Rivers don't connect smoothly across overmap boundaries

[sayke]

Describe the bug

Rivers, riverbanks, lakes, and roads don't seem to properly connect to each other across overmap boundaries.

Steps To Reproduce

Steps to reproduce:

1. Create a new character in a new world.
2. Use debug console to reveal map (overmap).
3. Use debug console to teleport to where a river crosses an overmap boundary.
4. Observe weirdly-connected river and riverbank tiles.

Expected behavior

I would expect rivers, lakes, and roads to connect smoothly across overmap boundaries, rather than forming sharp lines along them.

Screenshots

These screenshots illustrate the problem both on the local map and on the overmap.

Versions and configuration

• OS: MacOs
• Game Version: 0.D-10932-g9eb7975 [64-bit]
• Graphics version: Tiles (UndeadPeople)
• Mods loaded: [dda, no_npc_food, No_Rail_Stations, sleepdeprivation, StatsThroughSkills]

Additional context

Rivers, lakes, and road connections all seem to get weird across overmap tiles, so it looks like this may have something to do with the build_connection code that gets used during overmap generation...?

[ZhilkinSerg]

That looks like map extra placed over invalid overmap terrain.

[sayke]

It might look like that in those screenshots, but check this out - could a map extra result in such a smooth line cutting off the lake across the overmap boundary like this? I'm pretty sure it's happening right across the overmap boundary here:

[Night-Pryanik]

Seems like resurrection of #18583?

[sayke]

Seems like resurrection of #18583?

This seems different in that it only shows up along overmap boundaries, but it has to be at least somewhat related. I'm just not familiar enough with the map generation process to figure out how connection-building (I suspect that may be involved?) is supposed to interface with overmap creation.

[ralreegorganon]

Lakes do connect smoothly across overmap boundaries, by design. In all of the screenshots here, all of the waterbodies are rivers. Rivers absolutely do have boundary problems.

[Diabolus-Engi]

Do roads have this issue as well then ? Or just the rivers ?

[ralreegorganon]

Just rivers. Roads will attempt to continue their connections across overmap boundaries, and ever since #33949 and #33996 other linear features like subways and sewers can do so as well (though no code currently pushes them up to the boundaries such that this would be triggered). Roads have a separate problem with nonsensical connectivity between locations, but that is a different issue.