ConformalLabpp/CHANGELOG.md

Changelog

All notable changes to conformallab++ are recorded here. Format follows Keep a Changelog; the project uses Semantic Versioning.

---

[0.9.0] — 2026-05-22

The “DCE-complete + CGAL-surface-complete” release. Two new discrete- conformal models, the analytic-Hessian optimisation for HyperIdeal, the CGAL public API surface for all five models, and a full documentation audit that corrects four pre-existing port-vs-research mis-labels.

Added — new functionals (Phase 9a)

• code/include/cp_euclidean_functional.hpp — CP-Euclidean functional (face-based circle packing), Bobenko-Pinkall-Springborn 2010. Direct port of CPEuclideanFunctional.java (260 Java lines + 88-line test). Analytic 2×2-per-edge Hessian h_jk = sin θ / (cosh Δρ − cos θ).
• code/include/inversive_distance_functional.hpp — Inversive-Distance functional (vertex-based, Luo 2004 + Glickenstein 2011). No Java original — implemented from the literature with Bowers-Stephenson 2004 initialisation. Cross-validated against the Euclidean functional at the natural initial geometry (Glickenstein §5).

Added — Newton solvers (Phase 9a-Newton)

• newton_cp_euclidean() — uses the analytic Hessian.
• newton_inversive_distance() — uses FD Hessian; analytic via Glickenstein 2011 eq. (4.6) tracked in research-track.md as Phase 9a.2-analytic.

Added — Hessian optimisation (Phase 9b)

• hyper_ideal_hessian_block_fd() — per-face 6×6 block-local Hessian for HyperIdeal. 96.5× speed-up measured on a 200-face mesh (V=202, 603 DOFs), full-FD 226 ms → block-FD 2.3 ms.
• Java parity note: HyperIdealFunctional.java:295-298 declares hasHessian() == false; both FD variants are conformallab++ research extensions beyond the Java port.

Added — CGAL public API surface (Phase 8b-Lite)

• <CGAL/Discrete_conformal_map.h> extended with discrete_conformal_map_spherical() and discrete_conformal_map_hyper_ideal().
• <CGAL/Discrete_circle_packing.h> — Default_cp_euclidean_traits + discrete_circle_packing_euclidean().
• <CGAL/Discrete_inversive_distance.h> — Default_inversive_distance_traits
  • discrete_inversive_distance_map().
• <CGAL/Conformal_layout.h> — thin CGAL-namespace re-exports of euclidean_layout, spherical_layout, hyper_ideal_layout.

All five DCE models are now reachable from a single #include <CGAL/Discrete_*.h>.

Added — documentation

• doc/roadmap/research-track.md — new consolidated catalogue of every conformallab++ item that goes beyond the Java port, with full literature citations and acceptance criteria. Includes the Phase 9b-analytic plan (Schläfli 1858 + Springborn 2020 §4 + Cho-Kim 1999 + Glickenstein 2011 §4).
• doc/architecture/phase-9a-validation.md — line-by-line mapping CPEuclideanFunctional.java ↔ C++ port, plus three special-case verifications of Luo’s edge-length formula.
• doc/roadmap/phases.md — Phase 9 split into 9a.1 (Java port) / 9a.2 (research) / 9b (research); new Phase 11+ section with optional Schottky uniformisation and Riemann-map sub-packages.
• doc/math/references.md — five new primary literature entries (Bowers-Stephenson 2004, Glickenstein 2011, BPS 2010, Schläfli 1858/60, plus a reframed Luo 2004 entry).

Changed

• Four port-vs-research mis-labels corrected (full audit documented in research-track.md):
  • InversiveDistanceFunctional.java does not exist in the Java repo; the C++ implementation is research, not a port.
  • HyperIdeal Hessian: Java has hasHessian()==false; C++ Hessians are research, not ports.
  • add-inversive-distance.md tutorial rewritten end-to-end.
  • references.md and java-parity.md reframed.
• Discrete_conformal_map.h (Phase 8a MVP wrapper) now deduces the kernel from TriangleMesh::Point via CGAL::Kernel_traits rather than hard-coding Simple_cartesian<double>. Regression-guarded by KernelIsDeducedFromMeshPointType test.

Removed

• Three stale stub test files in code/tests/ (15 GTEST_SKIPs total):
  • test_spherical_functional.cpp
  • test_hyper_ideal_functional.cpp
  • test_hyper_ideal_hyperelliptic_utility.cpp They referenced a "HDS port (Phase 4)" that never happened — CoHDS was intentionally replaced by CGAL::Surface_mesh, and the functional tests live in code/tests/cgal/test_*_functional.cpp.

CI / Infrastructure

• .gitea/workflows/cpp-tests.yml — test-cgal memory fixed (1400→1600 MB, -j2 → -j1). Addresses OOM on ARM64 runner.
• .gitea/workflows/doc-build.yaml — soft-fail Doxygen job (no merge-blocking).
• Doxyfile + CMake doc target — cmake --build build --target doc.
• 12 macOS Finder-duplicate files removed from code/include/.

Test counts

v0.7.0:  176 CGAL + 36 non-CGAL = 212 total,  13 skipped (HDS stubs)
v0.9.0:  227 CGAL + 23 non-CGAL = 250 total,   0 skipped   (+38 net, +51 CGAL)

Non-CGAL count dropped from 36 → 23 because three stale HDS-port stubs were removed (see "Removed" above) — the functionality is fully covered in the CGAL test suite where it actually lives.

Five test suites added: CGALConformalTraits, CGALDiscreteConformalMap, CPEuclideanFunctional, InversiveDistanceFunctional, HyperIdealHessian, NewtonPhase9a, CGALPhase8bLite.

---

[0.7.0] — 2026-05-18

The “mathematician-ready” release. See the v0.7.0 announcement in README.md (legacy) or CITATION.cff for the corresponding citation entry. Phases 1–7 complete: three DCE geometry modes (Euclidean / Spherical / HyperIdeal), Newton solver, BFS-trilateration layout, Gauss-Bonnet, tree-cotree cut graph, Möbius holonomy, period matrix for genus 1, fundamental domain (genus 1), texture atlas.

---

How to update this file

Every new release adds a new top-level section above the previous one. For non-trivial PRs that don't trigger a release, add an entry under an [Unreleased] section at the top; promote it to the next release header at tag time.

Categories (Keep-A-Changelog convention):

• Added — new features / files / public APIs.
• Changed — behaviour-altering changes to existing features.
• Deprecated — features still present but slated for removal.
• Removed — deleted features / files.
• Fixed — bug fixes.
• Security — security-relevant fixes.