Handle polygon vertex intersections without false crossings

[Copilot]

Duplicate edge intersections at polygon vertices were being collapsed into a single crossing, incorrectly changing extrusion override occupancy when a segment only touched a vertex.

• Intersection handling
  • Preserve all vertex-generated intersections.
  • Classify occupancy immediately before and after each hit.
  • Update override state only according to the actual geometric transition.

const bool before = area.inside(position_before, true);
const bool after = area.inside(position_after, true);
areas_under_segments[index] = after;

[Erwan MATHIEU (wawanbreton)]

Copilot Doing a double inside() call for every intersection seems a bit too much calculation, especially since this function is called for every single extrusion segment. Can you make a version that would be more optimized ?

[Copilot]

Copilot Doing a double inside() call for every intersection seems a bit too much calculation, especially since this function is called for every single extrusion segment. Can you make a version tha...

Optimized in commit a3f5d9e: ordinary single-edge intersections now use the existing toggle path, while only clustered near-equal vertex hits perform one inside() classification.

[Erwan MATHIEU (wawanbreton)]

Well, this is still a bit reducing: the intersections cluster could actually be spread over multiple override areas. In order to be complete, you should implement a loop that goes over the intersections lists and keeps adding elements to the clusters as long as it find any element that is at a distance of actual_last_intersection+epsilon_factor.

[Copilot]

Well, this is still a bit reducing: the intersections cluster could actually be spread over multiple override areas. In order to be complete, you should implement a loop that goes over the intersectio...

Implemented in commit c6d2e8f: clusters now grow across all override-area intersection lists, repeatedly extending the boundary from the latest hit plus epsilon_factor.

[Erwan MATHIEU (wawanbreton)]

Proposed solution is still not complete, finishing it manually in the branch.