Some review comments

src/SdCardFontSystem.cpp

@@ -120,15 +120,8 @@ void SdCardFontSystem::ensureLoaded(GfxRenderer& renderer) {
       SETTINGS.sdFontFamilyName[0] = '\0';
       return;
     }
-    uint8_t bestPt = 0;
-    int bestDiff = INT32_MAX;
-    for (const auto& f : family->files) {
-      int diff = abs(static_cast<int>(f.pointSize) - static_cast<int>(targetPt));
-      if (diff < bestDiff) {
-        bestDiff = diff;
-        bestPt = f.pointSize;
-      }
-    }
+    const auto* best = family->pickClosestSize(targetPt);
+    const uint8_t bestPt = best ? best->pointSize : 0;
     if (bestPt == manager_.currentPointSize()) return;  // already loaded with the right size
     LOG_DBG("SDFS", "Reloading %s: size %u -> %u (target %u)", wantedFamily, manager_.currentPointSize(), bestPt,
             targetPt);

src/activities/reader/EpubReaderMenuActivity.cpp

@@ -5,10 +5,31 @@
 
 #include "KOReaderCredentialStore.h"
 #include "MappedInputManager.h"
+#include "SdCardFontGlobals.h"
 #include "activities/settings/SettingsSubmenuActivity.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
 
+namespace {
+// Returns the localized name of the family currently used as the global default
+// for the reader. When the user has selected an SD card font globally, the
+// override menu's "Default" label should reflect that family by name even
+// though the per-book override list itself is built-in only.
+std::string defaultFontFamilyLabel(const SettingInfo& item) {
+  if (SETTINGS.sdFontFamilyName[0] != '\0') {
+    return std::string(SETTINGS.sdFontFamilyName);
+  }
+  // Built-in: enumValues[0] is STR_DEFAULT_VALUE, [1..3] are the three families
+  // in the same order as CrossPointSettings::FONT_FAMILY (BOOKERLY, NOTOSANS,
+  // OPENDYSLEXIC).
+  const auto idx = static_cast<size_t>(SETTINGS.fontFamily + 1);
+  if (idx < item.enumValues.size()) {
+    return I18N.get(item.enumValues[idx]);
+  }
+  return {};
+}
+}  // namespace
+
 EpubReaderMenuActivity::EpubReaderMenuActivity(GfxRenderer& renderer, MappedInputManager& mappedInput,
                                                const std::string& title, const int currentPage, const int totalPages,
                                                const int bookProgressPercent, const uint8_t currentOrientation,
@@ -290,9 +311,9 @@ std::string EpubReaderMenuActivity::getItemValueString(int index) const {
       }
     }
     if (item.nameId == StrId::STR_FONT_FAMILY && pendingFontFamilyOverride < 0) {
-      const auto defaultIndex = static_cast<size_t>(SETTINGS.fontFamily + 1);
-      if (defaultIndex < item.enumValues.size()) {
-        return std::string(tr(STR_DEFAULT_VALUE)) + " (" + I18N.get(item.enumValues[defaultIndex]) + ")";
+      const auto label = defaultFontFamilyLabel(item);
+      if (!label.empty()) {
+        return std::string(tr(STR_DEFAULT_VALUE)) + " (" + label + ")";
       }
     }
     if (item.nameId == StrId::STR_FONT_SIZE && pendingFontSizeOverride < 0) {
@@ -324,9 +345,9 @@ void EpubReaderMenuActivity::openSubmenu(const SettingInfo& submenuEntry) {
       }
     }
     if (item.nameId == StrId::STR_FONT_FAMILY && pendingFontFamilyOverride < 0) {
-      const auto valueIndex = static_cast<size_t>(SETTINGS.fontFamily + 1);
-      if (valueIndex < item.enumValues.size()) {
-        return std::string(tr(STR_DEFAULT_VALUE)) + " (" + I18N.get(item.enumValues[valueIndex]) + ")";
+      const auto label = defaultFontFamilyLabel(item);
+      if (!label.empty()) {
+        return std::string(tr(STR_DEFAULT_VALUE)) + " (" + label + ")";
       }
     }
     if (item.nameId == StrId::STR_FONT_SIZE && pendingFontSizeOverride < 0) {