• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
Irlan

Advice on Component Based System

3 posts in this topic

Well I've read probably most of the Component Based Architeture articles but I need to know if I'm getting somewhere.
The Sync Struct is the data needed for the System works. When a new entity is created the method adds the specific components to the
corresponding system. The System (logically) operates one and modifies other (on that specific case).
 

class Actor;
class RigidBody;

struct PhysicsSync {
Actor* actor;
RigidBody* body;
};

class PhysicsSystem {
public:

void Update(float dt)
{
this->CheckCollisions();
for (size_t i = 0; i < sync.size(); ++i) {
sync[i].body->Update(dt); //temp (not updates itself)
sync[i].actor->SetTransform(sync[i].body->BuildTransform()); //temp (not builds itself)
}
} 
void PushSync(Actor* _actor, RigidBody* _body)  
{ 
PhysicsSync target; 
target.actor = _actor; 
target.body = _body; 
sync.push_back(target); 
}

void RemoveSync(Actor* actor, RigidBody* _body)  
{  
//...
}

void ClearSync() { sync.clear(); } 

private: 
void CheckCollisions(); 
std::vector<PhysicsSync> sync; 
};

If I'm correct the trickiest part now It's find some way of implementing a flexible and simple event/messaging system.

 

I think that with this approach one of the things that I can do is...

struct ResponseSync { //collision response
Entity* entity; //assuming that component holds a owner pointer 
RigidBody* 
}

Basically the ResponseSync takes the form of a Event/Message.

Edited by irlanrobson
0

Share this post


Link to post
Share on other sites

What are Actor and RigidBody? Are those components?

 

This means that there is some outside code that knows specifically about a PhysicsSystem, and more importantly that entities with Actor and RigidBody should be added via PhysicsSystem.PushSync.

 

Instead, I would think this logic would exist in the PhysicsSystem. e.g. systems in general implement a common interface that has methods for adding/removing entities. When it's called, the PhysicsSystem itself knows that it's interested in entities with Actor and Rigid body, and can then add them to some internal list. That way you don't need outside logic that knows about the PhysicsSystem (other than a single line of code that says, "create a PhysicsSystem and add it to the list of systems") and that it depends on Actor & RigidBody.

0

Share this post


Link to post
Share on other sites

What are Actor and RigidBody? Are those components?

 

This means that there is some outside code that knows specifically about a PhysicsSystem, and more importantly that entities with Actor and RigidBody should be added via PhysicsSystem.PushSync.

 

Instead, I would think this logic would exist in the PhysicsSystem. e.g. systems in general implement a common interface that has methods for adding/removing entities. When it's called, the PhysicsSystem itself knows that it's interested in entities with Actor and Rigid body, and can then add them to some internal list. That way you don't need outside logic that knows about the PhysicsSystem (other than a single line of code that says, "create a PhysicsSystem and add it to the list of systems") and that it depends on Actor & RigidBody.

 

1. Yes

2. Was just a simple way of saying...

3. I completely agree with you in that case. Now, following your method, becomes:

class Entity {
public:
template <class T> 
T* GetComponent(const std::string& _id)
{
std::map<std::string, Component*>::iterator it = component.find(_id);
if (it != component.end()) {
return static_cast<T>(it->second);
} else {
return 0;
}
}
};
class PhysicsSystem {
public:
PushComponent(Entity* _entity)
{
Actor* actor = _entity->GetComponent<Actor*>("Actor");
RigidBody* rbody = _entity->GetComponent<RigidBody*>("RigidBody");

if (rbody && actor)  {
PhysicsSync sync(actor, body);
sync.push_back(sync);
}
}
};
Edited by irlanrobson
1

Share this post


Link to post
Share on other sites
Now I'm looking for a way to handle messages (the communication between components)...
 
Eg.:
 
AIAgent inherits a Component Interface.
Inside that agent a script runs and tells that a bullet needs to be spawned with some properties.
In my Point of VIew:
 
The Entity holds a Reference of the EntityFactory (an EntityManager in that case) and the Component holds a Reference to the Entity. Then I get a component from some Entity that satisfy the message and create a Bullet in the EntityFactory. If I'm correct, the EntityFactory will notify the subsystems for the Entity and those take the correct components.
 
When an Entity is invalidated from a component condition, hard work it's required to find his components and remove those from the Systems.
 
Passing Messages to the Components (for me) doesn't help a lot. If a Bullet needs to be spawned, the interaction isn't with the component itself but, instead, with the EntityFactory and the Systems.
 
In my actual implementation I don't use many Components so I'm just passing a reference directly...
 
class RigidBody : public Component {
public:
SceneNode* snode; //sends a world transform to the component when updated
};
 
Both approaches leads to a insane class dependency that I think should be avoided. Someone got other approaches that fits better for the component model?
0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0