feat: structure api (#523)

Co-authored-by: daoge_cmd <3523206925@qq.com>

CHANGELOG.md

@@ -16,6 +16,7 @@ and any changes to API will have a prefix `(API)`.
 
 - (API) Added `TextFormat#MATERIAL_RESIN`.
 - (API) Entity#teleport method now accepts an extra `Reason` argument.
+- (API) Added structure API by @harry-xi.
 
 ### Changed
 
@@ -30,6 +31,7 @@ and any changes to API will have a prefix `(API)`.
 - Entity#teleport method now will reset fall distance correctly.
 - Fixed visual flashes when eating chorus fruits.
 - Fixed incorrect comparison of `Position3x#dimension`.
+- Fixed a number of falling block related bugs.
 
 ## [0.1.0](https://github.com/AllayMC/Allay/releases/tag/0.1.0) (API 0.1.0) - 2024-12-22
 

api/src/main/java/org/allaymc/api/block/type/BlockStateSafeGetter.java

@@ -1,25 +1,72 @@
 package org.allaymc.api.block.type;
 
 import lombok.experimental.UtilityClass;
+import lombok.extern.slf4j.Slf4j;
 import org.allaymc.api.block.property.type.BlockPropertyType;
+import org.allaymc.api.network.ProtocolInfo;
 import org.allaymc.api.registry.Registries;
+import org.allaymc.api.utils.HashUtils;
 import org.allaymc.api.utils.Identifier;
 import org.allaymc.updater.block.BlockStateUpdaters;
 import org.cloudburstmc.nbt.NbtMap;
 import org.cloudburstmc.nbt.NbtMapBuilder;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.TreeMap;
 
 /**
  * BlockStateSafeGetter is used to get a block state safely, which means that
  * the plugin developers can get an item type without worrying about being broken
  * in the next minecraft version compared to using {@link BlockTypes} directly.
  *
- * @author daoge_cmd
+ * @author daoge_cmd | harry-xi
  */
+@Slf4j
 @UtilityClass
 public final class BlockStateSafeGetter {
+
+    /**
+     * Get the block state from the block state NBT.
+     *
+     * @param nbt the block state NBT.
+     *
+     * @return the block state, or the default state of {@code BlockTypes.UNKNOWN}
+     * if the block state is not found, or the block state version is too new.
+     */
+    public static BlockState fromNBT(NbtMap nbt) {
+        var version = nbt.getInt("version");
+        if (version > ProtocolInfo.BLOCK_STATE_VERSION_NUM) {
+            log.warn("Block state version is too new: {}", nbt);
+            return BlockTypes.UNKNOWN.getDefaultState();
+        }
+
+        if (version < ProtocolInfo.BLOCK_STATE_VERSION_NUM) {
+            nbt = BlockStateUpdaters.updateBlockState(nbt, BlockStateUpdaters.LATEST_VERSION);
+        }
+
+        // Make sure that tree map is used
+        // If the map inside states nbt is not tree map
+        // the block state hash will be wrong!
+        var states = new TreeMap<>(nbt.getCompound("states"));
+        // To calculate the hash of the block state
+        // "name" field must be in the first place
+        var tag = NbtMap.builder()
+                .putString("name", nbt.getString("name"))
+                .putCompound("states", NbtMap.fromMap(states))
+                .build();
+        int blockStateHash = HashUtils.fnv1a_32_nbt(tag);
+
+        // Get block state by hash
+        BlockState blockState = Registries.BLOCK_STATE_PALETTE.get(blockStateHash);
+        if (blockState != null) {
+            return blockState;
+        }
+
+        log.warn("Block state not found: {}", nbt);
+        return BlockTypes.UNKNOWN.getDefaultState();
+    }
+
     /**
      * Get a block type by its name.
      *

api/src/main/java/org/allaymc/api/utils/AllayNbtUtils.java

@@ -103,10 +103,26 @@ public static Vector3f readVector3f(NbtMap nbt, String rootName, String f1, Stri
      * @param vector3f the vector3.
      */
     public static void writeVector3f(NbtMapBuilder nbt, String rootName, String f1, String f2, String f3, Vector3fc vector3f) {
+        writeVector3f(nbt, rootName, f1, f2, f3, vector3f.x(), vector3f.y(), vector3f.z());
+    }
+
+    /**
+     * Write a vector3 to NBT.
+     *
+     * @param nbt      the NBT builder.
+     * @param rootName the root name.
+     * @param f1       the x field.
+     * @param f2       the y field.
+     * @param f3       the z field.
+     * @param x        the x value.
+     * @param y        the y value.
+     * @param z        the z value.
+     */
+    public static void writeVector3f(NbtMapBuilder nbt, String rootName, String f1, String f2, String f3, float x, float y, float z) {
         var pos = NbtMap.builder()
-                .putFloat(f1, vector3f.x())
-                .putFloat(f2, vector3f.y())
-                .putFloat(f3, vector3f.z())
+                .putFloat(f1, x)
+                .putFloat(f2, y)
+                .putFloat(f3, z)
                 .build();
         nbt.putCompound(rootName, pos);
     }
@@ -177,4 +193,17 @@ public static void writeVector2f(NbtMapBuilder nbt, String rootName, String f1,
                 .build();
         nbt.putCompound(rootName, pos);
     }
+
+    /**
+     * Remove the position tag from NBT.
+     *
+     * @param nbt the NBT map.
+     *
+     * @return the NBT map without the position tag.
+     */
+    public static NbtMap removePosTag(NbtMap nbt) {
+        var builder = nbt.toBuilder();
+        builder.remove("Pos");
+        return builder.build();
+    }
 }