From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Fri, 29 Apr 2016 20:02:00 -0400
Subject: [PATCH] Improve Maps (in item frames) performance and bug fixes

Maps used a modified version of rendering to support plugin controlled
imaging on maps. The Craft Map Renderer is much slower than Vanilla,
causing maps in item frames to cause a noticeable hit on server performance.

This updates the map system to not use the Craft system if we detect that no
custom renderers are in use, defaulting to the much simpler Vanilla system.

Additionally, numerous issues to player position tracking on maps has been fixed.

diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
index afc1639c96c01197c6c11873fcd5d779e4ed93a9..7106f388aed2ef2ce14a2228eb85b51092cb983d 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -2582,6 +2582,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
                             {
                                 if ( iter.next().player == entity )
                                 {
+                                    map.decorations.remove(entity.getName().getString()); // Paper
                                     iter.remove();
                                 }
                             }
diff --git a/src/main/java/net/minecraft/world/entity/player/Player.java b/src/main/java/net/minecraft/world/entity/player/Player.java
index 70d225dbf5649e6a3fa658291de734f54a6f73dc..72b3e64cf6d184e90a6e2c0d822b83312312d67d 100644
--- a/src/main/java/net/minecraft/world/entity/player/Player.java
+++ b/src/main/java/net/minecraft/world/entity/player/Player.java
@@ -789,6 +789,14 @@ public abstract class Player extends LivingEntity {
                 return null;
             }
             // CraftBukkit end
+            // Paper start - remove player from map on drop
+            if (itemstack.getItem() == Items.FILLED_MAP) {
+                net.minecraft.world.level.saveddata.maps.MapItemSavedData worldmap = net.minecraft.world.item.MapItem.getSavedData(itemstack, this.level());
+                if (worldmap != null) {
+                    worldmap.tickCarriedBy(this, itemstack);
+                }
+            }
+            // Paper end
 
             return entityitem;
         }
diff --git a/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java b/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
index ad24a79e190d07c75d8e29e816fc398894771c2c..cf8ae635fce7ea66d4e1ab1dc05575f035fa95ef 100644
--- a/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
+++ b/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
@@ -78,6 +78,7 @@ public class MapItemSavedData extends SavedData {
     public final Map<String, MapDecoration> decorations = Maps.newLinkedHashMap();
     private final Map<String, MapFrame> frameMarkers = Maps.newHashMap();
     private int trackedDecorationCount;
+    private org.bukkit.craftbukkit.map.RenderData vanillaRender = new org.bukkit.craftbukkit.map.RenderData(); // Paper
 
     // CraftBukkit start
     public final CraftMapView mapView;
@@ -104,6 +105,7 @@ public class MapItemSavedData extends SavedData {
         // CraftBukkit start
         this.mapView = new CraftMapView(this);
         this.server = (CraftServer) org.bukkit.Bukkit.getServer();
+        this.vanillaRender.buffer = colors; // Paper
         // CraftBukkit end
     }
 
@@ -178,6 +180,7 @@ public class MapItemSavedData extends SavedData {
         if (abyte.length == 16384) {
             worldmap.colors = abyte;
         }
+        worldmap.vanillaRender.buffer = abyte; // Paper
 
         RegistryOps<Tag> registryops = registryLookup.createSerializationContext(NbtOps.INSTANCE);
         List<MapBanner> list = (List) MapBanner.LIST_CODEC.parse(registryops, nbt.get("banners")).resultOrPartial((s) -> {
@@ -583,6 +586,21 @@ public class MapItemSavedData extends SavedData {
 
     public class HoldingPlayer {
 
+        // Paper start
+        private void addSeenPlayers(java.util.Collection<MapDecoration> icons) {
+            org.bukkit.entity.Player player = (org.bukkit.entity.Player) this.player.getBukkitEntity();
+            MapItemSavedData.this.decorations.forEach((name, mapIcon) -> {
+                // If this cursor is for a player check visibility with vanish system
+                org.bukkit.entity.Player other = org.bukkit.Bukkit.getPlayerExact(name); // Spigot
+                if (other == null || player.canSee(other)) {
+                    icons.add(mapIcon);
+                }
+            });
+        }
+        private boolean shouldUseVanillaMap() {
+            return mapView.getRenderers().size() == 1 && mapView.getRenderers().get(0).getClass() == org.bukkit.craftbukkit.map.CraftMapRenderer.class;
+        }
+        // Paper end
         public final Player player;
         private boolean dirtyData = true;
         private int minDirtyX;
@@ -616,7 +634,9 @@ public class MapItemSavedData extends SavedData {
         @Nullable
         Packet<?> nextUpdatePacket(MapId mapId) {
             MapItemSavedData.MapPatch worldmap_b;
-            org.bukkit.craftbukkit.map.RenderData render = MapItemSavedData.this.mapView.render((org.bukkit.craftbukkit.entity.CraftPlayer) this.player.getBukkitEntity()); // CraftBukkit
+            if (!this.dirtyData && this.tick % 5 != 0) { this.tick++; return null; } // Paper - this won't end up sending, so don't render it!
+            boolean vanillaMaps = shouldUseVanillaMap(); // Paper
+            org.bukkit.craftbukkit.map.RenderData render = !vanillaMaps ? MapItemSavedData.this.mapView.render((org.bukkit.craftbukkit.entity.CraftPlayer) this.player.getBukkitEntity()) : MapItemSavedData.this.vanillaRender; // CraftBukkit // Paper
 
             if (this.dirtyData) {
                 this.dirtyData = false;
@@ -632,6 +652,8 @@ public class MapItemSavedData extends SavedData {
                 // CraftBukkit start
                 java.util.Collection<MapDecoration> icons = new java.util.ArrayList<MapDecoration>();
 
+                if (vanillaMaps) addSeenPlayers(icons); // Paper
+
                 for (org.bukkit.map.MapCursor cursor : render.cursors) {
                     if (cursor.isVisible()) {
                         icons.add(new MapDecoration(CraftMapCursor.CraftType.bukkitToMinecraftHolder(cursor.getType()), cursor.getX(), cursor.getY(), cursor.getDirection(), Optional.ofNullable(PaperAdventure.asVanilla(cursor.caption()))));
diff --git a/src/main/java/org/bukkit/craftbukkit/map/RenderData.java b/src/main/java/org/bukkit/craftbukkit/map/RenderData.java
index 256a131781721c86dd6cdbc329335964570cbe8c..5768cd512ec166f1e8d1f4a28792015347297c3f 100644
--- a/src/main/java/org/bukkit/craftbukkit/map/RenderData.java
+++ b/src/main/java/org/bukkit/craftbukkit/map/RenderData.java
@@ -5,7 +5,7 @@ import org.bukkit.map.MapCursor;
 
 public class RenderData {
 
-    public final byte[] buffer;
+    public byte[] buffer; // Paper
     public final ArrayList<MapCursor> cursors;
 
     public RenderData() {