Closes the UX gap identified in the Phase-8b-Lite design discussion:
the four classical-DCE CGAL entries now optionally run their `*_layout()`
step internally if the caller supplies `CGAL::parameters::output_uv_map(pmap)`.
Before this PR, the workflow was:
auto res = CGAL::discrete_conformal_map_euclidean(mesh);
// ... user has to re-set up maps, re-pin vertex, then ...
auto layout = euclidean_layout(mesh, res.x, maps);
// ... and copy coordinates into a property map manually.
After this PR:
auto uv = mesh.add_property_map<Vertex_index, K::Point_2>("uv", ...).first;
CGAL::discrete_conformal_map_euclidean(
mesh, CGAL::parameters::output_uv_map(uv));
// ... uv now populated for every vertex.
Coverage
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* `discrete_conformal_map_euclidean` — `Point_2` per vertex.
* `discrete_conformal_map_spherical` — `Point_3` per vertex (on S²).
* `discrete_conformal_map_hyper_ideal` — `Point_2` per vertex (Poincaré disk).
CP-Euclidean and Inversive-Distance entries do not yet support
`output_uv_map` — face-based packing has no per-vertex UV concept, and
inversive-distance needs a dedicated layout routine that uses Luo's
edge-length formula (planned follow-up).
New named parameters (`code/include/CGAL/Conformal_map/internal/parameters.h`)
─────────────────────────────────────────────────────────────────────────────
* `output_uv_map(pmap)` — write coordinates into pmap after layout.
* `normalise_layout(bool)` — apply post-layout canonical normalisation
(PCA centroid for Euclidean, north-pole alignment for Spherical,
Möbius centring for Hyper-ideal).
Both follow the existing Phase-8a-MVP named-parameter convention.
Chained syntax (`.output_uv_map(...).normalise_layout(true)`) is not
yet supported — pass them one at a time.
Tests (5 new in test_cgal_phase8b_lite.cpp)
───────────────────────────────────────────
* `OutputUvMap_Euclidean_PopulatesPmap` — UVs are finite + non-trivial.
* `OutputUvMap_Spherical_PopulatesXyz` — every output on unit S².
* `OutputUvMap_HyperIdeal_PointsInPoincareDisk` — |p|² ≤ 1 if converged.
* `OutputUvMap_Absent_DoesNotRunLayout` — no parameter ⇒ no layout.
* `OutputUvMap_NormaliseLayout_TakesEffect` — both raw + norm calls
return finite UVs (named-parameter chaining limitation documented).
All five pass. Full CGAL suite: 232/232, 0 skipped (was 227).
doc/api/tests.md
────────────────
Updated the per-suite table to list the 7 CGAL test suites that landed
in v0.9.0 (8a MVP + 9a + 9b + 8b-Lite) but had not yet been added to the
canonical table. Total: 227 → 232. This brings the doc back in sync
with `ctest` output and unblocks future `scripts/check-test-counts.sh`
runs.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
First step of the Phase 8 Hybrid MVP. Adds a thin CGAL-conformant public
API layer over the existing implementation, validated by 7 acceptance
tests. Total CGAL test count: 183 (was 176), 0 skipped.
New public headers
──────────────────
* code/include/CGAL/Conformal_map_traits.h
- ConformalMapTraits concept documentation
- Default_conformal_map_traits<Surface_mesh<P>, K> specialisation
- Static property-map accessors: vertex_points, theta_map,
vertex_index_map, lambda0_map
* code/include/CGAL/Discrete_conformal_map.h
- User-facing entry: discrete_conformal_map_euclidean(mesh, np)
- Conformal_map_result<FT> struct (u, iter, ‖G‖, converged flags)
- Natural-theta default: x = 0 is the equilibrium when no Θ supplied
- Honours user-provided Θ via vertex_curvature_map named parameter
* code/include/CGAL/Conformal_map/internal/parameters.h
- 4 named-parameter tags in CGAL::Conformal_map::internal_np:
vertex_curvature_map, gradient_tolerance,
max_iterations, fixed_vertex_map
- User-facing helpers in CGAL::parameters::*
Tests (test_cgal_traits_mvp.cpp, 7 cases)
─────────────────────────────────────────
* DefaultTraitsTypes: compile-time type sanity (static_assert)
* AccessorsReuseExistingMaps: traits accessors return identical pmaps
* SingleTriangleConverges,
QuadStripConverges: end-to-end Euclidean wrapper passes
* MaxIterationsTakesEffect: named parameter is read
* GradientToleranceTakesEffect: tolerance override changes Newton end-state
* WrapperMatchesLegacyAPI: cross-API result equality at 1e-10
Architecture
────────────
3-layer wrapper as designed (doc/api/cgal-package.md):
Layer 1: code/include/*.hpp (existing algorithms, unchanged)
Layer 2: CGAL/Conformal_map/internal/ (adapter, parameter tags)
Layer 3: CGAL/Conformal_map_traits.h, CGAL/Discrete_conformal_map.h
(user-facing)
No algorithm duplication. Existing 176 + 36 tests untouched.
Next: Phase 9a (Inversive-Distance) as the second client of this API —
the real acceptance test for the trait design.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
