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extends Reference
class LSBLZWBitUnpacker:
var chunk_stream: PoolByteArray
var bit_index: int = 0
var byte: int
var byte_index: int = 0
func _init(_chunk_stream: PoolByteArray):
chunk_stream = _chunk_stream
self.get_byte()
func get_bit(value: int, index: int) -> int:
return (value >> index) & 1
func set_bit(value: int, index: int) -> int:
return value | (1 << index)
func get_byte():
byte = chunk_stream[byte_index]
byte_index += 1
bit_index = 0
func read_bits(bits_count: int) -> int:
var result: int = 0
var result_bit_index: int = 0
for _i in range(bits_count):
if self.get_bit(byte, bit_index) == 1:
result = self.set_bit(result, result_bit_index)
result_bit_index += 1
bit_index += 1
if bit_index == 8:
self.get_byte()
return result
func remove_bits(bits_count: int) -> void:
self.read_bits(bits_count)
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