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Merge pull request #156 from jpirnay/feat-bionic

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feat: Add yet another bionic reader implementation
This commit is contained in:
jpirnay
2026-04-30 15:11:10 +02:00
committed by GitHub
parent da7ad888c7 0dda02cafc
commit 42ad7667c4
17 changed files with 285 additions and 54 deletions
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lib/Epub/Epub/ParsedText.cpp
+148
View File
@@ -11,6 +11,7 @@
#include <set>
#include <vector>
#include "hyphenation/HyphenationCommon.h"
#include "hyphenation/Hyphenator.h"
constexpr int MAX_COST = std::numeric_limits<int>::max();
@@ -123,6 +124,71 @@ std::string buildLinePreview(const std::vector<std::string>& words, const std::v
return preview;
}
constexpr int kBionicReadingMinCodepoints = 4;
constexpr int kBionicReadingMinBoldPrefix = 1;
constexpr int kBionicReadingBoldPrefixNumerator = 1;
constexpr int kBionicReadingBoldPrefixDenominator = 2;
struct TokenSpan {
size_t start;
size_t end;
bool isWord;
};
static int computeBionicBoldPrefixCount(const int codepointCount) {
return std::max(kBionicReadingMinBoldPrefix,
(codepointCount * kBionicReadingBoldPrefixNumerator + kBionicReadingBoldPrefixDenominator - 1) /
kBionicReadingBoldPrefixDenominator);
}
static bool isBionicWordCodepoint(const uint32_t cp) {
if (cp == 0) {
return false;
}
if (utf8IsCombiningMark(cp)) {
return true;
}
return isAlphabetic(cp) || isAsciiDigit(cp) || isApostrophe(cp);
}
// Split a word token into contiguous spans of "word-like" characters and non-word characters.
// This avoids applying bionic bolding to punctuation, digits-only runs, or other separators.
// Only spans marked as word-like are eligible for the bionic prefix transform.
static std::vector<TokenSpan> tokenizeBionicWord(const std::string& word) {
std::vector<TokenSpan> spans;
spans.reserve(2);
const unsigned char* base = reinterpret_cast<const unsigned char*>(word.c_str());
const unsigned char* ptr = base;
const unsigned char* segmentStart = ptr;
bool currentIsWord = false;
bool haveCurrent = false;
while (true) {
const unsigned char* cpStart = ptr;
uint32_t cp = utf8NextCodepoint(&ptr);
if (cp == 0) {
break;
}
bool cpIsWord = isBionicWordCodepoint(cp);
if (!haveCurrent) {
currentIsWord = cpIsWord;
haveCurrent = true;
} else if (!utf8IsCombiningMark(cp) && cpIsWord != currentIsWord) {
spans.push_back({static_cast<size_t>(segmentStart - base), static_cast<size_t>(cpStart - base), currentIsWord});
segmentStart = cpStart;
currentIsWord = cpIsWord;
}
}
if (haveCurrent) {
spans.push_back({static_cast<size_t>(segmentStart - base), word.size(), currentIsWord});
}
return spans;
}
} // namespace
void ParsedText::addWord(std::string word, const EpdFontFamily::Style fontStyle, const bool underline,
@@ -149,6 +215,9 @@ void ParsedText::layoutAndExtractLines(
// Apply fixed transforms before any per-line layout work.
applyParagraphIndent();
if (bionicReadingEnabled) {
applyBionicReadingTransform();
}
// Ensure SD card font glyph metrics are loaded before measuring word widths.
// For flash-based fonts isSdCardFont() returns false and this block is skipped
@@ -506,6 +575,85 @@ void ParsedText::applyParagraphIndent() {
}
}
void ParsedText::applyBionicReadingTransform() {
if (words.empty()) {
return;
}
std::vector<std::string> transformedWords;
std::vector<EpdFontFamily::Style> transformedStyles;
std::vector<bool> transformedContinues;
transformedWords.reserve(words.size() * 2);
transformedStyles.reserve(wordStyles.size() * 2);
transformedContinues.reserve(wordContinues.size() * 2);
for (size_t i = 0; i < words.size(); ++i) {
std::string source = std::move(words[i]);
const auto originalStyle = wordStyles[i];
const bool originalAttachToPrevious = wordContinues[i];
const char* raw = source.c_str();
const auto spans = tokenizeBionicWord(source);
if (spans.empty()) {
continue;
}
bool attachToPrevious = originalAttachToPrevious;
for (size_t spanIndex = 0; spanIndex < spans.size(); ++spanIndex) {
const TokenSpan span = spans[spanIndex];
const size_t spanLength = span.end - span.start;
std::string token;
if (spans.size() == 1 && spanIndex == 0) {
token = std::move(source);
} else {
token.assign(raw + span.start, spanLength);
}
if (span.isWord) {
const unsigned char* ptr = reinterpret_cast<const unsigned char*>(token.c_str());
int codepointCount = 0;
while (utf8NextCodepoint(&ptr)) {
codepointCount++;
}
if (codepointCount >= kBionicReadingMinCodepoints) {
const int boldPrefixCount = computeBionicBoldPrefixCount(codepointCount);
ptr = reinterpret_cast<const unsigned char*>(token.c_str());
const unsigned char* prefixEnd = ptr;
for (int j = 0; j < boldPrefixCount && *prefixEnd; ++j) {
utf8NextCodepoint(&prefixEnd);
}
const size_t prefixByteCount =
static_cast<size_t>(prefixEnd - reinterpret_cast<const unsigned char*>(token.c_str()));
if (prefixByteCount < token.size()) {
std::string suffix(reinterpret_cast<const char*>(prefixEnd), token.size() - prefixByteCount);
token.resize(prefixByteCount);
const auto boldStyle = static_cast<EpdFontFamily::Style>(originalStyle | EpdFontFamily::BOLD);
transformedWords.push_back(std::move(token));
transformedStyles.push_back(boldStyle);
transformedContinues.push_back(attachToPrevious);
transformedWords.push_back(std::move(suffix));
transformedStyles.push_back(originalStyle);
transformedContinues.push_back(true);
attachToPrevious = true;
continue;
}
}
}
transformedWords.push_back(std::move(token));
transformedStyles.push_back(originalStyle);
transformedContinues.push_back(attachToPrevious);
attachToPrevious = true;
}
}
words = std::move(transformedWords);
wordStyles = std::move(transformedStyles);
wordContinues = std::move(transformedContinues);
}
// Builds break indices while opportunistically splitting the word that would overflow the current line.
std::vector<size_t> ParsedText::computeHyphenatedLineBreaks(const GfxRenderer& renderer, const int fontId,
const int pageWidth, std::vector<uint16_t>& wordWidths,
lib/Epub/Epub/ParsedText.h
+7 -2
View File
@@ -26,8 +26,10 @@ class ParsedText {
BlockStyle blockStyle;
bool extraParagraphSpacing;
bool hyphenationEnabled;
bool bionicReadingEnabled;
void applyParagraphIndent();
void applyBionicReadingTransform();
std::vector<size_t> computeLineBreaks(const GfxRenderer& renderer, int fontId, int pageWidth,
std::vector<uint16_t>& wordWidths, std::vector<bool>& continuesVec);
std::vector<size_t> computeHyphenatedLineBreaks(const GfxRenderer& renderer, int fontId, int pageWidth,
@@ -60,8 +62,11 @@ class ParsedText {
public:
explicit ParsedText(const bool extraParagraphSpacing, const bool hyphenationEnabled = false,
const BlockStyle& blockStyle = BlockStyle())
: blockStyle(blockStyle), extraParagraphSpacing(extraParagraphSpacing), hyphenationEnabled(hyphenationEnabled) {}
const BlockStyle& blockStyle = BlockStyle(), const bool bionicReadingEnabled = false)
: blockStyle(blockStyle),
extraParagraphSpacing(extraParagraphSpacing),
hyphenationEnabled(hyphenationEnabled),
bionicReadingEnabled(bionicReadingEnabled) {}
~ParsedText() = default;
void addWord(std::string word, EpdFontFamily::Style fontStyle, bool underline = false, bool attachToPrevious = false);
lib/Epub/Epub/Section.cpp
+15 -9
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@@ -12,7 +12,7 @@
#include "parsers/ChapterHtmlSlimParser.h"
namespace {
constexpr uint8_t SECTION_FILE_VERSION = 23;
constexpr uint8_t SECTION_FILE_VERSION = 24;
constexpr uint32_t HEADER_SIZE = sizeof(uint8_t) + // SECTION_FILE_VERSION
sizeof(int) + // fontId
sizeof(float) + // lineCompression
@@ -23,6 +23,7 @@ constexpr uint32_t HEADER_SIZE = sizeof(uint8_t) + // SECTION_FILE_VERSION
sizeof(uint16_t) + // pageCount (stored as 16-bit in header)
sizeof(bool) + // hyphenationEnabled
sizeof(bool) + // embeddedStyle
sizeof(bool) + // bionicReadingEnabled
sizeof(uint8_t) + // imageRendering
sizeof(uint32_t) + // page LUT offset
sizeof(uint32_t) + // anchor map offset
@@ -55,7 +56,8 @@ uint32_t Section::onPageComplete(std::unique_ptr<Page> page) {
void Section::writeSectionFileHeader(const int fontId, const float lineCompression, const bool extraParagraphSpacing,
const uint8_t paragraphAlignment, const uint16_t viewportWidth,
const uint16_t viewportHeight, const bool hyphenationEnabled,
const bool embeddedStyle, const uint8_t imageRendering) {
const bool embeddedStyle, const bool bionicReadingEnabled,
const uint8_t imageRendering) {
if (!file) {
LOG_DBG("SCT", "File not open for writing header");
return;
@@ -63,8 +65,8 @@ void Section::writeSectionFileHeader(const int fontId, const float lineCompressi
static_assert(HEADER_SIZE == sizeof(SECTION_FILE_VERSION) + sizeof(fontId) + sizeof(lineCompression) +
sizeof(extraParagraphSpacing) + sizeof(paragraphAlignment) + sizeof(viewportWidth) +
sizeof(viewportHeight) + sizeof(pageCount) + sizeof(hyphenationEnabled) +
sizeof(embeddedStyle) + sizeof(imageRendering) + sizeof(uint32_t) +
sizeof(uint32_t) + sizeof(uint32_t),
sizeof(embeddedStyle) + sizeof(bionicReadingEnabled) + sizeof(imageRendering) +
sizeof(uint32_t) + sizeof(uint32_t) + sizeof(uint32_t),
"Header size mismatch");
serialization::writePod(file, SECTION_FILE_VERSION);
serialization::writePod(file, fontId);
@@ -75,6 +77,7 @@ void Section::writeSectionFileHeader(const int fontId, const float lineCompressi
serialization::writePod(file, viewportHeight);
serialization::writePod(file, hyphenationEnabled);
serialization::writePod(file, embeddedStyle);
serialization::writePod(file, bionicReadingEnabled);
serialization::writePod(file, imageRendering);
serialization::writePod(file, pageCount); // Placeholder for page count (will be initially 0, patched later)
serialization::writePod(file, static_cast<uint32_t>(0)); // Placeholder for LUT offset (patched later)
@@ -85,7 +88,7 @@ void Section::writeSectionFileHeader(const int fontId, const float lineCompressi
bool Section::loadSectionFile(const int fontId, const float lineCompression, const bool extraParagraphSpacing,
const uint8_t paragraphAlignment, const uint16_t viewportWidth,
const uint16_t viewportHeight, const bool hyphenationEnabled, const bool embeddedStyle,
const uint8_t imageRendering) {
const bool bionicReadingEnabled, const uint8_t imageRendering) {
if (!Storage.openFileForRead("SCT", filePath, file)) {
return false;
}
@@ -107,6 +110,7 @@ bool Section::loadSectionFile(const int fontId, const float lineCompression, con
uint8_t fileParagraphAlignment;
bool fileHyphenationEnabled;
bool fileEmbeddedStyle;
bool fileBionicReadingEnabled;
uint8_t fileImageRendering;
serialization::readPod(file, fileFontId);
serialization::readPod(file, fileLineCompression);
@@ -116,13 +120,14 @@ bool Section::loadSectionFile(const int fontId, const float lineCompression, con
serialization::readPod(file, fileViewportHeight);
serialization::readPod(file, fileHyphenationEnabled);
serialization::readPod(file, fileEmbeddedStyle);
serialization::readPod(file, fileBionicReadingEnabled);
serialization::readPod(file, fileImageRendering);
if (fontId != fileFontId || lineCompression != fileLineCompression ||
extraParagraphSpacing != fileExtraParagraphSpacing || paragraphAlignment != fileParagraphAlignment ||
viewportWidth != fileViewportWidth || viewportHeight != fileViewportHeight ||
hyphenationEnabled != fileHyphenationEnabled || embeddedStyle != fileEmbeddedStyle ||
imageRendering != fileImageRendering) {
bionicReadingEnabled != fileBionicReadingEnabled || imageRendering != fileImageRendering) {
LOG_ERR("SCT", "Deserialization failed: Parameters do not match");
clearCache(); // closes file before removal
return false;
@@ -188,7 +193,8 @@ bool Section::clearCache() {
bool Section::createSectionFile(const int fontId, const float lineCompression, const bool extraParagraphSpacing,
const uint8_t paragraphAlignment, const uint16_t viewportWidth,
const uint16_t viewportHeight, const bool hyphenationEnabled, const bool embeddedStyle,
const uint8_t imageRendering, const std::function<void(int)>& progressFn) {
const bool bionicReadingEnabled, const uint8_t imageRendering,
const std::function<void(int)>& progressFn) {
const uint32_t phaseTotalStart = millis();
const auto localPath = epub->getSpineItem(spineIndex).href;
@@ -210,7 +216,7 @@ bool Section::createSectionFile(const int fontId, const float lineCompression, c
return false;
}
writeSectionFileHeader(fontId, lineCompression, extraParagraphSpacing, paragraphAlignment, viewportWidth,
viewportHeight, hyphenationEnabled, embeddedStyle, imageRendering);
viewportHeight, hyphenationEnabled, embeddedStyle, bionicReadingEnabled, imageRendering);
std::vector<uint32_t> lut = {};
// Derive the content base directory and image cache path prefix for the parser
@@ -243,7 +249,7 @@ bool Section::createSectionFile(const int fontId, const float lineCompression, c
ChapterHtmlSlimParser visitor(
epub, renderer, fontId, lineCompression, extraParagraphSpacing, paragraphAlignment, viewportWidth, viewportHeight,
hyphenationEnabled,
hyphenationEnabled, bionicReadingEnabled,
[this, &lut](std::unique_ptr<Page> page) { lut.emplace_back(this->onPageComplete(std::move(page))); },
embeddedStyle, contentBase, imageBasePath, imageRendering, std::move(tocAnchors), progressFn, cssParser);
Hyphenator::setPreferredLanguage(epub->getLanguage());
lib/Epub/Epub/Section.h
+4 -3
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@@ -20,7 +20,7 @@ class Section {
void writeSectionFileHeader(int fontId, float lineCompression, bool extraParagraphSpacing, uint8_t paragraphAlignment,
uint16_t viewportWidth, uint16_t viewportHeight, bool hyphenationEnabled,
bool embeddedStyle, uint8_t imageRendering);
bool embeddedStyle, bool bionicReadingEnabled, uint8_t imageRendering);
uint32_t onPageComplete(std::unique_ptr<Page> page);
struct TocBoundary {
@@ -50,11 +50,12 @@ class Section {
~Section() = default;
bool loadSectionFile(int fontId, float lineCompression, bool extraParagraphSpacing, uint8_t paragraphAlignment,
uint16_t viewportWidth, uint16_t viewportHeight, bool hyphenationEnabled, bool embeddedStyle,
uint8_t imageRendering);
bool bionicReadingEnabled, uint8_t imageRendering);
bool clearCache();
bool createSectionFile(int fontId, float lineCompression, bool extraParagraphSpacing, uint8_t paragraphAlignment,
uint16_t viewportWidth, uint16_t viewportHeight, bool hyphenationEnabled, bool embeddedStyle,
uint8_t imageRendering, const std::function<void(int)>& progressFn = nullptr);
bool bionicReadingEnabled, uint8_t imageRendering,
const std::function<void(int)>& progressFn = nullptr);
std::unique_ptr<Page> loadPageFromSectionFile();
// Given a page in this section, return the TOC index for that page.
lib/Epub/Epub/parsers/ChapterHtmlSlimParser.cpp
+1 -1
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@@ -255,7 +255,7 @@ void ChapterHtmlSlimParser::startNewTextBlock(const BlockStyle& blockStyle) {
anchorData.push_back({std::move(pendingAnchorId), static_cast<uint16_t>(completedPageCount)});
pendingAnchorId.clear();
}
currentTextBlock.reset(new ParsedText(extraParagraphSpacing, hyphenationEnabled, blockStyle));
currentTextBlock.reset(new ParsedText(extraParagraphSpacing, hyphenationEnabled, blockStyle, bionicReadingEnabled));
wordsExtractedInBlock = 0;
}
lib/Epub/Epub/parsers/ChapterHtmlSlimParser.h
+10 -10
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@@ -128,6 +128,7 @@ class ChapterHtmlSlimParser final : public Print {
int currentFootnoteLinkTextLen = 0;
std::vector<std::pair<int, FootnoteEntry>> pendingFootnotes; // <wordIndex, entry>
int wordsExtractedInBlock = 0;
bool bionicReadingEnabled = false;
// Per-chapter caches: resolveStyle and parseInlineStyle are called for every HTML element;
// caching by (tag|classAttr) and styleAttr avoids repeated string operations and hash lookups.
@@ -149,16 +150,14 @@ class ChapterHtmlSlimParser final : public Print {
static void XMLCALL endElement(void* userData, const XML_Char* name);
public:
explicit ChapterHtmlSlimParser(std::shared_ptr<Epub> epub, GfxRenderer& renderer, const int fontId,
const float lineCompression, const bool extraParagraphSpacing,
const uint8_t paragraphAlignment, const uint16_t viewportWidth,
const uint16_t viewportHeight, const bool hyphenationEnabled,
const std::function<void(std::unique_ptr<Page>)>& completePageFn,
const bool embeddedStyle, const std::string& contentBase,
const std::string& imageBasePath, const uint8_t imageRendering = 0,
std::vector<std::string> tocAnchors = {},
const std::function<void(int)>& progressFn = nullptr,
const CssParser* cssParser = nullptr)
explicit ChapterHtmlSlimParser(
std::shared_ptr<Epub> epub, GfxRenderer& renderer, const int fontId, const float lineCompression,
const bool extraParagraphSpacing, const uint8_t paragraphAlignment, const uint16_t viewportWidth,
const uint16_t viewportHeight, const bool hyphenationEnabled, const bool bionicReadingEnabled,
const std::function<void(std::unique_ptr<Page>)>& completePageFn, const bool embeddedStyle,
const std::string& contentBase, const std::string& imageBasePath, const uint8_t imageRendering = 0,
std::vector<std::string> tocAnchors = {}, const std::function<void(int)>& progressFn = nullptr,
const CssParser* cssParser = nullptr)
: epub(epub),
renderer(renderer),
@@ -169,6 +168,7 @@ class ChapterHtmlSlimParser final : public Print {
viewportWidth(viewportWidth),
viewportHeight(viewportHeight),
hyphenationEnabled(hyphenationEnabled),
bionicReadingEnabled(bionicReadingEnabled),
completePageFn(completePageFn),
progressFn(progressFn),
cssParser(cssParser),
lib/I18n/translations/english.yaml
+2
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@@ -598,3 +598,5 @@ STR_KB_HINT_SECONDARY_CHAR: "Hold SELECT for secondary char"
STR_KB_HINT_UPPER_SECONDARY: "Hold SELECT for UPPERCASE or secondary char"
STR_KB_HINT_LOWER_SECONDARY: "Hold SELECT for lowercase or secondary char"
STR_KB_HINT_URL_SNIPPETS: "Press URL for snippets"
STR_BIONIC_READING: "Bionic Reading"
STR_BTN_ACT_TOGGLE_BIONIC_READING: "Toggle Bionic Reading"