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 7be0547f6225a6be6ca1037f63f4aff8759b5dc4..e79329ee9b02a11b55253cf2ce4e08b2fc39a43f 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -1516,12 +1516,17 @@ 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 705cfb8ac38ee49adfb36a93b6939c975bbe95e9..8faebe25c0242eaf15a6b67fb1ade71cc46d263e 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -1957,8 +1957,19 @@ 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