Remove block entity blocks from the octree and remove the unused invisible field.

chunky/src/java/se/llbit/chunky/block/Block.java

@@ -13,6 +13,7 @@
 import se.llbit.nbt.CompoundTag;
 import se.llbit.nbt.Tag;
 
+import java.util.Collection;
 import java.util.Random;
 
 public abstract class Block extends Material {
@@ -25,13 +26,6 @@ public abstract class Block extends Material {
    */
   public boolean localIntersect = false;
 
-  /**
-   * Invisible blocks are not rendered as regular voxels (they are not added to the voxel octree).
-   * This is used for blocks that are rendered as entities, and blocks that are not implemented
-   * yet.
-   */
-  public boolean invisible = false;
-
   public Block(String name, Texture texture) {
     super(name, texture);
   }
@@ -97,31 +91,67 @@ public String toString() {
     return name;
   }
 
+  /**
+   * Check if this block is a block entity, i.e. {@link #createBlockEntity(Vector3, CompoundTag)} should be invoked to
+   * create an entity from this block and its entity data tag. This is used for blocks that need to create a new entity
+   * that needs the block entity data, e.g. signs.
+   * <p>
+   * This is mutually exclusive with {@link #hasEntities()}, use that one if you don't need block entity data.
+   *
+   * @return True if this block is a block entity, false otherwise
+   */
   public boolean isBlockEntity() {
     return false;
   }
 
-  public Entity toBlockEntity(Vector3 position, CompoundTag entityTag) {
-    throw new Error("This block type can not be converted to a block entity: "
+  /**
+   * Create a block entity from this block and the given block entity tag at the specified position.
+   *
+   * @param position  Position
+   * @param entityTag Block entity tag
+   * @return The block entity created from this block's data and the entity tag
+   * @throws UnsupportedOperationException If this block is not a block entity (i.e. {@link #isBlockEntity()} returns false
+   */
+  public Entity createBlockEntity(Vector3 position, CompoundTag entityTag) {
+    throw new UnsupportedOperationException("This block type can not be converted to a block entity: "
       + getClass().getSimpleName());
   }
 
-  public boolean isEntity() {
+  /**
+   * Check if this block has entities, i.e. {@link #createEntities(Vector3)} should be invoked to create entities from this
+   * block. A block can create multiple entities (e.g. the lectern may create a lectern and a book entity).
+   * <p>
+   * This is mutually exclusive with {@link #isBlockEntity()}, use that one if you need block entity data.
+   *
+   * @return True if this block has entities, false otherwise
+   */
+  public boolean hasEntities() {
     return false;
   }
 
   /**
-   * If this returns true, the block won't be removed from the octree even if this is an entity
-   * (i.e. {@link #isEntity()} returns true). This can be used for blocks that also contain
-   * entities, e.g. candle (where the candle flame is an entity).
+   * Create entities from this block at the specified position.
+   * <p>
+   * This may return multiple entities, e.g. the lectern has a lectern entity and an optional book entity.
+   *
+   * @param position Position
+   * @return The entities created from this block's data
+   * @throws UnsupportedOperationException If this block is not a block entity (i.e. {@link #hasEntities()} returns false
    */
-  public boolean isBlockWithEntity() {
-    return false;
+  public Collection<Entity> createEntities(Vector3 position) {
+    throw new UnsupportedOperationException("This block type can not be converted to entities: "
+      + getClass().getSimpleName());
   }
 
-  public Entity toEntity(Vector3 position) {
-    throw new Error("This block type can not be converted to an entity: "
-      + getClass().getSimpleName());
+  /**
+   * Whether to remove this block from the octree if it contains entities (i.e. {@link #hasEntities()} or {@link #isBlockEntity()}
+   * return true).
+   * <p>
+   * Most blocks are replaced by their entities (eg. signs create a sign entity that does the rendering and the block itself
+   * does nothing, but some blocks use block model and entities, e.g. candle (where the candle flame is an entity but the candle is a block).
+   */
+  public boolean isReplacedByEntities() {
+    return true;
   }
 
   /**

chunky/src/java/se/llbit/chunky/block/legacy/blocks/LegacyBanner.java

@@ -46,7 +46,6 @@ public class LegacyBanner extends MinecraftBlockTranslucent {
   public LegacyBanner(String name, CompoundTag tag) {
     super(name, Texture.whiteWool);
     localIntersect = true;
-    invisible = true;
     rotation = tag.get("Data").intValue(0);
   }
 
@@ -56,15 +55,10 @@ public boolean isBlockEntity() {
   }
 
   @Override
-  public Entity toBlockEntity(Vector3 position, CompoundTag entityTag) {
+  public Entity createBlockEntity(Vector3 position, CompoundTag entityTag) {
     return new StandingBanner(position, rotation, parseDesign(entityTag));
   }
 
-  @Override
-  public boolean intersect(Ray ray, Scene scene) {
-    return false;
-  }
-
   /**
    * Parse a banner design from the given Minecraft 1.12 or older banner entity tag and convert the
    * colors to 1.13+ values.

chunky/src/java/se/llbit/chunky/block/legacy/blocks/LegacySkull.java

@@ -30,7 +30,6 @@ public LegacySkull(String name, CompoundTag tag) {
     super(name, Texture.steve);
     this.placement = tag.get("Data").intValue(0);
     localIntersect = true;
-    invisible = true;
   }
 
   @Override
@@ -39,7 +38,7 @@ public boolean isBlockEntity() {
   }
 
   @Override
-  public Entity toBlockEntity(Vector3 position, CompoundTag entityTag) {
+  public Entity createBlockEntity(Vector3 position, CompoundTag entityTag) {
     Kind kind = getSkullKind(entityTag.get("SkullType").byteValue(0));
     int rotation = entityTag.get("Rot").byteValue(0);
     if (kind == Kind.PLAYER) {
@@ -55,11 +54,6 @@ public Entity toBlockEntity(Vector3 position, CompoundTag entityTag) {
     return new SkullEntity(position, kind, rotation, placement);
   }
 
-  @Override
-  public boolean intersect(Ray ray, Scene scene) {
-    return false;
-  }
-
   private static Kind getSkullKind(int skullType) {
     switch (skullType) {
       case 0:

chunky/src/java/se/llbit/chunky/block/legacy/blocks/LegacyWallBanner.java

@@ -22,7 +22,6 @@ public class LegacyWallBanner extends MinecraftBlockTranslucent {
   public LegacyWallBanner(String name, CompoundTag tag) {
     super(name, Texture.whiteWool);
     localIntersect = true;
-    invisible = true;
     facing = tag.get("Data").intValue(2);
   }
 
@@ -32,12 +31,7 @@ public boolean isBlockEntity() {
   }
 
   @Override
-  public Entity toBlockEntity(Vector3 position, CompoundTag entityTag) {
+  public Entity createBlockEntity(Vector3 position, CompoundTag entityTag) {
     return new WallBanner(position, facing, LegacyBanner.parseDesign(entityTag));
   }
-
-  @Override
-  public boolean intersect(Ray ray, Scene scene) {
-    return false;
-  }
 }

chunky/src/java/se/llbit/chunky/block/minecraft/Air.java

@@ -28,6 +28,5 @@ private Air() {
     super("air", Texture.air);
     solid = false;
     opaque = false;
-    invisible = true;
   }
 }

chunky/src/java/se/llbit/chunky/block/minecraft/Banner.java

@@ -39,22 +39,16 @@ public class Banner extends MinecraftBlockTranslucent {
 
   public Banner(String name, Texture texture, int rotation, BannerDesign.Color color) {
     super(name, texture);
-    invisible = true;
     opaque = false;
-    localIntersect = true;
     this.rotation = rotation % 16;
     this.color = color;
   }
 
-  @Override public boolean intersect(Ray ray, Scene scene) {
-    return false;
-  }
-
   @Override public boolean isBlockEntity() {
     return true;
   }
 
-  @Override public Entity toBlockEntity(Vector3 position, CompoundTag entityTag) {
+  @Override public Entity createBlockEntity(Vector3 position, CompoundTag entityTag) {
     JsonObject design = StandingBanner.parseDesign(entityTag);
     design.set("base", Json.of(color.id)); // Base color is not included in the entity tag in Minecraft 1.13+.
     return new StandingBanner(position, rotation, design);

chunky/src/java/se/llbit/chunky/block/minecraft/Beacon.java

@@ -36,8 +36,8 @@ public Beacon() {
   }
 
   @Override
-  public boolean isBlockWithEntity() {
-    return true;
+  public boolean isReplacedByEntities() {
+    return false;
   }
 
   @Override
@@ -46,7 +46,7 @@ public boolean isBlockEntity() {
   }
 
   @Override
-  public Entity toBlockEntity(Vector3 position, CompoundTag entityTag) {
+  public Entity createBlockEntity(Vector3 position, CompoundTag entityTag) {
     if (entityTag.get("Levels").intValue(0) > 0) {
       return new BeaconBeam(position);
     }

chunky/src/java/se/llbit/chunky/block/minecraft/CakeWithCandle.java

@@ -25,6 +25,8 @@
 import se.llbit.chunky.resources.Texture;
 import se.llbit.math.Vector3;
 
+import java.util.Collection;
+import java.util.Collections;
 import java.util.Random;
 
 public class CakeWithCandle extends AbstractModelBlock {
@@ -51,18 +53,18 @@ public String description() {
   }
 
   @Override
-  public boolean isEntity() {
+  public boolean hasEntities() {
     return isLit();
   }
 
   @Override
-  public boolean isBlockWithEntity() {
-    return true;
+  public boolean isReplacedByEntities() {
+    return false;
   }
 
   @Override
-  public Entity toEntity(Vector3 position) {
-    return new FlameParticles(position, entity);
+  public Collection<Entity> createEntities(Vector3 position) {
+    return Collections.singleton(new FlameParticles(position, entity));
   }
 
   @Override

chunky/src/java/se/llbit/chunky/block/minecraft/CalibratedSculkSensor.java

@@ -25,6 +25,9 @@
 import se.llbit.chunky.resources.Texture;
 import se.llbit.math.Vector3;
 
+import java.util.Collection;
+import java.util.Collections;
+
 public class CalibratedSculkSensor extends AbstractModelBlock {
   private final String phase;
   private final String facing;
@@ -46,17 +49,17 @@ public String description() {
   }
 
   @Override
-  public boolean isEntity() {
+  public boolean hasEntities() {
     return true;
   }
 
   @Override
-  public boolean isBlockWithEntity() {
-    return true;
+  public boolean isReplacedByEntities() {
+    return false;
   }
 
   @Override
-  public Entity toEntity(Vector3 position) {
-    return new CalibratedSculkSensorAmethyst(position, this.facing, isActive(), this);
+  public Collection<Entity> createEntities(Vector3 position) {
+    return Collections.singleton(new CalibratedSculkSensorAmethyst(position, this.facing, isActive(), this));
   }
 }

chunky/src/java/se/llbit/chunky/block/minecraft/Campfire.java

@@ -35,26 +35,19 @@ public class Campfire extends MinecraftBlockTranslucent {
 
     public Campfire(String name, se.llbit.chunky.entity.Campfire.Kind kind, String facing, boolean lit) {
         super(name, Texture.campfireLog);
-        invisible = true;
         opaque = false;
-        localIntersect = true;
         this.kind = kind;
         this.facing = facing;
         this.isLit = lit;
     }
 
-    @Override
-    public boolean intersect(Ray ray, Scene scene) {
-        return false;
-    }
-
     @Override
     public boolean isBlockEntity() {
         return true;
     }
 
     @Override
-    public Entity toBlockEntity(Vector3 position, CompoundTag entityTag) {
+    public Entity createBlockEntity(Vector3 position, CompoundTag entityTag) {
         return new se.llbit.chunky.entity.Campfire(this.kind, position, this.facing, this.isLit, this);
     }
 

chunky/src/java/se/llbit/chunky/block/minecraft/Candle.java

@@ -27,6 +27,8 @@
 import se.llbit.chunky.world.material.TextureMaterial;
 import se.llbit.math.Vector3;
 
+import java.util.Collection;
+import java.util.Collections;
 import java.util.Random;
 
 public class Candle extends AbstractModelBlock {
@@ -79,21 +81,21 @@ public boolean isLit() {
   }
 
   @Override
-  public boolean isEntity() {
+  public boolean hasEntities() {
     return isLit();
   }
 
   @Override
-  public boolean isBlockWithEntity() {
-    return true;
+  public boolean isReplacedByEntities() {
+    return false;
   }
 
   @Override
-  public Entity toEntity(Vector3 position) {
+  public Collection<Entity> createEntities(Vector3 position) {
     if (entity != null) {
-      return new FlameParticles(position, entity);
+      return Collections.singleton(new FlameParticles(position, entity));
     } else {
-      return new FlameParticles(position, this, new Vector3[0]);
+      return Collections.singleton(new FlameParticles(position, this, new Vector3[0]));
     }
   }
 

chunky/src/java/se/llbit/chunky/block/minecraft/CoralFan.java

@@ -26,16 +26,17 @@
 import se.llbit.math.Ray;
 import se.llbit.math.Vector3;
 
+import java.util.Collection;
+import java.util.Collections;
+
 public class CoralFan extends MinecraftBlockTranslucent {
 
   private final String coralType;
 
   public CoralFan(String name, String coralType) {
     super(name, coralTexture(coralType));
     this.coralType = coralType;
-    localIntersect = true;
     solid = false;
-    invisible = true;
   }
 
   public static Texture coralTexture(String coralType) {
@@ -64,15 +65,11 @@ public static Texture coralTexture(String coralType) {
     }
   }
 
-  @Override public boolean intersect(Ray ray, Scene scene) {
-    return false;
-  }
-
-  @Override public boolean isEntity() {
+  @Override public boolean hasEntities() {
     return true;
   }
 
-  @Override public Entity toEntity(Vector3 position) {
-    return new CoralFanEntity(position, coralType);
+  @Override public Collection<Entity> createEntities(Vector3 position) {
+    return Collections.singleton(new CoralFanEntity(position, coralType));
   }
 }