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/level/WorldServer.java b/src/main/java/net/minecraft/server/level/WorldServer.java
index 1e9884e819ac2afe58b5f50b89355c2d58ed73d5..3876958f20e675c4c8fd505c5fb333ccb9cdc8c9 100644
--- a/src/main/java/net/minecraft/server/level/WorldServer.java
+++ b/src/main/java/net/minecraft/server/level/WorldServer.java
@@ -170,7 +170,7 @@ public class WorldServer extends World implements GeneratorAccessSeed {
     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
     public final ChunkProviderServer chunkProvider; // Paper - public
     boolean tickingEntities;
     private final MinecraftServer server;
@@ -1477,12 +1477,17 @@ public class WorldServer extends World implements GeneratorAccessSeed {
     }
 
     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 4e255f2ca75ac0c1e1572f312a669cb6d3b60121..dfc3a2f6221c9e172d0d40510cb5edfc23649e53 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -2353,11 +2353,17 @@ 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