1 #!/usr/bin/python 2 # Copyright 2015 Google Inc. All rights reserved. 3 # 4 # Licensed under the Apache License, Version 2.0 (the "License"); 5 # you may not use this file except in compliance with the License. 6 # You may obtain a copy of the License at 7 # 8 # http://www.apache.org/licenses/LICENSE-2.0 9 # 10 # Unless required by applicable law or agreed to in writing, software 11 # distributed under the License is distributed on an "AS IS" BASIS, 12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 # See the License for the specific language governing permissions and 14 # limitations under the License. 15 16 # To run this file, use `python_sample.sh`. 17 18 # Append paths to the `flatbuffers` and `MyGame` modules. This is necessary 19 # to facilitate executing this script in the `samples` folder, and to root 20 # folder (where it gets placed when using `cmake`). 21 import os 22 import sys 23 sys.path.append(os.path.join(os.path.dirname(__file__), '../python')) 24 25 import flatbuffers 26 import MyGame.Sample.Color 27 import MyGame.Sample.Equipment 28 import MyGame.Sample.Monster 29 import MyGame.Sample.Vec3 30 import MyGame.Sample.Weapon 31 32 # Example of how to use FlatBuffers to create and read binary buffers. 33 34 def main(): 35 builder = flatbuffers.Builder(0) 36 37 # Create some weapons for our Monster ('Sword' and 'Axe'). 38 weapon_one = builder.CreateString('Sword') 39 weapon_two = builder.CreateString('Axe') 40 41 MyGame.Sample.Weapon.WeaponStart(builder) 42 MyGame.Sample.Weapon.WeaponAddName(builder, weapon_one) 43 MyGame.Sample.Weapon.WeaponAddDamage(builder, 3) 44 sword = MyGame.Sample.Weapon.WeaponEnd(builder) 45 46 MyGame.Sample.Weapon.WeaponStart(builder) 47 MyGame.Sample.Weapon.WeaponAddName(builder, weapon_two) 48 MyGame.Sample.Weapon.WeaponAddDamage(builder, 5) 49 axe = MyGame.Sample.Weapon.WeaponEnd(builder) 50 51 # Serialize the FlatBuffer data. 52 name = builder.CreateString('Orc') 53 54 MyGame.Sample.Monster.MonsterStartInventoryVector(builder, 10) 55 # Note: Since we prepend the bytes, this loop iterates in reverse order. 56 for i in reversed(range(0, 10)): 57 builder.PrependByte(i) 58 inv = builder.EndVector(10) 59 60 MyGame.Sample.Monster.MonsterStartWeaponsVector(builder, 2) 61 # Note: Since we prepend the data, prepend the weapons in reverse order. 62 builder.PrependUOffsetTRelative(axe) 63 builder.PrependUOffsetTRelative(sword) 64 weapons = builder.EndVector(2) 65 66 pos = MyGame.Sample.Vec3.CreateVec3(builder, 1.0, 2.0, 3.0) 67 68 MyGame.Sample.Monster.MonsterStart(builder) 69 MyGame.Sample.Monster.MonsterAddPos(builder, pos) 70 MyGame.Sample.Monster.MonsterAddHp(builder, 300) 71 MyGame.Sample.Monster.MonsterAddName(builder, name) 72 MyGame.Sample.Monster.MonsterAddInventory(builder, inv) 73 MyGame.Sample.Monster.MonsterAddColor(builder, 74 MyGame.Sample.Color.Color().Red) 75 MyGame.Sample.Monster.MonsterAddWeapons(builder, weapons) 76 MyGame.Sample.Monster.MonsterAddEquippedType( 77 builder, MyGame.Sample.Equipment.Equipment().Weapon) 78 MyGame.Sample.Monster.MonsterAddEquipped(builder, axe) 79 orc = MyGame.Sample.Monster.MonsterEnd(builder) 80 81 builder.Finish(orc) 82 83 # We now have a FlatBuffer that we could store on disk or send over a network. 84 85 # ...Saving to file or sending over a network code goes here... 86 87 # Instead, we are going to access this buffer right away (as if we just 88 # received it). 89 90 buf = builder.Output() 91 92 # Note: We use `0` for the offset here, since we got the data using the 93 # `builder.Output()` method. This simulates the data you would store/receive 94 # in your FlatBuffer. If you wanted to read from the `builder.Bytes` directly, 95 # you would need to pass in the offset of `builder.Head()`, as the builder 96 # actually constructs the buffer backwards. 97 monster = MyGame.Sample.Monster.Monster.GetRootAsMonster(buf, 0) 98 99 # Note: We did not set the `Mana` field explicitly, so we get a default value. 100 assert monster.Mana() == 150 101 assert monster.Hp() == 300 102 assert monster.Name() == 'Orc' 103 assert monster.Color() == MyGame.Sample.Color.Color().Red 104 assert monster.Pos().X() == 1.0 105 assert monster.Pos().Y() == 2.0 106 assert monster.Pos().Z() == 3.0 107 108 # Get and test the `inventory` FlatBuffer `vector`. 109 for i in xrange(monster.InventoryLength()): 110 assert monster.Inventory(i) == i 111 112 # Get and test the `weapons` FlatBuffer `vector` of `table`s. 113 expected_weapon_names = ['Sword', 'Axe'] 114 expected_weapon_damages = [3, 5] 115 for i in xrange(monster.WeaponsLength()): 116 assert monster.Weapons(i).Name() == expected_weapon_names[i] 117 assert monster.Weapons(i).Damage() == expected_weapon_damages[i] 118 119 # Get and test the `equipped` FlatBuffer `union`. 120 assert monster.EquippedType() == MyGame.Sample.Equipment.Equipment().Weapon 121 122 # An example of how you can appropriately convert the table depending on the 123 # FlatBuffer `union` type. You could add `elif` and `else` clauses to handle 124 # the other FlatBuffer `union` types for this field. 125 if monster.EquippedType() == MyGame.Sample.Equipment.Equipment().Weapon: 126 # `monster.Equipped()` returns a `flatbuffers.Table`, which can be used 127 # to initialize a `MyGame.Sample.Weapon.Weapon()`, in this case. 128 union_weapon = MyGame.Sample.Weapon.Weapon() 129 union_weapon.Init(monster.Equipped().Bytes, monster.Equipped().Pos) 130 131 assert union_weapon.Name() == "Axe" 132 assert union_weapon.Damage() == 5 133 134 print 'The FlatBuffer was successfully created and verified!' 135 136 if __name__ == '__main__': 137 main() 138
