http://bugs.winehq.org/show_bug.cgi?id=60358 Bug ID: 60358 Summary: Mouse-look input stutters in 32-bit DirectInput game under WoW64; smooth under genuine win32 prefix (pre-9.0 Wine) Product: Wine Version: 11.17 Hardware: x86-64 OS: Linux Status: UNCONFIRMED Severity: normal Priority: P2 Component: dinput Assignee: wine-bugs@list.winehq.org Reporter: igor-t@live.com Target Milestone: --- Distribution: --- Mouse-look input becomes stuttery/laggy in 32-bit DirectInput game "Archangel" (2002) when run under WoW64 (unified 32/64-bit Wine); smooth under a genuine pre-9.0 32-bit-only Wine build on identical hardware/config Wine version tested (broken): 11.17 (system package, unified WoW64 architecture) Wine version tested (working): Wine-GE-Custom 8-26 (based on Wine 8.0-staging, pre-WoW64-unification), run in a genuine WINEARCH=win32 prefix What's happening: Archangel (2002, Metropolis Software) is a 32-bit-only game (PE32, i386) that uses DirectInput (dinput.dll/DirectInputCreateA) for mouse-look, with ClipCursor/SetCursorPos for cursor confinement. Under a modern 64-bit Wine prefix (WoW64, 32-bit game translated through the unified 64-bit process), camera-turn mouse movement is inconsistent — described by the reporter as "rubber-band/overshoot" and chopping, specifically on left/right (yaw) camera rotation. Character movement and other input (keyboard) are unaffected; only mouse-look is bad. Steps to reproduce: 1. Create a standard 64-bit Wine prefix (default WINEARCH, i.e. WoW64) with a recent Wine (9.0+, tested on 11.17). 2. Install/run Archangel (2002) — game.exe is 32-bit only. 3. In-game, enter any menu or gameplay screen using mouse-look camera control and move the mouse left/right at a normal, steady speed. Actual results: Camera rotation is jerky/stutters, with a rubber-band/overshoot feel — the view seems to lag then catch up rather than tracking the mouse 1:1. Expected results: Smooth 1:1 camera tracking, matching behavior seen under a genuine 32-bit-only Wine build (see below). What we ruled out (all tested, none fixed it): - In-game mouse sensitivity slider (tested 20–299 range) and per-axis Mouse_sensitivity_X/Mouse_sensitivity_Y values - In-game mouse smoothing option (made it worse — added lag, not the reported symptom) - HKCU\Software\Wine\DirectInput\MouseWarpOverride in all three modes: enable, disable, force - Disabling DXVK/VKD3D/DXVK-NVAPI entirely (game only uses native OpenGL, confirmed no D3D/Vulkan involvement) - GPU load/vsync (vblank_mode), render quality, and resolution changes — no effect on the stutter pattern - Confirmed not a general system/hardware input issue: mouse is smooth in other Wine games and the desktop on th What fixed it: Recreating the Wine prefix as genuinely 32-bit (WINEARCH=win32) using Wine-GE-Custom 8-26 (Wine 8.0-staging base, i.e. before Wine's 9.0 WoW64 unification) immediately resolved the issue — mouse-look became fully smooth with no other changes. This strongly points to the WoW64 32-to-64-bit syscall translation path (used by all current Wine ≥9.0 builds for 32-bit processes) introducing latency/quantization specifically in this game's DirectInput mouse-polling loop. System info: - OS: CachyOS (Arch-based), Wayland session (game runs via Xwayland) - GPU: Intel HD Graphics 4600 (Haswell) + NVIDIA GeForce GTX 950M (Optimus laptop) - Renderer used by game: native OpenGL (OPENGL32.dll/GLU32.dll), no D3D/DXVK/VKD3D involved AppDB entry: [paste the appdb.winehq.org link for Archangel here] -- Do not reply to this email, post in Bugzilla using the above URL to reply. You are receiving this mail because: You are watching all bug changes.