In vertical type every character now sits in its own cell down the column:
"10" and "22" in 「10月22日」 stand side by side in one em, centred on the
column, and 月/日 start right after them. Justified (Justify All) columns
no longer split a tate-chu-yoko block, and tracked or justified upright
characters stay on the column's centre line instead of drifting across it.
Root cause: in 0.3.1 (the reporter's build) upright glyphs were placed by
the font's ascent rather than the ideographic em box, so a font with a tall
ascent (Noto Sans CJK JP, 1.16 em) drew each upright character ~0.28 em
down into the next cell, onto the sideways digits; #208 (after 0.3.1)
replaced that with em-box placement and tate-chu-yoko, which this commit
locks in with regression tests. Two defects of the same kind remained:
Justify All added its inter-character gap inside a tate-chu-yoko block
(the block's second digit slid down the column, away from the first), and
upright glyphs turned about the middle of their advance, which tracking and
justification lengthen, instead of the middle of their own cell.
Tests: the issue's layout with bundled glyphs (cells one after the other,
every ink inside its cell and no overlaps, 2-3 digit blocks one em and
centred, single digits and 2026 on their side advancing by their length,
spaces), the issue's string with craft-fonts' Japanese face (skips without
craft-fonts), Justify All with a block, tracking.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Builds on the vertical type from #145 (same data, commands and tools).
- Kinsoku (the strict set, horizontal Japanese too): no line starts with a
closing bracket, 、。, a middle dot, colon, !?, the long vowel mark,
iteration marks or small kana; no line ends with an opening bracket.
Hyphenation breaks obey it too.
- Tate-chu-yoko: a run of two or three half-width digits (10月, 第100回)
stands upright across the column as one block one em long, squeezed to
the em when wider; longer numbers stay on their side.
- Upright or on its side by Unicode's Vertical_Orientation: CJK and
symbols upright, marks that need a vertical form on their side when the
font has none; upright glyphs advance at least one em, centred, and turn
about the ideographic em box centre so they sit on the column's centre
line. Point type keeps its anchor on the first column's centre line.
- `vrt2` is no longer requested: its glyphs are already on their side, so
with the layout turning Latin and digits too they came out upside down
(and tate-chu-yoko blocks broke) in fonts that have it, e.g. Hiragino.
- The line→text mapping is one affine (`TextLayout::line_xf`, an exact
quarter turn plus the point-type offset); `logical_point` and
`physical_point` use it. Pixel snapping skips vertical type.
- Tests: kinsoku in both directions, tate-chu-yoko blocks, upright vs
sideways, anchor on the centre line, arrows along columns.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
