feat: add RTL support in epub and txt readers (#1700)

Co-authored-by: Zach Nelson <zach@zdnelson.com>

lib/Epub/Epub/ParsedText.h

@@ -21,8 +21,17 @@ class ParsedText {
   bool extraParagraphSpacing;
   bool hyphenationEnabled;
   bool focusReadingEnabled;
+  bool isNaturalAlign;
+  bool hasRtlWord;
+  std::vector<std::string> reorderedWordsScratch;
+  std::vector<EpdFontFamily::Style> reorderedStylesScratch;
+  std::vector<uint16_t> reorderedWidthsScratch;
+  std::vector<bool> reorderedContinuesScratch;
+  std::vector<bool> reorderedFocusSuffixScratch;
+  std::vector<uint16_t> visualOrderScratch;
 
   void applyParagraphIndent();
+  int resolveFirstLineIndent(bool isFirstLine) const;
   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,
@@ -41,7 +50,9 @@ class ParsedText {
       : blockStyle(blockStyle),
         extraParagraphSpacing(extraParagraphSpacing),
         hyphenationEnabled(hyphenationEnabled),
-        focusReadingEnabled(focusReadingEnabled) {}
+        focusReadingEnabled(focusReadingEnabled),
+        isNaturalAlign(false),
+        hasRtlWord(false) {}
   ~ParsedText() = default;
 
   void addWord(std::string word, EpdFontFamily::Style fontStyle, bool underline = false, bool attachToPrevious = false);
@@ -52,4 +63,4 @@ class ParsedText {
   void layoutAndExtractLines(const GfxRenderer& renderer, int fontId, uint16_t viewportWidth,
                              const std::function<void(std::shared_ptr<TextBlock>)>& processLine,
                              bool includeLastLine = true);
-};
+};