Fix some stuff and make it more ugly

BauSystem_Main/src/de/steamwar/bausystem/features/tracer/Trace.java

@@ -159,7 +159,7 @@ public class Trace { // TODO: Add UUID for file saving and so on!
     private void render(List<TNTPoint> records, REntityServer entityServer, PlayerTraceShowData playerTraceShowData) {
         if (records.isEmpty()) return;
 
-        List<TNTPoint> workingRecords = records;
+        List<TNTPoint> workingRecords = new ArrayList<>(records);
         Set<ViewFlag> flagList = playerTraceShowData.getEffectiveViewFlags();
 
         //Apply filters

BauSystem_Main/src/de/steamwar/bausystem/features/tracer/TraceManager.java

@@ -194,6 +194,10 @@ public class TraceManager implements Listener {
 
     public boolean follow(Player follower, Player following) {
         if (followerMap.containsKey(follower)) return false;
+        if (followerMap.entrySet().stream().anyMatch(playerSetEntry -> playerSetEntry.getValue().contains(follower))) {
+            unfollow(follower);
+        }
+
         followerMap.computeIfAbsent(following, ignored -> new HashSet<>()).add(follower);
 
         showDataPerRegionPerPlayer.forEach((region, playerPlayerTraceShowDataMap) -> {
@@ -215,13 +219,21 @@ public class TraceManager implements Listener {
     public void unfollow(Player follower) {
         if (followerMap.containsKey(follower)) return;
         List<Player> toRemove = new ArrayList<>();
+        Set<Player> toHide = new HashSet<>();
         followerMap.forEach((player, players) -> {
-            players.remove(player);
+            if (players.remove(follower)) toHide.add(follower);
             if (players.isEmpty()) toRemove.add(player);
         });
         toRemove.forEach(followerMap::remove);
 
         showDataPerRegionPerPlayer.forEach((region, playerPlayerTraceShowDataMap) -> {
+            toHide.forEach(player -> {
+                if (!playerPlayerTraceShowDataMap.containsKey(player)) return;
+                tracesByRegion.getOrDefault(region, Collections.emptyMap()).forEach((integer, trace) -> {
+                    trace.hide(follower);
+                });
+            });
+
             PlayerTraceShowData playerTraceShowData = playerPlayerTraceShowDataMap.get(follower);
             if (playerTraceShowData == null) return;
             tracesByRegion.getOrDefault(region, Collections.emptyMap()).forEach((integer, trace) -> {

BauSystem_Main/src/de/steamwar/bausystem/features/tracer/rendering/TraceEntity.java

@@ -19,18 +19,24 @@
 
 package de.steamwar.bausystem.features.tracer.rendering;
 
+import com.comphenix.tinyprotocol.Reflection;
 import de.steamwar.bausystem.BauSystem;
 import de.steamwar.bausystem.features.tracer.TNTPoint;
+import de.steamwar.core.Core;
+import de.steamwar.entity.REntity;
 import de.steamwar.entity.REntityServer;
-import de.steamwar.entity.RFallingBlockEntity;
+import de.steamwar.techhider.BlockIds;
 import lombok.Getter;
 import org.bukkit.Location;
 import org.bukkit.Material;
+import org.bukkit.entity.EntityType;
 import org.bukkit.entity.Player;
 
 import java.util.List;
 
-public class TraceEntity extends RFallingBlockEntity {
+public class TraceEntity extends REntity {
+
+    private static final Reflection.MethodInvoker addEntityMethod = Reflection.getMethod(REntityServer.class, "addEntity", REntity.class);
 
     /**
      * The records represented by this REntity
@@ -39,9 +45,10 @@ public class TraceEntity extends RFallingBlockEntity {
     private final List<TNTPoint> records;
 
     public TraceEntity(REntityServer server, Location location, boolean isExplosion, List<TNTPoint> records) {
-        super(server, location, isExplosion ? Material.RED_STAINED_GLASS : Material.TNT);
+        super(server, EntityType.FALLING_BLOCK, location, BlockIds.impl.materialToId(isExplosion ? Material.RED_STAINED_GLASS : Material.TNT) >> (Core.getVersion() <= 12 ? 4 : 0));
         setNoGravity(true);
         this.records = records;
+        addEntityMethod.invoke(server, this);
     }
 
     public void printIntoChat(Player player) {