Greek support: fonts, hyphenation and UI translation (#767), branch ready

[Somnius]

Following up on #767. You said there you'd consider Greek if it doesn't add too much to the firmware, so I went and measured it. I know the repo doesn't take PRs, so it's all on a branch in my fork you can look at or cherry-pick if you want: Somnius/CrossInk feat/greek-support (diff against main).

Short version: Greek on its own adds about 195 KB to each build, and all four still fit the 6.25 MB app partition. There's also an optional last commit that takes out Vietnamese and Arabic, and with that every build comes out smaller than v1.6.0. If you'd rather keep those, just leave that commit out.

It's not only the UI. Bitter and Lexend Deca have no Greek at all, so Greek books render as ◆ boxes too. Inter does have Greek, it just wasn't in the ranges that get converted.

Commits on the branch

1. Greek hyphenation: the hyph-el-monoton trie from typst/hypher (2 KB), same source as the other languages, used for books tagged el (or gre/ell). HyphenationCommon gets isGreekLetter()/toLowerGreek() (incl. the tonos capitals), Greek letters count as alphabetic, and ;/· are trimmed like other punctuation. Breaks come out as κα-λη-μέ-ρα, ηλε-κτρο-νι-κός, Κων-στα-ντι-νού-πο-λη, προ-ϋ-πό-θε-ση.
2. Greek in the built-in fonts: Greek-only subsets of Noto Serif (next to Bitter) and Noto Sans (next to Lexend Deca), all 4 styles, ~20 KB of source each, OFL. Modern (monotonic) Greek only. Inter just gets the Greek ranges. fontconvert.py gets --font-exclude-intervals, used so the few Greek letters Bitter/Lexend already have (Δ Ω μ π) come from the Noto face too, otherwise a word like "Πόλη" mixes two designs. Kerning/ligature lookup now follows the same include/exclude rules as glyph lookup. With the old arguments the output is byte for byte the same as the committed fonts, I checked.
3. Greek UI translation: all 843 keys, placeholders match English.
4. Docs/changelog.
5. Drop Vietnamese and Arabic (optional): the Vietnamese precomposed range out of the default font intervals, the Arabic presentation forms out of the Inter UI fonts, and vi/ar out of custom_i18n_builtin_langs. Vietnamese and Arabic books still work with SD card fonts, and a device saved on vi/ar UI falls back to English like any language that isn't built in.

Size

firmware.bin, all built the same way (pioarduino core 6.1.19, like CI):

env	main (b25beb1)	+ Greek (commits 1-4)	+ drop vi/ar (all 5)
default (X3/X4)	6,105,600	6,300,512 (+194.9 KB)	6,048,224 (−57.4 KB)
x4-pro	6,072,544	6,267,600 (+195.1 KB)	6,015,296 (−57.2 KB)
sticky	5,981,856	6,176,880 (+195.0 KB)	5,924,576 (−57.3 KB)
x4-classic	5,906,384	6,101,456 (+195.1 KB)	5,849,136 (−57.2 KB)

App partition is 6,553,600, so Greek alone still leaves ~250 KB on the biggest one (default). My main builds for x4-pro, sticky and x4-classic come out byte for byte the same size as the v1.6.0 release files, so the numbers should line up with yours.

Roughly where the 195 KB goes: ~165 KB is the Greek glyphs in the 32 reading fonts + 5 UI fonts, ~28 KB the Greek strings, 2 KB the hyphenation trie.

And the #767 case, English UI with a Greek book on Home:

Testing

• Built default, sticky, x4-pro and x4-classic at both commit 4 and commit 5.
• Native tests: the hyphenation eval passes for every language, plus a new Greek set. 566/570 overall. The other 4 (SectionPersistenceTest, ChapterHtmlSlimParserTest, EpubTextGrayscaleTest, PersistableStoreAtomicTest) don't compile with GCC 16 on my machine, same on unmodified main.
• bin/clang-format-fix with clang-format 21, no changes. pio check -e default with the CI flags, no defects.
• x4-pro-simulator: a Greek EPUB (Cavafy's Ιθάκη plus a paragraph of long words) in both fonts, justified, hyphenation on. Greek UI through the settings tabs. Home with a Greek title and author, which is what Greek supporting interface font #767 was about.
• esptool image-info on the x4-pro bin matches the v1.6.0 release (ESP32-S3, DIO 80m, 16MB, same IDF, checksum and hash valid), and the CROSSPOINT-BOARD-V1:x4pro; tag is there.

Not on real hardware yet. A friend with an X4 Pro is going to try it, there's a test build on my fork for that.

A few things I left out on purpose:

• Polytonic Greek. Greek Extended is ~230 more glyphs in every font, SD card fonts already cover it.
• Hyphenation only kicks in when the book says it's el. A Greek book with no dc:language still reads fine, it just doesn't hyphenate, same as the other languages.
• The patterns are the standard hyph-el-monoton ones, so ια/ιο stay together (βι-βλιο-θή-κη) instead of βι-βλι-ο-θή-κη.

🤖 Generated with Claude Code

[satpanos]

hello, works great , thank you