Code/net/minecraft/world/level/levelgen/DebugLevelSource.java

package net.minecraft.world.level.levelgen;

import com.mojang.serialization.MapCodec;
import com.mojang.serialization.codecs.RecordCodecBuilder;
import com.mojang.serialization.codecs.RecordCodecBuilder.Instance;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.stream.Collectors;
import java.util.stream.StreamSupport;
import net.minecraft.core.BlockPos;
import net.minecraft.core.Holder;
import net.minecraft.core.SectionPos;
import net.minecraft.core.registries.BuiltInRegistries;
import net.minecraft.resources.RegistryOps;
import net.minecraft.server.level.WorldGenRegion;
import net.minecraft.util.Mth;
import net.minecraft.world.level.ChunkPos;
import net.minecraft.world.level.LevelHeightAccessor;
import net.minecraft.world.level.NoiseColumn;
import net.minecraft.world.level.StructureManager;
import net.minecraft.world.level.WorldGenLevel;
import net.minecraft.world.level.biome.Biome;
import net.minecraft.world.level.biome.BiomeManager;
import net.minecraft.world.level.biome.Biomes;
import net.minecraft.world.level.biome.FixedBiomeSource;
import net.minecraft.world.level.block.Block;
import net.minecraft.world.level.block.Blocks;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.chunk.ChunkAccess;
import net.minecraft.world.level.chunk.ChunkGenerator;
import net.minecraft.world.level.levelgen.blending.Blender;

public class DebugLevelSource extends ChunkGenerator {
    public static final MapCodec<DebugLevelSource> CODEC = RecordCodecBuilder.mapCodec(
        p_255576_ -> p_255576_.group(RegistryOps.retrieveElement(Biomes.PLAINS)).apply(p_255576_, p_255576_.stable(DebugLevelSource::new))
    );
    private static final int BLOCK_MARGIN = 2;
    private static final List<BlockState> ALL_BLOCKS = StreamSupport.stream(BuiltInRegistries.BLOCK.spliterator(), false)
        .flatMap(p_208208_ -> p_208208_.getStateDefinition().getPossibleStates().stream())
        .collect(Collectors.toList());
    private static final int GRID_WIDTH = Mth.ceil(Mth.sqrt(ALL_BLOCKS.size()));
    private static final int GRID_HEIGHT = Mth.ceil((float)ALL_BLOCKS.size() / GRID_WIDTH);
    protected static final BlockState AIR = Blocks.AIR.defaultBlockState();
    protected static final BlockState BARRIER = Blocks.BARRIER.defaultBlockState();
    public static final int HEIGHT = 70;
    public static final int BARRIER_HEIGHT = 60;

    public DebugLevelSource(Holder.Reference<Biome> p_255723_) {
        super(new FixedBiomeSource(p_255723_));
    }

    @Override
    protected MapCodec<? extends ChunkGenerator> codec() {
        return CODEC;
    }

    @Override
    public void buildSurface(WorldGenRegion p_223978_, StructureManager p_223979_, RandomState p_223980_, ChunkAccess p_223981_) {
    }

    @Override
    public void applyBiomeDecoration(WorldGenLevel p_223983_, ChunkAccess p_223984_, StructureManager p_223985_) {
        BlockPos.MutableBlockPos blockpos$mutableblockpos = new BlockPos.MutableBlockPos();
        ChunkPos chunkpos = p_223984_.getPos();
        int i = chunkpos.x;
        int j = chunkpos.z;

        for (int k = 0; k < 16; k++) {
            for (int l = 0; l < 16; l++) {
                int i1 = SectionPos.sectionToBlockCoord(i, k);
                int j1 = SectionPos.sectionToBlockCoord(j, l);
                p_223983_.setBlock(blockpos$mutableblockpos.set(i1, 60, j1), BARRIER, 2);
                BlockState blockstate = getBlockStateFor(i1, j1);
                p_223983_.setBlock(blockpos$mutableblockpos.set(i1, 70, j1), blockstate, 2);
            }
        }
    }

    @Override
    public CompletableFuture<ChunkAccess> fillFromNoise(Blender p_223992_, RandomState p_223993_, StructureManager p_223994_, ChunkAccess p_223995_) {
        return CompletableFuture.completedFuture(p_223995_);
    }

    @Override
    public int getBaseHeight(int p_223964_, int p_223965_, Heightmap.Types p_223966_, LevelHeightAccessor p_223967_, RandomState p_223968_) {
        return 0;
    }

    @Override
    public NoiseColumn getBaseColumn(int p_223959_, int p_223960_, LevelHeightAccessor p_223961_, RandomState p_223962_) {
        return new NoiseColumn(0, new BlockState[0]);
    }

    @Override
    public void addDebugScreenInfo(List<String> p_223987_, RandomState p_223988_, BlockPos p_223989_) {
    }

    public static BlockState getBlockStateFor(int p_64149_, int p_64150_) {
        BlockState blockstate = AIR;
        if (p_64149_ > 0 && p_64150_ > 0 && p_64149_ % 2 != 0 && p_64150_ % 2 != 0) {
            p_64149_ /= 2;
            p_64150_ /= 2;
            if (p_64149_ <= GRID_WIDTH && p_64150_ <= GRID_HEIGHT) {
                int i = Mth.abs(p_64149_ * GRID_WIDTH + p_64150_);
                if (i < ALL_BLOCKS.size()) {
                    blockstate = ALL_BLOCKS.get(i);
                }
            }
        }

        return blockstate;
    }

    @Override
    public void applyCarvers(
        WorldGenRegion p_223970_, long p_223971_, RandomState p_223972_, BiomeManager p_223973_, StructureManager p_223974_, ChunkAccess p_223975_
    ) {
    }

    @Override
    public void spawnOriginalMobs(WorldGenRegion p_188511_) {
    }

    @Override
    public int getMinY() {
        return 0;
    }

    @Override
    public int getGenDepth() {
        return 384;
    }

    @Override
    public int getSeaLevel() {
        return 63;
    }
}