Check the presence of glyphs when selecting font

third_party/txt/src/minikin/FontCollection.cpp

@@ -509,7 +509,9 @@ void FontCollection::itemize(const uint16_t* string,
     if (!shouldContinueRun) {
       const std::shared_ptr<FontFamily>& family = getFamilyForChar(
           ch, isVariationSelector(nextCh) ? nextCh : 0, langListId, variant);
-      if (utf16Pos == 0 || family.get() != lastFamily) {
+
+      if (utf16Pos == 0 || family.get() != lastFamily ||
+          family.get()->getLastMatchedCodePoint() != ch) {
         size_t start = utf16Pos;
         // Workaround for combining marks and emoji modifiers until we implement
         // per-cluster font selection: if a combining mark or an emoji modifier
@@ -528,8 +530,8 @@ void FontCollection::itemize(const uint16_t* string,
           }
           start -= prevChLength;
         }
-        result->push_back(
-            {family->getClosestMatch(style), static_cast<int>(start), 0});
+        result->push_back({family->getClosestMatchWithChar(style, ch),
+                           static_cast<int>(start), 0});
         run = &result->back();
         lastFamily = family.get();
       }

third_party/txt/src/minikin/FontFamily.cpp

@@ -164,6 +164,46 @@ FakedFont FontFamily::getClosestMatch(FontStyle style) const {
   return FakedFont{nullptr, FontFakery()};
 }
 
+FakedFont FontFamily::getClosestMatchWithChar(FontStyle style,
+                                              uint32_t codepoint) {
+  int bestMatch = INT_MAX;
+  const Font* bestFont = nullptr;
+  if (mLastMatchedCodePoint == codepoint && style == mLastMatchedFontStyle) {
+    if (mFonts.size() > mLastMatchedFontIndex) {
+      bestFont = &mFonts[mLastMatchedFontIndex];
+      return FakedFont{bestFont->typeface.get(),
+                       computeFakery(style, bestFont->style)};
+    }
+  }
+
+  for (size_t i = 0; i < mFonts.size(); i++) {
+    const Font& font = mFonts[i];
+    int match = computeMatch(font.style, style);
+    bool result = false;
+    {
+      hb_font_t* hb_font = getHbFontLocked(font.typeface.get());
+      uint32_t unusedGlyph;
+      result = hb_font_get_glyph(hb_font, codepoint, 0, &unusedGlyph);
+      hb_font_destroy(hb_font);
+    }
+
+    if (result) {
+      if (match < bestMatch) {
+        bestFont = &font;
+        bestMatch = match;
+        mLastMatchedFontIndex = i;
+      }
+    }
+  }
+  if (bestFont != nullptr) {
+    mLastMatchedFontStyle = style;
+    mLastMatchedCodePoint = codepoint;
+    return FakedFont{bestFont->typeface.get(),
+                     computeFakery(style, bestFont->style)};
+  }
+  return FakedFont{nullptr, FontFakery()};
+}
+
 bool FontFamily::isColorEmojiFamily() const {
   const FontLanguages& languageList = FontLanguageListCache::getById(mLangId);
   for (size_t i = 0; i < languageList.size(); ++i) {

third_party/txt/src/minikin/FontFamily.h

@@ -141,6 +141,7 @@ class FontFamily {
                            int* weight,
                            bool* italic);
   FakedFont getClosestMatch(FontStyle style) const;
+  FakedFont getClosestMatchWithChar(FontStyle style, uint32_t codepoint);
 
   uint32_t langId() const { return mLangId; }
   int variant() const { return mVariant; }
@@ -173,6 +174,8 @@ class FontFamily {
   std::shared_ptr<FontFamily> createFamilyWithVariation(
       const std::vector<FontVariation>& variations) const;
 
+  uint32_t getLastMatchedCodePoint() { return mLastMatchedCodePoint; }
+
  private:
   void computeCoverage();
 
@@ -184,6 +187,10 @@ class FontFamily {
   SparseBitSet mCoverage;
   bool mHasVSTable;
 
+  uint mLastMatchedFontIndex;
+  uint32_t mLastMatchedCodePoint;
+  FontStyle mLastMatchedFontStyle;
+
   // Forbid copying and assignment.
   FontFamily(const FontFamily&) = delete;
   void operator=(const FontFamily&) = delete;

third_party/txt/src/txt/platform_linux.cc

@@ -13,6 +13,9 @@
 namespace txt {
 
 std::vector<std::string> GetDefaultFontFamilies() {
+#ifdef FLUTTER_USE_FONTCONFIG
+  return {"TizenDefaultFont"};
+#else
   return {
       "SamsungOneUI",
       "SamsungOneUIArabic",
@@ -72,11 +75,12 @@ std::vector<std::string> GetDefaultFontFamilies() {
       "BreezeSansFallback",
       "BreezeColorEmoji",
   };
+#endif
 }
 
 sk_sp<SkFontMgr> GetDefaultFontManager() {
 #ifdef FLUTTER_USE_FONTCONFIG
-  return SkFontMgr_New_FontConfig(nullptr);
+  return SkFontMgr::RefDefault();
 #else
   return SkFontMgr_New_Custom_Directory("/usr/share/fonts");
 #endif