A couple of fixes

lib/Epub/Epub/ParsedText.cpp

@@ -149,6 +149,9 @@ 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 +509,69 @@ 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) {
+    const std::string& word = words[i];
+    const auto originalStyle = wordStyles[i];
+    const bool attachToPrevious = wordContinues[i];
+
+    const unsigned char* ptr = reinterpret_cast<const unsigned char*>(word.c_str());
+    int codepointCount = 0;
+    while (utf8NextCodepoint(&ptr)) {
+      codepointCount++;
+    }
+
+    if (codepointCount <= 3) {
+      transformedWords.push_back(word);
+      transformedStyles.push_back(originalStyle);
+      transformedContinues.push_back(attachToPrevious);
+      continue;
+    }
+
+    const int boldPrefixCount = std::max(1, (codepointCount + 1) / 2);
+    ptr = reinterpret_cast<const unsigned char*>(word.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*>(word.c_str()));
+    if (prefixByteCount >= word.size()) {
+      transformedWords.push_back(word);
+      transformedStyles.push_back(originalStyle);
+      transformedContinues.push_back(attachToPrevious);
+      continue;
+    }
+
+    const std::string prefix(word.data(), prefixByteCount);
+    const std::string suffix(word.data() + prefixByteCount, word.size() - prefixByteCount);
+    const auto boldStyle = static_cast<EpdFontFamily::Style>(originalStyle | EpdFontFamily::BOLD);
+
+    transformedWords.push_back(prefix);
+    transformedStyles.push_back(boldStyle);
+    transformedContinues.push_back(attachToPrevious);
+
+    transformedWords.push_back(suffix);
+    transformedStyles.push_back(originalStyle);
+    transformedContinues.push_back(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/Section.cpp

@@ -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(embeddedStyle) + sizeof(bionicReadingEnabled) + sizeof(imageRendering) +
-                                   sizeof(uint32_t) + sizeof(uint32_t),
+                                   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

@@ -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

@@ -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

@@ -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,
+  explicit ChapterHtmlSlimParser(
-                                 const float lineCompression, const bool extraParagraphSpacing,
+      std::shared_ptr<Epub> epub, GfxRenderer& renderer, const int fontId, const float lineCompression,
-                                 const uint8_t paragraphAlignment, const uint16_t viewportWidth,
+      const bool extraParagraphSpacing, const uint8_t paragraphAlignment, const uint16_t viewportWidth,
-                                 const uint16_t viewportHeight, const bool hyphenationEnabled,
+      const uint16_t viewportHeight, const bool hyphenationEnabled, const bool bionicReadingEnabled,
-                                 const std::function<void(std::unique_ptr<Page>)>& completePageFn,
+      const std::function<void(std::unique_ptr<Page>)>& completePageFn, const bool embeddedStyle,
-                                 const bool embeddedStyle, const std::string& contentBase,
+      const std::string& contentBase, const std::string& imageBasePath, const uint8_t imageRendering = 0,
-                                 const std::string& imageBasePath, const uint8_t imageRendering = 0,
+      std::vector<std::string> tocAnchors = {}, const std::function<void(int)>& progressFn = nullptr,
-                                 std::vector<std::string> tocAnchors = {},
+      const CssParser* cssParser = nullptr)
-                                 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),

src/CrossPointSettings.h

@@ -249,6 +249,8 @@ class CrossPointSettings {
   uint8_t imageDithering = IMAGE_DITHER_BAYER;
   // Enable synthetic TOC fallback for malformed/sparse TOC books (1 = enabled, 0 = disabled)
   uint8_t syntheticTocFallback = 1;
+  // Default bionic reading in EPUB pages when no per-book override is set (1 = enabled, 0 = disabled)
+  uint8_t bionicReading = 0;
   // Automatically push reading progress to the KOReader sync server when leaving the reader
   // (1 = enabled, 0 = disabled). The push only fires when credentials are configured and the
   // reader session advanced at least 3 pages, and is skipped when remote progress is already ahead.

src/JsonSettingsIO.cpp

@@ -456,7 +456,7 @@ bool JsonSettingsIO::loadRecentBooks(RecentBooksStore& store, const char* json)
     book.fontFamilyOverride =
         clampInt8(obj["fontFamilyOverride"] | -1, -1, CrossPointSettings::FONT_FAMILY_COUNT - 1, -1);
     book.fontSizeOverride = clampInt8(obj["fontSizeOverride"] | -1, -1, CrossPointSettings::FONT_SIZE_COUNT - 1, -1);
-    book.bionicReadingOverride = obj["bionicReadingOverride"] | false;
+    book.bionicReadingOverride = clampInt8(obj["bionicReadingOverride"] | -1, -1, 1, -1);
     store.recentBooks.push_back(book);
   }
 

src/RecentBooksStore.cpp

@@ -26,7 +26,7 @@ void RecentBooksStore::addBook(const std::string& path, const std::string& title
   int8_t imageRenderingOverride = -1;
   int8_t fontFamilyOverride = -1;
   int8_t fontSizeOverride = -1;
-  bool bionicReadingOverride = false;
+  int8_t bionicReadingOverride = -1;
 
   // Remove existing entry if present
   auto it =

src/RecentBooksStore.h

@@ -17,7 +17,8 @@ struct RecentBook {
   int8_t fontFamilyOverride = -1;
   // -1 = use global setting, otherwise CrossPointSettings::FONT_SIZE value.
   int8_t fontSizeOverride = -1;
-  bool bionicReadingOverride = false;
+  // -1 = use global default, otherwise explicit per-book override (0 = off, 1 = on).
+  int8_t bionicReadingOverride = -1;
 
   bool operator==(const RecentBook& other) const { return path == other.path; }
 };

src/SettingsList.h

@@ -117,6 +117,8 @@ inline const std::vector<SettingInfo> list = {
                         StrId::STR_CAT_READER),
     SettingInfo::Toggle(StrId::STR_HYPHENATION, &CrossPointSettings::hyphenationEnabled, "hyphenationEnabled",
                         StrId::STR_CAT_READER),
+    SettingInfo::Toggle(StrId::STR_BIONIC_READING, &CrossPointSettings::bionicReading, "bionicReading",
+                        StrId::STR_CAT_READER),
     SettingInfo::Enum(StrId::STR_IMAGES, &CrossPointSettings::imageRendering,
                       {StrId::STR_IMAGES_DISPLAY, StrId::STR_IMAGES_PLACEHOLDER, StrId::STR_IMAGES_SUPPRESS},
                       "imageRendering", StrId::STR_CAT_READER),

src/activities/reader/EpubReaderActivity.cpp

@@ -191,7 +191,9 @@ void EpubReaderActivity::onEnter() {
   bookImageRenderingOverride = currentBook.imageRenderingOverride;
   bookFontFamilyOverride = currentBook.fontFamilyOverride;
   bookFontSizeOverride = currentBook.fontSizeOverride;
-  bookBionicReadingOverride = currentBook.bionicReadingOverride;
+  bookBionicReadingOverride = (currentBook.bionicReadingOverride >= 0)
+                                  ? static_cast<bool>(currentBook.bionicReadingOverride)
+                                  : static_cast<bool>(SETTINGS.bionicReading);
   logReaderMemSnapshot("onEnter_after_recent_books");
 
   // Trigger first update
@@ -1254,7 +1256,8 @@ void EpubReaderActivity::render(RenderLock&& lock) {
 
     if (!section->loadSectionFile(getEffectiveReaderFontId(), getEffectiveReaderLineCompression(),
                                   SETTINGS.extraParagraphSpacing, SETTINGS.paragraphAlignment, viewportWidth,
-                                  viewportHeight, SETTINGS.hyphenationEnabled, embeddedStyle, imageRendering)) {
+                                  viewportHeight, SETTINGS.hyphenationEnabled, embeddedStyle, bookBionicReadingOverride,
+                                  imageRendering)) {
       LOG_DBG("ERS", "Cache not found, building...");
       lastRenderStats.cacheRebuilt = true;
 
@@ -1275,8 +1278,8 @@ void EpubReaderActivity::render(RenderLock&& lock) {
       renderer.clearSdCardFontAccumulation();
       if (!section->createSectionFile(getEffectiveReaderFontId(), getEffectiveReaderLineCompression(),
                                       SETTINGS.extraParagraphSpacing, SETTINGS.paragraphAlignment, viewportWidth,
-                                      viewportHeight, SETTINGS.hyphenationEnabled, embeddedStyle, imageRendering,
+                                      viewportHeight, SETTINGS.hyphenationEnabled, embeddedStyle,
-                                      progressFn)) {
+                                      bookBionicReadingOverride, imageRendering, progressFn)) {
         LOG_ERR("ERS", "Failed to persist page data to SD");
         section.reset();
         return;
@@ -1430,7 +1433,8 @@ void EpubReaderActivity::silentIndexNextChapterIfNeeded(const uint16_t viewportW
   Section nextSection(epub, nextSpineIndex, renderer);
   if (nextSection.loadSectionFile(getEffectiveReaderFontId(), getEffectiveReaderLineCompression(),
                                   SETTINGS.extraParagraphSpacing, SETTINGS.paragraphAlignment, viewportWidth,
-                                  viewportHeight, SETTINGS.hyphenationEnabled, embeddedStyle, imageRendering)) {
+                                  viewportHeight, SETTINGS.hyphenationEnabled, embeddedStyle, bookBionicReadingOverride,
+                                  imageRendering)) {
     return;
   }
 
@@ -1439,7 +1443,8 @@ void EpubReaderActivity::silentIndexNextChapterIfNeeded(const uint16_t viewportW
   renderer.clearSdCardFontAccumulation();
   if (!nextSection.createSectionFile(getEffectiveReaderFontId(), getEffectiveReaderLineCompression(),
                                      SETTINGS.extraParagraphSpacing, SETTINGS.paragraphAlignment, viewportWidth,
-                                     viewportHeight, SETTINGS.hyphenationEnabled, embeddedStyle, imageRendering)) {
+                                     viewportHeight, SETTINGS.hyphenationEnabled, embeddedStyle,
+                                     bookBionicReadingOverride, imageRendering)) {
     LOG_ERR("ERS", "Failed silent indexing for chapter: %d", nextSpineIndex);
   }
 }
@@ -1822,12 +1827,13 @@ bool EpubReaderActivity::drawCurrentPageToBuffer(const std::string& filePath, Gf
   if (!section->loadSectionFile(getEffectiveFontId(effectiveFontFamily, effectiveFontSize), effectiveLineCompression,
                                 SETTINGS.extraParagraphSpacing, SETTINGS.paragraphAlignment, viewportWidth,
                                 viewportHeight, SETTINGS.hyphenationEnabled, SETTINGS.embeddedStyle,
-                                SETTINGS.imageRendering)) {
+                                static_cast<bool>(SETTINGS.bionicReading), SETTINGS.imageRendering)) {
     LOG_DBG("SLP", "EPUB: section cache not found for spine %d, rebuilding", spineIndex);
     if (!section->createSectionFile(getEffectiveFontId(effectiveFontFamily, effectiveFontSize),
                                     effectiveLineCompression, SETTINGS.extraParagraphSpacing,
                                     SETTINGS.paragraphAlignment, viewportWidth, viewportHeight,
-                                    SETTINGS.hyphenationEnabled, SETTINGS.embeddedStyle, SETTINGS.imageRendering)) {
+                                    SETTINGS.hyphenationEnabled, SETTINGS.embeddedStyle,
+                                    static_cast<bool>(SETTINGS.bionicReading), SETTINGS.imageRendering)) {
       LOG_ERR("SLP", "EPUB: failed to rebuild section cache for spine %d", spineIndex);
       return false;
     }