Design principles¶

Each of these is enforced by the code or asserted by a test.

Millimetres everywhere. Every internal length is a float in millimetres and one SVG user unit is one millimetre. YAML may carry units; they are converted once, on the way in. Nothing else ever thinks about points or pixels.

Modules snap; what they draw is theirs. The layout engine places every module on the module grid. Inside its rectangle a module draws what it likes. journalkit check tests the first and ignores the second.

Both grids are page-anchored. The module grid and the dot lattice are defined from the page origin, so alignment across modules and across pages is automatic rather than arranged. A module never chooses a phase.

Mirroring happens once. inner and outer margins become left and right when the content rectangle is computed. No module branches on the side.

Text is drawn from the font file. Glyph outlines, cap heights and advance widths are read directly, so the output does not depend on the machine that renders it.

Dots are dropped, never shifted. Where a dot would collide with a label it is omitted; the survivors stay on the lattice.

One colour, many roles. Every colour defaults to $theme.ink. Any role can be pinned. Knockouts stay white.

Warnings are loud and non-fatal. A snapped height or an overflow is printed to stderr and the build succeeds, because the output is still useful for looking at. --strict is there for scripts. Only sizes the author wrote are worth warning about; intrinsic sizes snap silently.

A template is written once. It works on a recto and a verso, in any project, with any theme.