Spawn Enemies

[thombruce]

closes #111 closes #83 closes #13

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Internal use. Do not delete.

• [x] Tests passing
• [x] Coverage sufficient
• [x] Manual review
• [x] No A11y regression
• [x] Translations provided or not needed

[thombruce]

TODO

• [x] Spawn indicators for newly spawned enemies
• [x] Spawn at semi-random location
• [x] Guarantee spawning outside of player view
• [x] Guarantee spawning greater than given distance from player
• [x] Cap/limit enemy spawning to under a given number

[thombruce]

Main thing above is to spawn indicators... This is going to be a bit tricky, as presently the indicator system spawns during setup.

We need to get the indicator container inside a different system, and spawn an indicator based on... the event of a new entity having been spawned. This could use the events system.

Key to how this works, we must not spawn new indicators every tick for entities that already have indicators. It is a one-and-done deal. So the indicator system must retain some knowledge or... if we use events, it matters a little less.

I think probably we should prefer to check each tick for entities without indicators and spawn for them.

So... iterate over entities, filtering for those that do not presently have a shown indicator, and spawn the indicator for them.

[thombruce]

Justification for adding #13 to the list of issues to be closed:

The "game" is officially "gamified".

There's a random element, it becomes harder and harder to outlast and survive, the player is rewarded with a score for every hit and every confirmed kill.

There's plenty more to add, like weapon and shield/invulnerability power-ups, different enemy types, more ways to increase your score, health drops, etc. etc. but some of this may be post-v0.1. The basic gameplay that the issue was setup to suggest be done... is now done.