Making it easier to work under multiple contexts

Hi,

One of the annoyances of having multiple contexts is having logical entities that are decomposed across two or more contexts, two examples that spring to mind are:

• An enemy in an NPC context having a Player character from a PC context as its attack target.
• Player Chracters, NPCs, Projectiles are each a context, and they are represented on the map in a Tiles context

Handling these kinds of relationships require lots of boiler-plate code, and it would be nice if code generation could be utilized to avoid it. It could be nice to have something like:

class MetaEntity
{
    public EnemyEntity enemy;
    public PlayerCharacterEntity target;
    public ProjectileEntity hittingProjectile;
}

class MetaSytem<MetaEntity> 
{
    ....

    public void Execute(MetaEntity entity) 
    {
    }

    ...
}

Generating the code to create the MetaEntity and MetaSystem would be trivial if the relationship between all three entities would be formalized by indexes or some other component annotation. It would really make working with multiple contexts easier and more worthwhile.

WDYT?

[svanderweele]

I agree with this, being able to use contexts to organise my code better would be incredible.

[thygrrr]

I only kind of agree.

The only problem is in having an entity that contains a bunch of references to other entities.

I solve this with extensions to ContextEntity, which minimizes boilerplate. So if I have an InputEntity e, that has a GameEntity associated with it, through an extension, I can do e.game.hasWhateverGameComponent.

It will obviously throw errors (as it should!) if e doesn’t have a GameLinkComponent or whatever I call it.

Some boilerplate persists when cleaning these puppies up. At times I wish I could get the Component that was removed one last time in some kind of GraveyardSystem. (I wrote that once using delegates, but it wasn’t really worth it, and it broke the timing of the systems). The inability to get the data of a removed component one last time in a System means that you end up with hacky secondary entities “destroyGameLink”, that have their own system.

However, until that triggers, you can’t reuse your original component. Meaning you might need to wait until the next tick (with everything that entails…)