Add subway maps

[wapcaplet]

Summary

SUMMARY: Content "Add subway maps and spawn locations/itemgroups"

Purpose of change

Lots of other great maps existed in game, but none showing subway lines.

Describe the solution

Based directly on existing maps, this subway map can be found in motels, subways, and in a few itemgroups alongside its brethren only in subway tool rooms with a 75% drop rate. When activated, it reveals the location of subway stations, underground subway stations, and subway lines (yellow and blue "S" tiles).

Describe alternatives you've considered

None really Considered NOT showing the blue "S", but reconsidered.

Testing

Tested with debug; spawned a subway map, activated, and saw yellow "S" all over the map, and both yellow and blue "S" underground, with subway lines connecting them. Didn't reveal any other terrain.

Additional context

Inspired by the signs found inside the subway stations that say "Subway map", but (still) aren't an actual map of the subways.

[anothersimulacrum]

Subway labs are probably secret, these probably shouldn't show them.

[I-am-Erk]

Hm, I'm not sure a regular subway map would show the lines. It probably had a schematic diagram of them but not a useful map. It could identify the stations though, and you could make a rarer subway maintenance map that shows the lines themselves?

[Brian-Otten]

I think the map you find in the world would have the stations and lines marked, because to find the stations you usually use a map of the area with the subway overlayed on it, so you could actually find the subway stations using the local roads. See how google maps handles subways.
The subway station themselves would have the "schematic" map, which would probably tell you neither line nor station location, just which station connects to which.

[wapcaplet]

Does the game have any implementation of schematic (as opposed to geographical) maps? I don't even know how such a thing would work in-game. All the in-game maps that I know of are strictly geographical - you can stand on top of a wheat silo for 10 seconds and get a 100% accurate survey of the whole area (not just a crudely sketched schematic, as would be more realistic).

How would you know that Bobsville and Johnstown are connected via subway, if the map is not allowed to display the lines between them? A map that shows only the subway stops seems fairly useless.

I am not keen on building a whole new schematic map feature just to support this. If the map should be rarer, or only drop inside the subway maintenance room or something, would that mitigate complaints that it's too OP?

[mrkybe]

Does the subway map reveal/make obvious subway lab locations (is that what the blue S is?)? If so, I think its a bit OP and should be some rarer maintenance closet thing. Otherwise, I think its fine as is.

[wapcaplet]

Does the subway map reveal/make obvious subway lab locations (is that what the blue S is?)?

Yes, I confirmed with teleport and map reveal that the blue "S" is indeed a microlab subway entrance. This is strange, because those are defined as a separate terrain microlab_sub_station that my map does not specifically reveal:

Cataclysm-DDA/data/json/overmap/overmap_terrain/overmap_terrain_microlab.json

Lines 33 to 36 in bab7781

	"id": "microlab_sub_station",
	"name": "subway station?",
	"sym": "S",
	"color": "light_blue",

But after testing I learned that revealing sub_station alone reveals sub_station, sub_station_roof, sewer_sub_station, and microlab_sub_station (and anything else with sub_station as a sub_string, hah)

Cataclysm-DDA/src/iuse_actor.cpp

Lines 1154 to 1157 in 7a0ad59

	for( const JsonValue entry : obj.get_array( "terrain" ) ) {
	if( entry.test_string() ) {
	ter = entry.get_string();
	ter_match_type = ot_match_type::contains;

Even if the yellow and blue S'es could be revealed separately, the subway lines would kind of give away where they are anyway. And in my experience, even knowing where they are doesn't help a lot, since they often don't have an aboveground entrance, and it's a pain to loot them through half a mile of subway track and two or more staircases.

Edit: I figured out how to avoid revealing the blue "S" lab entrances. You can still see where they are, but gotta be looking for it. Hint: They're fricking everywhere.

Edit2: Now might be a good time to mention that the regular "Road map" you can find just about anywhere also reveals hidden underground blue S subways, through the above string-matching rule:

Cataclysm-DDA/data/json/items/book/maps.json

Line 74 in ffc3ce3

"sub_station",

[wapcaplet]

My latest commits could be summarized thus:

• The subway map is now a "subway maintenance map"
• The only place you can find it is in the back tool room of L-1 of Subway buildings (with 75% chance)
• It no longer shows the blue "S" where underground lab entrances are

Here it is, alongside the 3 brick kilns, 1 electric kiln, 5 concrete mixers, 2 metallic smoothers and a toolbox (is the loot back here always this ridiculous?):

I got a curious message when I tried to activate it. Not sure how the subway workers managed:

It worked aboveground though. Frankly I want to put the blue "S" reveals back in; the map looks almost bugged without them, and the player can easily guess where they are. (Hint: everywhere. I am starting to believe underground labs are more common than regular subway stops.)

[wapcaplet]

Given that the regular "Road map" displays the super-secret blue "S", and this new subway map only drops in one place now, and given that restoring the blue "S" to my map makes the JSON 4 ugly lines shorter, I went ahead and did it. This is my final version, unless anyone has reason to object.

[Night-Pryanik]

You can specify to reveal only the exact location you need by using the following syntax in the list of terrains

{ "om_terrain": "location_id_you_need", "om_terrain_match_type": "TYPE" },

[ZhilkinSerg]

You can use different overmap terrain match type if you need it, e.g.:

Suggested change

	"terrain": [ "subway", "sub_station" ],
	"terrain": [ { "om_terrain": "subway", "om_terrain_match_type": "TYPE" }, "sub_station" ],

[wapcaplet]

Thanks—I did something like this in previous revisions, but was happier with the “contains” matching I got from the plain string.

[wapcaplet]

Since this one is waiting on content freeze anyway, I made one more change (7daac7e) to the regular road map, so it no longer shows underground subway stations. Now, the "subway maintenance map" will be the only map that reveals the underground blue "S", and the regular "road map" will only reveal above-ground yellow "S" (public subway entrances).