Support for hashed block network ID's

index.d.ts

@@ -11,6 +11,7 @@ interface Effect {
     duration: number;
 }
 
+type States = { [key: string]: string | number }
 
 export type Shape = [number, number, number, number, number, number]; 
 
@@ -42,6 +43,9 @@ export declare class Block {
     // Contains a full NBT, unserialized object
     entity: NBT | null;
 
+    // (Bedrock Edition) A hash to uniquely represent block name and properties
+    hash?: number
+
     /**
      * A biome instance.
      * @see https://github.com/prismarinejs/prismarine-biome#api.
@@ -170,14 +174,21 @@ export declare class Block {
      * @param properties - A dictionary of block states to build from.
      * @param biomeId - The biome this block is in.
      */
-    static fromProperties(typeId: number | string, properties: { [key: string]: string | number }, biomeId: number): Block;
+    static fromProperties(typeId: number | string, properties: States, biomeId: number): Block;
 
     /**
      * Create a block from a given string.
      * @param stateString - the string representation of a block 
      * @param biomeId - the biome numerical id
      */
     static fromString(stateString: string, biomeId: number): Block;
+
+    /**
+     * (Bedrock Edition) Returns an integer hash to reperesent the block state
+     * @param name name of the block, with a minecraft: prefix
+     * @param states a record of block state properties
+     */
+    static getHash(prefixedName: string, states: States): number | undefined
 }
 
 /** @deprecated */

index.js

@@ -195,6 +195,10 @@ function provider (registry, { Biome, version }) {
       if (this.name.includes('sign')) {
         mergeObject(this, blockMethods.sign)
       }
+
+      if (blockEnum && registry.supportFeature('blockHashes')) {
+        this.hash = Block.getHash(this.name, this._properties)
+      }
     }
 
     static fromStateId (stateId, biomeId) {
@@ -269,6 +273,21 @@ function provider (registry, { Biome, version }) {
       return Object.assign(this._properties, this.computedStates)
     }
 
+    static getHash (name, states) {
+      if (registry.supportFeature('blockHashes')) {
+        const sortedStates = {}
+        for (const key of Object.keys(states).sort()) {
+          sortedStates[key] = states[key]
+        }
+        const tag = nbt.comp({
+          name: { type: 'string', value: name.includes(':') ? name : `minecraft:${name}` },
+          states: nbt.comp(sortedStates)
+        })
+        const buf = nbt.writeUncompressed(tag, 'little')
+        return computeFnv1a32Hash(buf)
+      }
+    }
+
     canHarvest (heldItemType) {
       if (!this.harvestTools) { return true }; // for blocks harvestable by hand
       return heldItemType && this.harvestTools && this.harvestTools[heldItemType]
@@ -391,3 +410,13 @@ function provider (registry, { Biome, version }) {
 function mergeObject (to, from) {
   Object.defineProperties(to, Object.getOwnPropertyDescriptors(from))
 }
+
+function computeFnv1a32Hash (buf) {
+  const FNV1_OFFSET_32 = 0x811c9dc5
+  let h = FNV1_OFFSET_32
+  for (let i = 0; i < buf.length; i++) {
+    h ^= buf[i] & 0xff
+    h += (h << 1) + (h << 4) + (h << 7) + (h << 8) + (h << 24)
+  }
+  return h & 0xffffffff
+}

test/basic.test.js

@@ -172,9 +172,29 @@ describe('fromString', () => {
     '1.20': 'minecraft:candle[lit=true]'
   }
   for (const [version, str] of Object.entries(versions)) {
+    it(version, () => {
+      const Block = require('prismarine-block')(version)
+      const block = Block.fromString(str, 0)
+      // console.log(block)
+      expect(block.getProperties().lit).toBeTruthy()
+    })
+  }
+})
+
+describe('Block hash computation', () => {
+  for (const version of ['bedrock_1.20.0']) {
     const Block = require('prismarine-block')(version)
-    const block = Block.fromString(str, 0)
-    console.log(block)
-    expect(block.getProperties().lit).toBeTruthy()
+    it('minecraft:soul_soil', function () {
+      const block = Block.fromString('minecraft:soul_soil', 0)
+      expect(block.hash).toBe(601701031)
+    })
+    it('minecraft:planks', function () {
+      const block = Block.fromString('minecraft:planks', 0)
+      expect(block.hash).toBe(1835335165)
+    })
+    it('minecraft:stone', function () {
+      const block = Block.fromString('minecraft:stone', 0)
+      expect(block.hash).toBe(-1177000405)
+    })
   }
 })