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 376443dfc846f7511c60125cb7714757d15590ea..81eb2d57045dd9d692109b33fc10804ff3d68d54 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -2496,6 +2496,7 @@ public class ServerLevel extends Level implements WorldGenLevel, ca.spottedleaf.
                             {
                                 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 d0b51d96d6795b5fa03bc195b90324680545b752..09bcbc0ae36e4e69fee87a7e0c49acf496117a39 100644
--- a/src/main/java/net/minecraft/world/entity/player/Player.java
+++ b/src/main/java/net/minecraft/world/entity/player/Player.java
@@ -808,6 +808,14 @@ 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 a43544704109f21bab230dd9bf0401e28f878582..6794466051dd4b725d579b2136c37844995a648e 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
@@ -79,6 +79,7 @@ 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;
@@ -105,6 +106,7 @@ 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
     }
 
@@ -179,6 +181,7 @@ 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) -> {
@@ -348,7 +351,7 @@ public class MapItemSavedData extends SavedData {
             --this.trackedDecorationCount;
         }
 
-        this.setDecorationsDirty();
+        if (mapicon != null) this.setDecorationsDirty(); // Paper - only mark dirty if a change occurs
     }
 
     public static void addTargetDecoration(ItemStack stack, BlockPos pos, String id, Holder<MapDecorationType> decorationType) {
@@ -588,6 +591,21 @@ 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;
@@ -621,7 +639,9 @@ 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;
@@ -637,6 +657,8 @@ 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() {