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Bug 312

Summary: mouse is jumpy when on fullscreen (relative mouse motion)
Product: SDL Reporter: Dimitrios <sehh>
Component: *don't know*Assignee: Ryan C. Gordon <icculus>
Status: RESOLVED WORKSFORME QA Contact: Sam Lantinga <slouken>
Severity: normal    
Priority: P2    
Version: don't know   
Hardware: x86   
OS: Windows (XP)   

Description Dimitrios 2006-08-27 11:25:31 UTC 
When running SDL applications in fullscreen which use relative mouse motion (as i've been told), the mouse pointer is jumpy. One such application is "dosbox" (dosbox.sourceforge.net).

I believe the problem could be related to synergy (synergy2.sourceforge.net). An application that shares a single keyboard/mouse across multiple systems (different architectures, operating systems, etc).

My configuration is as follows:


System 1 - synergy client, running dosbox:

Opteron 64bit with Windows Server 2003 64bit SP1
DOSBox 0.65 - SDL application
Synergy 1.3.1 - mouse/keyboard sharing application (client mode)


System 2 - synergy server

AMD Athlon 64 X2 with Fedora Core 5 Linux 64bit
Synergy 1.3.1 - mouse/keyboard sharing application (server mode)


Thus, i use system 2 which has the keyboard/mouse connected to its USB ports and manage/use system 1 other the network.

For some reason, SDL has problems with the way synergy makes the mouse pointer move around, when the SDL application is in fullscreen.

Here is some debug output:

WINDOWED MODE:

mouse motion: xrel 1, yrel 2, posx 283, posy 138
mouse motion: xrel 0, yrel 1, posx 283, posy 139
mouse motion: xrel 1, yrel 2, posx 284, posy 141
mouse motion: xrel 0, yrel 1, posx 284, posy 142
mouse motion: xrel 1, yrel 1, posx 285, posy 143
mouse motion: xrel 1, yrel 1, posx 286, posy 144
mouse motion: xrel 1, yrel 1, posx 287, posy 145
mouse motion: xrel 1, yrel 1, posx 288, posy 146
mouse motion: xrel 1, yrel 1, posx 289, posy 147
mouse motion: xrel 1, yrel 0, posx 290, posy 147
mouse motion: xrel 1, yrel 0, posx 291, posy 147
mouse motion: xrel 1, yrel 0, posx 292, posy 147
mouse motion: xrel 1, yrel -1, posx 293, posy 146
mouse motion: xrel 1, yrel 0, posx 294, posy 146
mouse motion: xrel 1, yrel -1, posx 295, posy 145
mouse motion: xrel 1, yrel 0, posx 296, posy 145
mouse motion: xrel 0, yrel -1, posx 296, posy 144 


FULLSCREEN MODE:

mouse motion: xrel 0, yrel 385, posx 0, posy 1023
mouse motion: xrel 205, yrel 1793, posx 205, posy 1023
mouse motion: xrel 102, yrel 257, posx 307, posy 1023
mouse motion: xrel 1025, yrel 1537, posx 1279, posy 1023
mouse motion: xrel 820, yrel 769, posx 1279, posy 1023
mouse motion: xrel 1230, yrel 512, posx 1279, posy 1023
mouse motion: xrel 1230, yrel 256, posx 1279, posy 1023
mouse motion: xrel 1639, yrel 0, posx 1279, posy 1023
mouse motion: xrel 1435, yrel -512, posx 1279, posy 511
mouse motion: xrel 1845, yrel -769, posx 1279, posy 0
mouse motion: xrel 1639, yrel -1025, posx 1279, posy 0
mouse motion: xrel 1230, yrel -1025, posx 1279, posy 0
mouse motion: xrel 1025, yrel -1281, posx 1279, posy 0
mouse motion: xrel 820, yrel -1025, posx 1279, posy 0
mouse motion: xrel 614, yrel -1281, posx 1279, posy 0
mouse motion: xrel 52, yrel -320, posx 1279, posy 0
mouse motion: xrel 51, yrel -257, posx 1279, posy 0 

As you can see, the mouse movement is completely screwed when in full screen.
Comment 1 Dimitrios 2006-09-09 10:54:21 UTC 
Please help?
Comment 2 Ryan C. Gordon 2007-02-12 06:27:02 UTC 
I guess the first question is: does this happen on that system without Synergy?

--ryan.
Comment 3 Dimitrios 2007-02-13 04:11:07 UTC 
Everything is fine when i'm using a local mouse.

The issue happens when the SDL application/game is using relative mouse motion (or thats what i've been told by the dosbox developers).

I was given a debug .exe that i used to generate the mouse motion X/Y position and its obvious the values have gone crazy.
Comment 4 Ryan C. Gordon 2007-02-13 11:37:41 UTC 
Roger that. I'll try to get Synergy installed and track this down. I may have to say it's their bug, though. We'll see what I find.

--ryan.
Comment 5 Dimitrios 2007-02-14 13:35:13 UTC 
I eliminated that possibility (that its a bug in dosbox only).

I downloaded and installed several SDL games and found out that it happened in half of them.

For example, the problem appears in these games:

- dosbox (http://dosbox.sourceforge.net)
- BZFlag (http://bzflag.org/)
Comment 6 Sam Lantinga 2007-07-05 23:48:42 UTC 
Ryan, any luck reproducing this?
Comment 7 Ryan C. Gordon 2007-07-06 04:00:03 UTC 
I tried it here, WinXP box as client, linux/amd64 as server, Synergy 1.3.1 on both, and bzflag on the Windows box. Worked fine.

Either bzflag or x.org or SDL had an issue, I guess, but whatever it is, it appears to be fixed.

--ryan.