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/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
index f31d403420294f479e116013b200ea7e87ac901e..82947c9743433df9c03732e0a3229563de0ab53c 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -1510,12 +1510,17 @@ public class ServerLevel extends Level implements WorldGenLevel {
     }
 
     public <T extends ParticleOptions> int sendParticles(ServerPlayer 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
+        return sendParticles(players, sender, t0, d0, d1, d2, i, d3, d4, d5, d6, force);
+    }
+    public <T extends ParticleOptions> int sendParticles(List<ServerPlayer> receivers, @Nullable ServerPlayer sender, T t0, double d0, double d1, double d2, int i, double d3, double d4, double d5, double d6, boolean force) {
+        // Paper end - Particle API
         ClientboundLevelParticlesPacket packetplayoutworldparticles = new ClientboundLevelParticlesPacket(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) {
-            ServerPlayer entityplayer = (ServerPlayer) this.players.get(k);
+        for (Player entityhuman : receivers) { // Paper - Particle API
+            ServerPlayer entityplayer = (ServerPlayer) entityhuman; // Paper - Particle API
             if (sender != null && !entityplayer.getBukkitEntity().canSee(sender.getBukkitEntity())) continue; // CraftBukkit
 
             if (this.sendParticles(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 8fea8bc0117b5b9ebff1979a73783446b7afe228..6bca713e3cc3d63ec69b06cb7ec1820dd61cd88f 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -1982,8 +1982,19 @@ public class CraftWorld extends CraftRegionAccessor 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
+        this.spawnParticle(particle, null, null, x, y, z, count, offsetX, offsetY, offsetZ, extra, data, force);
+    }
+    @Override
+    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 - Particle API
+        data = CraftParticle.convertLegacy(data);
+        if (data != null) {
+            Preconditions.checkArgument(particle.getDataType().isInstance(data), "data (%s) should be %s", data.getClass(), particle.getDataType());
+        }
         this.getHandle().sendParticles(
-                null, // Sender
+                receivers == null ? this.getHandle().players() : receivers.stream().map(player -> ((CraftPlayer) player).getHandle()).collect(java.util.stream.Collectors.toList()), // Paper -  Particle API
+                sender != null ? ((CraftPlayer) sender).getHandle() : null, // Sender // Paper - Particle API
                 CraftParticle.createParticleParam(particle, data), // Particle
                 x, y, z, // Position
                 count,  // Count