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 9cb02b168384f597fce1251696e77a1e74f0d774..95c3b8524faac2218a4966965d4a8e322c0bdcd7 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -1542,12 +1542,17 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
     }
 
     public <T extends ParticleOptions> int sendParticlesSource(ServerPlayer sender, T t0, boolean flag, boolean flag1, double d0, double d1, double d2, int i, double d3, double d4, double d5, double d6) {
+        // Paper start - Particle API
+        return this.sendParticlesSource(this.players, sender, t0, flag, flag1, d0, d1, d2, i, d3, d4, d5, d6);
+    }
+    public <T extends ParticleOptions> int sendParticlesSource(List<ServerPlayer> receivers, @Nullable ServerPlayer sender, T t0, boolean flag, boolean flag1, double d0, double d1, double d2, int i, double d3, double d4, double d5, double d6) {
+        // Paper end - Particle API
         // CraftBukkit end
         ClientboundLevelParticlesPacket packetplayoutworldparticles = new ClientboundLevelParticlesPacket(t0, flag, flag1, d0, d1, d2, (float) d3, (float) d4, (float) d5, (float) d6, i);
         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, flag, d0, d1, d2, packetplayoutworldparticles)) {
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
index cf38f75050ef947d9f853374f40a25504ec987a6..a403507c0729f5c26172c82caa9dca65214d0319 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -1989,8 +1989,19 @@ 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().sendParticlesSource(
-                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
                 false, force,
                 x, y, z, // Position