[Bug 31691] New: Raw mouse input is erratic and/or causes major performance drops

http://bugs.winehq.org/show_bug.cgi?id=31691

Bug #: 31691
           Summary: Raw mouse input is erratic and/or causes major
                    performance drops
           Product: Wine
           Version: unspecified
          Platform: x86-64
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: user32
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]
    Classification: Unclassified

This bug emerged from the implementation of #20395 "Mouse / keyboard input not
handled (RawInput)" (http://bugs.winehq.org/show_bug.cgi?id=20395).

Filing it as a separate bug, as suggested here:
http://bugs.winehq.org/show_bug.cgi?id=20395#c134

After compiling and testing a git version (>1.5.12) including the "official"
raw mouse input patch (not to be confused with the "raw3" input hack)
http://source.winehq.org/git/wine.git/commitdiff/faaf3d388eb6db8c2594cb11f76...
with Guild Wars 2 (in which the camera is rotated around the character by
holding down the left or right mouse button and then dragging), I made the
observations listed below. Please understand them as a feedback directed to
providing viable information for debugging.

- Basically, the camera can now be turned using the mouse.
- Doing so has a major impact on the game's performance. For me, it drops from
40-50 to ~3 FPS.
- Actually, trying to turn the view with the mouse is not even necessary to
cause the FPS drop: Simply moving the cursor e.g. in a constant circle, not
even pressing a mouse button, leads to the very same result.
- Moving the cursor was already possible before the patch was merged to the
git. Thus, it seems to me like the game only uses the raw input path when
click-dragging the mouse.
- Before the patch was merged, moving the pointer did not cause a performance
drop.
- The previous two points seem to contradict -- I suspect a conflict/bug
somewhere in there.
- Turning the view with the keyboard is perfectly smooth, but it cannot be
considered an option regarding gameplay.
- All in all, the camera angle kind of performs jumps instead of smooth
transitions. This makes the game unplayable.

I'm quite sure to speak for many gamers out there when I say: Thank you for
your efforts, Henri - we greatly appreciate your work! Ofc, this also goes to
anyone else who was involved. Anyway, we'd love to see further improvements on
this - it looks like raw mouse input is almost done except for performance
tweaks.

A very similar issue seems to occur with Anarchy Online, as described here
http://bugs.winehq.org/show_bug.cgi?id=20395#c133
, so this does not appear to be a Guild Wars 2 specific problem.