Port blue budding crystal formations (#57)

src/main/java/net/dnorberg/rivencraft/block/BuddingCrystalBlock.java

@@ -0,0 +1,45 @@
+package net.dnorberg.rivencraft.block;
+
+import net.dnorberg.rivencraft.registry.ModBlocks;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.util.RandomSource;
+import net.minecraft.world.level.block.AmethystBlock;
+import net.minecraft.world.level.block.AmethystClusterBlock;
+import net.minecraft.world.level.block.Block;
+import net.minecraft.world.level.block.BuddingAmethystBlock;
+import net.minecraft.world.level.block.state.BlockBehaviour;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.material.Fluids;
+
+/** Vanilla amethyst growth, mapped to Rivencraft's blue crystal stages. */
+public final class BuddingCrystalBlock extends AmethystBlock {
+    public BuddingCrystalBlock(BlockBehaviour.Properties properties) {
+        super(properties);
+    }
+
+    @Override
+    protected void randomTick(BlockState state, ServerLevel level, BlockPos pos, RandomSource random) {
+        if (random.nextInt(5) != 0) return;
+        Direction direction = Direction.values()[random.nextInt(Direction.values().length)];
+        BlockPos target = pos.relative(direction);
+        BlockState existing = level.getBlockState(target);
+        Block next = nextStage(existing, direction);
+        if (next == null) return;
+        level.setBlockAndUpdate(target, next.defaultBlockState()
+                .setValue(AmethystClusterBlock.FACING, direction)
+                .setValue(AmethystClusterBlock.WATERLOGGED,
+                        existing.getFluidState().getType() == Fluids.WATER));
+    }
+
+    public static Block nextStage(BlockState existing, Direction direction) {
+        if (BuddingAmethystBlock.canClusterGrowAtState(existing)) return ModBlocks.SMALL_CRYSTAL_BUD.get();
+        if (!existing.hasProperty(AmethystClusterBlock.FACING)
+                || existing.getValue(AmethystClusterBlock.FACING) != direction) return null;
+        if (existing.is(ModBlocks.SMALL_CRYSTAL_BUD)) return ModBlocks.MEDIUM_CRYSTAL_BUD.get();
+        if (existing.is(ModBlocks.MEDIUM_CRYSTAL_BUD)) return ModBlocks.LARGE_CRYSTAL_BUD.get();
+        if (existing.is(ModBlocks.LARGE_CRYSTAL_BUD)) return ModBlocks.CRYSTAL_CLUSTER.get();
+        return null;
+    }
+}

src/main/java/net/dnorberg/rivencraft/book/AgeFeatureSelection.java

@@ -32,6 +32,7 @@ public final class AgeFeatureSelection {
     private static final List<ResourceLocation> FLUID_FEATURES = List.of(
             id("surface_lakes"), id("deep_lakes"), id("lava_lakes"));
     private static final long RANDOM_SKYLANDS_SALT = 0x534B594C414E4453L;
+    public static final ResourceLocation CRYSTAL_FORMATIONS = id("crystal_formations");
 
     private AgeFeatureSelection() {}
 
@@ -173,6 +174,8 @@ public final class AgeFeatureSelection {
         if (profile.terrain() == AgeRuntimeProfile.Terrain.NOISE
                 && Math.floorMod(mix(ageSeed ^ RANDOM_SKYLANDS_SALT), 8) == 0)
             choices.add(new Choice(id("skylands"), Optional.empty()));
+        if (error(CRYSTAL_FORMATIONS, profile, registries) == null && random.nextInt(10) == 0)
+            choices.add(new Choice(CRYSTAL_FORMATIONS, Optional.empty()));
         AgeBiomeSelection biomes = AgeBiomeSelection.compile(WritingGrammar.parse(OrderedWriting.EMPTY),
                 AgeTraits.select(ageSeed), profile, ageSeed, registries);
         choices.addAll(AgeStructureSelection.randomChoices(ageSeed, profile, biomes, registries));
@@ -204,6 +207,11 @@ public final class AgeFeatureSelection {
             return AgeStructureSelection.error(choice, profile, null, registries);
         if (choice.equals(AgeDenseOres.ID))
             return AgeDenseOres.error(profile, null, registries);
+        if (choice.equals(CRYSTAL_FORMATIONS)) {
+            if (AgeBiomeSelection.isCave(profile) || profile.terrain() == AgeRuntimeProfile.Terrain.VOID)
+                return "Feature " + choice + " needs exposed solid ground, not Cave or Void terrain";
+            return null;
+        }
         if (skylands(choice)) return null;
         if (tendrils(choice)) return null;
         if (spheres(choice)) return null;

src/main/java/net/dnorberg/rivencraft/book/FeatureWritingGameTests.java

@@ -40,7 +40,7 @@ public final class FeatureWritingGameTests {
                 "feature/bastions", "feature/buried_treasure", "feature/shipwrecks",
                 "feature/ocean_ruins", "feature/pillager_outposts", "feature/ruined_portals",
                 "feature/nether_fossils", "feature/ancient_cities", "feature/trail_ruins",
-                "feature/dense_ores", "feature/obelisks");
+                "feature/dense_ores", "feature/obelisks", "feature/crystal_formations");
         helper.assertTrue(PageItem.bundledCreativeSymbols().containsAll(pages),
                 "Supported feature pages must appear in the creative and JEI symbol feed");
         for (String path : pages) {
@@ -73,6 +73,7 @@ public final class FeatureWritingGameTests {
                     || AgeFeatureSelection.spheres(choice.id())
                     || AgeFeatureSelection.spikes(choice.id())
                     || AgeFeatureSelection.obelisks(choice.id())
+                    || choice.id().equals(AgeFeatureSelection.CRYSTAL_FORMATIONS)
                     || choice.id().equals(AgeDenseOres.ID)) continue;
             var placement = AgeFeatureSelection.placedFeature(choice.id());
             helper.assertTrue(registries.lookupOrThrow(Registries.PLACED_FEATURE)

src/main/java/net/dnorberg/rivencraft/client/ClientEvents.java

@@ -2,9 +2,12 @@ package net.dnorberg.rivencraft.client;
 
 import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.registry.ModBlockEntities;
+import net.dnorberg.rivencraft.registry.ModBlocks;
 import net.dnorberg.rivencraft.registry.ModDataComponents;
 import net.dnorberg.rivencraft.registry.ModItems;
 import net.minecraft.client.renderer.item.ItemProperties;
+import net.minecraft.client.renderer.ItemBlockRenderTypes;
+import net.minecraft.client.renderer.RenderType;
 import net.minecraft.resources.ResourceLocation;
 import net.neoforged.api.distmarker.Dist;
 import net.neoforged.bus.api.SubscribeEvent;
@@ -62,11 +65,18 @@ public final class ClientEvents {
 
     @SubscribeEvent
     public static void clientSetup(FMLClientSetupEvent event) {
-        event.enqueueWork(() -> ItemProperties.register(
-                ModItems.LINKING_BOOK.get(),
-                ResourceLocation.fromNamespaceAndPath(Rivencraft.MOD_ID, "bound"),
-                (stack, level, entity, seed) -> stack.has(ModDataComponents.LINK_TARGET.get()) ? 1.0F : 0.0F
-        ));
+        event.enqueueWork(() -> {
+            ItemProperties.register(
+                    ModItems.LINKING_BOOK.get(),
+                    ResourceLocation.fromNamespaceAndPath(Rivencraft.MOD_ID, "bound"),
+                    (stack, level, entity, seed) -> stack.has(ModDataComponents.LINK_TARGET.get()) ? 1.0F : 0.0F
+            );
+            // Some renderers still query the block layer instead of the model's render_type hint.
+            ItemBlockRenderTypes.setRenderLayer(ModBlocks.SMALL_CRYSTAL_BUD.get(), RenderType.cutout());
+            ItemBlockRenderTypes.setRenderLayer(ModBlocks.MEDIUM_CRYSTAL_BUD.get(), RenderType.cutout());
+            ItemBlockRenderTypes.setRenderLayer(ModBlocks.LARGE_CRYSTAL_BUD.get(), RenderType.cutout());
+            ItemBlockRenderTypes.setRenderLayer(ModBlocks.CRYSTAL_CLUSTER.get(), RenderType.cutout());
+        });
         NeoForge.EVENT_BUS.addListener(ClientBookInteractionHandler::onRightClickItem);
         NeoForge.EVENT_BUS.addListener(ClientBookInteractionHandler::onRightClickBlock);
         NeoForge.EVENT_BUS.addListener(ClientBookExploreOverlay::onClientTickPre);

src/main/java/net/dnorberg/rivencraft/registry/ModBlocks.java

@@ -5,7 +5,11 @@ import net.dnorberg.rivencraft.block.BookStandBlock;
 import net.dnorberg.rivencraft.block.BookBinderBlock;
 import net.dnorberg.rivencraft.block.WritingDeskBlock;
 import net.dnorberg.rivencraft.block.InkMixerBlock;
+import net.dnorberg.rivencraft.block.BuddingCrystalBlock;
+import net.minecraft.world.level.block.AmethystClusterBlock;
+import net.minecraft.world.level.block.Block;
 import net.minecraft.world.level.block.Blocks;
+import net.minecraft.world.level.material.MapColor;
 import net.minecraft.world.level.block.state.BlockBehaviour;
 import net.neoforged.bus.api.IEventBus;
 import net.neoforged.neoforge.registries.DeferredBlock;
@@ -31,6 +35,23 @@ public final class ModBlocks {
             "ink_mixer", InkMixerBlock::new,
             BlockBehaviour.Properties.ofFullCopy(Blocks.CRAFTING_TABLE).noOcclusion()
     );
+    public static final DeferredBlock<Block> CRYSTAL_BLOCK = BLOCKS.registerBlock("crystal_block",
+            Block::new, BlockBehaviour.Properties.ofFullCopy(Blocks.AMETHYST_BLOCK).mapColor(MapColor.COLOR_BLUE));
+    public static final DeferredBlock<BuddingCrystalBlock> BUDDING_CRYSTAL = BLOCKS.registerBlock("budding_crystal",
+            BuddingCrystalBlock::new, BlockBehaviour.Properties.ofFullCopy(Blocks.BUDDING_AMETHYST)
+                    .mapColor(MapColor.COLOR_BLUE));
+    public static final DeferredBlock<AmethystClusterBlock> CRYSTAL_CLUSTER = BLOCKS.registerBlock("crystal_cluster",
+            properties -> new AmethystClusterBlock(7.0F, 3.0F, properties),
+            BlockBehaviour.Properties.ofFullCopy(Blocks.AMETHYST_CLUSTER));
+    public static final DeferredBlock<AmethystClusterBlock> LARGE_CRYSTAL_BUD = BLOCKS.registerBlock("large_crystal_bud",
+            properties -> new AmethystClusterBlock(5.0F, 3.0F, properties),
+            BlockBehaviour.Properties.ofFullCopy(Blocks.LARGE_AMETHYST_BUD));
+    public static final DeferredBlock<AmethystClusterBlock> MEDIUM_CRYSTAL_BUD = BLOCKS.registerBlock("medium_crystal_bud",
+            properties -> new AmethystClusterBlock(4.0F, 3.0F, properties),
+            BlockBehaviour.Properties.ofFullCopy(Blocks.MEDIUM_AMETHYST_BUD));
+    public static final DeferredBlock<AmethystClusterBlock> SMALL_CRYSTAL_BUD = BLOCKS.registerBlock("small_crystal_bud",
+            properties -> new AmethystClusterBlock(3.0F, 4.0F, properties),
+            BlockBehaviour.Properties.ofFullCopy(Blocks.SMALL_AMETHYST_BUD));
 
     private ModBlocks() {
     }

src/main/java/net/dnorberg/rivencraft/registry/ModCreativeTabs.java

@@ -31,6 +31,13 @@ public final class ModCreativeTabs {
                         output.accept(ModItems.WRITING_DESK.get());
                         output.accept(ModItems.INK_MIXER.get());
                         output.accept(ModItems.BOOK_BINDER.get());
+                        output.accept(ModItems.CRYSTAL_BLOCK.get());
+                        output.accept(ModItems.BUDDING_CRYSTAL.get());
+                        output.accept(ModItems.CRYSTAL_CLUSTER.get());
+                        output.accept(ModItems.LARGE_CRYSTAL_BUD.get());
+                        output.accept(ModItems.MEDIUM_CRYSTAL_BUD.get());
+                        output.accept(ModItems.SMALL_CRYSTAL_BUD.get());
+                        output.accept(ModItems.CRYSTAL_SHARD.get());
                     })
                     .build());
 

src/main/java/net/dnorberg/rivencraft/registry/ModItems.java

@@ -43,6 +43,13 @@ public final class ModItems {
     public static final DeferredItem<BlockItem> WRITING_DESK = ITEMS.registerSimpleBlockItem(ModBlocks.WRITING_DESK);
     public static final DeferredItem<BlockItem> BOOK_BINDER = ITEMS.registerSimpleBlockItem(ModBlocks.BOOK_BINDER);
     public static final DeferredItem<BlockItem> INK_MIXER = ITEMS.registerSimpleBlockItem(ModBlocks.INK_MIXER);
+    public static final DeferredItem<BlockItem> CRYSTAL_BLOCK = ITEMS.registerSimpleBlockItem(ModBlocks.CRYSTAL_BLOCK);
+    public static final DeferredItem<BlockItem> BUDDING_CRYSTAL = ITEMS.registerSimpleBlockItem(ModBlocks.BUDDING_CRYSTAL);
+    public static final DeferredItem<BlockItem> CRYSTAL_CLUSTER = ITEMS.registerSimpleBlockItem(ModBlocks.CRYSTAL_CLUSTER);
+    public static final DeferredItem<BlockItem> LARGE_CRYSTAL_BUD = ITEMS.registerSimpleBlockItem(ModBlocks.LARGE_CRYSTAL_BUD);
+    public static final DeferredItem<BlockItem> MEDIUM_CRYSTAL_BUD = ITEMS.registerSimpleBlockItem(ModBlocks.MEDIUM_CRYSTAL_BUD);
+    public static final DeferredItem<BlockItem> SMALL_CRYSTAL_BUD = ITEMS.registerSimpleBlockItem(ModBlocks.SMALL_CRYSTAL_BUD);
+    public static final DeferredItem<Item> CRYSTAL_SHARD = ITEMS.registerSimpleItem("crystal_shard");
 
     private ModItems() {
     }

src/main/java/net/dnorberg/rivencraft/world/AgeFeatureChunkGenerator.java

@@ -163,6 +163,7 @@ public final class AgeFeatureChunkGenerator extends NoiseBasedChunkGenerator {
         Map<AgeFeatureSelection.Choice, Integer> occurrences = new HashMap<>();
         Map<ResourceLocation, Integer> spikeOccurrences = new HashMap<>();
         int obeliskOccurrence = 0;
+        int crystalOccurrence = 0;
         for (int index = 0; index < features.size(); index++) {
             AgeFeatureSelection.Choice choice = features.get(index);
             int occurrence = occurrences.merge(choice, 1, Integer::sum) - 1;
@@ -175,6 +176,10 @@ public final class AgeFeatureChunkGenerator extends NoiseBasedChunkGenerator {
                 ObelisksFeature.generate(level, chunk, ageSeed, choice, obeliskOccurrence++);
                 continue;
             }
+            if (choice.id().equals(AgeFeatureSelection.CRYSTAL_FORMATIONS)) {
+                CrystalFormationsFeature.generate(level, chunk, ageSeed, crystalOccurrence++);
+                continue;
+            }
             if (choice.id().equals(AgeDenseOres.ID)) {
                 AgeDenseOres.place(level, chunk, this, ageSeed, occurrence);
                 continue;

src/main/java/net/dnorberg/rivencraft/world/CrystalFormationsFeature.java

@@ -0,0 +1,82 @@
+package net.dnorberg.rivencraft.world;
+
+import net.dnorberg.rivencraft.registry.ModBlocks;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
+import net.minecraft.util.RandomSource;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.WorldGenLevel;
+import net.minecraft.world.level.block.AmethystClusterBlock;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.levelgen.Heightmap;
+
+/** A surface crystal mound with budding hearts and initially seeded buds. */
+final class CrystalFormationsFeature {
+    private static final long SALT = 0x4352595354414C53L;
+    private static final int CHANCE = 15; // Legacy's authored crystal formation frequency.
+
+    private CrystalFormationsFeature() {}
+
+    record Site(int x, int z, long seed) {}
+
+    static Site site(long ageSeed, ChunkPos chunk, int occurrence) {
+        long seed = mix(ageSeed ^ SALT ^ (long) chunk.x * 341873128712L
+                ^ (long) chunk.z * 132897987541L ^ (long) occurrence * 0x9E3779B97F4A7C15L);
+        RandomSource random = RandomSource.create(seed);
+        if (random.nextInt(CHANCE) != 0) return null;
+        return new Site(chunk.getMinBlockX() + 5 + random.nextInt(6),
+                chunk.getMinBlockZ() + 5 + random.nextInt(6), seed);
+    }
+
+    static void generate(WorldGenLevel level, ChunkAccess chunk, long ageSeed, int occurrence) {
+        Site site = site(ageSeed, chunk.getPos(), occurrence);
+        if (site == null) return;
+        RandomSource random = RandomSource.create(site.seed() ^ 0x42554444494E474CL);
+        int y = level.getHeight(Heightmap.Types.WORLD_SURFACE_WG, site.x(), site.z());
+        if (y <= level.getMinBuildHeight() + 1 || y + 4 >= level.getMaxBuildHeight()) return;
+        BlockPos.MutableBlockPos pos = new BlockPos.MutableBlockPos();
+        for (int dx = -1; dx <= 1; dx++) {
+            for (int dz = -1; dz <= 1; dz++) {
+                int x = site.x() + dx;
+                int z = site.z() + dz;
+                if (Math.abs(level.getHeight(Heightmap.Types.WORLD_SURFACE_WG, x, z) - y) > 1) return;
+                BlockState floor = level.getBlockState(pos.set(x, y - 1, z));
+                if (!floor.isFaceSturdy(level, pos, Direction.UP) || !floor.getFluidState().isEmpty()
+                        || floor.hasBlockEntity()) return;
+                for (int h = 0; h < 4; h++) {
+                    BlockState existing = level.getBlockState(pos.set(x, y + h, z));
+                    if (!existing.isAir() && !existing.canBeReplaced()) return;
+                }
+            }
+        }
+        for (int dx = -1; dx <= 1; dx++) {
+            for (int dz = -1; dz <= 1; dz++) {
+                boolean center = dx == 0 && dz == 0;
+                int height = center ? 3 : random.nextInt(3) == 0 ? 2 : 1;
+                for (int h = 0; h < height; h++) {
+                    boolean budding = h == height - 1 && (center || random.nextBoolean());
+                    level.setBlock(pos.set(site.x() + dx, y + h, site.z() + dz),
+                            budding ? ModBlocks.BUDDING_CRYSTAL.get().defaultBlockState()
+                                    : ModBlocks.CRYSTAL_BLOCK.get().defaultBlockState(), 2);
+                }
+                if (buddingTop(level.getBlockState(pos.set(site.x() + dx, y + height - 1, site.z() + dz)))
+                        && random.nextBoolean()) {
+                    level.setBlock(pos.set(site.x() + dx, y + height, site.z() + dz),
+                            ModBlocks.SMALL_CRYSTAL_BUD.get().defaultBlockState()
+                                    .setValue(AmethystClusterBlock.FACING, Direction.UP), 2);
+                }
+            }
+        }
+    }
+
+    private static boolean buddingTop(BlockState state) {
+        return state.is(ModBlocks.BUDDING_CRYSTAL);
+    }
+
+    private static long mix(long value) {
+        value = (value ^ value >>> 30) * 0xBF58476D1CE4E5B9L;
+        value = (value ^ value >>> 27) * 0x94D049BB133111EBL;
+        return value ^ value >>> 31;
+    }
+}

src/main/java/net/dnorberg/rivencraft/world/CrystalFormationsGameTests.java

@@ -0,0 +1,75 @@
+package net.dnorberg.rivencraft.world;
+
+import java.util.List;
+import java.util.Objects;
+import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.block.BuddingCrystalBlock;
+import net.dnorberg.rivencraft.book.AgeFeatureSelection;
+import net.dnorberg.rivencraft.book.AgeGenerationPlan;
+import net.dnorberg.rivencraft.book.AgeGenerationProfiles;
+import net.dnorberg.rivencraft.book.AgeTraits;
+import net.dnorberg.rivencraft.item.PageItem;
+import net.dnorberg.rivencraft.registry.ModBlocks;
+import net.dnorberg.rivencraft.writing.OrderedWriting;
+import net.dnorberg.rivencraft.writing.SymbolReference;
+import net.dnorberg.rivencraft.writing.WritingEntry;
+import net.minecraft.core.Direction;
+import net.minecraft.gametest.framework.GameTest;
+import net.minecraft.gametest.framework.GameTestHelper;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.block.AmethystClusterBlock;
+import net.minecraft.world.level.block.Blocks;
+import net.neoforged.neoforge.gametest.GameTestHolder;
+import net.neoforged.neoforge.gametest.PrefixGameTestTemplate;
+
+@GameTestHolder(Rivencraft.MOD_ID)
+@PrefixGameTestTemplate(false)
+public final class CrystalFormationsGameTests {
+    private CrystalFormationsGameTests() {}
+
+    @GameTest(template = "empty")
+    public static void authoredCrystalPageAndGrowth(GameTestHelper helper) {
+        var page = PageItem.createBundledCreativePage("feature/crystal_formations");
+        helper.assertTrue(PageItem.isUsableWriting(page), "Crystal Formations page must be writable");
+        var plan = AgeGenerationPlan.compile(new OrderedWriting(List.of(
+                        WritingEntry.linkPanel(),
+                        WritingEntry.symbol(new SymbolReference(ResourceLocation.fromNamespaceAndPath(
+                                Rivencraft.MOD_ID, "terrain/standard"))),
+                        WritingEntry.symbol(new SymbolReference(ResourceLocation.fromNamespaceAndPath(
+                                Rivencraft.MOD_ID, "feature/crystal_formations"))))),
+                57L, AgeGenerationProfiles.STANDARD, AgeTraits.select(57L),
+                helper.getLevel().registryAccess());
+        helper.assertValueEqual(AgeFeatureSelection.resolved(plan).getFirst().id(),
+                AgeFeatureSelection.CRYSTAL_FORMATIONS, "Page must compile to the crystal feature");
+        helper.assertValueEqual(AgeFeatureSelection.resolved(AgeGenerationPlan.load(plan.save())),
+                AgeFeatureSelection.resolved(plan), "Crystal choice must survive saving");
+        helper.assertValueEqual(BuddingCrystalBlock.nextStage(Blocks.AIR.defaultBlockState(), Direction.UP),
+                ModBlocks.SMALL_CRYSTAL_BUD.get(), "Air must begin the blue bud sequence");
+        helper.assertValueEqual(BuddingCrystalBlock.nextStage(
+                        ModBlocks.SMALL_CRYSTAL_BUD.get().defaultBlockState()
+                                .setValue(AmethystClusterBlock.FACING, Direction.UP), Direction.UP),
+                ModBlocks.MEDIUM_CRYSTAL_BUD.get(), "Small buds must grow into medium buds");
+        helper.assertValueEqual(BuddingCrystalBlock.nextStage(
+                        ModBlocks.MEDIUM_CRYSTAL_BUD.get().defaultBlockState()
+                                .setValue(AmethystClusterBlock.FACING, Direction.UP), Direction.UP),
+                ModBlocks.LARGE_CRYSTAL_BUD.get(), "Medium buds must grow into large buds");
+        helper.assertValueEqual(BuddingCrystalBlock.nextStage(
+                        ModBlocks.LARGE_CRYSTAL_BUD.get().defaultBlockState()
+                                .setValue(AmethystClusterBlock.FACING, Direction.UP), Direction.UP),
+                ModBlocks.CRYSTAL_CLUSTER.get(), "Large buds must grow into shard-bearing clusters");
+        helper.assertTrue(BuddingCrystalBlock.nextStage(
+                        ModBlocks.LARGE_CRYSTAL_BUD.get().defaultBlockState()
+                                .setValue(AmethystClusterBlock.FACING, Direction.NORTH), Direction.UP) == null,
+                "Growth must not change a bud facing away from its budding block");
+        helper.assertTrue(ModBlocks.BUDDING_CRYSTAL.get().defaultBlockState().isRandomlyTicking(),
+                "Budding crystals must receive random growth ticks");
+        var site = CrystalFormationsFeature.site(57L, new ChunkPos(10, -3), 0);
+        helper.assertTrue(Objects.equals(site, CrystalFormationsFeature.site(57L, new ChunkPos(10, -3), 0)),
+                "Formation placement must be deterministic per Age and chunk");
+        helper.assertTrue(java.util.stream.IntStream.range(0, 100).anyMatch(x ->
+                        CrystalFormationsFeature.site(57L, new ChunkPos(x, -3), 0) != null),
+                "Authored crystal formations must have reachable placement sites");
+        helper.succeed();
+    }
+}

src/main/resources/assets/rivencraft/blockstates/budding_crystal.json

@@ -0,0 +1 @@
+{"variants":{"":{"model":"rivencraft:block/budding_crystal"}}}

src/main/resources/assets/rivencraft/blockstates/crystal_block.json

@@ -0,0 +1 @@
+{"variants":{"":{"model":"rivencraft:block/crystal_block"}}}

src/main/resources/assets/rivencraft/blockstates/crystal_cluster.json

@@ -0,0 +1,56 @@
+{
+  "variants": {
+    "facing=down,waterlogged=false": {
+      "model": "rivencraft:block/crystal_cluster",
+      "x": 180
+    },
+    "facing=down,waterlogged=true": {
+      "model": "rivencraft:block/crystal_cluster",
+      "x": 180
+    },
+    "facing=up,waterlogged=false": {
+      "model": "rivencraft:block/crystal_cluster"
+    },
+    "facing=up,waterlogged=true": {
+      "model": "rivencraft:block/crystal_cluster"
+    },
+    "facing=north,waterlogged=false": {
+      "model": "rivencraft:block/crystal_cluster",
+      "x": 90
+    },
+    "facing=north,waterlogged=true": {
+      "model": "rivencraft:block/crystal_cluster",
+      "x": 90
+    },
+    "facing=south,waterlogged=false": {
+      "model": "rivencraft:block/crystal_cluster",
+      "x": 90,
+      "y": 180
+    },
+    "facing=south,waterlogged=true": {
+      "model": "rivencraft:block/crystal_cluster",
+      "x": 90,
+      "y": 180
+    },
+    "facing=east,waterlogged=false": {
+      "model": "rivencraft:block/crystal_cluster",
+      "x": 90,
+      "y": 90
+    },
+    "facing=east,waterlogged=true": {
+      "model": "rivencraft:block/crystal_cluster",
+      "x": 90,
+      "y": 90
+    },
+    "facing=west,waterlogged=false": {
+      "model": "rivencraft:block/crystal_cluster",
+      "x": 90,
+      "y": 270
+    },
+    "facing=west,waterlogged=true": {
+      "model": "rivencraft:block/crystal_cluster",
+      "x": 90,
+      "y": 270
+    }
+  }
+}

src/main/resources/assets/rivencraft/blockstates/large_crystal_bud.json

@@ -0,0 +1,56 @@
+{
+  "variants": {
+    "facing=down,waterlogged=false": {
+      "model": "rivencraft:block/large_crystal_bud",
+      "x": 180
+    },
+    "facing=down,waterlogged=true": {
+      "model": "rivencraft:block/large_crystal_bud",
+      "x": 180
+    },
+    "facing=up,waterlogged=false": {
+      "model": "rivencraft:block/large_crystal_bud"
+    },
+    "facing=up,waterlogged=true": {
+      "model": "rivencraft:block/large_crystal_bud"
+    },
+    "facing=north,waterlogged=false": {
+      "model": "rivencraft:block/large_crystal_bud",
+      "x": 90
+    },
+    "facing=north,waterlogged=true": {
+      "model": "rivencraft:block/large_crystal_bud",
+      "x": 90
+    },
+    "facing=south,waterlogged=false": {
+      "model": "rivencraft:block/large_crystal_bud",
+      "x": 90,
+      "y": 180
+    },
+    "facing=south,waterlogged=true": {
+      "model": "rivencraft:block/large_crystal_bud",
+      "x": 90,
+      "y": 180
+    },
+    "facing=east,waterlogged=false": {
+      "model": "rivencraft:block/large_crystal_bud",
+      "x": 90,
+      "y": 90
+    },
+    "facing=east,waterlogged=true": {
+      "model": "rivencraft:block/large_crystal_bud",
+      "x": 90,
+      "y": 90
+    },
+    "facing=west,waterlogged=false": {
+      "model": "rivencraft:block/large_crystal_bud",
+      "x": 90,
+      "y": 270
+    },
+    "facing=west,waterlogged=true": {
+      "model": "rivencraft:block/large_crystal_bud",
+      "x": 90,
+      "y": 270
+    }
+  }
+}

src/main/resources/assets/rivencraft/blockstates/medium_crystal_bud.json

@@ -0,0 +1,56 @@
+{
+  "variants": {
+    "facing=down,waterlogged=false": {
+      "model": "rivencraft:block/medium_crystal_bud",
+      "x": 180
+    },
+    "facing=down,waterlogged=true": {
+      "model": "rivencraft:block/medium_crystal_bud",
+      "x": 180
+    },
+    "facing=up,waterlogged=false": {
+      "model": "rivencraft:block/medium_crystal_bud"
+    },
+    "facing=up,waterlogged=true": {
+      "model": "rivencraft:block/medium_crystal_bud"
+    },
+    "facing=north,waterlogged=false": {
+      "model": "rivencraft:block/medium_crystal_bud",
+      "x": 90
+    },
+    "facing=north,waterlogged=true": {
+      "model": "rivencraft:block/medium_crystal_bud",
+      "x": 90
+    },
+    "facing=south,waterlogged=false": {
+      "model": "rivencraft:block/medium_crystal_bud",
+      "x": 90,
+      "y": 180
+    },
+    "facing=south,waterlogged=true": {
+      "model": "rivencraft:block/medium_crystal_bud",
+      "x": 90,
+      "y": 180
+    },
+    "facing=east,waterlogged=false": {
+      "model": "rivencraft:block/medium_crystal_bud",
+      "x": 90,
+      "y": 90
+    },
+    "facing=east,waterlogged=true": {
+      "model": "rivencraft:block/medium_crystal_bud",
+      "x": 90,
+      "y": 90
+    },
+    "facing=west,waterlogged=false": {
+      "model": "rivencraft:block/medium_crystal_bud",
+      "x": 90,
+      "y": 270
+    },
+    "facing=west,waterlogged=true": {
+      "model": "rivencraft:block/medium_crystal_bud",
+      "x": 90,
+      "y": 270
+    }
+  }
+}

src/main/resources/assets/rivencraft/blockstates/small_crystal_bud.json

@@ -0,0 +1,56 @@
+{
+  "variants": {
+    "facing=down,waterlogged=false": {
+      "model": "rivencraft:block/small_crystal_bud",
+      "x": 180
+    },
+    "facing=down,waterlogged=true": {
+      "model": "rivencraft:block/small_crystal_bud",
+      "x": 180
+    },
+    "facing=up,waterlogged=false": {
+      "model": "rivencraft:block/small_crystal_bud"
+    },
+    "facing=up,waterlogged=true": {
+      "model": "rivencraft:block/small_crystal_bud"
+    },
+    "facing=north,waterlogged=false": {
+      "model": "rivencraft:block/small_crystal_bud",
+      "x": 90
+    },
+    "facing=north,waterlogged=true": {
+      "model": "rivencraft:block/small_crystal_bud",
+      "x": 90
+    },
+    "facing=south,waterlogged=false": {
+      "model": "rivencraft:block/small_crystal_bud",
+      "x": 90,
+      "y": 180
+    },
+    "facing=south,waterlogged=true": {
+      "model": "rivencraft:block/small_crystal_bud",
+      "x": 90,
+      "y": 180
+    },
+    "facing=east,waterlogged=false": {
+      "model": "rivencraft:block/small_crystal_bud",
+      "x": 90,
+      "y": 90
+    },
+    "facing=east,waterlogged=true": {
+      "model": "rivencraft:block/small_crystal_bud",
+      "x": 90,
+      "y": 90
+    },
+    "facing=west,waterlogged=false": {
+      "model": "rivencraft:block/small_crystal_bud",
+      "x": 90,
+      "y": 270
+    },
+    "facing=west,waterlogged=true": {
+      "model": "rivencraft:block/small_crystal_bud",
+      "x": 90,
+      "y": 270
+    }
+  }
+}

src/main/resources/assets/rivencraft/lang/en_us.json

@@ -287,6 +287,15 @@
   "symbol.rivencraft.feature.dense_ores.description": "Repeat compatible vanilla and modded ore placements once per page in this Age.",
   "symbol.rivencraft.feature.obelisks": "Obelisks",
   "symbol.rivencraft.feature.obelisks.description": "Add rare tall obelisks on exposed solid ground, with a random or selected block material.",
+  "symbol.rivencraft.feature.crystal_formations": "Crystal Formations",
+  "symbol.rivencraft.feature.crystal_formations.description": "Add blue crystal formations whose budding blocks grow harvestable clusters.",
+  "block.rivencraft.crystal_block": "Crystal Block",
+  "block.rivencraft.budding_crystal": "Budding Crystal",
+  "block.rivencraft.small_crystal_bud": "Small Crystal Bud",
+  "block.rivencraft.medium_crystal_bud": "Medium Crystal Bud",
+  "block.rivencraft.large_crystal_bud": "Large Crystal Bud",
+  "block.rivencraft.crystal_cluster": "Crystal Cluster",
+  "item.rivencraft.crystal_shard": "Crystal Shard",
   "symbol.rivencraft.feature.lava_lakes": "Small Lakes",
   "symbol.rivencraft.feature.lava_lakes.description": "Add small surface lakes using a random fluid, or specify one with a fluid page.",
   "generator.rivencraft.standard": "Standard",

src/main/resources/assets/rivencraft/models/block/budding_crystal.json

@@ -0,0 +1 @@
+{"parent":"minecraft:block/cube_all","textures":{"all":"rivencraft:block/budding_crystal"}}

src/main/resources/assets/rivencraft/models/block/crystal_block.json

@@ -0,0 +1 @@
+{"parent":"minecraft:block/cube_all","textures":{"all":"rivencraft:block/crystal_block"}}

src/main/resources/assets/rivencraft/models/block/crystal_cluster.json

@@ -0,0 +1 @@
+{"parent":"minecraft:block/cross","render_type":"minecraft:cutout","textures":{"cross":"rivencraft:block/crystal_cluster"}}

src/main/resources/assets/rivencraft/models/block/large_crystal_bud.json

@@ -0,0 +1 @@
+{"parent":"minecraft:block/cross","render_type":"minecraft:cutout","textures":{"cross":"rivencraft:block/large_crystal_bud"}}

src/main/resources/assets/rivencraft/models/block/medium_crystal_bud.json

@@ -0,0 +1 @@
+{"parent":"minecraft:block/cross","render_type":"minecraft:cutout","textures":{"cross":"rivencraft:block/medium_crystal_bud"}}

src/main/resources/assets/rivencraft/models/block/small_crystal_bud.json

@@ -0,0 +1 @@
+{"parent":"minecraft:block/cross","render_type":"minecraft:cutout","textures":{"cross":"rivencraft:block/small_crystal_bud"}}

src/main/resources/assets/rivencraft/models/item/budding_crystal.json

@@ -0,0 +1 @@
+{"parent":"rivencraft:block/budding_crystal"}

src/main/resources/assets/rivencraft/models/item/crystal_block.json

@@ -0,0 +1 @@
+{"parent":"rivencraft:block/crystal_block"}

src/main/resources/assets/rivencraft/models/item/crystal_cluster.json

@@ -0,0 +1 @@
+{"parent":"minecraft:item/generated","textures":{"layer0":"rivencraft:block/crystal_cluster"}}

src/main/resources/assets/rivencraft/models/item/crystal_shard.json

@@ -0,0 +1 @@
+{"parent":"minecraft:item/generated","textures":{"layer0":"rivencraft:item/crystal_shard"}}

src/main/resources/assets/rivencraft/models/item/large_crystal_bud.json

@@ -0,0 +1 @@
+{"parent":"minecraft:item/generated","textures":{"layer0":"rivencraft:block/large_crystal_bud"}}

src/main/resources/assets/rivencraft/models/item/medium_crystal_bud.json

@@ -0,0 +1 @@
+{"parent":"minecraft:item/generated","textures":{"layer0":"rivencraft:block/medium_crystal_bud"}}

src/main/resources/assets/rivencraft/models/item/small_crystal_bud.json

@@ -0,0 +1 @@
+{"parent":"minecraft:item/generated","textures":{"layer0":"rivencraft:block/small_crystal_bud"}}

src/main/resources/data/minecraft/tags/block/mineable/pickaxe.json

@@ -0,0 +1 @@
+{"replace":false,"values":["rivencraft:crystal_block","rivencraft:budding_crystal","rivencraft:small_crystal_bud","rivencraft:medium_crystal_bud","rivencraft:large_crystal_bud","rivencraft:crystal_cluster"]}

src/main/resources/data/minecraft/tags/item/cluster_max_harvestables.json

@@ -0,0 +1 @@
+{"replace":false,"values":["rivencraft:crystal_block","rivencraft:budding_crystal","rivencraft:small_crystal_bud","rivencraft:medium_crystal_bud","rivencraft:large_crystal_bud","rivencraft:crystal_cluster"]}

src/main/resources/data/rivencraft/loot_table/blocks/budding_crystal.json

@@ -0,0 +1,4 @@
+{
+  "type": "minecraft:block",
+  "random_sequence": "rivencraft:blocks/budding_crystal"
+}

src/main/resources/data/rivencraft/loot_table/blocks/crystal_block.json

@@ -0,0 +1,21 @@
+{
+  "type": "minecraft:block",
+  "pools": [
+    {
+      "bonus_rolls": 0.0,
+      "conditions": [
+        {
+          "condition": "minecraft:survives_explosion"
+        }
+      ],
+      "entries": [
+        {
+          "type": "minecraft:item",
+          "name": "rivencraft:crystal_block"
+        }
+      ],
+      "rolls": 1.0
+    }
+  ],
+  "random_sequence": "rivencraft:blocks/crystal_block"
+}

src/main/resources/data/rivencraft/loot_table/blocks/crystal_cluster.json

@@ -0,0 +1,81 @@
+{
+  "type": "minecraft:block",
+  "pools": [
+    {
+      "bonus_rolls": 0.0,
+      "entries": [
+        {
+          "type": "minecraft:alternatives",
+          "children": [
+            {
+              "type": "minecraft:item",
+              "conditions": [
+                {
+                  "condition": "minecraft:match_tool",
+                  "predicate": {
+                    "predicates": {
+                      "minecraft:enchantments": [
+                        {
+                          "enchantments": "minecraft:silk_touch",
+                          "levels": {
+                            "min": 1
+                          }
+                        }
+                      ]
+                    }
+                  }
+                }
+              ],
+              "name": "rivencraft:crystal_cluster"
+            },
+            {
+              "type": "minecraft:alternatives",
+              "children": [
+                {
+                  "type": "minecraft:item",
+                  "conditions": [
+                    {
+                      "condition": "minecraft:match_tool",
+                      "predicate": {
+                        "items": "#minecraft:cluster_max_harvestables"
+                      }
+                    }
+                  ],
+                  "functions": [
+                    {
+                      "add": false,
+                      "count": 4.0,
+                      "function": "minecraft:set_count"
+                    },
+                    {
+                      "enchantment": "minecraft:fortune",
+                      "formula": "minecraft:ore_drops",
+                      "function": "minecraft:apply_bonus"
+                    }
+                  ],
+                  "name": "rivencraft:crystal_shard"
+                },
+                {
+                  "type": "minecraft:item",
+                  "functions": [
+                    {
+                      "add": false,
+                      "count": 2.0,
+                      "function": "minecraft:set_count"
+                    },
+                    {
+                      "function": "minecraft:explosion_decay"
+                    }
+                  ],
+                  "name": "rivencraft:crystal_shard"
+                }
+              ]
+            }
+          ]
+        }
+      ],
+      "rolls": 1.0
+    }
+  ],
+  "random_sequence": "rivencraft:blocks/crystal_cluster"
+}

src/main/resources/data/rivencraft/loot_table/blocks/large_crystal_bud.json

@@ -0,0 +1,33 @@
+{
+  "type": "minecraft:block",
+  "pools": [
+    {
+      "bonus_rolls": 0.0,
+      "conditions": [
+        {
+          "condition": "minecraft:match_tool",
+          "predicate": {
+            "predicates": {
+              "minecraft:enchantments": [
+                {
+                  "enchantments": "minecraft:silk_touch",
+                  "levels": {
+                    "min": 1
+                  }
+                }
+              ]
+            }
+          }
+        }
+      ],
+      "entries": [
+        {
+          "type": "minecraft:item",
+          "name": "rivencraft:large_crystal_bud"
+        }
+      ],
+      "rolls": 1.0
+    }
+  ],
+  "random_sequence": "rivencraft:blocks/large_crystal_bud"
+}

src/main/resources/data/rivencraft/loot_table/blocks/medium_crystal_bud.json

@@ -0,0 +1,33 @@
+{
+  "type": "minecraft:block",
+  "pools": [
+    {
+      "bonus_rolls": 0.0,
+      "conditions": [
+        {
+          "condition": "minecraft:match_tool",
+          "predicate": {
+            "predicates": {
+              "minecraft:enchantments": [
+                {
+                  "enchantments": "minecraft:silk_touch",
+                  "levels": {
+                    "min": 1
+                  }
+                }
+              ]
+            }
+          }
+        }
+      ],
+      "entries": [
+        {
+          "type": "minecraft:item",
+          "name": "rivencraft:medium_crystal_bud"
+        }
+      ],
+      "rolls": 1.0
+    }
+  ],
+  "random_sequence": "rivencraft:blocks/medium_crystal_bud"
+}

src/main/resources/data/rivencraft/loot_table/blocks/small_crystal_bud.json

@@ -0,0 +1,33 @@
+{
+  "type": "minecraft:block",
+  "pools": [
+    {
+      "bonus_rolls": 0.0,
+      "conditions": [
+        {
+          "condition": "minecraft:match_tool",
+          "predicate": {
+            "predicates": {
+              "minecraft:enchantments": [
+                {
+                  "enchantments": "minecraft:silk_touch",
+                  "levels": {
+                    "min": 1
+                  }
+                }
+              ]
+            }
+          }
+        }
+      ],
+      "entries": [
+        {
+          "type": "minecraft:item",
+          "name": "rivencraft:small_crystal_bud"
+        }
+      ],
+      "rolls": 1.0
+    }
+  ],
+  "random_sequence": "rivencraft:blocks/small_crystal_bud"
+}

src/main/resources/data/rivencraft/recipe/crystal_block.json

@@ -0,0 +1,6 @@
+{
+  "type": "minecraft:crafting_shaped",
+  "pattern": ["SS", "SS"],
+  "key": {"S": {"item": "rivencraft:crystal_shard"}},
+  "result": {"id": "rivencraft:crystal_block", "count": 1}
+}

src/main/resources/data/rivencraft/rivencraft/symbols/feature/crystal_formations.json

@@ -0,0 +1,8 @@
+{
+  "schema_version": 2,
+  "name": "symbol.rivencraft.feature.crystal_formations",
+  "description": "symbol.rivencraft.feature.crystal_formations.description",
+  "category": "rivencraft:feature",
+  "semantics": { "role": "feature", "value": "rivencraft:crystal_formations" },
+  "poem": "Crystal Formation Growth Blue"
+}