[Feature]: Overlappable chunks of topology

[kwvanderlinde]

Feature Request

At the moment, map topology is "flat", i.e., any point on a map either has a given type of topology or it doesn't. This is fine for Wall VBL and MBL which strictly block vision and pathfinding respectively, but it limits the effects that can be achieved for Hill VBL and Pit VBL.

The Solution you'd like

Make topology more like drawings in that there can be independent pieces of topology on the map. These would be able to be layered on top of one another without being merged into a single area.

Alternatives that you've considered.

Token topology could be modified to behave in this way. Any given token's topology is already separate from map topology and any other token topologies in the sense that it can be moved and manipulated and technically layered on top of each other. At the moment token topology is always merged with map topology on-the-fly when running the vision and pathfinding algorithms, but it seems natural to consider making them truly layered.

Another alternative is to Introduce a different/new system for line-of-sight and pathfinding. This system could focuses on higher-level concepts of like walls, doors, windows, etc. If such a system were based on drawing line segments rather than covering areas, it wouldn't have to worry about explicitly allowing layering as that could happen naturally.

Additional Context

A use case for layered topology is a multi-level tower, as seen from the exterior. This could be represented by a few circles of Hill VBL layered on top of one another.

Similarly, a layered pit could be achieved by layering some nested circles of Pit VBL on top of one another.

[kwvanderlinde]

The more time goes on, the more I believe an implementation based on thin, editable, and configurable walls would be far better than the area-based approach suggested in this FR. Wall VBL might still be useful as a mask, but everything else would be more intuitive if it was wall-based. And these walls would also be easier to hook into for other concepts that have floated around, like doors, windows, elevation, etc.