Support robots in cells in world description DSL

[byorgey]

It should be possible to define robots in the robots section of a scenario description, and then refer to them from within a world DSL term.

[byorgey]

I've been working on this in feature/world-dsl-robots, and just realized it's going to be a bigger change than I thought.

• Currently, when starting a scenario, we simply collect all the robots in the single world map, instantiate them and stick them in the robot map so they start running immediately.
• But now, if robots can occur in cells described by the world DSL, then robots can show up anywhere in the (essentially infinite) world, so it will no longer be remotely feasible to collect up all the robots all the robots in the world and start them running at the beginning. We will have to implement #29 , that is, spawn robots dynamically.

Some thoughts on how to do this:

• We will have to keep track somehow of which robots we have already spawned so we don't spawn the same robot multiple times.
• The easiest idea I think is that whenever we load/cache a tile, we spawn any robots contained on the tile. However, we will need to reconsider what it means for a tile to be loaded.
  • Currently, we only load tiles when they are to be drawn on the screen.
  • Instead, perhaps we should load a tile any time a robot gets "near enough" (whatever we define that to mean), whether we are viewing that robot or not.
  • However, it is easy to imagine robots setting off a "cascade" of tile loads that grind the game to a halt: loading a tile spawns a robot which wanders off to another tile, which spawns a robot that wanders off... etc. Probably only player-built robots should cause tile loads, whereas system robots should not.

As a separate feature, we may in the future want to allow certain robots to dynamically despawn as well as spawn. e.g. imagine that you encounter a town and there are robots representing "NPCs" who wander around and do stuff, let you interact with them, etc. Once we leave the town there is no reason to keep simulating those robots. But I think I will leave this to a future PR.

@kostmo , @xsebek , would love to hear your thoughts + ideas on this!

[xsebek]

I think we should really invest in our debugging capabilities first.

I would really like to visualise the tiles on world map, get a minimap of tiles, get a popup list of tiles and export tiles from Web API. There is more that we could show about robots, such as the waiting and evaluation queue.

That said, I would love to have robots spawn and despawn. It could make the world more interesting and force players to venture far from the initial base.

[xsebek]

Re: robot cascade - what if we just froze system robots that attempt to leave loaded tile boundary?

If player robots comes near the boundary, the tile will get loaded and system robots will get woken up. If we apply the limits of normal meet/etc. range, then the player will not be able to observe the frozen robots.