flatbuffers/samples/sample_binary.cpp

105 lines
3.8 KiB
C++

/*
* 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.
*/
#include "monster_generated.h" // Already includes "flatbuffers/flatbuffers.h".
using namespace MyGame::Sample;
// Example how to use FlatBuffers to create and read binary buffers.
int main(int /*argc*/, const char * /*argv*/ []) {
// Build up a serialized buffer algorithmically:
flatbuffers::FlatBufferBuilder builder;
// First, lets serialize some weapons for the Monster: A 'sword' and an 'axe'.
auto weapon_one_name = builder.CreateString("Sword");
short weapon_one_damage = 3;
auto weapon_two_name = builder.CreateString("Axe");
short weapon_two_damage = 5;
// Use the `CreateWeapon` shortcut to create Weapons with all fields set.
auto sword = CreateWeapon(builder, weapon_one_name, weapon_one_damage);
auto axe = CreateWeapon(builder, weapon_two_name, weapon_two_damage);
// Create a FlatBuffer's `vector` from the `std::vector`.
std::vector<flatbuffers::Offset<Weapon>> weapons_vector;
weapons_vector.push_back(sword);
weapons_vector.push_back(axe);
auto weapons = builder.CreateVector(weapons_vector);
// Second, serialize the rest of the objects needed by the Monster.
auto position = Vec3(1.0f, 2.0f, 3.0f);
auto name = builder.CreateString("MyMonster");
unsigned char inv_data[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
auto inventory = builder.CreateVector(inv_data, 10);
// Shortcut for creating monster with all fields set:
auto orc = CreateMonster(builder, &position, 150, 80, name, inventory,
Color_Red, weapons, Equipment_Weapon, axe.Union());
builder.Finish(orc); // Serialize the root of the object.
// We now have a FlatBuffer we can store on disk or send over a network.
// ** file/network code goes here :) **
// access builder.GetBufferPointer() for builder.GetSize() bytes
// Instead, we're going to access it right away (as if we just received it).
// Get access to the root:
auto monster = GetMonster(builder.GetBufferPointer());
// Get and test some scalar types from the FlatBuffer.
assert(monster->hp() == 80);
assert(monster->mana() == 150); // default
assert(monster->name()->str() == "MyMonster");
// Get and test a field of the FlatBuffer's `struct`.
auto pos = monster->pos();
assert(pos);
assert(pos->z() == 3.0f);
(void)pos;
// Get a test an element from the `inventory` FlatBuffer's `vector`.
auto inv = monster->inventory();
assert(inv);
assert(inv->Get(9) == 9);
(void)inv;
// Get and test the `weapons` FlatBuffers's `vector`.
std::string expected_weapon_names[] = { "Sword", "Axe" };
short expected_weapon_damages[] = { 3, 5 };
auto weps = monster->weapons();
for (unsigned int i = 0; i < weps->size(); i++) {
assert(weps->Get(i)->name()->str() == expected_weapon_names[i]);
assert(weps->Get(i)->damage() == expected_weapon_damages[i]);
}
(void)expected_weapon_names;
(void)expected_weapon_damages;
// Get and test the `Equipment` union (`equipped` field).
assert(monster->equipped_type() == Equipment_Weapon);
auto equipped = static_cast<const Weapon *>(monster->equipped());
assert(equipped->name()->str() == "Axe");
assert(equipped->damage() == 5);
(void)equipped;
printf("The FlatBuffer was successfully created and verified!\n");
}