From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Brody Beckwith <brody@beckwith.dev>
Date: Fri, 14 Jan 2022 00:41:11 -0500
Subject: [PATCH] Multi Block Change API Implementation


diff --git a/src/main/java/net/minecraft/network/protocol/game/ClientboundSectionBlocksUpdatePacket.java b/src/main/java/net/minecraft/network/protocol/game/ClientboundSectionBlocksUpdatePacket.java
index f96d61bdeb556665d6e6e5023f9d77fd82204e89..ccdc2345465313991f065e1176b58fb7d5e8722f 100644
--- a/src/main/java/net/minecraft/network/protocol/game/ClientboundSectionBlocksUpdatePacket.java
+++ b/src/main/java/net/minecraft/network/protocol/game/ClientboundSectionBlocksUpdatePacket.java
@@ -59,6 +59,14 @@ public class ClientboundSectionBlocksUpdatePacket implements Packet<ClientGamePa
 
     }
 
+    // Paper start - Multi Block Change API
+    public ClientboundSectionBlocksUpdatePacket(SectionPos sectionPos, it.unimi.dsi.fastutil.shorts.Short2ObjectMap<BlockState> blockChanges) {
+        this.sectionPos = sectionPos;
+        this.positions = blockChanges.keySet().toShortArray();
+        this.states = blockChanges.values().toArray(new BlockState[0]);
+    }
+    // Paper end - Multi Block Change API
+
     @Override
     public void write(FriendlyByteBuf buf) {
         buf.writeLong(this.sectionPos.asLong());
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index 8b89f46aad11628a50d9f6c65caf52a558b9ee18..87b241a8b78b6fe0144e0d318e04da69a3101bc7 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -850,6 +850,32 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
         this.getHandle().connection.send(packet);
     }
 
+    // Paper start
+    @Override
+    public void sendMultiBlockChange(final Map<? extends io.papermc.paper.math.Position, BlockData> blockChanges) {
+        if (this.getHandle().connection == null) return;
+
+        Map<SectionPos, it.unimi.dsi.fastutil.shorts.Short2ObjectMap<net.minecraft.world.level.block.state.BlockState>> sectionMap = new HashMap<>();
+
+        for (Map.Entry<? extends io.papermc.paper.math.Position, BlockData> entry : blockChanges.entrySet()) {
+            BlockData blockData = entry.getValue();
+            BlockPos blockPos = io.papermc.paper.util.MCUtil.toBlockPos(entry.getKey());
+            SectionPos sectionPos = SectionPos.of(blockPos);
+
+            it.unimi.dsi.fastutil.shorts.Short2ObjectMap<net.minecraft.world.level.block.state.BlockState> sectionData = sectionMap.computeIfAbsent(sectionPos, key -> new it.unimi.dsi.fastutil.shorts.Short2ObjectArrayMap<>());
+            sectionData.put(SectionPos.sectionRelativePos(blockPos), ((CraftBlockData) blockData).getState());
+        }
+
+        for (Map.Entry<SectionPos, it.unimi.dsi.fastutil.shorts.Short2ObjectMap<net.minecraft.world.level.block.state.BlockState>> entry : sectionMap.entrySet()) {
+            SectionPos sectionPos = entry.getKey();
+            it.unimi.dsi.fastutil.shorts.Short2ObjectMap<net.minecraft.world.level.block.state.BlockState> blockData = entry.getValue();
+
+            net.minecraft.network.protocol.game.ClientboundSectionBlocksUpdatePacket packet = new net.minecraft.network.protocol.game.ClientboundSectionBlocksUpdatePacket(sectionPos, blockData);
+            this.getHandle().connection.send(packet);
+        }
+    }
+    // Paper end
+
     @Override
     public void sendBlockChanges(Collection<BlockState> blocks) {
         Preconditions.checkArgument(blocks != null, "blocks must not be null");