sample.cpp

/*
Copyright (c) 2016 Sam Bloomberg

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

#include <iostream>

#include "ECS.h"

ECS_TYPE_IMPLEMENTATION;

using namespace ECS;

struct Position
{
	ECS_DECLARE_TYPE;

	Position(float x, float y) : x(x), y(y) {}
	Position() {}

	float x;
	float y;
};

ECS_DEFINE_TYPE(Position);

struct Rotation
{
	ECS_DECLARE_TYPE;

	Rotation(float angle) : angle(angle) {}
	Rotation() {}

	float angle;
};

ECS_DEFINE_TYPE(Rotation);

struct SomeComponent
{
	ECS_DECLARE_TYPE;

	SomeComponent() {}
};

ECS_DEFINE_TYPE(SomeComponent);

struct SomeEvent
{
	ECS_DECLARE_TYPE;

	int num;
};

ECS_DEFINE_TYPE(SomeEvent);

class TestSystem : public EntitySystem,
	public EventSubscriber<Events::OnEntityCreated>,
	public EventSubscriber<Events::OnEntityDestroyed>,
	public EventSubscriber<Events::OnComponentRemoved<Position>>,
	public EventSubscriber<Events::OnComponentRemoved<Rotation>>,
	public EventSubscriber<SomeEvent>
{
public:
	virtual ~TestSystem() {}

	virtual void configure(class World* world) override
	{
		world->subscribe<Events::OnEntityCreated>(this);
		world->subscribe<Events::OnEntityDestroyed>(this);
		world->subscribe<Events::OnComponentRemoved<Position>>(this);
		world->subscribe<Events::OnComponentRemoved<Rotation>>(this);
		world->subscribe<SomeEvent>(this);
	}

	virtual void unconfigure(class World* world) override
	{
		world->unsubscribeAll(this);
	}

	virtual void tick(class World* world, float deltaTime) override
	{
		world->each<Position, Rotation>([&](Entity* ent, ComponentHandle<Position> pos, ComponentHandle<Rotation> rot) -> void {
			pos->x += deltaTime;
			pos->y += deltaTime;
			rot->angle += deltaTime * 2;
		});
	}

	virtual void receive(class World* world, const Events::OnEntityCreated& event) override
	{
		std::cout << "An entity was created!" << std::endl;
	}

	virtual void receive(class World* world, const Events::OnEntityDestroyed& event) override
	{
		std::cout << "An entity was destroyed!" << std::endl;
	}

	virtual void receive(class World* world, const Events::OnComponentRemoved<Position>& event) override
	{
		std::cout << "A position component was removed!" << std::endl;
	}

	virtual void receive(class World* world, const Events::OnComponentRemoved<Rotation>& event) override
	{
		std::cout << "A rotation component was removed!" << std::endl;
	}

	virtual void receive(class World* world, const SomeEvent& event) override
	{
		std::cout << "I received SomeEvent with value " << event.num << "!" << std::endl;

		// Let's delete an entity while iterating because why not?
		world->all([&](Entity* ent) {
			if (ent->getEntityId() + 1 == event.num)
				world->destroy(world->getById(event.num));

			if (ent->getEntityId() == event.num)
				std::cout << "Woah, we shouldn't get here!" << std::endl;
		});
	}
};

int main(int argc, char** argv)
{
	std::cout << "EntityComponentSystem Test" << std::endl
		<< "==========================" << std::endl;

	World* world = World::createWorld();

	EntitySystem* testSystem = world->registerSystem(new TestSystem());

	Entity* ent = world->create();
	auto pos = ent->assign<Position>(0.f, 0.f);
	auto rot = ent->assign<Rotation>(0.f);

	std::cout << "Initial values: position(" << pos->x << ", " << pos->y << "), rotation(" << rot->angle << ")" << std::endl;

	world->tick(10.f);

	std::cout << "After tick(10): position(" << pos->x << ", " << pos->y << "), rotation(" << rot->angle << ")" << std::endl;

	world->disableSystem(testSystem);

	world->tick(10.f);

	std::cout << "After tick(10) and DisableSystem(testSystem): position(" << pos->x << ", " << pos->y << "), rotation(" << rot->angle << ")" << std::endl;

	world->enableSystem(testSystem);

	world->tick(10.f);

	std::cout << "After tick(10) and EnableSystem(testSystem): position(" << pos->x << ", " << pos->y << "), rotation(" << rot->angle << ")" << std::endl;

	ent->remove<Position>();
	ent->remove<Rotation>();

	std::cout << "Creating more entities..." << std::endl;

	for (int i = 0; i < 10; ++i)
	{
		ent = world->create();
		ent->assign<SomeComponent>();
	}

	int count = 0;
	std::cout << "Counting entities with SomeComponent..." << std::endl;
	// range based for loop
	for (auto ent : world->each<SomeComponent>())
	{
		++count;
		std::cout << "Found entity #" << ent->getEntityId() << std::endl;
	}
	std::cout << count << " entities have SomeComponent!" << std::endl;

	// Emitting events
	world->emit<SomeEvent>({ 4 });

	std::cout << "We have " << world->getCount() << " entities right now." << std::endl;
	world->cleanup();
	std::cout << "After a cleanup, we have " << world->getCount() << " entities." << std::endl;

	std::cout << "Destroying the world..." << std::endl;

	world->destroyWorld();

	std::cout << "Press any key to exit..." << std::endl;
	std::getchar();

	return 0;
}