[neovolgan]

Implements section 4 of the transfer contract (#2). It is stacked on #3 because both raise the world format to 7. Merge #3 first; this PR then retargets to develop.

Why a separate layer:

• LinearFeature allows 64 features per map, and fences built as decorations take the single decoration slot of a cell.
• One Pilna section has more than 1000 fence lines and about 41k fence edges, so neither fits.

Model (FenceLines.cs; MapProject and WorldProject both get Fences, FenceStyles and GateStyles):

• FenceLine:
  • grid points; runs must be horizontal or vertical along cell edges;
  • a style;
  • PostSpacing, with posts at corners and every N edges;
  • gates;
  • source ID, tags and lon/lat path.
• FenceStyle: W, N, optional NW corner, Post, and WAlt/NAlt every AltEvery edges (a brick pillar between forged sections).
• GateStyle: 1–8 edges wide, closed pieces plus optional open pieces. OpensTo = left mirrors the piece order.

Composition and export:

• A horizontal edge gives N on the cell to its south, and a vertical edge gives W on the cell to its east.
• When both edges of one style are plain, the cell gets NW.
• Edge pieces carry the native navigation bits (2 = N, 4 = W). Gates carry none.
• Edges on building footprints or water are skipped and counted per reason; overlaps are counted too.
• TileComposer adds the pieces after decorations, so a fence and a decoration (bush, lamp, bench) share a cell.
• World fences are projected into every section they cross, with section-local coordinates, and clipped per cell, so a fence stays continuous across seams.
• A style ID used by both the world and a section must mean the same tiles, otherwise validation fails.

Formats:

• A fence layer raises the map format to 12 and the world format to 7, in C# and JS.
• Geographic reimport with Preserve edits keeps fences.
• The editor accepts format 12. Drawing and editing fences in the UI is left to the editor-side work, per the split in docs: real-place transfer contract v1 #2.

Tests (FenceLineTests):

• edges, NW merge, double gate order, opened wicket, navigation bits, pillar pattern;
• left-opening mirror, post spacing, blocked and counted building edges;
• validation:
  • diagonal runs;
  • unknown style;
  • a gate around a corner;
  • overlapping gates;
  • bad opening side;
  • a gate set open without open pieces;
  • bad tile;
  • duplicate line;
• JSON round-trip and format 12;
• a fence and a decoration on the same cell both reach the native .lotheader;
• a world fence crossing a 256-tile seam has 6 + 6 continuous edges and reaches both cells' lot headers;
• conflicting world and section styles are rejected.

Results: dotnet run --project tests/SimplePZMapmaker.Tests 343/343 passed, npm test 184/184 passed.

Next from my side: GeoJSON barrier=* lines → fence lines (style mapping, staircase for diagonals, gate points), and the Pilna pipeline switching its fences to this layer.

🤖 Generated with Claude Code

https://claude.ai/code/session_015ECCGjSrSADcjxBmXdCBpm

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