Generic producer/consumer system

[olanti-p]

This idea is an evolution of energy distribution grids we have, and something I hope would be possible with the introduction of actors system.

We have a lot of different sources of ammo, items and charges:

• character, monster and vehicle inventories
• items on the floor
• certain terrains (e.g. water sources)
• vehicle tanks (via taps or siphoning)
• distribution grids (batteries, solars)
• vehicle power (batteries, generators)
• UPS
• character bionic power (storage, generators)
• standalone and integrated batteries and magazines
• charger stations
• items themselves (e.g. solar backpack)
• abstract environment sources (e.g. rain)

And we have a lot of consumers (destinations) of said ammo, items and charges:

• characters directly consuming items (eating/drinking/powering bionics)
• crafting and construction recipes
• most activatable and active tools
• guns (used by characters, monsters or vehicle turrets)
• power armor
• characters charging bionic power banks with cables
• character bionics
• vehicle starters and engines
• distribution grids (lamps, fridges, stationary tools)
• vehicle-mounted tools (hotplates, foodco, water purifier, etc.)
• certain terrains (e.g. cisterns, or water sources annihilating any poured liquid)
• charger stations drawing power

At the moment, many such interactions have to be coded into the game manually (e.g. laser turrets drawing power from vehicles, or tools and items using UPS for power, or various generators producing power for their respective systems). However, this results in a lot of individual cases that are hard to keep track of, test and debug, which leads to constant trickle of bugs like "item x doesn't work with UPS" or "crafting x is bugged when using y that comes via z".

It would be nice if there was a single system that, given a resource demand and destination, would explore the surrounding world and search for reachable providers that could satisfy that demand.

For example: let's say we have a plasma rifle that works off batteries and hydrogen canisters. It needs 50 kJ of energy and 1 charge of hydrogen to fire once, so for each shot it'd create a demand of 50 kJ and 1 hydrogen, and tell our theoretical system to search for them within specified item. Since it's a basic unmodified handheld gun, the system would check within the item's gunmods and magazines, meaning the loaded rifle battery and loaded canister. If they do have enough charges, they'd be consumed and the system would report back to the shooter actor that the demand has been satisfied, and the rifle can fire a projectile.
Let's say the player character has removed the rifle battery and installed UPS conversion mod. Now when the system searches for power to consume, it'd see the UPS conversion mod that acts as a redirect to the source of UPS power on character. That may be either the UPS item with a battery, or the UPS bionic interface that acts as another redirect. For former, our system will analyze contents of the item's battery. For latter, it will keep searching for power within connected bionic power sources: power storage bionic, or a sufficiently powerful generator like the minireactor, or the cable interface bionic that acts as yet another redirect into connected vehicle or house grid, etc.

If this system is abstract enough, it could deal with arbitrary sources and destinations, as well as item types.

Quick list of examples that could be implemented or simplified with such system:

• generators producing power to fill up all connected batteries
• guns using multiple ammo types
• guns using multiple magazines for same ammo type
• flamethrowers and sprayers drawing napalm or fungicide from worn tanks when held, or from vehicle tanks when mounted
• guns mounted as stationary turrets in houses
• characters or monsters sharing resources (e.g. mech could be powered from/provide power for character's bionics)
• monsters (including friendlies) using any guns
• autoloaders for turrets (just dump your 66mm HEAT rounds into the cargo space, and it'll work)
• mounted tools drawing power from vehicle/grid
• tool and gun convertion mods (external magazine, different magazine, UPS convertion, power plug to work off the grid power, hose to work off the vehicle or stationary tanks)