disable chat heads when it find custom characters used for head in vanilla clients

Author: Fourmisain

common/src/main/java/dzwdz/chat_heads/ChatHeads.java

@@ -76,6 +76,7 @@ public class ChatHeads {
     public static float lastOpacity = 0.0f;
     public static int lastChatOffset;
     public static boolean serverSentUuid = false;
+    public static boolean serverSentCustomCharacter = false;
 
     public static final Set<ResourceLocation> blendedHeadTextures = new HashSet<>();
 
@@ -92,6 +93,19 @@ public static void resetLineOwner() {
     }
 
     public static void handleAddedMessage(Component message, @Nullable ChatType.Bound bound, @Nullable PlayerInfo playerInfo) {
+        if (!ChatHeads.serverSentCustomCharacter) {
+            Component sender = getSenderDecoration(bound);
+            if (sender != null && containsCustomCharacters(sender) || containsCustomCharacters(message)) {
+                ChatHeads.serverSentCustomCharacter = true;
+            }
+        }
+
+        // TODO check assets
+        if (ChatHeads.serverSentCustomCharacter) {
+            ChatHeads.lastSender = null;
+            return;
+        }
+
         if (ChatHeads.CONFIG.senderDetection() != HEURISTIC_ONLY) {
             if (playerInfo != null) {
                 ChatHeads.lastSender = playerInfo;
@@ -182,6 +196,11 @@ private static PlayerInfo getPlayerInfo(String name, ClientPacketListener connec
         return getPlayerFromNickname(name, connection, nicknameCache);
     }
 
+    public static boolean containsCustomCharacters(Component component) {
+        // characters \uE000-\uE007 are used for drawing heads in vanilla clients via a custom font
+        return component.getString().codePoints().filter(c -> '\uE000' <= c && c <= '\uE007').findAny().isPresent();
+    }
+
     /**
      * Finds a value v in `collection` such that `keyFunction(v)` equals `key`.
      * Uses an (initially empty) cache to speed up subsequent calls.

common/src/main/java/dzwdz/chat_heads/mixin/MinecraftMixin.java

@@ -14,5 +14,6 @@ public abstract class MinecraftMixin {
 	public void chatheads$resetServerKnowledge(ClientLevel clientLevel, CallbackInfo ci) {
 		// reset every time we enter a world, be it singleplayer or multiplayer
 		ChatHeads.serverSentUuid = false;
+		ChatHeads.serverSentCustomCharacter = false;
 	}
 }