Source code for SEAScope.types.shape
# vim: ts=4:sts=4:sw=4
#
# @author: <sylvain.herledan@oceandatalab.com>
# @date: 2016-09-09
#
# This file is part of SEAScope, a 3D visualisation and analysis application
# for satellite, in-situ and numerical model data.
#
# Copyright (C) 2014-2023 OceanDataLab
#
# SEAScope is free software: you can redistribute it and/or modify it under
# the terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 3 of the License, or (at your option)
# any later version.
#
# SEAScope 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 Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with SEAScope. If not, see <https://www.gnu.org/licenses/>.
"""
This module handles the serialization and deserialization of shape objects
"""
import logging
import flatbuffers
import SEAScope.API.Shape
import SEAScope.types.gcp
logger = logging.getLogger(__name__)
[docs]
def serialize(builder, shp_obj):
"""
Serialize a shape using FlatBuffers.
Parameters
----------
builder : flatbuffers.builder.Builder
The FlatBuffers builder instance which serializes data. If this
parameter is None, then a new builder will be created
shp_obj : dict
Dictionary which contains information about the shape to serialize
It must have three keys:
- ``xArity`` : an :obj:`int` which tells SEAScope how many columns it
must allocate when reconstructing the GCPs matrix
- ``yArity`` : an :obj:`int` which tells SEAScope how many rows it
must allocate when reconstructing the GCPs matrix
- ``gcps`` : a :obj:`list` of :obj:`dict` containing information
about the GCPs of the shape.
Each :obj:`dict` object must have all the keys required by
:func:`SEAScope.types.gcp.serialize`
Returns
-------
tuple(flatbuffers.builder.Builder, int)
A tuple which contains two elements:
- the :obj:`flatbuffers.builder.Builder` instance which has been used
to serialize data
- an :obj:`int` which is the address/offset of the serialized object
in the builder buffer
"""
if builder is None:
builder = flatbuffers.Builder(0)
x_arity = int(shp_obj['xArity'])
y_arity = int(shp_obj['yArity'])
gcps_len = len(shp_obj['gcps'])
SEAScope.API.Shape.ShapeStartGcpsVector(builder, gcps_len)
for gcp in shp_obj['gcps'][::-1]:
_, _gcp = SEAScope.types.gcp.serialize(builder, gcp)
gcps = builder.EndVector(gcps_len)
cls = SEAScope.API.Shape
cls.ShapeStart(builder)
cls.ShapeAddXArity(builder, x_arity)
cls.ShapeAddYArity(builder, y_arity)
cls.ShapeAddGcps(builder, gcps)
shape = cls.ShapeEnd(builder)
return builder, shape
[docs]
def deserialize(o):
"""
Rebuild a shape from a FlatBuffers buffer.
Parameters
----------
buf : bytearray
The buffer which contains the shape object serialized with FlatBuffers
Returns
-------
dict
The deserialized shape object as a dictionary.
"""
deserializer = SEAScope.types.gcp.deserialize
s_obj = {}
s_obj['xArity'] = o.XArity()
s_obj['yArity'] = o.YArity()
gcps_count = o.GcpsLength()
s_obj['gcps'] = [deserializer(o.Gcps(x)) for x in range(0, gcps_count)]
return s_obj