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# Copyright 2018-2019 The glTF-Blender-IO authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import struct
import base64
from os.path import dirname, join, isfile, basename
from urllib.parse import unquote
class BinaryData():
"""Binary reader."""
def __new__(cls, *args, **kwargs):
raise RuntimeError("%s should not be instantiated" % cls)
@staticmethod
def get_binary_from_accessor(gltf, accessor_idx):
"""Get binary from accessor."""
accessor = gltf.data.accessors[accessor_idx]
bufferView = gltf.data.buffer_views[accessor.buffer_view] # TODO initialize with 0 when not present!
if bufferView.buffer in gltf.buffers.keys():
buffer = gltf.buffers[bufferView.buffer]
else:
# load buffer
gltf.load_buffer(bufferView.buffer)
buffer = gltf.buffers[bufferView.buffer]
accessor_offset = accessor.byte_offset
bufferview_offset = bufferView.byte_offset
if accessor_offset is None:
accessor_offset = 0
if bufferview_offset is None:
bufferview_offset = 0
return buffer[accessor_offset + bufferview_offset:accessor_offset + bufferview_offset + bufferView.byte_length]
@staticmethod
def get_data_from_accessor(gltf, accessor_idx, cache=False):
"""Get data from accessor."""
if accessor_idx in gltf.accessor_cache:
return gltf.accessor_cache[accessor_idx]
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accessor = gltf.data.accessors[accessor_idx]
bufferView = gltf.data.buffer_views[accessor.buffer_view] # TODO initialize with 0 when not present!
buffer_data = BinaryData.get_binary_from_accessor(gltf, accessor_idx)
fmt_char = gltf.fmt_char_dict[accessor.component_type]
component_nb = gltf.component_nb_dict[accessor.type]
fmt = '<' + (fmt_char * component_nb)
stride_ = struct.calcsize(fmt)
# TODO data alignment stuff
if bufferView.byte_stride:
stride = bufferView.byte_stride
else:
stride = stride_
data = []
offset = 0
while len(data) < accessor.count:
element = struct.unpack_from(fmt, buffer_data, offset)
data.append(element)
offset += stride
if accessor.sparse:
sparse_indices_data = BinaryData.get_data_from_sparse(gltf, accessor.sparse, "indices")
sparse_values_values = BinaryData.get_data_from_sparse(
gltf,
accessor.sparse,
"values",
accessor.type,
accessor.component_type
)
# apply sparse
for cpt_idx, idx in enumerate(sparse_indices_data):
data[idx[0]] = sparse_values_values[cpt_idx]
# Normalization
if accessor.normalized:
for idx, tuple in enumerate(data):
new_tuple = ()
for i in tuple:
if accessor.component_type == 5120:
new_tuple += (max(float(i / 127.0 ), -1.0),)
elif accessor.component_type == 5121:
new_tuple += (float(i / 255.0),)
elif accessor.component_type == 5122:
new_tuple += (max(float(i / 32767.0), -1.0),)
elif accessor.component_type == 5123:
new_tuple += (i / 65535.0,)
else:
new_tuple += (float(i),)
if cache:
gltf.accessor_cache[accessor_idx] = data
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return data
@staticmethod
def get_data_from_sparse(gltf, sparse, type_, type_val=None, comp_type=None):
"""Get data from sparse."""
if type_ == "indices":
bufferView = gltf.data.buffer_views[sparse.indices.buffer_view]
offset = sparse.indices.byte_offset
component_nb = gltf.component_nb_dict['SCALAR']
fmt_char = gltf.fmt_char_dict[sparse.indices.component_type]
elif type_ == "values":
bufferView = gltf.data.buffer_views[sparse.values.buffer_view]
offset = sparse.values.byte_offset
component_nb = gltf.component_nb_dict[type_val]
fmt_char = gltf.fmt_char_dict[comp_type]
if bufferView.buffer in gltf.buffers.keys():
buffer = gltf.buffers[bufferView.buffer]
else:
# load buffer
gltf.load_buffer(bufferView.buffer)
buffer = gltf.buffers[bufferView.buffer]
bin_data = buffer[bufferView.byte_offset + offset:bufferView.byte_offset + offset + bufferView.byte_length]
fmt = '<' + (fmt_char * component_nb)
stride_ = struct.calcsize(fmt)
# TODO data alignment stuff ?
if bufferView.byte_stride:
stride = bufferView.byte_stride
else:
stride = stride_
data = []
offset = 0
while len(data) < sparse.count:
element = struct.unpack_from(fmt, bin_data, offset)
data.append(element)
offset += stride
return data
@staticmethod
def get_image_data(gltf, img_idx):
"""Get data from image."""
pyimage = gltf.data.images[img_idx]
image_name = "Image_" + str(img_idx)
if pyimage.uri:
sep = ';base64,'
if pyimage.uri[:5] == 'data:':
idx = pyimage.uri.find(sep)
if idx != -1:
data = pyimage.uri[idx + len(sep):]
return base64.b64decode(data), image_name
if isfile(join(dirname(gltf.filename), unquote(pyimage.uri))):
with open(join(dirname(gltf.filename), unquote(pyimage.uri)), 'rb') as f_:
return f_.read(), basename(join(dirname(gltf.filename), unquote(pyimage.uri)))
gltf.log.error("Missing file (index " + str(img_idx) + "): " + pyimage.uri)
return None, None
if pyimage.buffer_view is None:
return None, None
bufferView = gltf.data.buffer_views[pyimage.buffer_view]
if bufferView.buffer in gltf.buffers.keys():
buffer = gltf.buffers[bufferView.buffer]
else:
# load buffer
gltf.load_buffer(bufferView.buffer)
buffer = gltf.buffers[bufferView.buffer]
bufferview_offset = bufferView.byte_offset
if bufferview_offset is None:
bufferview_offset = 0
return buffer[bufferview_offset:bufferview_offset + bufferView.byte_length], image_name