## #43: Prevent players from swimming up waterfalls

modules/build.gradle.kts

@@ -4,6 +4,8 @@ subprojects {
     apply(plugin = "java")
     apply(plugin = "net.ltgt.errorprone")
 
+    group = "net.hollowcube.libmmo"
+
     repositories {
         mavenCentral()
         maven(url = "https://jitpack.io")

modules/common/src/main/java/net/hollowcube/registry/MissingEntryException.java

@@ -0,0 +1,22 @@
+package net.hollowcube.registry;
+
+import org.jetbrains.annotations.NotNull;
+
+public class MissingEntryException extends RuntimeException{
+    private final @NotNull Registry<?> registry;
+    private final @NotNull String key;
+
+    public MissingEntryException(@NotNull Registry<?> registry, @NotNull String key) {
+        super("Missing registry entry: " + key + " in " + registry + "!");
+        this.registry = registry;
+        this.key = key;
+    }
+
+    public @NotNull Registry<?> registry() {
+        return registry;
+    }
+
+    public @NotNull String key() {
+        return key;
+    }
+}

modules/common/src/main/java/net/hollowcube/registry/Registry.java

@@ -164,7 +164,7 @@ static <T extends Resource> Registry<T> codec(@NotNull String name, @NotNull Cod
 
     default @NotNull T required(String namespace) {
         T result = get(namespace);
-        Check.notNull(result, "Missing required registry entry: " + namespace);
+        if (result == null) throw new MissingEntryException(this, namespace);
         return result;
     }
 

modules/common/src/test/java/net/hollowcube/registry/TestMissingEntry.java

@@ -0,0 +1,17 @@
+package net.hollowcube.registry;
+
+import com.google.gson.JsonParser;
+import com.mojang.serialization.JsonOps;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+public class TestMissingEntry {
+
+    @Test
+    public void testMissingRegistryEntry() {
+        var json = JsonParser.parseString("{\"type\": \"missing\"}");
+        assertThrows(MissingEntryException.class, () -> JsonOps.INSTANCE.withDecoder(TestResource.CODEC).apply(json));
+    }
+
+}

modules/common/src/test/java/net/hollowcube/registry/TestResource.java

@@ -0,0 +1,26 @@
+package net.hollowcube.registry;
+
+import com.mojang.serialization.Codec;
+import net.minestom.server.utils.NamespaceID;
+import org.jetbrains.annotations.NotNull;
+
+public interface TestResource extends Resource {
+
+    Codec<TestResource> CODEC = Factory.CODEC.dispatch(Factory::from, Factory::codec);
+
+    abstract class Factory extends ResourceFactory<TestResource> {
+        static Registry<Factory> REGISTRY = Registry.service("test_resource", Factory.class);
+        static Registry.Index<Class<?>, Factory> TYPE_REGISTRY = REGISTRY.index(Factory::type);
+
+        static Codec<Factory> CODEC = Codec.STRING.xmap(ns -> REGISTRY.required(ns), Factory::name);
+
+        public Factory(NamespaceID namespace, Class<? extends TestResource> type, Codec<? extends TestResource> codec) {
+            super(namespace, type, codec);
+        }
+
+        public static @NotNull Factory from(@NotNull TestResource resource) {
+            return TYPE_REGISTRY.get(resource.getClass());
+        }
+    }
+
+}

modules/development/src/main/java/net/hollowcube/server/dev/Main.java

@@ -69,9 +69,48 @@ public static void main(String[] args) {
             player.setAllowFlying(true);
 
             // Testing
-            event.getSpawnInstance().setBlock(5, 43, 5, Ore.fromNamespaceId("unnamed:gold_ore").asBlock());
-            event.getSpawnInstance().setBlock(4, 43, 5, Ore.fromNamespaceId("unnamed:diamond_ore").asBlock());
-            player.getInventory().addItemStack(Item.fromNamespaceId("unnamed:diamond_pickaxe").asItemStack());
+            event.getSpawnInstance().setBlock(5, 43, 5, Ore.fromNamespaceId("starlight:gold_ore").asBlock());
+            event.getSpawnInstance().setBlock(4, 43, 5, Ore.fromNamespaceId("starlight:diamond_ore").asBlock());
+
+            event.getSpawnInstance().setBlock(10, 40, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 41, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 42, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 43, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 44, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 45, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 46, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 47, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 48, 5, Block.BUBBLE_COLUMN);
+
+            event.getSpawnInstance().setBlock(11, 40, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 41, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 42, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 43, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 44, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 45, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 46, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 47, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 48, 5, Block.WATER);
+
+            event.getSpawnInstance().setBlock(10, 40, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 41, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 42, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 43, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 44, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 45, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 46, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 47, 5, Block.BUBBLE_COLUMN);
+            event.getSpawnInstance().setBlock(10, 48, 5, Block.BUBBLE_COLUMN);
+
+            event.getSpawnInstance().setBlock(11, 40, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 41, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 42, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 43, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 44, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 45, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 46, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 47, 5, Block.WATER);
+            event.getSpawnInstance().setBlock(11, 48, 5, Block.WATER);
 
             //todo this needs to be done elsewhere
             player.addEffect(new Potion(PotionEffect.MINING_FATIGUE, (byte) -1, Short.MAX_VALUE, (byte) 0x0));

modules/item/src/main/java/net/hollowcube/item/ItemComponentHandler.java

@@ -14,7 +14,7 @@ public interface ItemComponentHandler<C extends ItemComponent> extends Resource
 
     // Cannot be a method ref because REGISTRY may be mid-initialization when this is initialized.
     @SuppressWarnings("Convert2MethodRef")
-    Codec<ItemComponentHandler<?>> CODEC = Codec.STRING.xmap(namespace -> ItemComponentRegistry.REGISTRY.get(namespace), ItemComponentHandler::name);
+    Codec<ItemComponentHandler<?>> CODEC = Codec.STRING.xmap(namespace -> ItemComponentRegistry.REGISTRY.required(namespace), ItemComponentHandler::name);
 
 
     // Descriptors

modules/item/src/main/java/net/hollowcube/item/ItemManager.java

@@ -17,7 +17,7 @@ public class ItemManager implements Facet {
 
     @Override
     public void hook(@NotNull ServerWrapper server) {
-        EventNode<Event> eventNode = EventNode.all("unnamed:item/facet");
+        EventNode<Event> eventNode = EventNode.all("starlight:item/facet");
         server.addEventNode(eventNode);
 
         // Component handlers

modules/item/src/main/java/net/hollowcube/item/impl/RarityHandler.java

@@ -13,7 +13,7 @@ public class RarityHandler implements ItemComponentHandler<Rarity> {
 
     @Override
     public @NotNull NamespaceID namespace() {
-        return NamespaceID.from("unnamed:rarity");
+        return NamespaceID.from("starlight:rarity");
     }
 
     @Override

modules/loot-table/src/main/java/net/hollowcube/loot/LootEntry.java

@@ -24,7 +24,7 @@ abstract class Factory extends ResourceFactory<LootEntry<?>> {
         static Registry<Factory> REGISTRY = Registry.service("loot_entries", Factory.class);
         static Registry.Index<Class<?>, Factory> TYPE_REGISTRY = REGISTRY.index(Factory::type);
 
-        static Codec<Factory> CODEC = Codec.STRING.xmap(ns -> REGISTRY.get(ns), Factory::name);
+        static Codec<Factory> CODEC = Codec.STRING.xmap(ns -> REGISTRY.required(ns), Factory::name);
 
         public Factory(NamespaceID namespace, Class<? extends LootEntry<?>> type, Codec<? extends LootEntry<?>> codec) {
             super(namespace, type, codec);

modules/loot-table/src/main/java/net/hollowcube/loot/LootModifier.java

@@ -20,7 +20,7 @@ abstract class Factory extends ResourceFactory<LootModifier> {
         static Registry<Factory> REGISTRY = Registry.service("loot_modifiers", LootModifier.Factory.class);
         static Registry.Index<Class<?>, Factory> TYPE_REGISTRY = REGISTRY.index(Factory::type);
 
-        static Codec<Factory> CODEC = Codec.STRING.xmap(ns -> REGISTRY.get(ns), Factory::name);
+        static Codec<Factory> CODEC = Codec.STRING.xmap(ns -> REGISTRY.required(ns), Factory::name);
 
         public Factory(NamespaceID namespace, Class<? extends LootModifier> type, Codec<? extends LootModifier> codec) {
             super(namespace, type, codec);

modules/loot-table/src/main/java/net/hollowcube/loot/LootPredicate.java

@@ -25,7 +25,7 @@ abstract class Factory extends ResourceFactory<LootPredicate> {
         static Registry<Factory> REGISTRY = Registry.service("loot_predicates", LootPredicate.Factory.class);
         static Registry.Index<Class<?>, Factory> TYPE_REGISTRY = REGISTRY.index(Factory::type);
 
-        public static final Codec<Factory> CODEC = Codec.STRING.xmap(ns -> REGISTRY.get(ns), Factory::name);
+        public static final Codec<Factory> CODEC = Codec.STRING.xmap(ns -> REGISTRY.required(ns), Factory::name);
 
         public Factory(NamespaceID namespace, Class<? extends LootPredicate> type, Codec<? extends LootPredicate> codec) {
             super(namespace, type, codec);

modules/player/src/main/java/net/hollowcube/damage/weapon/WeaponHandler.java

@@ -9,15 +9,15 @@
 
 public class WeaponHandler implements ItemComponentHandler<Weapon> {
 
-    private final EventNode<Event> eventNode = EventNode.all("unnamed:weapon/item_component_handler");
+    private final EventNode<Event> eventNode = EventNode.all("starlight:weapon/item_component_handler");
 
     public WeaponHandler() {
 
     }
 
     @Override
     public @NotNull NamespaceID namespace() {
-        return NamespaceID.from("unnamed:weapon");
+        return NamespaceID.from("starlight:weapon");
     }
 
     @Override

modules/player/src/main/java/net/hollowcube/player/PlayerImpl.java

@@ -6,13 +6,15 @@
 import net.hollowcube.player.event.PlayerLongDiggingStartEvent;
 import net.minestom.server.MinecraftServer;
 import net.minestom.server.coordinate.Point;
+import net.minestom.server.coordinate.Pos;
 import net.minestom.server.entity.Player;
 import net.minestom.server.event.player.PlayerPacketEvent;
 import net.minestom.server.instance.Instance;
 import net.minestom.server.instance.block.Block;
 import net.minestom.server.instance.block.BlockFace;
 import net.minestom.server.network.packet.client.ClientPacket;
 import net.minestom.server.network.packet.client.play.ClientPlayerDiggingPacket;
+import net.minestom.server.network.packet.client.play.ClientPlayerPositionPacket;
 import net.minestom.server.network.packet.server.play.BlockBreakAnimationPacket;
 import net.minestom.server.network.player.PlayerConnection;
 import org.jetbrains.annotations.NotNull;
@@ -34,6 +36,10 @@ public class PlayerImpl extends Player {
     private int diggingBlockMaxHealth = 0;
     private BlockFace diggingFace = null;
 
+    // Bubble column sink event state
+    private int bubbleColumnSinkEnergyLevel = -1;
+    private boolean wasLastSeenInBubbleColumn = false;
+
     private final Map<String, ModifierList> currentModifiers = new HashMap<>();
 
     private final Logger logger = LoggerFactory.getLogger(PlayerImpl.class);
@@ -58,6 +64,10 @@ private void handlePacket(PlayerPacketEvent event) {
         if (packet instanceof ClientPlayerDiggingPacket diggingPacket) {
             handleDiggingPacket(diggingPacket);
         }
+
+        if (packet instanceof ClientPlayerPositionPacket positionPacket) {
+            handlePositionPacket(positionPacket);
+        }
     }
 
     private void handleDiggingPacket(ClientPlayerDiggingPacket packet) {
@@ -94,6 +104,30 @@ private void handleDiggingPacket(ClientPlayerDiggingPacket packet) {
         }
     }
 
+    private void handlePositionPacket(ClientPlayerPositionPacket packet) {
+        Pos playerPos = this.getPosition();
+        Block blockAtPlayerPos = this.getInstance().getBlock(playerPos);
+
+        if (packet.onGround()) {
+
+        }
+        else {
+            if (blockAtPlayerPos == Block.BUBBLE_COLUMN) {
+                if (!this.wasLastSeenInBubbleColumn) {
+                    this.wasLastSeenInBubbleColumn = true;
+                    this.bubbleColumnSinkEnergyLevel = this.getFood();
+                    this.setFood(6);
+                }
+            }
+        }
+
+        if ((this.wasLastSeenInBubbleColumn) && (blockAtPlayerPos != Block.BUBBLE_COLUMN)) {
+            this.wasLastSeenInBubbleColumn = false;
+            this.setFood(this.bubbleColumnSinkEnergyLevel);
+            this.bubbleColumnSinkEnergyLevel = -1;
+        }
+    }
+
     private void tickLongDigging() {
         if (diggingBlock == null) return;
 

modules/player/src/main/java/net/hollowcube/player/event/PlayerBubbleColumnSinkEvent.java

@@ -0,0 +1,37 @@
+package net.hollowcube.player.event;
+
+import net.minestom.server.entity.Player;
+import net.minestom.server.event.trait.PlayerInstanceEvent;
+import net.minestom.server.instance.block.Block;
+import org.jetbrains.annotations.NotNull;
+
+public class PlayerBubbleColumnSinkEvent implements PlayerInstanceEvent {
+    private final Player player;
+    private final int energyLevel;
+
+    public PlayerBubbleColumnSinkEvent(Player player, int energyLevel) {
+        this.player = player;
+        this.energyLevel = energyLevel;
+    }
+
+    @Override
+    public @NotNull Player getPlayer() {
+        return player;
+    }
+
+    public int getEnergyLevel() {
+        return energyLevel;
+    }
+
+    public void cancelPlayerSwimming() {
+        if (player.getInstance().getBlock(player.getPosition()) == Block.BUBBLE_COLUMN) {
+            player.setFood(6);
+        }
+    }
+
+    public void restorePlayerEnergy() {
+        if (player.getInstance().getBlock(player.getPosition()) != Block.BUBBLE_COLUMN) {
+            player.setFood(energyLevel);
+        }
+    }
+}