aa.kt

            val palette = it.getLongArray("BlockStates")
            val bits = palette.size.logCap(2)
            val maxEntryValue = (1 shl bits) - 1L

            for (y in 0 until ySizeAbs) {
                for (z in 0 until zSizeAbs) {
                    for (x in 0 until xSizeAbs) {
                        val index = (y * xSizeAbs * zSizeAbs) + z * xSizeAbs + x

                        val startOffset = index * bits
                        val startArrIndex = startOffset / 64
                        val endArrIndex = ((index + 1) * bits - 1) / 64
                        val startBitOffset = startOffset % 64

                        val stateId =
                            if (startArrIndex == endArrIndex) palette[startArrIndex] ushr startBitOffset and maxEntryValue
                            else (palette[startArrIndex] ushr startBitOffset or palette[endArrIndex] shl (64 - startBitOffset)) and maxEntryValue

                        newBlocks.add(NbtCompound().apply {
                            putIntList("pos", x, y, z)
                            putInt("state", stateId.toInt())
                        })
                    }
                }
            }