Layer scheme

A master's layers say what happens to each part of the page. The prefix on a layer's name decides whether its content becomes exported artwork, is drawn by the firmware or is kept for reference only. Nothing is lost from the mockup, because everything stays in one file.

Figure 1: The layer stack of the wind page master.

Name every layer with its prefix

Prefix	Meaning	Example
CODE	Drawn by the firmware. Kept in the master so the page can be judged, and read for positions, sizes and fonts	CODE text, CODE dial, CODE hub
ART	Exported as artwork, one layer per asset, named with its asset ID	ART art_needle_apparent, ART art_vessel
REF	Reference only, never exported	REF safe area, REF pivots, REF background

• Source. ux/design/README.md, layers.

Stack the layers in the order the page is seen

The layers run in the order the parts sit on the page, from the readout on top down to the background. On the wind page the window and its digits sit above the needle, the needle above the badges and the vessel. The dial and its surround sit below them all.

• Source. ux/design/wind/MDD_Page_Wind.vectorcraft, read with vectorcraft-cli.

Give each asset one ID and one layer

Every artwork asset has one asset ID, such as art_needle_apparent, and its own ART layer. An asset used on several pages keeps one page-neutral ID and is drawn once, in the page where it first appears, such as art_dial_surround.

• Two colours. A two-colour asset is two layers, such as art_alert_fill and art_alert_outline.
• Night forms. A shape that differs at night by more than colour has its own layer, such as art_logo_night and art_alert_snoozed_night.
• Source. ux/design/README.md, shared assets and drawing artwork.

Mark every pivot

Each rotation centre is marked with a small #FF00FF cross on REF pivots. The layer is left printing, so the tools can read the crosses from the exported file.

• Source. ux/design/README.md, layers. ux/design/LEARNINGS.md, entry 7.

Show every layer the tools must read

A hidden layer is exported empty, so art on it never reaches the board. Show any layer the push tool must read. Live effects such as drop shadows are also left out of the export, because the tool draws shadows and glows itself.

• Source. VectorCraft runbook, the four export facts.

Push the master to the bench display

tools/push_to_device.py exports each master to a layered PDF with vectorcraft-cli, renders it and writes the images to the Waveshare Smart 86 Box running the bench viewer, in about a minute.

View	Layers shown	Use
<page>_page	ART and CODE	The page as it will look in service
<page>_art	ART only	The artwork that becomes images
<page>_check	Every printing layer, including REF pivots	Checking pivots and alignment

• On the board. A swipe changes view and a tap switches between day and night.
• 16-bit viewer. The viewer runs the panel at 16-bit colour, so smooth dark gradients show steps there.
• Source. ux/design/README.md, viewing the page on the device.