Decorators.java

// count: CountDecorator
// - UniformInt count (min: -10, max: 128, maxSpread: 128)
return IntStream.range(0, count.sample(random))
   .mapToObj((e) -> pos);

// count_noise: CountNoiseDecorator
// - double noise_level
// - int below_noise
// - int above_noise
double noise = Biome.BIOME_INFO_NOISE.getValue(posX / 200, posZ / 200, false);
int totalCount = noise < noise_level ? below_noise : above_noise;
return IntStream.range(0, totalCount)
   .mapToObj((e) -> pos);

// count_noise_biased: NoiseBasedDecorator
// - double noise_factor
// - double noise_offset
// - int noise_to_count_ratio
double noise = Biome.BIOME_INFO_NOISE.getValue(posX / noise_factor, posZ / noise_factor, false);
int totalCount = Math.ceil((noise + noise_offset) * noise_to_count_ratio);
return IntStream.range(0, totalCount)
   .mapToObj((e) -> pos);

// count_extra: CountWithExtraChanceDecorator
// - int count
// - int extra_count
// - float extra_chance
int totalCount = count + (random.nextFloat() < extra_chance ? extra_count : 0);
return IntStream.range(0, totalCount)
   .mapToObj((e) -> pos);

// range: RangeDecorator
// - int bottom_offset
// - int top_offset
// - int maximum
int y = random.nextInt(maximum - top_offset) + bottom_offset;
// range_biased: BiasedRangeDecorator
int y = random.nextInt(random.nextInt(maximum - top_offset) + bottom_offset);
// range_very_biased: VeryBiasedRangeDecorator
int y = random.nextInt(random.nextInt(random.nextInt(maximum - top_offset) + bottom_offset) + bottom_offset);
return Stream.of(new BlockPos(posX, y, posZ));

// carving_mask: CarvingMaskDecorator
// - String step (air|liquid)
// - float probability
ChunkPos chunkPos = new ChunkPos(pos);
BitSet mask = context.getCarvingMask(chunkPos, step);
return IntStream.range(0, mask.length())
   .filter((i) -> mask.get(i) && random.nextFloat() < probability)
   .mapToObj((i) -> {
      int x = chunkPos.getMinBlockX() + i & 15;
      int y = i >> 8;
      int z = chunkPos.getMinBlockZ() + i >> 4 & 15;
      return new BlockPos(x, y, z)
   });

// heightmap: HeightmapDecorator -> BaseHeightmapDecorator
int y = context.getHeight(Heightmap.Types.MOTION_BLOCKING, posX, posZ);
return y > 0 ? Stream.of(new BlockPos(posX, y, posZ)) : Stream.of();

// top_solid_heightmap: TopSolidHeightMapDecorator
int y = context.getHeight(Heightmap.Types.OCEAN_FLOOR_WG, posX, posZ);
return y > 0 ? Stream.of(new BlockPos(posX, y, posZ)) : Stream.of();

// heightmap_world_surface: HeightMapWorldSurfaceDecorator
int y = context.getHeight(Heightmap.Types.WORLD_SURFACE_WG, posX, posZ);
return y > 0 ? Stream.of(new BlockPos(posX, y, posZ)) : Stream.of();

// heightmap_spread_double: HeightmapDoubleDecorator
int y = context.getHeight(Heightmap.Types.MOTION_BLOCKING, posX, posZ);
return y > 0 ? Stream.of(new BlockPos(posX, random.nextInt(y * 2), posZ)): Stream.of();

// square: SquareDecorator
int x = random.nextInt(16) + posX;
int z = random.nextInt(16) + posY;
return Stream.of(new BlockPos(x, posY, z));

// depth_average: DepthAverageDecorator
// - int baseline
// - int spread
int y = random.nextInt(spread) + random.nextInt(spread) - spread + baseline;
return Stream.of(new BlockPos(posX, y, posZ));

// spread_32_above: Spread32Decorator
int y = random.nextInt(posY + 32);
return Stream.of(new BlockPos(posX, y, posZ));

// magma: MagmaDecorator
int y = context.getSeaLevel() - 5 + random.nextInt(10);
return Stream.of(new BlockPos(posX, y, posZ));

// glowstone
// - UniformInt count (min: -10, max: 128, maxSpread: 128)
int totalCount = random.nextInt(random.nextInt(count.sample(random)) + 1);
return IntStream.range(0, totalCount)
   .mapToObj((e) -> {
      int x = random.nextInt(16) + posX;
      int z = random.nextInt(16) + posZ;
      int y = random.nextInt(120) + 4;
      return new BlockPos(x, y, z);
   });