Initial commit of new FBX 7.4 binary exporter

What to expect:
* Static export of empties, meshes, cameras and lamps, as well as materials and (image!) textures should work OK.
  There are a few advanced topics still TODO regarding meshes and mat/tex, though.
* Custom properties from objects/meshes/lamps/cameras/armatures/bones/materials/textures are exported too (only simple ones, ints/floats/strings).
* Armature export: this needs testing by people having *native* FBX aplications, linking between bones and meshes seems to work, but I have doubts about bones orientations.
* Animation: still a complete TODO.

Note that old FBX ASCII 6.1 exporter is still available (top dropdown in exporter's UI).

Many thanks to Campbell, which did the ground work of decyphering FBX binary format and wrote basic code to read/write it.

1 files changed, 320 insertions, 0 deletions

diff --git a/io_scene_fbx/encode_bin.py b/io_scene_fbx/encode_bin.py
new file mode 100644
index 00000000..5cd3b744
--- /dev/null
+++ b/io_scene_fbx/encode_bin.py
@@ -0,0 +1,320 @@
+# ##### BEGIN GPL LICENSE BLOCK #####
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+# ##### END GPL LICENSE BLOCK #####
+
+# <pep8 compliant>
+
+# Script copyright (C) 2013 Campbell Barton
+
+try:
+    from . import data_types
+except:
+    import data_types
+
+from struct import pack
+import array
+import zlib
+
+_BLOCK_SENTINEL_LENGTH = 13
+_BLOCK_SENTINEL_DATA = (b'\0' * _BLOCK_SENTINEL_LENGTH)
+_IS_BIG_ENDIAN = (__import__("sys").byteorder != 'little')
+_HEAD_MAGIC = b'Kaydara FBX Binary\x20\x20\x00\x1a\x00'
+
+# fbx has very strict CRC rules, all based on file timestamp
+# until we figure these out, write files at a fixed time. (workaround!)
+
+# Assumes: CreationTime
+_TIME_ID = b'1970-01-01 10:00:00:000'
+_FILE_ID = b'\x28\xb3\x2a\xeb\xb6\x24\xcc\xc2\xbf\xc8\xb0\x2a\xa9\x2b\xfc\xf1'
+_FOOT_ID = b'\xfa\xbc\xab\x09\xd0\xc8\xd4\x66\xb1\x76\xfb\x83\x1c\xf7\x26\x7e'
+
+
+class FBXElem:
+    __slots__ = (
+        "id",
+        "props",
+        "props_type",
+        "elems",
+
+        "_props_length",  # combine length of props
+        "_end_offset",  # byte offset from the start of the file.
+        )
+
+    def __init__(self, id):
+        assert(len(id) < 256)  # length must fit in a uint8
+        self.id = id
+        self.props = []
+        self.props_type = bytearray()
+        self.elems = []
+        self._end_offset = -1
+        self._props_length = -1
+
+    def add_bool(self, data):
+        assert(isinstance(data, bool))
+        data = pack('?', data)
+
+        self.props_type.append(data_types.BOOL)
+        self.props.append(data)
+
+    def add_int16(self, data):
+        assert(isinstance(data, int))
+        data = pack('<h', data)
+
+        self.props_type.append(data_types.INT16)
+        self.props.append(data)
+
+    def add_int32(self, data):
+        assert(isinstance(data, int))
+        data = pack('<i', data)
+
+        self.props_type.append(data_types.INT32)
+        self.props.append(data)
+
+    def add_int64(self, data):
+        assert(isinstance(data, int))
+        data = pack('<q', data)
+
+        self.props_type.append(data_types.INT64)
+        self.props.append(data)
+
+    def add_float32(self, data):
+        assert(isinstance(data, float))
+        data = pack('<f', data)
+
+        self.props_type.append(data_types.FLOAT32)
+        self.props.append(data)
+
+    def add_float64(self, data):
+        assert(isinstance(data, float))
+        data = pack('<d', data)
+
+        self.props_type.append(data_types.FLOAT64)
+        self.props.append(data)
+
+    def add_bytes(self, data):
+        assert(isinstance(data, bytes))
+        data = pack('<I', len(data)) + data
+
+        self.props_type.append(data_types.BYTES)
+        self.props.append(data)
+
+    def add_string(self, data):
+        assert(isinstance(data, bytes))
+        data = pack('<I', len(data)) + data
+
+        self.props_type.append(data_types.STRING)
+        self.props.append(data)
+
+    def add_string_unicode(self, data):
+        assert(isinstance(data, str))
+        data = data.encode('utf8')
+        data = pack('<I', len(data)) + data
+
+        self.props_type.append(data_types.STRING)
+        self.props.append(data)
+
+    def _add_array_helper(self, data, array_type, prop_type):
+        assert(isinstance(data, array.array))
+        assert(data.typecode == array_type)
+
+        length = len(data)
+
+        if _IS_BIG_ENDIAN:
+            data = data[:]
+            data.byteswap()
+        data = data.tobytes()
+
+        # mimic behavior of fbxconverter (also common sense)
+        # we could make this configurable.
+        encoding = 0 if len(data) <= 128 else 1
+        if encoding == 0:
+            pass
+        elif encoding == 1:
+            data = zlib.compress(data, 1)
+
+        comp_len = len(data)
+
+        data = pack('<3I', length, encoding, comp_len) + data
+
+        self.props_type.append(prop_type)
+        self.props.append(data)
+
+    def add_int32_array(self, data):
+        if not isinstance(data, array.array):
+            data = array.array(data_types.ARRAY_INT32, data)
+        self._add_array_helper(data, data_types.ARRAY_INT32, data_types.INT32_ARRAY)
+
+    def add_int64_array(self, data):
+        if not isinstance(data, array.array):
+            data = array.array(data_types.ARRAY_INT64, data)
+        self._add_array_helper(data, data_types.ARRAY_INT64, data_types.INT64_ARRAY)
+
+    def add_float32_array(self, data):
+        if not isinstance(data, array.array):
+            data = array.array(data_types.ARRAY_FLOAT32, data)
+        self._add_array_helper(data, data_types.ARRAY_FLOAT32, data_types.FLOAT32_ARRAY)
+
+    def add_float64_array(self, data):
+        if not isinstance(data, array.array):
+            data = array.array(data_types.ARRAY_FLOAT64, data)
+        self._add_array_helper(data, data_types.ARRAY_FLOAT64, data_types.FLOAT64_ARRAY)
+
+    def add_bool_array(self, data):
+        if not isinstance(data, array.array):
+            data = array.array(data_types.ARRAY_BOOL, data)
+        self._add_array_helper(data, data_types.ARRAY_BOOL, data_types.BOOL_ARRAY)
+
+    def add_byte_array(self, data):
+        if not isinstance(data, array.array):
+            data = array.array(data_types.ARRAY_BYTE, data)
+        self._add_array_helper(data, data_types.ARRAY_BYTE, data_types.BYTE_ARRAY)
+
+    # -------------------------
+    # internal helper functions
+
+    def _calc_offsets(self, offset, is_last):
+        """
+        Call before writing, calculates fixed offsets.
+        """
+        assert(self._end_offset == -1)
+        assert(self._props_length == -1)
+
+        # print("Offset", offset)
+        offset += 12  # 3 uints
+        offset += 1 + len(self.id)  # len + idname
+
+        props_length = 0
+        for data in self.props:
+            # 1 byte for the prop type
+            props_length += 1 + len(data)
+        self._props_length = props_length
+        offset += props_length
+
+        offset = self._calc_offsets_children(offset, is_last)
+
+        self._end_offset = offset
+        return offset
+
+    def _calc_offsets_children(self, offset, is_last):
+        if self.elems:
+            elem_last = self.elems[-1]
+            for elem in self.elems:
+                offset = elem._calc_offsets(offset, (elem is elem_last))
+            offset += _BLOCK_SENTINEL_LENGTH
+        elif not self.props:
+            if not is_last:
+                offset += _BLOCK_SENTINEL_LENGTH
+
+        return offset
+
+    def _write(self, write, tell, is_last):
+        assert(self._end_offset != -1)
+        assert(self._props_length != -1)
+
+        # print(self.id, self._end_offset, len(self.props), self._props_length)
+        write(pack('<3I', self._end_offset, len(self.props), self._props_length))
+
+        write(bytes((len(self.id),)))
+        write(self.id)
+
+        for i, data in enumerate(self.props):
+            write(bytes((self.props_type[i],)))
+            write(data)
+
+        self._write_children(write, tell, is_last)
+
+        if tell() != self._end_offset:
+            raise IOError("scope length not reached, "
+                          "something is wrong (%d)" % (end_offset - tell()))
+
+    def _write_children(self, write, tell, is_last):
+        if self.elems:
+            elem_last = self.elems[-1]
+            for elem in self.elems:
+                assert(elem.id != b'')
+                elem._write(write, tell, (elem is elem_last))
+            write(_BLOCK_SENTINEL_DATA)
+        elif not self.props:
+            if not is_last:
+                write(_BLOCK_SENTINEL_DATA)
+
+
+def _write_timedate_hack(elem_root):
+    # perform 2 changes
+    # - set the FileID
+    # - set the CreationTime
+
+    ok = 0
+    for elem in elem_root.elems:
+        if elem.id == b'FileId':
+            assert(elem.props_type[0] == b'R'[0])
+            assert(len(elem.props_type) == 1)
+            elem.props.clear()
+            elem.props_type.clear()
+
+            elem.add_bytes(_FILE_ID)
+            ok += 1
+        elif elem.id == b'CreationTime':
+            assert(elem.props_type[0] == b'S'[0])
+            assert(len(elem.props_type) == 1)
+            elem.props.clear()
+            elem.props_type.clear()
+
+            elem.add_string(_TIME_ID)
+            ok += 1
+
+        if ok == 2:
+            break
+
+    if ok != 2:
+        print("Missing fields!")
+
+
+def write(fn, elem_root, version):
+    assert(elem_root.id == b'')
+
+    with open(fn, 'wb') as f:
+        write = f.write
+        tell = f.tell
+
+        write(_HEAD_MAGIC)
+        write(pack('<I', version))
+
+        # hack since we don't decode time.
+        # ideally we would _not_ modify this data.
+        _write_timedate_hack(elem_root)
+
+        elem_root._calc_offsets_children(tell(), False)
+        elem_root._write_children(write, tell, False)
+
+        write(_FOOT_ID)
+        write(b'\x00' * 4)
+
+        # padding for alignment (values between 1 & 16 observed)
+        # if already aligned to 16, add a full 16 bytes padding.
+        ofs = tell()
+        pad = ((ofs + 15) & ~15) - ofs
+        if pad == 0:
+            pad = 16
+
+        write(b'\0' * pad)
+
+        write(pack('<I', version))
+
+        # unknown magic (always the same)
+        write(b'\0' * 120)
+        write(b'\xf8\x5a\x8c\x6a\xde\xf5\xd9\x7e\xec\xe9\x0c\xe3\x75\x8f\x29\x0b')