Patterns

A Supernote plugin that fills a box you have drawn with a pattern: a dot grid, crosses, ruled lines, squares, or a to-do list.

Draw a rough rectangle, lasso it, tap Patterns, and choose the spacing in millimetres, how big the marks are and how dark. Or place one from the sidebar on an empty page.

Status: working, tested on both panels. 40 unit tests, plus an on-device probe suite run on an A5X2 (Manta) and an A6X2 (Nomad). Every mark lands, the drawing time shown on screen is accurate to within half a second, and the mark sizes and tones are what a photographed ladder says the panel can actually tell apart.

Download Patterns.snplg → copy it to the device → Settings → Apps → Plugins → Add Plugin.

What it does

• Five patterns — dots, crosses, ruled lines for writing on, squares, or a to-do list.
• To-do, added in 1.1.0 — ruled lines, each with an empty box at the left standing on its own rule. Four ink strokes and a rule; there is nothing to tap, you tick it with the pen like paper. The box is six tenths of the row, so the other four tenths are always clear paper between it and the line above. 8 or 10mm suits it.
• Spacing in millimetres, from 2.5mm to 20mm. 5mm is what dot grid paper uses; 8mm suits writing.
• Three mark sizes and two tones — black or grey. For a lighter grid still, grey at the fine size.
• No border. The pattern fills the region and stops; it does not draw a frame around itself, and the rough box you drew is rubbed out once the pattern is in.
• Its own layer where the device allows it, so erasing your writing cannot rub out the grid.

Two things worth knowing

Millimetres, not pixels. Both current panels are 300dpi in the space elements are addressed in — an A5X2 is 1920×2560 over 10.7 inches, an A6X2 1404×1872 over 7.8 — so a millimetre is the same number of pixels on each, and a 5mm grid is the same size in the hand whichever device drew it.

A dot is a stroke with nowhere to go. There is no circle primitive worth using and no fill. What there is, measured on hardware, is that a stroke paints a round cap of half its own width past each end. So a dot here is a stroke one pixel long: the caps do the rest, and the result is a round blob whose diameter is just the pen width. One code path draws every pattern.

And there is no transparency. Geometry has a penColor and nothing else — no alpha, no blend — and the panel has one ink. The firmware accepts exactly four values and the plugin offers the two that are useful. A grey mark is light ink rather than a see-through one, which for a grid you write over is the better of the two anyway.

What it does not do

• Re-edit a pattern you have already drawn. A pattern is drawn once; to change the spacing, erase it and draw it again. (Its own layer makes that safe.)
• Rotated or non-rectangular regions.
• Anything that would take more than a minute to draw. Every mark is a separate element and the device spends about 38ms on each, so it refuses and tells you how long it would have been rather than drawing half of it.

Building it

Needs Node 18+, a JDK, and the Android SDK.

npx tsc --noEmit     # Metro does not typecheck; a type error still ships
npx eslint .
npx jest
rm -rf build         # or a stale native blob ships with a release build
./buildPlugin.sh     # -> build/outputs/Patterns.snplg

Architecture

Everything under src/grid/ imports no SDK at all and is unit-tested. sn-plugin-lib resolves a native module at import time that only exists on the device, so anything touching it cannot be tested off-device — which is why every decision lives on the pure side and src/adapter.ts is left doing nothing but reads and writes.

src/grid/types.ts	The primitives, the tones, the sizes, and millimetres.
src/grid/layout.ts	A rectangle and a spacing → marks. The whole plugin, really.
src/grid/ink.ts	A hand-drawn box → a rectangle.
src/adapter.ts	The only module that talks to the device.

HANDOFF.md is the engineering log, inherited from Tables: what this firmware actually does as opposed to what it is documented to do. Most of it was bought with a device round trip and several entries contradict the vendor documentation.

Licence

GPL-3.0-or-later. See LICENSE.