Vellscroll 0.1.1

Fixes the bug that made 0.1.0 do nothing. If you installed 0.1.0, please update.

What was wrong

A scroll event carries the same movement in three encodings — line, pixel and fixed-point — and setting one makes macOS recompute the others. 0.1.0 read and wrote them interleaved, so it negated already-negated values: the line delta came out flipped while the pixel delta was flipped straight back.

Most applications read the pixel delta. The result was scrolling behaving exactly as before, while the app itself reported that it had inverted every event.

Also in this release

• Universal binary (Apple silicon and Intel). 0.1.0 was arm64-only despite the download page saying otherwise.
• The menu now leads with what each device actually does — "Trackpad scrolls natural / Mouse scrolls traditional" — rather than what Vellscroll is doing to it. Since it only ever flips, the result depends on your macOS setting too, and one click fixes the combination if it ends up backwards.
• A diagnostics report, because every failure mode here is otherwise silent.

Known limitations

• A Magic Mouse counts as a trackpad. It scrolls by gesture, so macOS reports it as continuous.
• On some Macs the built-in trackpad's events never reach the event tap at all, which means the "invert trackpad" switch may do nothing. Inverting the mouse — the reason most people install this — works regardless.
• Switching between pointing devices has a brief pause before scrolling responds. This is macOS arbitrating between devices, not Vellscroll: it happens identically with Vellscroll quit.

Not notarized yet, so macOS will block it on first launch: System Settings → Privacy & Security → Open Anyway.

Vellscroll 0.1.0

First public release of Vellscroll — separate scroll direction for mouse and trackpad.

Universal binary (Apple silicon and Intel). Free, MIT licensed, no telemetry.

Why it exists

macOS has exactly one "Natural scrolling" switch, and it applies to every pointing device at once. If you want natural scrolling on a trackpad and traditional scrolling on an external mouse, System Settings can't express it. Vellscroll separates them.

What's in it

Four switches in a menu bar item, and nothing else: invert the mouse wheel, invert the trackpad, optionally invert horizontal too, and launch at login.

The menu leads with what each device actually does — "Trackpad scrolls natural / Mouse scrolls traditional" — because Vellscroll only ever flips, so the result depends on your system setting too. If the combination ends up backwards, one click fixes it.

Installing

1. Download and unzip, then drag Vellscroll to your Applications folder.
2. This build isn't notarized yet, so macOS will block it on first launch. To allow it: System Settings → Privacy & Security, scroll down to the message about Vellscroll, and click Open Anyway.
3. Vellscroll will ask for Accessibility access. Changing a scroll event — rather than just watching one — requires it. It reads no keystrokes and makes no network requests of any kind.

Moving it to /Applications before first launch matters: "Launch at login" can't register from a Downloads folder.

Known limitations

• A Magic Mouse counts as a trackpad. It scrolls by gesture, so macOS reports it as continuous and Vellscroll treats it accordingly. That's usually what you want, but it means the "mouse wheel" switch won't affect it.
• Only direction, for now. No scroll smoothing, no per-app rules, no speed adjustment.

Not notarized yet — that's coming.