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#!/usr/bin/python
# Copyright 2015 Google Inc. All rights reserved.
#
# 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.
# To run this file, use `python_sample.sh`.
# Append paths to the `flatbuffers` and `MyGame` modules. This is necessary
# to facilitate executing this script in the `samples` folder, and to root
# folder (where it gets placed when using `cmake`).
import os
import sys
sys.path.append(os.path.join(os.path.dirname(__file__), '../python'))
import flatbuffers
import MyGame.Sample.Color
import MyGame.Sample.Equipment
import MyGame.Sample.Monster
import MyGame.Sample.Vec3
import MyGame.Sample.Weapon
# Example of how to use FlatBuffers to create and read binary buffers.
def main():
builder = flatbuffers.Builder(0)
# Create some weapons for our Monster ('Sword' and 'Axe').
weapon_one = builder.CreateString('Sword')
weapon_two = builder.CreateString('Axe')
MyGame.Sample.Weapon.WeaponStart(builder)
MyGame.Sample.Weapon.WeaponAddName(builder, weapon_one)
MyGame.Sample.Weapon.WeaponAddDamage(builder, 3)
sword = MyGame.Sample.Weapon.WeaponEnd(builder)
MyGame.Sample.Weapon.WeaponStart(builder)
MyGame.Sample.Weapon.WeaponAddName(builder, weapon_two)
MyGame.Sample.Weapon.WeaponAddDamage(builder, 5)
axe = MyGame.Sample.Weapon.WeaponEnd(builder)
# Serialize the FlatBuffer data.
name = builder.CreateString('Orc')
MyGame.Sample.Monster.MonsterStartInventoryVector(builder, 10)
# Note: Since we prepend the bytes, this loop iterates in reverse order.
for i in reversed(range(0, 10)):
builder.PrependByte(i)
inv = builder.EndVector()
MyGame.Sample.Monster.MonsterStartWeaponsVector(builder, 2)
# Note: Since we prepend the data, prepend the weapons in reverse order.
builder.PrependUOffsetTRelative(axe)
builder.PrependUOffsetTRelative(sword)
weapons = builder.EndVector()
pos = MyGame.Sample.Vec3.CreateVec3(builder, 1.0, 2.0, 3.0)
MyGame.Sample.Monster.MonsterStart(builder)
MyGame.Sample.Monster.MonsterAddPos(builder, pos)
MyGame.Sample.Monster.MonsterAddHp(builder, 300)
MyGame.Sample.Monster.MonsterAddName(builder, name)
MyGame.Sample.Monster.MonsterAddInventory(builder, inv)
MyGame.Sample.Monster.MonsterAddColor(builder,
MyGame.Sample.Color.Color().Red)
MyGame.Sample.Monster.MonsterAddWeapons(builder, weapons)
MyGame.Sample.Monster.MonsterAddEquippedType(
builder, MyGame.Sample.Equipment.Equipment().Weapon)
MyGame.Sample.Monster.MonsterAddEquipped(builder, axe)
orc = MyGame.Sample.Monster.MonsterEnd(builder)
builder.Finish(orc)
# We now have a FlatBuffer that we could store on disk or send over a network.
# ...Saving to file or sending over a network code goes here...
# Instead, we are going to access this buffer right away (as if we just
# received it).
buf = builder.Output()
# Note: We use `0` for the offset here, since we got the data using the
# `builder.Output()` method. This simulates the data you would store/receive
# in your FlatBuffer. If you wanted to read from the `builder.Bytes` directly,
# you would need to pass in the offset of `builder.Head()`, as the builder
# actually constructs the buffer backwards.
monster = MyGame.Sample.Monster.Monster.GetRootAsMonster(buf, 0)
# Note: We did not set the `Mana` field explicitly, so we get a default value.
assert monster.Mana() == 150
assert monster.Hp() == 300
assert monster.Name() == b'Orc'
assert monster.Color() == MyGame.Sample.Color.Color().Red
assert monster.Pos().X() == 1.0
assert monster.Pos().Y() == 2.0
assert monster.Pos().Z() == 3.0
# Get and test the `inventory` FlatBuffer `vector`.
for i in range(monster.InventoryLength()):
assert monster.Inventory(i) == i
# Get and test the `weapons` FlatBuffer `vector` of `table`s.
expected_weapon_names = [b'Sword', b'Axe']
expected_weapon_damages = [3, 5]
for i in range(monster.WeaponsLength()):
assert monster.Weapons(i).Name() == expected_weapon_names[i]
assert monster.Weapons(i).Damage() == expected_weapon_damages[i]
# Get and test the `equipped` FlatBuffer `union`.
assert monster.EquippedType() == MyGame.Sample.Equipment.Equipment().Weapon
# An example of how you can appropriately convert the table depending on the
# FlatBuffer `union` type. You could add `elif` and `else` clauses to handle
# the other FlatBuffer `union` types for this field.
if monster.EquippedType() == MyGame.Sample.Equipment.Equipment().Weapon:
# `monster.Equipped()` returns a `flatbuffers.Table`, which can be used
# to initialize a `MyGame.Sample.Weapon.Weapon()`, in this case.
union_weapon = MyGame.Sample.Weapon.Weapon()
union_weapon.Init(monster.Equipped().Bytes, monster.Equipped().Pos)
assert union_weapon.Name() == b"Axe"
assert union_weapon.Damage() == 5
print('The FlatBuffer was successfully created and verified!')
if __name__ == '__main__':
main()
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