Code/net/minecraft/network/protocol/game/ClientboundLightUpdatePacketData.java

package net.minecraft.network.protocol.game;

import com.google.common.collect.Lists;
import io.netty.buffer.ByteBuf;
import java.util.BitSet;
import java.util.List;
import javax.annotation.Nullable;
import net.minecraft.core.SectionPos;
import net.minecraft.network.FriendlyByteBuf;
import net.minecraft.network.codec.ByteBufCodecs;
import net.minecraft.network.codec.StreamCodec;
import net.minecraft.world.level.ChunkPos;
import net.minecraft.world.level.LightLayer;
import net.minecraft.world.level.chunk.DataLayer;
import net.minecraft.world.level.lighting.LevelLightEngine;

public class ClientboundLightUpdatePacketData {
    private static final StreamCodec<ByteBuf, byte[]> DATA_LAYER_STREAM_CODEC = ByteBufCodecs.byteArray(2048);
    private final BitSet skyYMask;
    private final BitSet blockYMask;
    private final BitSet emptySkyYMask;
    private final BitSet emptyBlockYMask;
    private final List<byte[]> skyUpdates;
    private final List<byte[]> blockUpdates;

    public ClientboundLightUpdatePacketData(ChunkPos p_285385_, LevelLightEngine p_285143_, @Nullable BitSet p_285253_, @Nullable BitSet p_285051_) {
        this.skyYMask = new BitSet();
        this.blockYMask = new BitSet();
        this.emptySkyYMask = new BitSet();
        this.emptyBlockYMask = new BitSet();
        this.skyUpdates = Lists.newArrayList();
        this.blockUpdates = Lists.newArrayList();

        for (int i = 0; i < p_285143_.getLightSectionCount(); i++) {
            if (p_285253_ == null || p_285253_.get(i)) {
                this.prepareSectionData(p_285385_, p_285143_, LightLayer.SKY, i, this.skyYMask, this.emptySkyYMask, this.skyUpdates);
            }

            if (p_285051_ == null || p_285051_.get(i)) {
                this.prepareSectionData(p_285385_, p_285143_, LightLayer.BLOCK, i, this.blockYMask, this.emptyBlockYMask, this.blockUpdates);
            }
        }
    }

    public ClientboundLightUpdatePacketData(FriendlyByteBuf p_195737_, int p_195738_, int p_195739_) {
        this.skyYMask = p_195737_.readBitSet();
        this.blockYMask = p_195737_.readBitSet();
        this.emptySkyYMask = p_195737_.readBitSet();
        this.emptyBlockYMask = p_195737_.readBitSet();
        this.skyUpdates = p_195737_.readList(DATA_LAYER_STREAM_CODEC);
        this.blockUpdates = p_195737_.readList(DATA_LAYER_STREAM_CODEC);
    }

    public void write(FriendlyByteBuf p_195750_) {
        p_195750_.writeBitSet(this.skyYMask);
        p_195750_.writeBitSet(this.blockYMask);
        p_195750_.writeBitSet(this.emptySkyYMask);
        p_195750_.writeBitSet(this.emptyBlockYMask);
        p_195750_.writeCollection(this.skyUpdates, DATA_LAYER_STREAM_CODEC);
        p_195750_.writeCollection(this.blockUpdates, DATA_LAYER_STREAM_CODEC);
    }

    private void prepareSectionData(
        ChunkPos p_195742_, LevelLightEngine p_195743_, LightLayer p_195744_, int p_195745_, BitSet p_195746_, BitSet p_195747_, List<byte[]> p_195748_
    ) {
        DataLayer datalayer = p_195743_.getLayerListener(p_195744_).getDataLayerData(SectionPos.of(p_195742_, p_195743_.getMinLightSection() + p_195745_));
        if (datalayer != null) {
            if (datalayer.isEmpty()) {
                p_195747_.set(p_195745_);
            } else {
                p_195746_.set(p_195745_);
                p_195748_.add(datalayer.copy().getData());
            }
        }
    }

    public BitSet getSkyYMask() {
        return this.skyYMask;
    }

    public BitSet getEmptySkyYMask() {
        return this.emptySkyYMask;
    }

    public List<byte[]> getSkyUpdates() {
        return this.skyUpdates;
    }

    public BitSet getBlockYMask() {
        return this.blockYMask;
    }

    public BitSet getEmptyBlockYMask() {
        return this.emptyBlockYMask;
    }

    public List<byte[]> getBlockUpdates() {
        return this.blockUpdates;
    }
}