Quick fix for pc1.17 masks (#85)

Keep the 1.14 impl for now and just overwrite the mask (previously an integer) to be a BitArray as expected by prismarine-chunk

Author: extremeheat

src/1.14/chunk.js

@@ -6,6 +6,7 @@ module.exports = (mcVersion, worldVersion, noSpan) => {
   const ChunkSection = require('prismarine-chunk')(mcVersion).section
 
   return (Chunk, mcData) => {
+    const newFormat = mcData.supportFeature('newLightingDataFormat') // 1.17+
     function nbtChunkToPrismarineChunk (data) {
       const nbtd = nbt.simplify(data)
       const chunk = new Chunk()
@@ -113,6 +114,17 @@ module.exports = (mcVersion, worldVersion, noSpan) => {
         })
         readByteArray(chunk.skyLightSections[section.Y + 1], section.SkyLight)
       }
+
+      if (newFormat) {
+        chunk.blockLightMask = new BitArray({ bitsPerValue: 1, capacity: 16 })
+        chunk.skyLightMask = new BitArray({ bitsPerValue: 1, capacity: 16 })
+        chunk.sectionMask = new BitArray({ bitsPerValue: 1, capacity: 16 })
+        for (let i = 0; i < 16; i++) {
+          if (chunk.sections[i]) chunk.sectionMask.set(i, true)
+          if (chunk.blockLightSections[i]) chunk.blockLightMask.set(i, true)
+          if (chunk.skyLightSections[i]) chunk.skyLightMask.set(i, true)
+        }
+      }
     }
 
     function parseValue (value, state) {