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 926ff9be3d9e3f5d620e4c7ccb22b9f64865ff8c..1a37654aff9a9c86c9f7af10a1cf721371f0c5ec 100644
--- a/src/main/java/net/minecraft/network/protocol/game/ClientboundSectionBlocksUpdatePacket.java
+++ b/src/main/java/net/minecraft/network/protocol/game/ClientboundSectionBlocksUpdatePacket.java
@@ -62,6 +62,14 @@ 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
+
     private void write(FriendlyByteBuf buf) {
         buf.writeLong(this.sectionPos.asLong());
         buf.writeVarInt(this.positions.length);
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index fe22b3e26498cb08cac1e461b6cb23b181788fb9..f39c5c8e99671b6d36ffe118fa9d912eae72e7fc 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -930,6 +930,32 @@ 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");