Backup: Stable state with EPUB reader fixes (Freeze, OOM, Speed, State, Tooling)

lib/EpdFont/CustomEpdFont.h

@@ -0,0 +1,50 @@
+#pragma once
+
+#include <SDCardManager.h>
+
+#include <vector>
+
+#include "EpdFont.h"
+
+struct BitmapCacheEntry {
+  uint32_t codePoint = 0;
+  uint32_t lastAccess = 0;
+  uint8_t* data = nullptr;
+  uint16_t size = 0;
+};
+
+struct GlyphStructCacheEntry {
+  uint32_t codePoint = 0xFFFFFFFF;  // Invalid initial value
+  uint32_t lastAccess = 0;
+  EpdGlyph glyph;
+};
+
+class CustomEpdFont : public EpdFont {
+ public:
+  CustomEpdFont(const String& filePath, const EpdFontData* data, uint32_t offsetIntervals, uint32_t offsetGlyphs,
+                uint32_t offsetBitmaps);
+  ~CustomEpdFont() override;
+
+  const EpdGlyph* getGlyph(uint32_t cp, const EpdFontStyles::Style style = EpdFontStyles::REGULAR) const override;
+  const uint8_t* loadGlyphBitmap(const EpdGlyph* glyph, uint8_t* buffer,
+                                 const EpdFontStyles::Style style = EpdFontStyles::REGULAR) const override;
+
+ private:
+  String filePath;
+  mutable FsFile fontFile;
+  uint32_t offsetIntervals;
+  uint32_t offsetGlyphs;
+  uint32_t offsetBitmaps;
+
+  // Bitmap Cache (Pixel data)
+  static constexpr size_t BITMAP_CACHE_CAPACITY = 10;
+  mutable BitmapCacheEntry bitmapCache[BITMAP_CACHE_CAPACITY];
+
+  // Glyph Struct Cache (Metadata)
+  static constexpr size_t GLYPH_CACHE_CAPACITY = 200;
+  mutable GlyphStructCacheEntry glyphCache[GLYPH_CACHE_CAPACITY];
+
+  mutable uint32_t currentAccessCount = 0;
+
+  void clearCache() const;
+};