ArtemisD: A D port of Artemis Entity System Framework for games.

[Elvis Zhou]

On Monday, 7 October 2013 at 17:06:40 UTC, Kiith-Sa wrote:
> On Monday, 7 October 2013 at 15:21:00 UTC, Elvis Zhou wrote:
>> On Monday, 7 October 2013 at 14:19:20 UTC, Ali Çehreli wrote:
>>> On 10/07/2013 02:18 AM, Elvis Zhou wrote:
>>>
>>>> ArtemisD:
>>>> https://github.com/elvisxzhou/artemisd
>>>
>>> Just a little note: As it's more readable, you may want to 
>>> use 1000.msecs instead of dur!("msecs")(1000) in the example 
>>> program. 1000.msecs is the equivalent of the msecs(1000) 
>>> function call, which returns dur!("msecs")(1000).
>>>
>>> Ali
>>
>> Done, thank you!
>
> I'm implementing pretty much the same thing in my project, 
> although I'm probably
> more in line with the original blog post (e.g. every system can 
> only access
> specific components of an entity, which are statically 
> determined, entities are more lightweight, etc.). I'm using 
> much less OOP and more of a generic/metaprogramming approach. 
> Currently I'm trying to rewrite the code to add a concept of 
> "past" and "future" state; a System processes past Components 
> and outputs a future Component, past Components are const, and 
> no two systems may write to the same future Component. This 
> should allow very simple threading
> with little synchronization.
>
> I'll look at your code if there are interesting ideas.
>
> The previous version of my entity system is used in my ICE game:
>
> https://github.com/kiith-sa/ICE
>
> It's quite messy, though; which is why I'm rewriting it.
> The new version doesn't even compile at the moment, I'm working 
> on it slowly as I'm studying and working at the same time right 
> now.
>
> I'll look over the comment and post if I have any further 
> feedback. The only thing I can say right now is that there is 
> inconsistent tab-space indentation in some parts of the code 
> (e.g. 
> https://github.com/elvisxzhou/artemisd/blob/master/source/artemisd/entity.d 
> )

I'll give it a try, thank you!

My main concern in the D port is, since getComponent is the
most important and most used function, often in every frame,
but caching it is not a good idea cause any component may
be removed or added at any time, with an additional
mixin TypeId in component definition, component then can be
get with its TypeId(index of component list) in zero cost.
In other ports, like Java or C#, even in C++, a ComponentMapper
like stuff is used to hash a component type to find a registered
index before you can get it efficiently.

What do you think?