Basic Enemy AI

[thombruce]

See also #55 and #53.

I've decided to separate out enemy AI into its own issue, as it is a pretty involved system and the scope of #55 is already quite expansive.

[thombruce]

Looking into steering behaviours as a way to handle the basic AI: https://code.tutsplus.com/series/understanding-steering-behaviors--gamedev-12732

[thombruce]

Just reading the first page, it's clear the document used to have examples that ran in Flash. Clearly a very old article, but still useful...

I wonder if I can find something a little more up to date though.

[thombruce]

"Flocking" is a concept I hadn't considered too. big-brain would be good for deciding whether an entity should flock or fly solo, possibly switching between the two when necessary.

We won't implement that early. Just some basic pursuit and combat initially, but flocking advances the behaviour considerably towards feeling like the enemies have ideas of their own.