Code/net/minecraft/world/level/chunk/DataLayer.java

package net.minecraft.world.level.chunk;

import java.util.Arrays;
import javax.annotation.Nullable;
import net.minecraft.Util;
import net.minecraft.util.VisibleForDebug;

public class DataLayer {
    public static final int LAYER_COUNT = 16;
    public static final int LAYER_SIZE = 128;
    public static final int SIZE = 2048;
    private static final int NIBBLE_SIZE = 4;
    @Nullable
    protected byte[] data;
    private int defaultValue;

    public DataLayer() {
        this(0);
    }

    public DataLayer(int p_62554_) {
        this.defaultValue = p_62554_;
    }

    public DataLayer(byte[] p_62556_) {
        this.data = p_62556_;
        this.defaultValue = 0;
        if (p_62556_.length != 2048) {
            throw (IllegalArgumentException)Util.pauseInIde(new IllegalArgumentException("DataLayer should be 2048 bytes not: " + p_62556_.length));
        }
    }

    public int get(int p_62561_, int p_62562_, int p_62563_) {
        return this.get(getIndex(p_62561_, p_62562_, p_62563_));
    }

    public void set(int p_62565_, int p_62566_, int p_62567_, int p_62568_) {
        this.set(getIndex(p_62565_, p_62566_, p_62567_), p_62568_);
    }

    private static int getIndex(int p_62572_, int p_62573_, int p_62574_) {
        return p_62573_ << 8 | p_62574_ << 4 | p_62572_;
    }

    private int get(int p_62571_) {
        if (this.data == null) {
            return this.defaultValue;
        } else {
            int i = getByteIndex(p_62571_);
            int j = getNibbleIndex(p_62571_);
            return this.data[i] >> 4 * j & 15;
        }
    }

    private void set(int p_62558_, int p_62559_) {
        byte[] abyte = this.getData();
        int i = getByteIndex(p_62558_);
        int j = getNibbleIndex(p_62558_);
        int k = ~(15 << 4 * j);
        int l = (p_62559_ & 15) << 4 * j;
        abyte[i] = (byte)(abyte[i] & k | l);
    }

    private static int getNibbleIndex(int p_182482_) {
        return p_182482_ & 1;
    }

    private static int getByteIndex(int p_62579_) {
        return p_62579_ >> 1;
    }

    public void fill(int p_285142_) {
        this.defaultValue = p_285142_;
        this.data = null;
    }

    private static byte packFilled(int p_282176_) {
        byte b0 = (byte)p_282176_;

        for (int i = 4; i < 8; i += 4) {
            b0 = (byte)(b0 | p_282176_ << i);
        }

        return b0;
    }

    public byte[] getData() {
        if (this.data == null) {
            this.data = new byte[2048];
            if (this.defaultValue != 0) {
                Arrays.fill(this.data, packFilled(this.defaultValue));
            }
        }

        return this.data;
    }

    public DataLayer copy() {
        return this.data == null ? new DataLayer(this.defaultValue) : new DataLayer((byte[])this.data.clone());
    }

    @Override
    public String toString() {
        StringBuilder stringbuilder = new StringBuilder();

        for (int i = 0; i < 4096; i++) {
            stringbuilder.append(Integer.toHexString(this.get(i)));
            if ((i & 15) == 15) {
                stringbuilder.append("\n");
            }

            if ((i & 0xFF) == 255) {
                stringbuilder.append("\n");
            }
        }

        return stringbuilder.toString();
    }

    @VisibleForDebug
    public String layerToString(int p_156342_) {
        StringBuilder stringbuilder = new StringBuilder();

        for (int i = 0; i < 256; i++) {
            stringbuilder.append(Integer.toHexString(this.get(i)));
            if ((i & 15) == 15) {
                stringbuilder.append("\n");
            }
        }

        return stringbuilder.toString();
    }

    public boolean isDefinitelyHomogenous() {
        return this.data == null;
    }

    public boolean isDefinitelyFilledWith(int p_281763_) {
        return this.data == null && this.defaultValue == p_281763_;
    }

    public boolean isEmpty() {
        return this.data == null && this.defaultValue == 0;
    }
}