Overmap Zones

[vache]

Zone thoughts:

• Some created at OM generation, others when certain events occur.
• Should be able to have a density/strength value, but should not be necessary.
• Should have some mechanism to grow and shrink where possible. Zones that change terrain and furniture may be difficult to revert, unless we track what the zone looked like before which could be expensive.
• Could also have a mechanism to move around, especially if it were related to some mobile entity.
• Growing, shrinking, and moving could result in a need to be able to merge and split zones as well.
• This will probably require another processing step, possibly every N turns, to apply zone changes.
• Mapgen should use zones in post processing to apply whatever changes are necessary.
• Should be possible for multiple zones to affect the same area.

Universal Zones:

• Overgrown (Triffids): Lots of Triffids and plant growth. Vines cover buildings, inside areas are filled with roots, sealed areas should remain sealed though (bank vaults, lab entrances, bunker entrances, etc).
• Fungal: Fungus has covered the area, fungal creatures abound.
• Flooded: Area has been flooded. May not be possible until water is changed.
• Contaminated: Almost devoid of life. No grass, trees, or wildlife. Water may be nastier than normal. Nether creatures and zombies may remain, but in smaller numbers than would be expected. Non-sealed food is probably contaminated somehow. Prolonged exposure without protective gear causes sickness? Maybe litter the ground with corpses of all sorts?

City zones:

• Looted: Most shops and some houses have windows smashed and valuable items taken. Single casings, blood, and trash cover the ground. Some buildings burned down. Extra zombies, extra dead police/soldiers and their gear laying around.
• Bombed: Craters cover city, buildings destroyed. Fewer zombies as a whole, and they tend to congregate around bombed areas.
  • Some bombed cities also irradiated
• Locked down: Checkpoints at city entrances. Heavily armed robots patrol streets, turrets set up at key areas, dead soldiers. Fewer zombies due to being killed by robots.

Nether zones: These zones could be focused around interdimensional portals and other anomalies. All should have increased nether enemy spawns.

• Ice: Perpetual cold, think ice lab but not confined to lab environment.
• Hallucinogenic: Nether environment messes with players mind causing them to hallucinate uncontrollably while in the zone.
• Night: Severely reduced vision capacity in this zone, not aided by night vision.
• Madness: Hallucinations + severe morale penalty + disorienting (character occasionally steps in wrong direction). Could be a more intense type of hallucinogenic zone. Minimap and map blacked out or otherwise incorrect somehow?
• Freaky weather: Acid rain, weird electrical storms, etc.
• Nether colony: Alien flora and fauna have established a foothold.

Other uses for zones:

• Moving zones could be used for weather, like blizzards, storms, etc.
• Zones could also represent faction control/influence.
• Zones could represent an area of interest for hordes?

[vache]

overmap_zone class:

• methods:
  • void move(x, y, z) - shift all the points in the area by x, y, z amount
  • void add_area(tripoint) - add point to the area
  • void remove_area(tripoint) - remove point from area
  • void grow_area(int) - expand by int in each direction
  • void shrink_area(int) - shrink by int in each direction
  • void update() - recheck or reapply any effects of the zone
  • void increase_strength(int) - add int to zone strength
  • void decrease_strength(int) - remove int from zone strength
  • void set_strength(int) - set strength to int
  • bool point_in_zone(tripoint) - returns true if point is in zone area, otherwise false
  • int (float?) strength_at_point(tripoint) - returns strength at given location, taking fade into account
  • jsonObject save() - write out an object for save
  • void load(jsonObject) - load a zone from json
• properties
  • container tripoint area - collection of points that make up the zone. could be in omt coordinates or sm coordinates, and could be stored as offsets to the center point to ease in movement calculations
  • enum type - what kind of zone it is
  • int strength - how strong the zone is at its center
  • bool fade - does the effect of the zone fade near the edges
  • tripoint center - the center of the zone used for strength calculations
  • container int? hub_creatures - if the zone is creature based, these are the "queen" creatures that will cause the zone to lose strength and break apart. Examples: triffid heart, fungal tower, etc.

overmap class:

• methods:
  • void move_zone(overmap_zone &, tripoint) - move the zone towards the point
  • void place_zones() - put zones on the om
• members:
  • collection overmap_zone - the zones on the overmap

overmap_buffer class:

• methods:
  • void move_zone_across_overmaps(overmap_zone &, overmap) - moves zone to new overmap

mapgen:

• methods:
  • void post_process(type, int strength) - apply any special zone mapgen depending on type and strength

[vache]

Strength fade:

• Right now, city size is used as strength
• Other values could be used for other zones
• Maybe still use the 0-16 city size scale though
• The stored strength value represents the strength at the center of the zone
• Fade in general should be based on distance from center

[BorkBorkGoesTheCode]

@vache if you are still interested, could you work on this? The Nether areas in particular would really improve the game.

[vache]

I think @ZhilkinSerg said he was looking at reviving the branch. I don't have as much time to work on code for fun as I used to, but I have been tempted to contribute something lately, so maybe I will take a look at it. I'm currently more interested in improving cities right now, though this might be a good thing to warm up with if I exclude the more difficult features like movement and growth.