From 9a8ea2f1d45b9214b727ec7f95af856b3f92c8de Mon Sep 17 00:00:00 2001
From: Lixfel <agga-games@gmx.de>
Date: Mon, 7 Sep 2020 11:52:02 +0200
Subject: [PATCH] Prevent thread stacking with syncing up

Sending mbc-Packet sync takes now around 0-2ms, so its okeyish

Signed-off-by: Lixfel <agga-games@gmx.de>
---
 .../fightsystem/utils/TechHider_15.java       | 40 ++++++++++---------
 1 file changed, 21 insertions(+), 19 deletions(-)

diff --git a/FightSystem_15/src/de/steamwar/fightsystem/utils/TechHider_15.java b/FightSystem_15/src/de/steamwar/fightsystem/utils/TechHider_15.java
index 04f0c1d..1e2d231 100644
--- a/FightSystem_15/src/de/steamwar/fightsystem/utils/TechHider_15.java
+++ b/FightSystem_15/src/de/steamwar/fightsystem/utils/TechHider_15.java
@@ -34,11 +34,13 @@ import de.steamwar.fightsystem.Config;
 import de.steamwar.fightsystem.IFightSystem;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.UnpooledByteBufAllocator;
+import net.minecraft.server.v1_15_R1.Block;
+import net.minecraft.server.v1_15_R1.ChunkSection;
 import net.minecraft.server.v1_15_R1.PacketPlayOutMapChunk;
 import org.bukkit.Bukkit;
-import org.bukkit.Location;
 import org.bukkit.World;
 import org.bukkit.craftbukkit.v1_15_R1.CraftChunk;
+import org.bukkit.craftbukkit.v1_15_R1.CraftWorld;
 import org.bukkit.craftbukkit.v1_15_R1.entity.CraftPlayer;
 import org.bukkit.entity.Player;
 
@@ -211,7 +213,7 @@ public class TechHider_15 {
                         }*/
 
                         final int cY = chunkY;
-                        Bukkit.getScheduler().runTaskAsynchronously(IFightSystem.getPlugin(),
+                        Bukkit.getScheduler().runTask(IFightSystem.getPlugin(),
                                 () -> fullChunkHider(p, chunkX, cY, chunkZ));
                     }
 
@@ -230,38 +232,38 @@ public class TechHider_15 {
     }
 
     private static void fullChunkHider(Player player, int chunkX, int chunkY, int chunkZ){
-        ArrayList<MultiBlockChangeInfo> blockChangeList = new ArrayList<>();
+        if(!player.isOnline())
+            return;
 
-        Location location = new Location(WORLD, chunkX * 16f, chunkY * 16f, chunkZ * 16f);
-        int maxXp1 = (chunkX+1) * 16;
-        int maxYp1 = (chunkY+1) * 16;
-        int maxZp1 = (chunkZ+1) * 16;
-        while(location.getBlockX() < maxXp1){
-            while(location.getBlockY() < maxYp1){
-                while(location.getBlockZ() < maxZp1){
-                    if(Config.HiddenBlockTags.contains(WORLD.getBlockAt(location).getType().name()))
-                        blockChangeList.add(new MultiBlockChangeInfo(location, WRAPPED_BLOCK_DATA));
-                    location.setZ(location.getZ() + 1);
+        ArrayList<MultiBlockChangeInfo> blockChangeList = new ArrayList<>();
+        ChunkCoordIntPair chunkCoords = new ChunkCoordIntPair(chunkX, chunkZ);
+        ChunkSection chunk = ((CraftWorld) WORLD).getHandle().getChunkAt(chunkX, chunkZ).getSections()[chunkY]; //This takes ~70ms async.
+        if(ChunkSection.a(chunk))
+            return;
+
+        int minY = chunkY * 16;
+        for(int x = 0; x < 16; x++){
+            for(int y = 0; y < 16; y++){
+                for(int z = 0; z < 16; z++){
+                    if(Config.HiddenBlocks.contains(Block.REGISTRY_ID.getId(chunk.getType(x, y, z))))
+                        blockChangeList.add(new MultiBlockChangeInfo((short)(x << 12 | z << 8 | (y + minY)), WRAPPED_BLOCK_DATA, chunkCoords));
                 }
-                location.setY(location.getY() + 1);
-                location.setZ(chunkZ * 16f);
             }
-            location.setX(location.getX() + 1);
-            location.setY(chunkY * 16f);
-            location.setZ(chunkZ * 16f);
         }
 
         if(blockChangeList.isEmpty())
             return;
 
         PacketContainer packet = ProtocolLibrary.getProtocolManager().createPacket(PacketType.Play.Server.MULTI_BLOCK_CHANGE);
-        packet.getChunkCoordIntPairs().write(0, new ChunkCoordIntPair(chunkX, chunkZ));
+        packet.getChunkCoordIntPairs().write(0, chunkCoords);
         packet.getMultiBlockChangeInfoArrays().write(0, blockChangeList.toArray(new MultiBlockChangeInfo[0]));
 
         try {
             ProtocolLibrary.getProtocolManager().sendServerPacket(player, packet, false);
         } catch (InvocationTargetException e) {
             throw new SecurityException("Something went wrong sending the multiblockchange packet", e);
+        } catch (NullPointerException e){
+            //ignored, player offline
         }
     }
 }