE.

Every time I launch a fullscreen game, it clones itself on both displays - which I don't like. How can I set it up so that it'll only take up one screen? Or can I?

I know I can just have it set so that it basically just shows two X displays - but then I can't rearrange my windows across both screens, which I would like to do.

By the way I'm running Gentoo, and I'm using ATi's driver.

jhansonxi · 01-15-2009, 12:27 PM

You probably want what is sometimes referred to as "multi-head" where each monitor acts as an independent desktop. The advantage is that any app is confined to one monitor and they can have different resolutions and color depths. The disadvantage is that you can't move an app from one desktop to another, even if they have separate windows (like Firefox). Some apps don't care how many instances are running (like gedit) while Firefox won't let you start another on the other desktop. Depending on the desktop environment you can still drag-n-drop files and text between apps on different screens. Most distros don't have configuration tools for setting this up yet so you have to edit /etc/X11/xorg.conf manually. Below is a snippet of my configuration with an Nvidia card. The same card is listed twice and the Screen value refers to each connector on the card. The ATI driver may have different parameters so you have to check their documentation. The NoLogo statement (commented out) disables the Nvidia start-up logo. The ServerFlags section disables Composite which I think was interfering with some of my games.

Code:

Section "Device"
	Identifier	"GeForce 7300 GT Screen 0"
	Driver		"nvidia"
#	Option		"NoLogo"	"True"
        BusID		"PCI:1:0:0"
	Screen		0
EndSection

Section "Device"
	Identifier	"GeForce 7300 GT Screen 1"
	Driver		"nvidia"
#	Option		"NoLogo"	"True"
        BusID		"PCI:1:0:0"
	Screen		1
EndSection

Section "Monitor"
	Identifier     "SyncMaster 914v"
	Option         "DPMS"
EndSection

Section "Monitor"
        Identifier     "SyncMaster 712N"
        Option         "DPMS"
EndSection

Section "ServerLayout"
	Identifier	"Default Layout"
        Screen	0	"Side Screen" 0 0
	Screen	1	"Big Screen" RightOf "Side Screen"
        InputDevice	"Generic Keyboard"
        InputDevice	"Configured Mouse"
EndSection

Section "Screen"
    Identifier     "Big Screen"
    Device         "GeForce 7300 GT Screen 1"
    Monitor        "SyncMaster 914v"
    DefaultDepth    24
    SubSection     "Display"
        Depth       1
        Modes      "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
    EndSubSection
    SubSection     "Display"
        Depth       4
        Modes      "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
    EndSubSection
    SubSection     "Display"
        Depth       8
        Modes      "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
    EndSubSection
    SubSection     "Display"
        Depth       15
        Modes      "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
    EndSubSection
    SubSection     "Display"
        Depth       16
        Modes      "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
    EndSubSection
    SubSection     "Display"
        Depth       24
        Modes      "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
    EndSubSection
EndSection

Section "Screen"
    Identifier     "Side Screen"
    Device         "GeForce 7300 GT Screen 0"
    Monitor        "SyncMaster 712N"
    DefaultDepth    24
    SubSection     "Display"
        Depth       1
        Modes      "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
    EndSubSection
    SubSection     "Display"
        Depth       4
        Modes      "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
    EndSubSection
    SubSection     "Display"
        Depth       8
        Modes      "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
    EndSubSection
    SubSection     "Display"
        Depth       15
        Modes      "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
    EndSubSection
    SubSection     "Display"
        Depth       16
        Modes      "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
    EndSubSection
    SubSection     "Display"
        Depth       24
        Modes      "1280x1024" "1152x864" "1024x768" "832x624" "800x600" "720x400" "640x480"
    EndSubSection
EndSection

Section "ServerFlags"
    Option	"Composite"	"disable"
EndSection

bastidrazor · 01-15-2009, 12:50 PM

you need to add a metamode.. for example if you have the 1st monitor resolution at 1680x1050 and the 2nd at 1280x1024 you would use something similar to this to tell xorg it has the ability to turn on monitor off ::

Option "metamodes" "DFP-0: 1680x1050 +0+0, DFP-1: 1280x1024 +1680+0; DFP-0: 1680x1050 +0+0, DFP-1: NULL"

Notice this tells xorg DFP-0 (monitor 1) to have a resolution of 1680x1050 , while DFP-1 (monitor 2) has the resolution of 1280x1024. The second part tells xorg you have DFP-0 at 1680x1050 while DFP-1 has nothing (NULL) .. this allows you to 'turn off' in a sense the 2nd monitor when a fullscreen game is played.

NetRAVEN5000 · 01-16-2009, 06:06 PM

I will give that a try. Right now I am using dual-head but I really don't like not being able to drag windows across screens.

Ideally I'm not sure I really want to turn it off - but I'd prefer that over having it cloned on both screens. I'll play with the metamodes once this compile finishes.

NetRAVEN5000 · 01-16-2009, 08:45 PM

Thanks for trying to help out but that didn't work, it still shows the games on both screens.

Also, for some games when I close out, the screens stay cloned until I change the resolution again with KRandR.