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# SPDX-License-Identifier: GPL-2.0-or-later
# Script copyright (C) 2006-2012, assimp team
# Script copyright (C) 2013 Blender Foundation
__all__ = (
"parse",
"data_types",
"parse_version",
"FBXElem",
)
from struct import unpack
import array
import zlib
from . import data_types
# at the end of each nested block, there is a NUL record to indicate
# that the sub-scope exists (i.e. to distinguish between P: and P : {})
_BLOCK_SENTINEL_LENGTH = ...
_BLOCK_SENTINEL_DATA = ...
read_fbx_elem_uint = ...
_IS_BIG_ENDIAN = (__import__("sys").byteorder != 'little')
_HEAD_MAGIC = b'Kaydara FBX Binary\x20\x20\x00\x1a\x00'
from collections import namedtuple
FBXElem = namedtuple("FBXElem", ("id", "props", "props_type", "elems"))
del namedtuple
def read_uint(read):
return unpack(b'<I', read(4))[0]
def read_uint64(read):
return unpack(b'<Q', read(8))[0]
def read_ubyte(read):
return unpack(b'B', read(1))[0]
def read_string_ubyte(read):
size = read_ubyte(read)
data = read(size)
return data
def unpack_array(read, array_type, array_stride, array_byteswap):
length = read_uint(read)
encoding = read_uint(read)
comp_len = read_uint(read)
data = read(comp_len)
if encoding == 0:
pass
elif encoding == 1:
data = zlib.decompress(data)
assert(length * array_stride == len(data))
data_array = array.array(array_type, data)
if array_byteswap and _IS_BIG_ENDIAN:
data_array.byteswap()
return data_array
read_data_dict = {
b'Y'[0]: lambda read: unpack(b'<h', read(2))[0], # 16 bit int
b'C'[0]: lambda read: unpack(b'?', read(1))[0], # 1 bit bool (yes/no)
b'I'[0]: lambda read: unpack(b'<i', read(4))[0], # 32 bit int
b'F'[0]: lambda read: unpack(b'<f', read(4))[0], # 32 bit float
b'D'[0]: lambda read: unpack(b'<d', read(8))[0], # 64 bit float
b'L'[0]: lambda read: unpack(b'<q', read(8))[0], # 64 bit int
b'R'[0]: lambda read: read(read_uint(read)), # binary data
b'S'[0]: lambda read: read(read_uint(read)), # string data
b'f'[0]: lambda read: unpack_array(read, data_types.ARRAY_FLOAT32, 4, False), # array (float)
b'i'[0]: lambda read: unpack_array(read, data_types.ARRAY_INT32, 4, True), # array (int)
b'd'[0]: lambda read: unpack_array(read, data_types.ARRAY_FLOAT64, 8, False), # array (double)
b'l'[0]: lambda read: unpack_array(read, data_types.ARRAY_INT64, 8, True), # array (long)
b'b'[0]: lambda read: unpack_array(read, data_types.ARRAY_BOOL, 1, False), # array (bool)
b'c'[0]: lambda read: unpack_array(read, data_types.ARRAY_BYTE, 1, False), # array (ubyte)
}
# FBX 7500 (aka FBX2016) introduces incompatible changes at binary level:
# * The NULL block marking end of nested stuff switches from 13 bytes long to 25 bytes long.
# * The FBX element metadata (end_offset, prop_count and prop_length) switch from uint32 to uint64.
def init_version(fbx_version):
global _BLOCK_SENTINEL_LENGTH, _BLOCK_SENTINEL_DATA, read_fbx_elem_uint
_BLOCK_SENTINEL_LENGTH = ...
_BLOCK_SENTINEL_DATA = ...
read_fbx_elem_uint = ...
if fbx_version < 7500:
_BLOCK_SENTINEL_LENGTH = 13
read_fbx_elem_uint = read_uint
else:
_BLOCK_SENTINEL_LENGTH = 25
read_fbx_elem_uint = read_uint64
_BLOCK_SENTINEL_DATA = (b'\0' * _BLOCK_SENTINEL_LENGTH)
def read_elem(read, tell, use_namedtuple):
# [0] the offset at which this block ends
# [1] the number of properties in the scope
# [2] the length of the property list
end_offset = read_fbx_elem_uint(read)
if end_offset == 0:
return None
prop_count = read_fbx_elem_uint(read)
prop_length = read_fbx_elem_uint(read)
elem_id = read_string_ubyte(read) # elem name of the scope/key
elem_props_type = bytearray(prop_count) # elem property types
elem_props_data = [None] * prop_count # elem properties (if any)
elem_subtree = [] # elem children (if any)
for i in range(prop_count):
data_type = read(1)[0]
elem_props_data[i] = read_data_dict[data_type](read)
elem_props_type[i] = data_type
if tell() < end_offset:
while tell() < (end_offset - _BLOCK_SENTINEL_LENGTH):
elem_subtree.append(read_elem(read, tell, use_namedtuple))
if read(_BLOCK_SENTINEL_LENGTH) != _BLOCK_SENTINEL_DATA:
raise IOError("failed to read nested block sentinel, "
"expected all bytes to be 0")
if tell() != end_offset:
raise IOError("scope length not reached, something is wrong")
args = (elem_id, elem_props_data, elem_props_type, elem_subtree)
return FBXElem(*args) if use_namedtuple else args
def parse_version(fn):
"""
Return the FBX version,
if the file isn't a binary FBX return zero.
"""
with open(fn, 'rb') as f:
read = f.read
if read(len(_HEAD_MAGIC)) != _HEAD_MAGIC:
return 0
return read_uint(read)
def parse(fn, use_namedtuple=True):
root_elems = []
with open(fn, 'rb') as f:
read = f.read
tell = f.tell
if read(len(_HEAD_MAGIC)) != _HEAD_MAGIC:
raise IOError("Invalid header")
fbx_version = read_uint(read)
init_version(fbx_version)
while True:
elem = read_elem(read, tell, use_namedtuple)
if elem is None:
break
root_elems.append(elem)
args = (b'', [], bytearray(0), root_elems)
return FBXElem(*args) if use_namedtuple else args, fbx_version
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