Merge pull request #670 from emminizer/four-byte-utf8

osgText::String:createUTF8EncodedString() now supports 4-byte UTF-8 strings (code points over 0x100000)

src/osgText/String.cpp

@@ -312,12 +312,19 @@ std::string String::createUTF8EncodedString() const
             utf8string+=(char)(0xc0 | (currentChar>>6));
             utf8string+=(char)(0x80 | (currentChar & 0x3f));
         }
-        else
+        else if (currentChar < 0x10000)
         {
             utf8string+=(char)(0xe0 | (currentChar>>12));
             utf8string+=(char)(0x80 | ((currentChar>>6) & 0x3f));
             utf8string+=(char)(0x80 | (currentChar & 0x3f));
         }
+        else
+        {
+            utf8string+=(char)(0xf0 | (currentChar >> 18));
+            utf8string+=(char)(0x80 | ((currentChar >> 12) & 0x3f));
+            utf8string+=(char)(0x80 | ((currentChar >> 6) & 0x3f));
+            utf8string+=(char)(0x80 | (currentChar & 0x3f));
+        }
     }
     return utf8string;
 }