fix ios fallback font render bug

modules/skunicode/include/SkUnicode.h

@@ -150,6 +150,9 @@ class SKUNICODE_API SkUnicode {
         static SkString convertUtf16ToUtf8(const std::u16string& utf16);
         static std::u16string convertUtf8ToUtf16(const char* utf8, int utf8Units);
         static std::u16string convertUtf8ToUtf16(const SkString& utf8);
+        static bool isEmoji(SkUnichar utf8);
+        static bool isEmojiModifier(SkUnichar utf8);
+        static bool isEmojiBase(SkUnichar utf8);
 
         template <typename Appender8, typename Appender16>
         bool extractUtfConversionMapping(SkSpan<const char> utf8, Appender8&& appender8, Appender16&& appender16) {

modules/skunicode/src/SkUnicode_icu.cpp

@@ -564,6 +564,18 @@ class SkUnicode_icu : public SkUnicode {
     }
 };
 
+bool SkUnicode::isEmoji(SkUnichar utf8) {
+    return sk_u_hasBinaryProperty(utf8, UCHAR_EMOJI);
+}
+
+bool SkUnicode::isEmojiModifier(SkUnichar utf8) {
+    return sk_u_hasBinaryProperty(utf8, UCHAR_EMOJI_MODIFIER);
+}
+
+bool SkUnicode::isEmojiBase(SkUnichar utf8) {
+    return sk_u_hasBinaryProperty(utf8, UCHAR_EMOJI_MODIFIER_BASE);
+}
+
 std::unique_ptr<SkUnicode> SkUnicode::Make() {
     #if defined(SK_USING_THIRD_PARTY_ICU)
     if (!SkLoadICU()) {

modules/skunicode/src/SkUnicode_icu.h

@@ -24,6 +24,7 @@
     SKICU_FUNC(u_iscntrl)             \
     SKICU_FUNC(u_isspace)             \
     SKICU_FUNC(u_isWhitespace)        \
+    SKICU_FUNC(u_hasBinaryProperty)   \
     SKICU_FUNC(u_strToUpper)          \
     SKICU_FUNC(ubidi_close)           \
     SKICU_FUNC(ubidi_getDirection)    \

src/ports/SkFontMgr_mac_ct.cpp

@@ -18,6 +18,7 @@
 #include <CoreGraphics/CoreGraphics.h>
 #include <CoreFoundation/CoreFoundation.h>
 #include <dlfcn.h>
+#include "modules/skunicode/include/SkUnicode.h"
 #endif
 
 #include "include/core/SkData.h"
@@ -507,6 +508,14 @@ class SkFontMgr_Mac : public SkFontMgr {
         if (!string) {
             return nullptr;
         }
+#ifdef SK_BUILD_FOR_IOS
+        if (familyName == NULL && SkUnicode::isEmoji(character)) {
+            CFStringRef fontName = CFSTR("Apple Color Emoji");
+            CGFloat fontSize =16;
+            SkUniqueCFRef<CTFontRef> ret(CTFontCreateWithName(fontName, fontSize, NULL));
+            return SkTypeface_Mac::Make(std::move(ret), OpszVariation(), nullptr).release();
+        }
+#endif
         CFRange range = CFRangeMake(0, CFStringGetLength(string.get()));  // in UniChar units.
         SkUniqueCFRef<CTFontRef> fallbackFont(
                 CTFontCreateForString(familyFont.get(), string.get(), range));