ZachFix v0.2.4

v0.2.4 - 2026-10-03

Native Gamepad and SDL3

• Replaced the production XInput-only native controller bridge with a provider-neutral Native Gamepad path. Backend = Auto now prefers SDL3 and falls back to XInput while preserving DP's existing configJ.cnf, action helpers, and CInput pipeline.
• Added a pinned SDL 3.4.16 provider, linked statically as the guaranteed runtime fallback. Advanced users can override it with an x86 ZachFix\SDL3.dll through SDL Dynamic API; an existing SDL3_DYNAMIC_API override is honored first.
• Kept the legacy NativeXInput INI key as a read-only migration alias. Saving settings writes the current NativeGamepad / Backend keys instead.

Input fixes

• Added the opt-in Experimental.AimFpuPrecisionFix, which forces x87 PC24 precision only while the native mode-2 aim handler runs and restores the caller control word afterward. This remains a best-effort workaround because the reported restricted-aim bug is not locally reproducible.
• Added LowLatencyInput, which moves the native CInput poll before the same-frame input commit while preserving the original fallback path.
• Reworked native controller ownership around the controller slot selected by DP, including controller handoff, disconnect, Auto Input Switch, analog LT/RT, combat-strafe input, and vibration lifecycle handling.
• Fixed diagnostic vibration behavior across keyboard/controller transitions, disabled vibration, live strength changes, controller changes, and failed output attempts.
• Preserved a prepared WinMM activity fallback when the native gamepad backend is unavailable.
• Documented Alt+Tab as a practical recovery path for the reported restricted aiming range when the issue occurs.

Save and runtime fixes

• Hardened transactional save handling so failed or incomplete writes cannot commit a bad dp.sav, while preserving valid synchronous positioned writes.
• Fixed Reload INI → Apply → Save so newly loaded non-live settings are not overwritten by stale runtime values.
• Hardened runtime world-setting Hot Apply, including unavailable unchanged settings, effective-state rollback, and restart-required handling after an incomplete rollback.
• Fixed StretchRect replacement-surface coordinate handling for empty or invalid rectangles and preserved underlying Direct3D error results.
• Fixed fullscreen PostFX state handling for scissor and fill mode.
• Hardened screenshot batch naming and path-length handling.
• Fixed save-backup ordering to use filesystem timestamps instead of local filename timestamps.
• Improved failure cleanup and diagnostics for the restored difficulty selector.

Documentation and research

• Updated save, input, native UI, PhysX, player, timing, and engine-map research alongside the runtime changes.
• Updated SDL3 integration, licensing, installation, build documentation, and third-party attribution.