Chris Tsang 17a9a6e6c5 Add mosaic mode: seam-free tessellation (pixel + polygon) ...

Implements the topological mosaic pipeline from docs/design/mosaic.md, turning
`--hierarchical cutout` into a true gapless tessellation instead of the old
re-cluster-and-retrace fake.

  LabelMap (flatten Segmentation top-down)
    → boundary-graph extraction  (integer-exact: corners, node rule, segment
                                   and ring tracing on the pixel-corner lattice)
    → face assembly              (left-region successor rule; winding falls out,
                                   so each region is one nonzero-fill path)
    → fit each segment ONCE       (shared by both adjacent faces, reversed
                                   exactly → byte-identical shared boundaries)
    → compose per-region paths

Backends: PixelSegmentFitter (exact reference) and PolygonSegmentFitter
(symmetric open Douglas-Peucker collapsing staircases to the crack midline).
The spline segment fitter is still pending; mosaic + spline currently falls
back to polygon.

Compositing now owns its fitter (Stacked(CurveFitter) / Mosaic(SegmentFitter)).

Tests: single region, vertical split, T-junction, checkerboard pinch, nested
rings, border-touching, and a pixel round-trip property test over 40 random
maps (rasterize composed faces == input label map). Plus two mosaic goldens.

2026-07-23 23:26:18 +01:00

..

vtracer

Add mosaic mode: seam-free tessellation (pixel + polygon)

2026-07-23 23:26:18 +01:00

vtracer-cli

Rewrite into a vectorization framework (pillars 1–4)

2026-07-23 22:27:24 +01:00