Code/net/minecraft/server/level/ChunkTrackingView.java

package net.minecraft.server.level;

import com.google.common.annotations.VisibleForTesting;
import java.util.function.Consumer;
import net.minecraft.world.level.ChunkPos;

public interface ChunkTrackingView {
    ChunkTrackingView EMPTY = new ChunkTrackingView() {
        @Override
        public boolean contains(int p_298894_, int p_300849_, boolean p_299623_) {
            return false;
        }

        @Override
        public void forEach(Consumer<ChunkPos> p_298868_) {
        }
    };

    static ChunkTrackingView of(ChunkPos p_299839_, int p_298969_) {
        return new ChunkTrackingView.Positioned(p_299839_, p_298969_);
    }

    static void difference(ChunkTrackingView p_297320_, ChunkTrackingView p_298920_, Consumer<ChunkPos> p_300281_, Consumer<ChunkPos> p_298429_) {
        if (!p_297320_.equals(p_298920_)) {
            if (p_297320_ instanceof ChunkTrackingView.Positioned chunktrackingview$positioned
                && p_298920_ instanceof ChunkTrackingView.Positioned chunktrackingview$positioned1
                && chunktrackingview$positioned.squareIntersects(chunktrackingview$positioned1)) {
                int i = Math.min(chunktrackingview$positioned.minX(), chunktrackingview$positioned1.minX());
                int j = Math.min(chunktrackingview$positioned.minZ(), chunktrackingview$positioned1.minZ());
                int k = Math.max(chunktrackingview$positioned.maxX(), chunktrackingview$positioned1.maxX());
                int l = Math.max(chunktrackingview$positioned.maxZ(), chunktrackingview$positioned1.maxZ());

                for (int i1 = i; i1 <= k; i1++) {
                    for (int j1 = j; j1 <= l; j1++) {
                        boolean flag = chunktrackingview$positioned.contains(i1, j1);
                        boolean flag1 = chunktrackingview$positioned1.contains(i1, j1);
                        if (flag != flag1) {
                            if (flag1) {
                                p_300281_.accept(new ChunkPos(i1, j1));
                            } else {
                                p_298429_.accept(new ChunkPos(i1, j1));
                            }
                        }
                    }
                }
            } else {
                p_297320_.forEach(p_298429_);
                p_298920_.forEach(p_300281_);
            }
        }
    }

    default boolean contains(ChunkPos p_298506_) {
        return this.contains(p_298506_.x, p_298506_.z);
    }

    default boolean contains(int p_298205_, int p_299033_) {
        return this.contains(p_298205_, p_299033_, true);
    }

    boolean contains(int p_297637_, int p_299915_, boolean p_300628_);

    void forEach(Consumer<ChunkPos> p_301208_);

    default boolean isInViewDistance(int p_299368_, int p_297466_) {
        return this.contains(p_299368_, p_297466_, false);
    }

    static boolean isInViewDistance(int p_300363_, int p_300565_, int p_297699_, int p_299801_, int p_300142_) {
        return isWithinDistance(p_300363_, p_300565_, p_297699_, p_299801_, p_300142_, false);
    }

    static boolean isWithinDistance(int p_299483_, int p_297415_, int p_300799_, int p_299157_, int p_301327_, boolean p_301271_) {
        int i = p_301271_ ? 2 : 1;
        long j = Math.max(0, Math.abs(p_299157_ - p_299483_) - i);
        long k = Math.max(0, Math.abs(p_301327_ - p_297415_) - i);
        long l = j * j + k * k;
        int i1 = p_300799_ * p_300799_;
        return l < i1;
    }

    public record Positioned(ChunkPos center, int viewDistance) implements ChunkTrackingView {
        int minX() {
            return this.center.x - this.viewDistance - 1;
        }

        int minZ() {
            return this.center.z - this.viewDistance - 1;
        }

        int maxX() {
            return this.center.x + this.viewDistance + 1;
        }

        int maxZ() {
            return this.center.z + this.viewDistance + 1;
        }

        @VisibleForTesting
        protected boolean squareIntersects(ChunkTrackingView.Positioned p_300776_) {
            return this.minX() <= p_300776_.maxX()
                && this.maxX() >= p_300776_.minX()
                && this.minZ() <= p_300776_.maxZ()
                && this.maxZ() >= p_300776_.minZ();
        }

        @Override
        public boolean contains(int p_297345_, int p_300837_, boolean p_298477_) {
            return ChunkTrackingView.isWithinDistance(this.center.x, this.center.z, this.viewDistance, p_297345_, p_300837_, p_298477_);
        }

        @Override
        public void forEach(Consumer<ChunkPos> p_299048_) {
            for (int i = this.minX(); i <= this.maxX(); i++) {
                for (int j = this.minZ(); j <= this.maxZ(); j++) {
                    if (this.contains(i, j)) {
                        p_299048_.accept(new ChunkPos(i, j));
                    }
                }
            }
        }
    }
}