feat: dict based Hyphenation (#305)

## Summary

* Adds (optional) Hyphenation for English, French, German, Russian
languages

## Additional Context

* Included hyphenation dictionaries add approximately 280kb to the flash
usage (German alone takes 200kb)
* Trie encoded dictionaries are adopted from hypher project
(https://github.com/typst/hypher)
* Soft hyphens (and other explicit hyphens) take precedence over
dict-based hyphenation. Overall, the hyphenation rules are quite
aggressive, as I believe it makes more sense on our smaller screen.

---------

Co-authored-by: Dave Allie <dave@daveallie.com>
This commit is contained in:
Arthur Tazhitdinov
2026-01-19 12:56:26 +00:00
committed by GitHub
co-authored by Dave Allie
parent 0beaaaacba
commit 09f8fa84b9
40 changed files with 36465 additions and 52 deletions
+12 -4
View File
@@ -17,16 +17,24 @@ class ParsedText {
std::list<EpdFontFamily::Style> wordStyles;
TextBlock::Style style;
bool extraParagraphSpacing;
bool hyphenationEnabled;
std::vector<size_t> computeLineBreaks(int pageWidth, int spaceWidth, const std::vector<uint16_t>& wordWidths) const;
void applyParagraphIndent();
std::vector<size_t> computeLineBreaks(const GfxRenderer& renderer, int fontId, int pageWidth, int spaceWidth,
std::vector<uint16_t>& wordWidths);
std::vector<size_t> computeHyphenatedLineBreaks(const GfxRenderer& renderer, int fontId, int pageWidth,
int spaceWidth, std::vector<uint16_t>& wordWidths);
bool hyphenateWordAtIndex(size_t wordIndex, int availableWidth, const GfxRenderer& renderer, int fontId,
std::vector<uint16_t>& wordWidths, bool allowFallbackBreaks);
void extractLine(size_t breakIndex, int pageWidth, int spaceWidth, const std::vector<uint16_t>& wordWidths,
const std::vector<size_t>& lineBreakIndices,
const std::function<void(std::shared_ptr<TextBlock>)>& processLine);
std::vector<uint16_t> calculateWordWidths(const GfxRenderer& renderer, int fontId);
public:
explicit ParsedText(const TextBlock::Style style, const bool extraParagraphSpacing)
: style(style), extraParagraphSpacing(extraParagraphSpacing) {}
explicit ParsedText(const TextBlock::Style style, const bool extraParagraphSpacing,
const bool hyphenationEnabled = false)
: style(style), extraParagraphSpacing(extraParagraphSpacing), hyphenationEnabled(hyphenationEnabled) {}
~ParsedText() = default;
void addWord(std::string word, EpdFontFamily::Style fontStyle);
@@ -37,4 +45,4 @@ class ParsedText {
void layoutAndExtractLines(const GfxRenderer& renderer, int fontId, uint16_t viewportWidth,
const std::function<void(std::shared_ptr<TextBlock>)>& processLine,
bool includeLastLine = true);
};
};