SDL Centering issue/bug with TwinView

[test1000]

Hi, With all my SDL based fullscreen games i need to be quick to kinda drag(well i don't drag as in click-and-drag i just move the mousecursor) the game-screen into focus if i'm so fortunate that the game also has coded in some mouse-functionality. If i don't then for example i will only see half the game on my right-sided monitor.

Running latest _everything_; but this has been a longstanding issue for me spanning several nvidia drivers SDL versions and xorg.conf "revisions".

/etc/X11/xorg.conf:

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig: version 1.0 (buildmeister@builder3) Wed Dec 14 16:39:22 PST 2005

Section "ServerLayout"
Identifier "Layout0"
Screen 0 "Screen0"
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "Mouse0" "CorePointer"
EndSection
Section "Extensions"
Option "Composite" "true"
EndSection
Section "Files"
RgbPath "/usr/share/X11/rgb"
ModulePath "/usr/lib/xorg/modules"

FontPath "/usr/share/fonts/misc/:unscaled"
FontPath "/usr/share/fonts/Type1/"
FontPath "/usr/share/fonts/TTF/"
FontPath "/usr/share/fonts/local/"
FontPath "/usr/share/fonts/100dpi/:unscaled"

EndSection

Section "Module"
Load "dbe"
Load "extmod"
# Load "type1"
Load "freetype"
Load "glx"
EndSection

Section "InputDevice"
# generated from default
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/input/mice"
Option "Emulate3Buttons" "yes"
# Option "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
# generated from default
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/input/mice"
Option "Emulate3Buttons" "yes"
# Option "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
# generated from default
Identifier "Keyboard0"
Driver "keyboard"
Option "XkbRules" "xorg"
Option "XkbModel" "pc105"
Option "XkbLayout" "no"

EndSection

Section "Monitor"
Identifier "Monitor0"
VendorName "Unknown"
ModelName "Unknown"
HorizSync 30.0 - 110.0
VertRefresh 50.0 - 150.0
Option "DPMS"
EndSection

Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
Option "NoLogo" "true"
Option "TwinView"
# 1280x960 @ 85.00 Hz (GTF) hsync: 85.68 kHz; pclk: 149.43 MHz
# Modeline "1280x960_85.00" 149.43 1280 1376 1512 1744 960 961 964 1008 -HSync +Vsync
Option "MetaModes" "1280x960,1280x960; 1024x768,1024x768; 800x600,800x600"
Option "HorizSync" "CRT-0: 30.0-86.0; CRT-1: 30-110"
Option "VertRefresh" "CRT-0: 50-150; CRT-1: 50-150"
# Option "SecondMonitorHorizSync" "30.0-86.0"
# Option "SecondMonitorVertRefresh" "50-150"
Option "TwinViewOrientation" "CRT leftof CRT"
Option "ConnectedMonitor" "CRT, CRT"
Option "AllowGLXWithComposite" "true"
Option "RenderAccel" "true"
Option "UseEdidDpi" "FALSE"
Option "DPI" "96 x 96"
EndSection

Section "Screen"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
SubSection "Display"
Depth 24
Modes "1280x960" "1024x768" "800x600" "640x480"
EndSubSection
EndSection

I AM using ion3 wm, so maybe that makes stuff harder? I will try using another wm and repost.

[test1000]

nope, changes nothing. Is this an SDL, Xorg or nvidia bug?

[Thunderbird]

If I remember correctly not all SDL versions are build with Xinerama support which can be used to query the resolution on the displays. This can be your issue (I'm not sure if it is still the case). The other workaround is to lets say add a metamode like "1024x768, NULL" assuming you want to game at this resolution. When you start a game, select this 1024x768 and the other display will be disabled while playing a game.

[mETz]

Originally Posted by Thunderbird

If I remember correctly not all SDL versions are build with Xinerama support which can be used to query the resolution on the displays. This can be your issue (I'm not sure if it is still the case).

Looking at "ldd libSDL.so"-output makes me believe that SDL dlopens most of the libs it's using. Here it doesn't link against any X11-library at all (debian unstable).

The other workaround is to lets say add a metamode like "1024x768, NULL" assuming you want to game at this resolution. When you start a game, select this 1024x768 and the other display will be disabled while playing a game.

Unfortunately that does turn off the other display but still centers the game-display in the middle of both displays. I once had "fixed" this bug locally. SDL calculates some offset for xinerama, keeping the x-offset at 0 instead of doing any calculation fixed it here but back then it wasn't accepted into SDL. See also https://bugzilla.icculus.org/show_bug.cgi?id=1209 where I posted the patch loooong time ago.

Unfortunately this problem is still in latest SDL although they claimed to have fixed some sort of Xinerama problem.

[test1000]

hmm your patch fails on hunk 1. If you ever get this fixed i would be eternally happy and the best thing would be to get this into the sdl tree but either way please email me a working patch at kfs1 AT online DOT no if you get it working either way.