From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Tue, 15 Aug 2017 22:29:12 -0400
Subject: [PATCH] Expand World.spawnParticle API and add Builder

Adds ability to control who receives it and who is the source/sender (vanish API)
the standard API is to send the packet to everyone in the world, which is ineffecient.
Adds an option to control the force mode of the particle.

This adds a new Builder API which is much friendlier to use.

diff --git a/src/main/java/net/minecraft/server/WorldServer.java b/src/main/java/net/minecraft/server/WorldServer.java
index e428b3cb8c8ca5a662a0e867bf74d08775f1bacd..a834a77b2de8f7287be69fd5d002ff43261a9a85 100644
--- a/src/main/java/net/minecraft/server/WorldServer.java
+++ b/src/main/java/net/minecraft/server/WorldServer.java
@@ -56,7 +56,7 @@ public class WorldServer extends World {
     public final Int2ObjectMap<Entity> entitiesById = new Int2ObjectLinkedOpenHashMap();
     private final Map<UUID, Entity> entitiesByUUID = Maps.newHashMap();
     private final Queue<Entity> entitiesToAdd = Queues.newArrayDeque();
-    private final List<EntityPlayer> players = Lists.newArrayList();
+    public final List<EntityPlayer> players = Lists.newArrayList(); // Paper - private -> public
     boolean tickingEntities;
     private final MinecraftServer server;
     private final WorldNBTStorage dataManager;
@@ -1392,12 +1392,17 @@ public class WorldServer extends World {
     }
 
     public <T extends ParticleParam> int sendParticles(EntityPlayer sender, T t0, double d0, double d1, double d2, int i, double d3, double d4, double d5, double d6, boolean force) {
+        // Paper start - Particle API Expansion
+        return sendParticles(players, sender, t0, d0, d1, d2, i, d3, d4, d5, d6, force);
+    }
+    public <T extends ParticleParam> int sendParticles(List<EntityPlayer> receivers, EntityPlayer sender, T t0, double d0, double d1, double d2, int i, double d3, double d4, double d5, double d6, boolean force) {
+        // Paper end
         PacketPlayOutWorldParticles packetplayoutworldparticles = new PacketPlayOutWorldParticles(t0, force, d0, d1, d2, (float) d3, (float) d4, (float) d5, (float) d6, i);
         // CraftBukkit end
         int j = 0;
 
-        for (int k = 0; k < this.players.size(); ++k) {
-            EntityPlayer entityplayer = (EntityPlayer) this.players.get(k);
+        for (EntityHuman entityhuman : receivers) { // Paper - Particle API Expansion
+            EntityPlayer entityplayer = (EntityPlayer) entityhuman; // Paper - Particle API Expansion
             if (sender != null && !entityplayer.getBukkitEntity().canSee(sender.getBukkitEntity())) continue; // CraftBukkit
 
             if (this.a(entityplayer, force, d0, d1, d2, packetplayoutworldparticles)) { // CraftBukkit
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
index 13a83f285126123811a148453ccaea6f9bf197b4..1a3ca48485ebce128ae1288e6a50308c76ee0452 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -2287,11 +2287,17 @@ public class CraftWorld implements World {
 
     @Override
     public <T> void spawnParticle(Particle particle, double x, double y, double z, int count, double offsetX, double offsetY, double offsetZ, double extra, T data, boolean force) {
+        // Paper start - Particle API Expansion
+        spawnParticle(particle, null, null, x, y, z, count, offsetX, offsetY, offsetZ, extra, data, force);
+    }
+    public <T> void spawnParticle(Particle particle, List<Player> receivers, Player sender, double x, double y, double z, int count, double offsetX, double offsetY, double offsetZ, double extra, T data, boolean force) {
+        // Paper end
         if (data != null && !particle.getDataType().isInstance(data)) {
             throw new IllegalArgumentException("data should be " + particle.getDataType() + " got " + data.getClass());
         }
         getHandle().sendParticles(
-                null, // Sender
+                receivers == null ? getHandle().players : receivers.stream().map(player -> ((CraftPlayer) player).getHandle()).collect(java.util.stream.Collectors.toList()), // Paper -  Particle API Expansion
+                sender != null ? ((CraftPlayer) sender).getHandle() : null, // Sender // Paper - Particle API Expansion
                 CraftParticle.toNMS(particle, data), // Particle
                 x, y, z, // Position
                 count,  // Count