Commit Graph

50 Commits

Author SHA1 Message Date
Tarik Moussa
d1399ca82f docs: fix stale version, CGAL header, add LOW_MEMORY_BUILD docs (U4+U5+U7+U8)
U4 (README.md:17) — status line: v0.9.0 → v0.10.0, test count 0 → 277

U5 (Discrete_conformal_map.h:6-16) — \file Doxygen block rewritten:
  was: 'provides a single function … Spherical/hyperbolic scheduled for Phase 8b.2'
  now: lists all three discrete_conformal_map_* functions already present,
       plus pointers to the circle-packing companion headers

U7 (getting-started.md) — new 'Mode 4 — Low-memory build' section added
  after Mode 3; shows CONFORMALLAB_LOW_MEMORY_BUILD=ON with -j1 and explains
  the -O0 / no PCH / batch-1 tradeoffs for Raspberry Pi / ≤ 4 GB runners

U8 (README.md compile-time modes) — LOW_MEMORY_BUILD entry added to the
  compile-time workflow code block with a one-line explanation and the
  mandatory -j1 note

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-31 01:46:08 +02:00
Tarik Moussa
59a26123c8 fix(minor): all five MINOR findings — doc, accuracy, and DRY
MINOR-1 (spherical_functional.hpp:426)
  Wrong comment said "second derivative < 0 for a convex functional".
  The spherical energy is *concave* (NSD Hessian); the monotone-f argument
  applies to both convex and concave functionals equally.  Comment rewritten
  to explain the actual physics: increasing scale increases all angles and
  thus reduces Σ G_v.

MINOR-2 (spherical_functional.hpp:494-495)
  Forward finite difference O(ε) → central finite difference O(ε²):
    old: dft = (sum_Gv(t + fd_eps) - ft) / fd_eps
    new: dft = (sum_Gv(t + fd_eps) - sum_Gv(t - fd_eps)) / (2*fd_eps)
  Same cost when the extra sum_Gv(t - fd_eps) replaces the cached ft.

MINOR-3 (euclidean_functional.hpp, spherical_functional.hpp,
         inversive_distance_functional.hpp)
  New header gauss_legendre.hpp centralises the 10-point Gauss-Legendre
  nodes and weights (gl10_nodes() / gl10_weights()).  The three energy
  functions now use the shared accessors instead of duplicated local
  static arrays.

MINOR-4 (euclidean_functional.hpp, spherical_functional.hpp,
         hyper_ideal_functional.hpp, inversive_distance_functional.hpp)
  halfedge_to_index() centralised in conformal_mesh.hpp.  All four local
  aliases (eucl_hidx, spher_hidx, hidx, id_detail::hidx) now delegate to
  it as one-line wrappers; the aliases are kept for now to avoid a larger
  call-site churn, clearly documented as thin wrappers.

MINOR-5 (clausen.hpp:33-38)
  Added a comment above inits() explaining the intentional off-by-one
  return value and how it interacts with csevl() — matching the Java
  Clausen.inits() / csevl() contract.

277/277 CGAL + 26/26 pure-math tests pass, 0 failed.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-31 01:17:27 +02:00
Tarik Moussa
7534c62c3d fix(gradient-checks): use relative error in all FD check functions
Finding-E from doc/reviewer/external-audit-2026-05-30.md.
Scan also uncovered the same issue in inversive_distance_functional.hpp.

Three functions used absolute error `|analytic - fd| > tol` while the
rest of the library (euclidean_functional, spherical_functional,
euclidean_hessian, hyper_ideal_functional) all use relative error
`|analytic - fd| / max(1, |analytic|) > tol`.

Absolute error is too strict for large gradients (false failures) and
too lenient for small gradients.

Fixed:
  cp_euclidean_functional.hpp  gradient_check_cp_euclidean()
  cp_euclidean_functional.hpp  hessian_check_cp_euclidean()
  inversive_distance_functional.hpp  gradient_check_inversive_distance()

All three now use the relative criterion and accumulate all failures
before returning (ok=false instead of early return on first mismatch).
Default tol updated from 1e-6/1e-5 to 1e-4, matching the Java
FunctionalTest convention used by all other checks in the library.
Error message updated to print rel-err instead of raw diff.

266/266 CGAL tests pass, 0 failed.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-31 01:17:27 +02:00
Tarik Moussa
cfbbc1b21f fix(dof-assign): correct "pin before" docs + add gauge-vertex overloads
Finding-D from doc/reviewer/external-audit-2026-05-30.md.

All three DOF-assignment functions iterated over every vertex
unconditionally, overwriting any v_idx set before the call.  The
documentation said "pin before OR after" — the "before" option was
silently wrong (the pin would be overwritten).  For the
inversive-distance variant the doc explicitly said the pre-call pin
would make the function "a no-op for that vertex", which was false.

Changes (three headers):
- euclidean_functional.hpp  assign_euclidean_vertex_dof_indices()
- spherical_functional.hpp  assign_vertex_dof_indices()
- inversive_distance_functional.hpp  assign_inversive_distance_vertex_dof_indices()

For each:
  1. Single-arg overload: doc corrected to "pin AFTER, not before;
     pre-call pins are overwritten"
  2. New two-arg overload accepting a Vertex_index gauge: pins the
     requested vertex (v_idx=-1) in a single pass, preventing the
     user error entirely

Three new GTests in test_euclidean_functional.cpp:
  SingleArg_PinBeforeHasNoEffect        — documents the old pitfall
  TwoArg_GaugeIsPinnedOthersAreSequential — verifies the new overload
  TwoArg_NewtonConvergesWithGaugeOverload — end-to-end correctness

266/266 CGAL tests pass, 0 failed.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-31 01:17:27 +02:00
Tarik Moussa
bef5a0ceb7 docs(euclidean-hessian): fix wrong cotangent formula in two comment blocks
Finding-C from doc/reviewer/external-audit-2026-05-30.md.

The box comment at the top and the function-level comment above
euclidean_cot_weights() both stated:

  cot_k = (t_adj1·l123 − t_adj2·t_opp) / denom2   ← WRONG

The correct formula (verified numerically on a 3-4-5 right triangle,
expected cot1=4/3, cot2=3/4, cot3=0) is:

  cot_k = (t_opp · l123 − t_a · t_b) / denom2

where t_opp is the t-value of the edge OPPOSITE vertex k, and t_a/t_b
are the t-values of the two edges ADJACENT to vertex k.

The implementation in euclidean_cot_weights() was already correct;
only the documentation was wrong.

Changes (documentation only, zero code changes):
- Box comment: rewritten with correct formula and explicit per-vertex
  assignment (cot1: t_opp=t23, t_a=t12, t_b=t31; etc.)
- Box comment: added missing ½ factor to Hessian contribution lines
- Function-level comment: corrected to (t_opp·l123 − t_a·t_b)/(8·Area)
  with a pointer to the box comment for the full assignment
- Inline return comment in euclidean_cot_weights(): now shows the
  mapping (cot1: t_opp=t23, t_a=t12, t_b=t31) directly at the formula

263/263 CGAL tests pass, 0 failed.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-31 01:17:27 +02:00
Tarik Moussa
46c0b63de8 fix(gauss-bonnet): delete HyperIdeal overloads — wrong identity for hyperbolic metrics
Finding-B from doc/reviewer/external-audit-2026-05-30.md.

The Euclidean Gauss–Bonnet identity Σ(2π−Θ_v) = 2π·χ is ONLY valid for
flat/Euclidean and spherical metrics.  For hyperbolic metrics (HyperIdeal)
the correct identity is Σ(2π−Θ_v) − Area(M) = 2π·χ.  The previously
provided gauss_bonnet_sum(HyperIdealMaps) overload would silently pass the
wrong LHS to check_gauss_bonnet, which would always throw "deficit = ±Area"
for valid hyperbolic targets.

Fix:
- gauss_bonnet_sum(mesh, HyperIdealMaps)        → = delete + explanation comment
- enforce_gauss_bonnet(mesh, HyperIdealMaps&)   → = delete + explanation comment
- Header box comment rewritten with the correct hyperbolic Gauss–Bonnet
  identity and a clear "HyperIdeal: NOT SUPPORTED" section

New test in test_phase6.cpp:
- HyperIdeal_EuclideanSumDiscrepancy_DocumentsWhyCheckIsDeleted
  verifies numerically that the Euclidean sum = 0 but 2π·χ = 4π for a
  regular tetrahedron, documenting the −4π discrepancy that motivated
  the deletion
- Three compile-time static_asserts (SFINAE) confirm the overload is not
  invocable with HyperIdealMaps but remains so with Euclidean/SphericalMaps

263/263 CGAL tests pass, 0 failed.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-31 01:17:27 +02:00
Tarik Moussa
9afefcbb7b fix(hyper-ideal): guard face_energy() against unsupported multi-ideal faces
Finding-A from doc/reviewer/external-audit-2026-05-30.md.

Root cause: both the Java reference (HyperIdealFunctional.java:222-231)
and the C++ port silently applied the one-ideal-vertex volume formula
to the first ideal vertex found in a face, ignoring any additional ideal
vertices.  For two or three ideal vertices this produces a wrong energy
value with no diagnostic.

Fix: add an ideal_count guard at the top of face_energy() that throws
std::logic_error for ideal_count >= 2.  The one-ideal (Kolpakov-Mednykh)
and zero-ideal (Meyerhoff/Ushijima) paths are unchanged and correct.

Three new GTests cover the three guard cases:
  MultiIdealGuard_TwoIdealVertices_Throws        (two ideal  → throw)
  MultiIdealGuard_AllThreeIdealVertices_Throws   (all ideal  → throw)
  MultiIdealGuard_ExactlyOneIdeal_DoesNotThrow   (one ideal  → no throw)

262/262 CGAL tests pass, 0 failed.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-31 01:17:27 +02:00
Tarik Moussa
822a27da69 feat(euclidean): full analytic edge-DOF (cyclic) Hessian; Tier-2 Wente finding
Upgrades the cyclic Euclidean Hessian from block-FD to closed-form, satisfying
the novelty-statement §3.2 "analytic Hessians, not finite difference" claim for
the Euclidean path.

- euclidean_hessian.hpp: `euclidean_hessian_analytic` — closed-form cyclic
  Hessian from the law-of-cosines angle derivatives
    ∂α_i/∂s_i = ℓ_i²/4A,  ∂α_i/∂s_j = ½cot α_i − ℓ_j²/4A   (Σ_j = 0),
  chained to (u, λ_e) and sign-mapped to the gradient outputs (−α vertex,
  +α_opp edge). Reuses euclidean_cot_weights. Block-FD kept as cross-check.
- newton_solver.hpp: newton_euclidean cyclic path now uses the analytic Hessian.
- tests: CyclicHessian_Analytic_MatchesBlockFD_Tetrahedron — analytic == block-FD
  (1e-6), == gradient FD (1e-5), symmetric (1e-9). Existing cyclic convergence
  oracle still GREEN with the analytic Hessian routed in.

Tier-2 (Wente) finding: wente_torus02.obj is a QUAD mesh (1240 quads) and the
Java golden comes from cyclic (quad-net) uniformization; the C++ period-matrix
pipeline is triangle-based, so a faithful bit-vs-Java τ comparison needs a
quad/cyclic pipeline (Phase 9f). Deferred and documented; golden τ = ½+i√3/2.

244/244 cgal tests pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-05-30 17:32:02 +02:00
Tarik Moussa
ea5f01d73d feat(euclidean): block-FD edge-DOF Hessian → cyclic Newton + Java convergence oracle
Implements the edge-DOF (cyclic) Euclidean Hessian, unblocking the full cyclic
Newton solve, and enables the Java EuclideanCyclicConvergenceTest cross-validation.

- euclidean_hessian.hpp: `euclidean_hessian_block_fd` / `_sym` — per-face 6×6
  block FD over (u1,u2,u3,λ12,λ23,λ31), mirroring hyper_ideal_hessian_block_fd.
  Per-face outputs carry the gradient signs (−α vertex, +α_opp edge), so the
  result equals ∂G/∂x by construction (locality lemma). Analytic vertex-only
  cotangent Hessian unchanged (still used for vertex-only layouts).
- newton_solver.hpp: newton_euclidean routes cyclic layouts (edge DOFs present)
  through the block-FD Hessian; vertex-only path unchanged.
- tests:
  * CyclicCircularEdge_CatHead_JavaXVal (now GREEN) — prescribe φ=π−0.1 on one
    interior edge, solve, assert realised α_opp+α_opp = π−0.1 @1e-9.
  * CyclicCircularEdge_PhiEntersGradient_CatHead — solver-free φ-wiring check.
  * CyclicHessian_BlockFD_MatchesGradientFD_Tetrahedron — Hessian correctness.

243/243 cgal tests pass; vertex-only Euclidean Newton unaffected.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-05-30 17:32:02 +02:00
adfcb7b931 Merge pull request 'feat(geometry): pn_geometry.hpp — Pn projective-metric substrate (jReality port)' (#31) from feat/pn-geometry-substrate into main
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2026-05-30 15:26:23 +00:00
Tarik Moussa
149da15c64 feat(geometry): pn_geometry.hpp — Pn projective-metric substrate (jReality port)
Ports the small but pervasive de.jreality.math.Pn surface that the Java
algorithmic core uses across every not-yet-ported geometric phase:
HyperbolicLayout, SphericalLayout, FundamentalPolygon (9c), KoebePolyhedron
(10c'), quasi-isothermic (10e), hyperelliptic theta, CircleDomain (11c).
Porting it once unblocks all downstream consumers instead of re-deriving
the metric ad hoc per phase.

pn_geometry.hpp — header-only, Eigen, ~120 LOC:
  PnMetric { EUCLIDEAN=0, ELLIPTIC=+1, HYPERBOLIC=-1 } matching jReality.
  pn_inner_product  — bilinear form per signature.
  pn_norm / pn_dehomogenize / pn_set_to_length / pn_normalize.
  pn_distance_between — Euclidean (spatial), elliptic (acos), hyperbolic (acosh).
  pn_linear_interpolation — affine (E) and slerp (S/H constant-speed geodesic).

HYPERBOLIC uses the timelike-positive ("upper-sheet") convention, identical to
the already-verified projective_math.hpp::hyperbolicDistance; pn_distance_between
is regression-anchored against it in the tests.

test_pn_geometry.cpp — 6 tests, all GREEN:
  InnerProductSignatures, EuclideanDistance, EllipticDistanceIsAngle,
  HyperbolicDistanceClosedFormAndAnchor (+ projective_math.hpp anchor),
  NormAndScaling, LinearInterpolationGeodesic.

doc/roadmap/java-parity.md — new "Infrastructure / support layers" section:
  de.jreality.math.Pn   → pn_geometry.hpp (partial, 6 fns covering core usage)
  de.jreality.math.Rn   → Eigen (no separate port needed)
  MatrixBuilder         → not yet (only needed for hyperelliptic theta)
  conformallab XML types → not planned (GUI persistence, not algorithmic)

246/246 cgal tests pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-05-30 17:20:35 +02:00
Tarik Moussa
ba83974525 test: Java golden-value oracles for the five DCE math cores + P1-2/P1-3 fixes
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Add bit-for-bit (1e-12) golden-value oracle tests pinning the C++ pure-math
and functional cores against the compiled upstream Java library (openjdk 17):

- HyperIdealGoldenJava: Clausen/Л/ImLi2, ζ13/14/15/ζ, both tetrahedron-volume
  formulas (real de.varylab…Clausen / HyperIdealUtility).
- EuclideanGoldenJava / SphericalGoldenJava: angle formulas + β relations + Л
  energy terms, plus FULL-MESH oracles driving the real EuclideanCyclicFunctional
  / SphericalFunctional on a shared tetrahedron — per-vertex gradient (Θ−Σα) and
  ΔE = E(x)−E(0) (C++ Gauss-Legendre path integral vs Java closed form).
- SphericalGoldenJava.FullMeshEdgeDofGradient: edge-DOF gradient (vertex + edge
  components, α_opp⁺+α_opp⁻−θ_e) vs raw conformalEnergyAndGradient — locks
  Finding 3 at the solution level (audit items 4 & 5).
- PeriodMatrix.NormalizeModulus_GoldenJava: τ-reduction fold convention vs the
  real DiscreteEllipticUtility.normalizeModulus (audit items 7 & 8).

Subtlety documented: the spherical oracles call Java's raw
conformalEnergyAndGradient, not evaluate() (which pre-runs a Brent gauge
maximization that C++ factors into the Newton solver's spherical_gauge_shift).

Also:
- P1-2 (layout.hpp): Euclidean holonomy now uses a per-cut-edge rigid-motion fit
  g(z)=a·z+b, exposing residual_rotation = |arg(a)| as a diagnostic; non-
  regressive (flat case a=1 reduces to the old midpoint formula).
- P1-3 (period_matrix.hpp): is_in_fundamental_domain fixed to the correct
  half-open SL(2,ℤ) domain (−½ ≤ Re < ½). Updated the now-exposed
  ComputePeriodMatrix_ReducedTau_InFD to assert the normalizeModulus domain
  (closed +½ edge) instead.

Test counts (single source of truth = doc/api/tests.md): 272/272 pass, 0
skipped (26 non-CGAL + 246 CGAL).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-05-29 19:08:37 +02:00
Tarik Moussa
a3ee9576d4 fix+test: Euclidean holonomy/τ end-to-end + spherical edge-DOF oracle (2026-05-29 audit)
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Bundles the 2026-05-29 Java↔C++ math-correctness audit (doc/reviewer/
java-port-audit.md, 11 findings) with two follow-up fixes.

Audit code changes:
- Finding 3 (spherical_functional): edge-DOF replacement parameterization via
  spher_eff_lambda; edge gradient α_opp⁺+α_opp⁻−θ_e (drops additive −(S⁺+S⁻)/2)
- Finding 4 (spherical_hessian): always-compiled edge-DOF throw guard
- Finding 6 (period_matrix): faithful normalizeModulus (0≤Re≤½, Im≥0, |τ|≥1)
- Finding 9 (inversive_distance): degenerate-face limiting angles, no skip
- Findings 1/2 (euclidean): degenerate gradient limiting angles + Hessian guard

Euclidean holonomy/τ fix: develop the cut surface across the dual spanning tree
only (cut_graph now exposes is_dual_tree), so genus-1 cut edges yield
non-degenerate lattice generators. Previously τ came out 0 / NaN / 1e13 on the
bundled tori; now matches the analytic revolution modulus i·√(R²−r²)/r. Re-enabled
τ reporting in the Euclidean CLI; rewrote validation.md §3/§4 accordingly.

Tests (240 CGAL, 0 skipped):
- HolonomyEndToEnd ×3 — tori of revolution (4×4, hex 6×6, 8×8) vs analytic modulus
- SphericalFunctional.EdgeGradient_RegularTetClosedForm — independent closed-form
  π/3 oracle locking the Finding-3 edge formula (the path-integral FD check cannot
  detect a wrong-but-conservative gradient)

Also documents the latent spherical/hyperbolic holonomy-extraction bug (same
single-development pattern, dead code today) in research-track.md (Phase 9c/10),
and adds favour/normalisations to the codespell ignore list.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-29 12:50:16 +02:00
Tarik Moussa
e874f73e29 docs+lint: post-merge consistency fixes after PRs #17/#18/#19 landed
Three small cleanups surfaced by running the full gate sweep on the
merged main:

1. CGAL conventions (CGAL-2 \\file briefs)
   doc-only headers `Conformal_map/doxygen_groups.h` and
   `Conformal_map/doxygen_namespaces.h` were missing the `\\file`
   brief required by the CGAL conventions check.  Added both.

2. codespell — three new triggers
   `code/tests/cgal/CMakeLists.txt` uses "honour", `doc/reviewer/hub.html`
   uses `<thead>` (HTML tag, false-positive for "thread"), and
   `doc/roadmap/research-track.md` uses "optimiser".  All three are
   British-English / HTML usage; added to `.codespellrc` ignore list.

3. Doxygen warning in `doc/architecture/compile-time.md:250`
   A trailing backtick-quoted CMake flag at end-of-file confused
   Doxygen's markdown parser into starting a never-closing verbatim
   block.  Rewrote the line to put the prose first and the backtick
   in the middle, not at end-of-file.

All gates green again on the merged main:
   259/259 tests pass
   test-count consistency
   markdown links 166/166 resolve
   CGAL conventions 0/8 violations
   license-headers 68/68 carry MIT SPDX
   codespell 0 typos
   shellcheck 0 findings (18 scripts)
   Doxygen 100% coverage, 0 warnings

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-26 11:19:55 +02:00
Tarik Moussa
bc40a13e8d perf: architecture-touch quick-wins #6 + #10; skip #5 + #7 with honest notes
Evaluated all four mid-tier architecture-touch levers from
doc/architecture/compile-time.md.  Outcome: ship two opt-in
improvements, defer two with explicit rationale.

#6 — Eager-include reduction (Dense → Core)   shipped
─────────────────────────────────────────────────────
Three headers downgraded from `<Eigen/Dense>` to `<Eigen/Core>`:
  * projective_math.hpp
  * hyper_ideal_visualization_utility.hpp
  * mesh_utils.hpp

All three only use Matrix/Vector primitives, no Eigen decompositions.
The other five Dense-including headers were inspected and KEPT on
`<Eigen/Dense>` because they use `.inverse()`, `.determinant()`,
`ColPivHouseholderQR`, or `SelfAdjointEigenSolver`.

Measured Apple M1 cold rebuild after this change: 58 / 60 / 63 s
across three runs.  The prior analysis predicted ~10 % gain; reality
landed within the ±5 s natural variance band of repeated builds, so
the net build-time effect on the test target is "noise-level".

The change is still kept because downstream consumers who include
ONLY one of the three downgraded headers see a real per-TU drop
(Core preprocesses to ~250 k lines vs Dense's ~350 k).

#10 — Fast test-build mode (-O0 -g)   shipped
───────────────────────────────────────────────
New option CONFORMALLAB_FAST_TEST_BUILD (default OFF).  When ON,
both test targets (`conformallab_tests` and `conformallab_cgal_tests`)
compile with `-O0 -g -UNDEBUG`, overriding the inherited Release
`-O3 -DNDEBUG`.

Measured Apple clang: 51.6 s vs 46.8 s without -O0 → slightly slower.
The Backend phase that prior analysis predicted would drop from 9.3 s
to ~2 s doesn't dominate on Apple clang the way it does with GCC;
the bigger `-g` debug info also lengthens the link step.

Kept shipped because:
  * On Linux + g++ (CI runner) the picture flips — Backend dominates
    more, `-O0` typically delivers the predicted ~40 % build-time cut.
  * Cross-platform parity: users on Linux see the same CMake option
    they see locally.

Honest documentation in doc/architecture/compile-time.md notes that
the Apple-clang-local benefit is currently 0 %.  Tests RUN ~15× slower
under `-O0` (1.5 s → 23 s for 236 tests); acceptable for CI "did
anything break" loops, NOT acceptable for benchmark workloads.

#5 — Move detail:: impls to .inl files  ⏸ deferred
───────────────────────────────────────────────────
Pure enabler for #7.  Without #7 landing, the .inl extraction would
just add an extra hop to header reading.  Reconsider once a concrete
maintenance reason emerges (e.g. a downstream user wants to override a
detail helper).

#7 — Pimpl on newton_solver + priority_BFS  ⏸ deferred
───────────────────────────────────────────────────────
Honest assessment: Newton_solver is template-on-Functional, so a
faithful Pimpl would require either type erasure or a virtual-method
interface across the five solver instantiations.  Estimated 1-2 weeks
of refactor with measurable API-surface risk.  PCH already absorbs
the SimplicialLDLT + SparseQR template parse cost, so the remaining
delta is small.  Deferred until a concrete user reports compile-time
pain from these specific templates.

Documentation
─────────────
README.md gains a "Compile-time workflow modes" section with all six
opt-in switches (BUILD_TESTING, HEADERS_CHECK, DEV_BUILD, FAST_TEST_BUILD,
USE_PCH, USE_CCACHE) as ready-to-paste command lines.

doc/architecture/compile-time.md gains:
  * an "Architecture-touch quick-wins" section with the four-row
    status table (5 deferred / 6 shipped / 7 deferred / 10 shipped)
  * the FAST_TEST_BUILD row added to the workflow-modes table
  * the mode-matrix table updated with Linux-vs-macOS expected values
  * an honest "variance" note explaining the ±5 s spread between
    repeated cold builds and why #6's net effect lands in that noise

Verified: default build 55 s (within usual variance), 236/236 tests
pass under default; FAST_TEST_BUILD=ON build 52 s, 236/236 PASS.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-26 11:15:09 +02:00
Tarik Moussa
f25174ed69 feat: output_uv_map for InversiveDistance, error for CP-Euclidean, reviewer trio
Three reviewer-meeting deliverables in one commit.

(1) output_uv_map for the two remaining DCE entries
    ─────────────────────────────────────────────────
    * Discrete_inversive_distance.h: full implementation.  After Newton,
      reconstruct effective Euclidean edge lengths from the converged
      log-radii via the Bowers-Stephenson identity
      `ℓᵢⱼ² = rᵢ² + rⱼ² + 2·Iᵢⱼ·rᵢ·rⱼ`, populate a temporary
      EuclideanMaps with `lambda0 = log(ℓᵢⱼ²)`, and reuse the existing
      `euclidean_layout(mesh, 0, eucl)` priority-BFS.  Per-vertex
      Point_2 coordinates written into the user-supplied pmap.
      Optional `normalise_layout(true)` applies the canonical PCA
      centroid + major-axis rotation, same as the other 3 entries.

    * Discrete_circle_packing.h: throws std::runtime_error with a
      clear pointer to Phase 9c rather than silently producing
      nonsense.  CP-Euclidean is face-based; the faithful output is a
      per-face circle packing in ℝ², not a per-vertex Point_2 map.
      A true layout requires BPS-2010 §6 (~150 lines, on the porting
      roadmap as Phase 9c).  Failing loudly is the honest default.

    Tests: 2 new cases in test_cgal_phase8b_lite.cpp
    (OutputUvMap_InversiveDistance_PopulatesPmap;
    OutputUvMap_CPEuclidean_ThrowsClearly).  Both green.
    Suite total now 259 (was 257, +2).  CGAL subtotal: 234 → 236.

(2) Reviewer meeting documents
    ──────────────────────────
    New directory doc/reviewer/ with three files:

    * briefing.md  — one-page orientation for the reviewer.
      What the project is, where to look first
      (https://tmoussa.codeberg.page/ConformalLabpp/), the headline
      evidence (tests/coverage/sanitizers/license), what we want from
      them, what's deferred and why, and the 5 questions in a separate
      file.

    * questions.md — the 5 concrete decisions we want their second
      opinion on:
        Q1 Phase 9c (port-literal vs re-derive)
        Q2 Phase 9b-analytic (worth ~2 weeks for ~6× speedup?)
        Q3 CP-Euclidean output_uv_map (build now or defer?)
        Q4 CGAL submission strategy (one package or five?)
        Q5 geometry-central cross-validation co-authorship
      Plus an explicit "what would you say no to?" question at the
      bottom — negative feedback is the highest-value information.

    * agenda.md   — my own internal playbook (NOT to be sent).
      60-min flow: 5-min thank-you, 10-min architecture tour,
      30-min for Q1-Q5 in the order Q4-Q1-Q2-Q5-Q3, 5-min "no"
      question, 5-min wrap-up.  Includes post-meeting memo template
      to fill out in the 30 min after.

    * README.md    — index for the directory; says which file goes
      to whom and when to send.

(3) locked-vs-flexible.md known-limitations update
    ─────────────────────────────────────────────
    "output_uv_map covers 3 of 5 entries" → "covers 4 of 5".
    CP-Euclidean's throws-clearly behaviour documented as a Phase 9c
    deliverable rather than a passive gap.

Bonus: extended .codespellrc ignore list (acknowledgement, the
British-English spelling I used in agenda.md).

Verifications on this commit:
  259/259 tests pass (0 skipped)
  scripts/check-test-counts.sh:                OK (23 + 236 = 259)
  scripts/quality/license-headers.sh:          OK (66/66 SPDX)
  python3 scripts/quality/cgal-conventions.py: OK (0/6 violations)
  scripts/quality/codespell.sh:                OK (0 typos)
  scripts/quality/shellcheck.sh:               OK (0 findings)
  python3 scripts/check-markdown-links.py:     OK (143/143)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-26 11:15:09 +02:00
704f42bbfd Merge pull request 'ci+quality: structural gates (CI: 3 new; local: 7 new + .clang-tidy)' (#18) from ci/structural-tests into main
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2026-05-26 09:14:45 +00:00
Tarik Moussa
d3c08b3bc0 quality: 2 new gates (cmake-format, codespell) + SPDX rollout (60 files)
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This commit closes the remaining red gates so `run-all.sh --fast` is
green end-to-end on the canonical dev machine.

New gates
─────────
1. cmake-format / cmake-lint
   * scripts/quality/cmake-format.sh — dry-run by default,
     --strict to fail on drift, --fix to apply
   * .cmake-format.yaml — policy (lowercase commands, UPPERCASE
     keywords, 100-col loose limit; matches .clang-format choices)
   * Uses the pip-installed `cmakelang` package
     (`pip3 install --user cmakelang`)

2. codespell
   * scripts/quality/codespell.sh — exit 1 on any typo, --fix
     interactively
   * .codespellrc — extensive ignore-words-list capturing the
     project's British-English-leaning style (centre, behaviour,
     specialise, normalise, …) plus domain abbreviations (DOF,
     iff, fuchsiens), so the gate flags real typos only.
   * Validated: 0 typos across docs + code/include + scripts +
     code/{src,tests}.

SPDX rollout (license-headers --fix)
────────────────────────────────────
license-headers.sh gained a --fix mode that auto-inserts the
two-line header at the correct place (below `#pragma once` if
present, above the include guard otherwise, plain prepend for
.cpp).  Ran it on 60 of 66 files — 100 %-licensed now.

Verified the build is still clean after the textual edits:
   cmake -S code -B build-verify -DWITH_CGAL_TESTS=ON
   ctest --test-dir build-verify   → 257/257 PASS

run-all.sh + README updated to include the two new gates.

End-to-end style/convention block status (on this commit, this branch):

    license-headers     (66/66 carry MIT SPDX)
    cgal-conventions    (0/6 violations)
    clang-format        (0 drift; warn-mode for safety)
    cmake-format/-lint  (warn-mode for safety)
    codespell           (0 typos)
    markdown-links      (122/122 resolve)

The slow correctness/quality block (sanitizers, coverage, clang-tidy,
multi-compiler, cgal-version-matrix, reproducible-build) is left as
follow-up — toolchain is now installed locally, scripts are syntax-
clean, the slow runs themselves are a separate matter of patience.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-24 09:15:34 +02:00
Tarik Moussa
62b02f88b9 docs(doxygen): 100% public-API coverage (228 → 0 undocumented)
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Completes the work begun in the previous commit on this branch.  Every
public symbol under code/include/ now carries a brief Doxygen comment
(0 undocumented per scripts/doxygen-coverage.sh, with the `detail::`
implementation namespaces excluded as before).

Trajectory on this branch:
  start (after Doxyfile fix):  24.0 %  (165 / 437 in the no-detail set
                                       was 105 / 437 when detail counted)
  after PR #17 base commit  :  42.4 %  (165 / 396)
  this commit               : 100.0 %  (396 / 396)

Files touched (all .hpp / .h headers under code/include/):
  * cgal/Conformal_map_traits.h
  * clausen.hpp, conformal_mesh.hpp, constants.hpp (already docd)
  * cp_euclidean_functional.hpp, cut_graph.hpp, discrete_elliptic_utility.hpp
  * euclidean_functional.hpp, euclidean_geometry.hpp, euclidean_hessian.hpp
  * fundamental_domain.hpp, gauss_bonnet.hpp
  * hyper_ideal_{functional,geometry,hessian,utility,visualization_utility}.hpp
  * inversive_distance_functional.hpp, layout.hpp
  * matrix_utility.hpp, mesh_builder.hpp, mesh_io.hpp
  * newton_solver.hpp, p2_utility.hpp, period_matrix.hpp, projective_math.hpp
  * serialization.hpp, spherical_functional.hpp, spherical_geometry.hpp
  * spherical_hessian.hpp, viewer_utils.h

CI:
.gitea/workflows/doxygen-pages.yml now enforces
`scripts/doxygen-coverage.sh --threshold 100`, so any future regression
(a new public function landed without a `///` brief) fails the build
before the Doxygen HTML is published to Codeberg Pages.

Doxygen warnings remain at 0.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-24 04:22:49 +02:00
Tarik Moussa
e04515c423 docs(doxygen): fix critical extraction bug; baseline 24% → 42% on public API
ROOT CAUSE FIX
The Doxyfile EXCLUDE_PATTERNS line contained `*/* 2.hpp` (note the
space — a stray glob from macOS-style "foo 2.hpp" duplicate files).
That pattern was silently matching ALL .hpp / .h files, so Doxygen was
indexing nothing under code/include/.  The pre-existing 556 KB of HTML
output was effectively documenting only README.md, CLAUDE.md and a
small stub for std:: — not the C++ API at all.

After fixing the pattern (and properly escaping the space-prefixed
"foo 2.hpp / foo 2.h" macOS-dup patterns), Doxygen now extracts 141
compounds and emits 248 HTML pages from the public headers.

WHAT THIS PR ADDS
1. Doxyfile fix: correct EXCLUDE_PATTERNS; add GENERATE_XML for the
   coverage measurement script; add MathJax for `$$...$$` math in
   markdown; add the missing CGAL `\cgalParamNBegin/End/Description/
   Default/...` aliases so CGAL-style param blocks render correctly.

2. New headers:
   - code/include/CGAL/Conformal_map/doxygen_groups.h
     defines `PkgConformalMap{,Ref,Concepts,NamedParameters}`,
     resolving 17 prior "non-existing group" warnings.
   - code/include/CGAL/Conformal_map/doxygen_namespaces.h
     gives every namespace under `CGAL::` and `conformallab::` a
     brief description.

3. New tool: scripts/doxygen-coverage.sh
   Parses the XML output and reports % of public symbols (excluding
   the `detail::` implementation namespaces by default) that have a
   non-empty brief/detailed description.  Supports `--list-undoc`
   and `--threshold N` for CI integration.

4. Substantial docstring additions to the public CGAL headers:
   `Conformal_map_traits.h`, `Discrete_circle_packing.h`,
   `Discrete_inversive_distance.h`, `conformal_mesh.hpp`,
   `Discrete_conformal_map.h` (Hyper_ideal_map_result fields).

5. Markdown housekeeping that the strict-warning Doxygen run surfaced:
   tests.md (escape literal `#` in table cell),
   locked-vs-flexible.md (broken section anchor),
   overall_pipeline.md (replace `$$LaTeX$$` with inline-unicode math).

CURRENT NUMBERS

  before:  ~24%  documented (public API; the prior "87%" claim was
                 based on the broken extraction)
  after:    42%  documented   (165 of 396 public symbols)
  warnings: 0   (was 27 spurious + a flood of bogus undocumented
                  warnings hidden by the buggy EXCLUDE pattern)

NEXT (in a follow-up commit on this branch)
The remaining 231 public symbols (mostly in `layout.hpp`,
`hyper_ideal_functional.hpp`, `spherical_functional.hpp`, the per-mode
functional/Hessian files) can be brought to ~100% with another pass of
short `///` brief descriptions.  The coverage script is the gate; CI
can begin enforcing `--threshold 95` once the next pass lands.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-23 23:44:54 +02:00
Tarik Moussa
039cc26e36 Phase 8b-Lite: pipe-operator chaining for named parameters
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Adds `operator|` in `namespace CGAL` so package-local named parameters
can be combined left-to-right without modifying CGAL upstream:

    auto p = CGAL::parameters::gradient_tolerance(1e-12)
           | CGAL::parameters::max_iterations(500)
           | CGAL::parameters::output_uv_map(uv);
    CGAL::discrete_conformal_map_euclidean(mesh, p);

Why not the canonical `.a().b().c()` syntax
───────────────────────────────────────────
CGAL's standard chaining mechanism requires registering each named
parameter as a member function on `Named_function_parameters` via the
`CGAL_add_named_parameter` macro in
`CGAL/STL_Extension/internal/parameters_interface.h` — a vendored
upstream file that conformallab++ deliberately treats as read-only.

Adding member-function chainers for our package-local tags would
require either forking CGAL or modifying the vendored copy.  Neither
is acceptable for a library that wants to remain portable across
future CGAL releases.

The pipe-operator achieves the same compositional semantics via a
free function in `namespace CGAL` (so ADL finds it for
`Named_function_parameters` operands).  Implementation: rebuild the
right-hand-side `Named_function_parameters` with the left-hand-side
as its `Base`, producing an indistinguishable chain that every entry
function accepts unchanged.

Implementation: `code/include/CGAL/Conformal_map/internal/parameters.h`
lines 158-187.  The operator is constrained to right-hand-sides with
`No_property` base (i.e. fresh single-parameter packs from the helper
functions), so it never collides with any future CGAL operator on the
same type.

Tests (2 new, total Phase-8b-Lite suite 15 → 17)
────────────────────────────────────────────────
* CGALPhase8bLite.NamedParamPipe_MultipleParamsTakeEffect
    Chain three parameters; verify all three take effect (tight
    tolerance respected + UV pmap populated + iteration cap honoured).
* CGALPhase8bLite.NamedParamPipe_TwoParams
    Chain two parameters; verify max_iterations(0) blocks the loop
    even when combined with another param.

Full CGAL suite: 234/234 PASSED, 0 SKIPPED (was 232).
Total: 257/257 PASSED, 0 SKIPPED (was 255).
scripts/check-test-counts.sh: OK.

Documentation updates
─────────────────────
* doc/tutorials/add-output-uv-map.md §3.4: "Current limitation: no
  chaining" → "Chaining: use the pipe operator `|`".  Explains why
  CGAL's `.member()` syntax isn't available and shows the `|`
  workaround with a working code example.
* doc/architecture/locked-vs-flexible.md §8: chaining now flagged as
  shipped via pipe; recommended posture says `.member()` chaining
  only if a user pushes for the CGAL-canonical syntax.
* doc/roadmap/porting-status.md §5: API limitations table updated.
* doc/api/tests.md: CGALPhase8bLite row 15 → 17, total 232 → 234.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-22 13:43:52 +02:00
Tarik Moussa
b7e837815f Phase 8b-Lite extension: output_uv_map named parameter for integrated layout
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
────────
* `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>
2026-05-22 13:24:37 +02:00
Tarik Moussa
79f6757646 docs: add Doxygen docstrings to high-priority public functions (Phase-9a + setup)
Follow-up to the doc-audit: fills the 30 high-priority docstring gaps
identified across the public-API headers.  Code unchanged — comments
only.

Headers updated
───────────────
* code/include/cp_euclidean_functional.hpp     (5 docstrings added)
    - setup_cp_euclidean_maps              — defaults + naming convention
    - assign_cp_euclidean_face_dof_indices — gauge-pin semantics
    - (overload)                            — first-face convenience
    - cp_euclidean_dimension               — DOF counting
    (gradient, energy, Hessian, and FD-check were already documented
     via the header-block comments.)

* code/include/inversive_distance_functional.hpp  (4 docstrings added)
    - setup_inversive_distance_maps                 — defaults + Bowers-Stephenson init note
    - assign_inversive_distance_vertex_dof_indices — gauge-pin caveat
    - inversive_distance_dimension                 — DOF counting
    - compute_inversive_distance_init_from_mesh    — two-phase init + Bowers-Stephenson formula

* code/include/euclidean_functional.hpp        (4 docstrings added)
    - setup_euclidean_maps                  — defaults + naming convention
    - assign_euclidean_vertex_dof_indices  — gauge-pin caveat
    - assign_euclidean_all_dof_indices     — cyclic-functional usage
    - euclidean_dimension                  — DOF counting

* code/include/spherical_functional.hpp        (5 docstrings added)
    - setup_spherical_maps                  — defaults + naming convention
    - assign_vertex_dof_indices             — gauge-pin
    - assign_all_spherical_dof_indices      — cyclic-functional usage
    - spherical_dimension                   — DOF counting
    - compute_lambda0_from_mesh             — unit-sphere precondition

* code/include/hyper_ideal_functional.hpp      (3 docstrings added)
    - setup_hyper_ideal_maps                — defaults + cross-functional naming explanation
    - hyper_ideal_dimension                 — DOF counting
    - assign_all_dof_indices                — strictly-convex no-gauge usage

* code/include/mesh_utils.hpp                  (3 docstrings added)
    - cgal_to_eigen                        — libigl-style (V, F) conversion + side-effect note
    - simple_visualize_mesh                 — requires WITH_VIEWER, lifetime
    - get_vertex_map                       — zero-copy + lifetime warning
  File header upgraded to a proper Doxygen file-level comment block.

Total: 24 new Doxygen-style docstrings added.

Coverage statistics (per the doc-audit)
───────────────────────────────────────
Before:  110 / 154 public symbols documented (71.4%)
After:   134 / 154 public symbols documented (87.0%)

Remaining gaps (20 entries) cluster in lower-priority utilities
(p2_utility.hpp, period_matrix.hpp internal helpers, mesh_builder
already has block-comments above each factory).  These can be filled
in a future PR when the public-API surface for Phase 9c lands.

Verification
────────────
* Build: clean (no new compiler warnings).
* Tests: 250/250 PASSED, 0 SKIPPED.
* scripts/check-test-counts.sh: OK.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-22 13:24:37 +02:00
Tarik Moussa
7d10500811 Phase 8b-Lite: CGAL entries for all 5 DCE models + layout wrapper
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Completes the CGAL public API surface so all five discrete-conformal
functionals are reachable from <CGAL/Discrete_*.h>, not only Euclidean.

CGAL test count: 219 → 227 (+8).  Zero skips.

New public headers
──────────────────
* CGAL/Discrete_conformal_map.h                    extended
    Adds discrete_conformal_map_spherical() and
         discrete_conformal_map_hyper_ideal()
    plus the Hyper_ideal_map_result<FT> struct that carries both
    vertex DOFs (b_v) and edge DOFs (a_e).

* CGAL/Discrete_circle_packing.h                   new (180 lines)
    Face-based BPS-2010 circle packing.  Provides
         Default_cp_euclidean_traits<Mesh, K>
         Circle_packing_result<FT>
         discrete_circle_packing_euclidean()

* CGAL/Discrete_inversive_distance.h               new (180 lines)
    Vertex-based Luo-2004 packing.  Provides
         Default_inversive_distance_traits<Mesh, K>
         discrete_inversive_distance_map()
    reusing the existing Conformal_map_result<FT> for the u-vector.

* CGAL/Conformal_layout.h                          new (110 lines)
    Thin re-export of euclidean_layout / spherical_layout /
    hyper_ideal_layout into the CGAL:: namespace.

Architecture choice
───────────────────
Per Phase 8b architecture audit: Strategy C (functional-specific
default traits, one entry per functional, no fat shared trait).
Documented in each header's docblock.  This avoids speculative design
of a unified trait that would need to fit all 5 DOF layouts (vertex,
vertex+edge, face).

Conformal_map_traits.h is kept as the Euclidean-specific trait it
already is; new functionals have their own Default_*_traits classes
right next to their entry functions.

Test count after this merge
───────────────────────────
CGAL suite: 219 → 227 (8 new in test_cgal_phase8b_lite.cpp covering
all four new entries + the Euclidean+layout round-trip).

After-the-merge user contract
─────────────────────────────
A user can now write any of these and get a valid Newton-converged result:

  #include <CGAL/Discrete_conformal_map.h>
  auto r = CGAL::discrete_conformal_map_euclidean(mesh);
  auto r = CGAL::discrete_conformal_map_spherical(mesh);
  auto r = CGAL::discrete_conformal_map_hyper_ideal(mesh);

  #include <CGAL/Discrete_circle_packing.h>
  auto r = CGAL::discrete_circle_packing_euclidean(mesh);

  #include <CGAL/Discrete_inversive_distance.h>
  auto r = CGAL::discrete_inversive_distance_map(mesh);

  #include <CGAL/Conformal_layout.h>
  auto layout = CGAL::euclidean_layout(mesh, r.x, maps);

Not in this PR (intentionally deferred)
───────────────────────────────────────
* 8a.2 — Generic FaceGraph specialisation (still Surface_mesh-only).
* 8c   — User_manual + PackageDescription.txt (CGAL-submission prep).
* 8d   — CGAL-format test directory  (CGAL-submission prep).
* 8e   — YAML pipeline + CLI flag    (orthogonal).
* Named-parameter chaining (`a.b().c()`) — current parameter helpers
  return Named_function_parameters without member-function chainers;
  pass parameters one at a time for now.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-21 21:24:26 +02:00
Tarik Moussa
dd87b8007b Phase 9a-Newton: newton_cp_euclidean + newton_inversive_distance
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Wires the two Phase-9a functionals into the Newton-solver layer so
they are operational end-to-end.  CGAL test count: 212 → 219 (+7).

Solvers
───────
* newton_cp_euclidean(mesh, x0, m, tol, max_iter)
    - Uses cp_euclidean_hessian — analytic 2×2-per-edge BPS-2010
      formula h_jk = sin θ / (cosh Δρ − cos θ).
    - SparseQR fallback handles the gauge-singular case when no face
      is pinned (caller error, but we recover gracefully).
    - Strictly-convex energy ⇒ quadratic convergence near optimum.

* newton_inversive_distance(mesh, x0, m, tol, max_iter, hess_eps)
    - Uses an inline FD Hessian (n × gradient evaluations per step) —
      mirrors the Phase 4a HyperIdeal solver in spirit.
    - Analytic alternative via Glickenstein 2011 eq. (4.6) is tracked
      in doc/roadmap/research-track.md as Phase 9a.2-analytic.
    - Sensitive to initial point; the test suite always starts from
      a natural-theta setup (u = 0 is the equilibrium when
      compute_inversive_distance_init_from_mesh was called).

Tests (test_newton_phase9a.cpp, 7 cases)
────────────────────────────────────────
* CPEuclidean_NaturalPhi_ClosedTetrahedron_ConvergesInZeroIterations
* CPEuclidean_PerturbedStart_ConvergesBackToEquilibrium
* CPEuclidean_OpenTetrahedron_NaturalPhi_Converges
* InversiveDistance_NaturalTheta_Triangle_ConvergesInZero
* InversiveDistance_PerturbedQuadStrip_Converges
* InversiveDistance_PerturbedTetrahedron_Converges
* CPEuclidean_UsesAnalyticHessian
    Regression guard: 3-DOF problem converges in ≤ 10 iterations even
    with strong perturbation, confirming the analytic Hessian path is
    actually used.

All seven tests pass.  Full CGAL suite: 219/219 PASSED, 0 SKIPPED.

Roadmap additions (`doc/roadmap/phases.md`)
───────────────────────────────────────────
New Phase 11+ section flags two Java sub-packages as optional/deferred
ports, recorded for project memory but not roadmap commitments:

* 11a — Schottky uniformisation (Java plugin/schottky/*, ~3000 LoC)
        Hyperbolic loxodromic group acting on S²; complement of the
        Phase 10c Fuchsian-group representation in H².  Requires
        Phase 10b period matrix + Möbius-group machinery from Phase 7.
        Effort: very large (4-6 weeks).

* 11b — Riemann maps (Java plugin/riemannmap/*, ~1500 LoC)
        Discrete Riemann mapping theorem; texture mapping of bounded
        planar regions, classical conformal mapping for engineering.
        Requires Phase 10b' quasi-isothermic or Phase 9a.1 CP-Euclidean.
        Effort: large (3-4 weeks).

Both are explicitly NOT roadmap commitments — they live in the doc so
they aren't re-discovered.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-21 21:10:00 +02:00
Tarik Moussa
8c01a133d8 Phase 9a: dual circle-packing functionals (CP-Euclidean + Inversive Distance)
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Implements both Phase 9a sub-functionals — the face-dual circle-packing
functional from the Java original and the vertex-based inversive-distance
functional from Luo 2004 / Glickenstein 2011 — together with a side-by-side
mathematical validation report.

CGAL test count: 194 → 205 (+11 from 9a.2, +10 from 9a.1, was already
+1 from 9a.1's setup defaults regression).

Phase 9a.1 — CPEuclideanFunctional  (face-based, BPS 2010)
──────────────────────────────────────────────────────────
* code/include/cp_euclidean_functional.hpp  (320 lines)
  - Face-based DOFs ρ_f = log R_f
  - Per-edge intersection angle θ_e (default π/2 = orthogonal)
  - Per-face target angle sum φ_f (default 2π)
  - Energy:  Σ_f φ_f ρ_f + Σ_h [½ p(θ*,Δρ)·Δρ + Λ(θ*+p) − θ* ρ_left]
             with p(θ*, Δρ) = 2 atan(tan(θ*/2) tanh(Δρ/2))
                  Λ        = Clausen-Lobachevsky
  - Analytic Hessian:  h_jk = sin θ / (cosh Δρ − cos θ)
  - Java original: de.varylab.discreteconformal.functional.CPEuclideanFunctional
                   (260 lines, line-by-line mapping documented in
                    phase-9a-validation.md §1)

* code/tests/cgal/test_cp_euclidean_functional.cpp  (10 tests)
  - PFunctionKnownValues, SetupDefaults, AssignDofIndices_PinsOneFace
  - TangentialLimitGradientEqualsPhi  (closed-form θ=0 check)
  - FDGradientCheck on closed and open tetrahedron, random ρ seed=1
  - FDHessianCheck  on closed and open tetrahedron, random ρ seed=1
  - HessianIsPSD                      (BPS 2010 §6 convexity)
  - NaturalPhiMakesZeroTheEquilibrium (gauge fixing)

Phase 9a.2 — InversiveDistanceFunctional  (vertex-based, Luo 2004)
──────────────────────────────────────────────────────────────────
* code/include/inversive_distance_functional.hpp  (290 lines)
  - Vertex DOFs u_i = log r_i
  - Per-edge inversive distance I_ij from Bowers-Stephenson 2004:
        I_ij = (ℓ² − r_i² − r_j²) / (2 r_i r_j)
  - Edge length (Luo 2004 §3):
        ℓ_ij² = exp(2u_i) + exp(2u_j) + 2 I_ij exp(u_i+u_j)
  - Gradient (Luo 2004 Lemma 3.1):
        ∂E/∂u_v = Θ_v − Σ α_v(f)
  - Energy via 10-pt Gauss-Legendre path integral (matches Euclidean)
  - Hessian: finite-difference for MVP; Glickenstein 2011 eq. 4.6
    analytic form deferred (joins Phase 9b queue)

* code/tests/cgal/test_inversive_distance_functional.cpp  (11 tests)
  - Four edge-length-formula limits (tangential I=1 ⇒ ℓ=r_i+r_j,
    orthogonal I=0 ⇒ ℓ=√(r_i²+r_j²), inside-tangent I=−1, degenerate I<−1)
  - BowersStephensonRoundTrip   (Bowers-Stephenson 2004 identity)
  - InitProducesValidPositiveRadii
  - NaturalThetaGivesZeroGradientAtU0
  - FDGradientCheck on triangle, quad strip, tetrahedron
  - AngleDefectAtU0_AgreesWithEuclideanAtU0
        — cross-validation against euclidean_functional.hpp
          (Glickenstein 2011 §5: "different parametrisations of the
          same initial metric produce the same Newton-time-zero gradient")

Phase 9a Validation Report
──────────────────────────
* doc/architecture/phase-9a-validation.md  (350 lines)
  - Line-by-line mapping CPEuclideanFunctional.java ↔ C++ port
  - Three special-case verifications of Luo's edge-length formula
  - Comparison table euclidean / cp-euclidean / inversive-distance
  - Acceptance-criteria checklist (all met)
  - Full reference list

Roadmap and tutorial corrections (already committed earlier in this branch)
──────────────────────────────────────────────────────────────────────────
* doc/roadmap/phases.md      — Phase 9a split into 9a.1 + 9a.2,
                                clear math citations per sub-phase
* doc/tutorials/add-inversive-distance.md — corrects the prior claim
                                that InversiveDistanceFunctional.java
                                exists upstream (it does not); now
                                cites Luo 2004 + Glickenstein 2011 +
                                Bowers-Stephenson 2004 as primary sources
* CLAUDE.md                  — adds phase-9a-validation.md to doc map

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-21 21:01:34 +02:00
Tarik Moussa
f50ef4a305 Phase 9b: Hyper-ideal Hessian — block-FD optimisation (96× speed-up)
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Replaces the O(n·F) full-FD Hessian with an O(F·36) block-local variant
that exploits the per-face locality of the hyper-ideal functional.  Both
variants are kept (full-FD as correctness reference, block-FD as default)
and proven to match to FD rounding tolerance on all test configurations.

Java parity note
────────────────
HyperIdealFunctional.java line 295-298 declares:
    public boolean hasHessian() { return false; }
i.e. the upstream Java functional has NO Hessian implementation, analytic
or numerical.  Both Hessian variants in this file are conformallab++
extensions beyond the Java port.  Analytic Hessian via Schläfli-type
differentiation through (b_i, a_e) → l_ij → ζ_13/ζ_14/ζ_15 → α_ij/β_i
is deferred to a future PR.

Implementation
──────────────
* code/include/hyper_ideal_functional.hpp
  - New pure-math helper face_angles_from_local_dofs() takes 6 input DOFs
    (b1, b2, b3, a12, a23, a31) + variability flags and returns the 6
    output angles (β1, β2, β3, α12, α23, α31).
  - Used by block-FD Hessian as the inner loop; identical semantics to
    the existing compute_face_angles().

* code/include/hyper_ideal_hessian.hpp
  - hyper_ideal_hessian_block_fd()  — new, default production path
  - hyper_ideal_hessian_block_fd_sym() — symmetrised variant
  - hyper_ideal_hessian()  — full-FD baseline, kept for cross-validation
  - hyper_ideal_hessian_sym() — symmetrised baseline
  - Header docblock documents speed-up curve: ~33× at cathead.obj scale,
    ~1166× at brezel.obj scale.

Tests (7 new in test_hyper_ideal_hessian.cpp)
─────────────────────────────────────────────
* PureHelperMatchesMeshHelper — refactor sanity
* BlockFD_MatchesFullFD_ClosedTetrahedron
* BlockFD_MatchesFullFD_Open3FaceMesh (boundary edge path)
* BlockFD_MatchesFullFD_PinnedDOFs    (partial-DOF path)
* BlockFD_IsPSD                       (Springborn 2020 convexity)
* BlockFD_SparsityMatchesFaceAdjacency (structural correctness)
* BlockFD_FasterThanFullFD           (performance assertion: ≥ 3×)

Measured speed-up on the 200-face tet strip (603 DOFs):
    full-FD:   226 591 µs
    block-FD:    2 347 µs
    ratio:        96.5×
The assertion uses ≥ 3× to leave wide CI-hardware tolerance.

Test count
──────────
CGAL suite: 184 → 191 (+7).  Zero skips.

Why not full analytic now
─────────────────────────
Full analytic Hessian via the chain rule
    (b_i, a_e) → l_ij → ζ_{13,14,15} → α_ij / β_i
requires Schläfli-type differentiation with multiple cases for the
ideal / hyper-ideal vertex mix.  It would add another ~6× over
block-FD but at significantly higher implementation and verification
cost.  Block-FD already removes the practical bottleneck for meshes
up to ~10k faces; analytic optimisation can land later when justified
by a concrete profiling result.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-21 20:58:33 +02:00
Tarik Moussa
140f50f707 fixup: deduce kernel from mesh point type instead of hard-coding it
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Removes the only architectural lock-in spotted in the MVP audit before
Phase 9a starts: the wrapper hard-coded Simple_cartesian<double> as the
kernel inside discrete_conformal_map_euclidean.  This would have broken
any Surface_mesh<P> where P came from a different kernel (e.g. EPIC).

Change
──────
* CGAL::Kernel_traits<typename TriangleMesh::Point>::Kernel is now used
  to deduce the kernel from the mesh's point type.
* The full Default_traits<...> instantiation is wrapped in
  internal_np::Lookup_named_param_def so a future `geom_traits(...)`
  named parameter can override the entire traits class without changes
  to the wrapper body (CGAL idiom, used by every CGAL package).
* New test `KernelIsDeducedFromMeshPointType` pins the contract
  explicitly with static_asserts.

Why now
───────
Phase 9a (Inversive-Distance) will copy this same template pattern.
Fixing the kernel deduction once here keeps the design free for any
user kernel; doing it after 9a would mean two parallel hard-coded
kernel sites to refactor.

Tests
─────
CGAL suite: 184/184 passed, 0 skipped  (was 183).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-19 22:50:40 +02:00
Tarik Moussa
a1e74c1370 Phase 8a MVP: CGAL traits + Discrete_conformal_map.h Euclidean entry
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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>
2026-05-19 22:07:15 +02:00
Tarik Moussa
e958afbd19 chore: translate all German text to English across code, docs, and CI
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Unified the codebase language to English throughout. German text appeared
in code comments, test file headers, CI step names, and several markdown
documents. All natural-language text is now English; proper nouns
(Institut für Mathematik, Technische Universität Berlin) are unchanged.

Files changed:
- .gitea/workflows/cpp-tests.yml  — CI step names and job comments
- code/include/mesh_utils.hpp     — inline comment
- code/tests/cgal/CMakeLists.txt  — section comment block
- code/tests/cgal/test_geometry_utils.cpp — full file header + all test comments
- doc/math/references.md          — geometry-central section
- doc/math/validation.md          — Section 9 (geometry-central cross-validation)
- doc/roadmap/phases.md           — Optional geometry-central track (GC-1/2/3)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-19 00:09:09 +02:00
Tarik Moussa
88a99d8bd1 fix: correct 16 inconsistencies found by consistency audit
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Math / code:
- layout.hpp: add explanatory comment for Möbius deck transformation
  (from_three with z1=w1, z2=w2 encodes T fixing cut-edge endpoints)
- layout.hpp: document spherical holonomy limitation — Vector2d stores
  only (x,y) of 3-D position diff; full SO(3) representation deferred

Gradient sign convention (CLAUDE.md was wrong):
- Euclidean and Spherical both use G_v = Θ_v − actual (target minus actual)
- HyperIdeal uses G_v = actual − Θ_v
- Hessian sign differs: Euclidean PSD, Spherical NSD → −H, HyperIdeal PSD

Test counts (were inconsistent across all files):
- Actual: 176 CGAL tests, 2 GTEST_SKIP (not 173/170/174, not 1 skip)
- The 2 skips are EuclideanFunctional + SphericalFunctional Hessian gradient
  checks (Java @Ignore ports) — not HyperIdeal Hessian as previously stated
- doc/api/tests.md: add missing SmokeEuclidean suite (3 tests),
  EuclideanLayout (2), SphericalLayout (1), fix GaussBonnet 8→12,
  MeshIO 9→6, Layout 8→6, EuclideanFunctional 11→12,
  HomologyGenerators no longer a GTEST_SKIP stub (live test on brezel2.obj)
- doc/roadmap/phases.md: Phase 7 cumulative 158→176 tests
- doc/roadmap/phases.md: Phase 3 clarified — HyperIdeal Hessian is FD
- CLAUDE.md: suite count 28→34, test ref 173+36→174+36
- scripts/try_it.sh: expected output 173/1 skipped → 174/2 skipped

CI table (CLAUDE.md):
- test-cgal now triggers on pull requests only (not main/dev pushes)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-18 23:24:44 +02:00
Tarik Moussa
b235666725 docs: Doxygen-API + Validierungsprotokoll + Porting-Tutorial
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Für einen Mathematiker der unabhängig validieren und eigene Forschung
einbringen möchte.

Doxygen-Kommentare (code/include/):
  newton_solver.hpp — newton_euclidean(), newton_spherical(), newton_hyper_ideal()
    je mit \param, \return, \note, \see inkl. mathematischer Begründung
    (Konvexität, Vorzeichenkonvention, SparseQR-Fallback-Erklärung)
  layout.hpp — euclidean_layout(), spherical_layout(), hyper_ideal_layout()
    mit vollständiger Parameter-Doku, halfedge_uv-Semantik, Poincaré-Disk-Note

Neues Dokument:
  doc/math/validation-protocol.md
    7 reproduzierbare Checks mit konkreten Befehlen und erwartetem Output:
    0. 170 Tests, 1 Skip
    1. Gauss–Bonnet exakt (1e-10)
    2. FD-Gradientencheck < 1e-6 für alle 3 Geometrien
    3. Newton-Konvergenz < 50 Iterationen
    4. τ ∈ SL(2,ℤ)-Fundamentaldomäne (3 Invarianten)
    5. Möbius-Arithmetik (Inverse, Compose, from_three)
    6. End-to-End-Pipeline
    7. Manueller τ-Check für torus_4x4.off (Codebeispiel)

Neues Tutorial:
  doc/tutorials/add-inversive-distance.md
    Vollständiger Step-by-Step-Port von Phase 9a (Luo 2004):
    Header anlegen, Energie/Gradient implementieren, FD-Check,
    Newton-Wrapper, CMakeLists, Java-Referenzvergleich, Checkliste.

doc/getting-started.md:
  Abschnitt "Known issues": macOS-Finder-Duplikate (rm-Befehl),
  Warnung "First build 30–90s" (Tarball-Extraktion)

README.md:
  Zwei neue Links in der Dokumentationstabelle (validation-protocol,
  tutorial)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-18 01:19:44 +02:00
Tarik Moussa
e7dfaed56c feat(phase7): Java-parity layout — priority BFS, halfedge_uv, Möbius holonomy, period matrix, fundamental domain — 158 tests
Phase 7 adds seven features ported from the original Java ConformalLab:

  layout.hpp
  - Priority BFS (min-heap on BFS depth) replaces FIFO queue, minimising
    trilateration error accumulation from the root face outward.
  - MobiusMap struct: T(z)=(az+b)/(cz+d), identity/inverse/compose,
    from_three (3×3 complex least-squares fit), apply(Vector2d).
  - halfedge_uv[h.idx()] = UV of source(h) in face(h); seam halfedges
    carry the virtual unfolded position, enabling proper GPU texture atlases.
  - Hyperbolic holonomy stored as MobiusMap per cut edge (SU(1,1) isometry).
  - best_root_face: largest 3-D area face, 1.5× interior bonus.
  - normalise_euclidean also transforms halfedge_uv (centroid + PCA).
  - Face-area-weighted iterative Möbius centering (Fréchet mean, Phase 7).

  period_matrix.hpp  (new)
  - PeriodData: lattice generators ω_i as complex numbers, τ = ω₂/ω₁ ∈ ℍ.
  - reduce_to_fundamental_domain: SL(2,ℤ) reduction via alternating S/T steps.
  - is_in_fundamental_domain, compute_period_matrix.
  - NOTE: Siegel matrix Ω for genus g>1 intentionally deferred.

  fundamental_domain.hpp  (new)
  - FundamentalDomain: CCW parallelogram {0, ω₁, ω₁+ω₂, ω₂} for genus 1.
  - edge_identifications, generators stored.
  - 4g-polygon boundary-walk for g>1 marked TODO(Phase 8) with full algorithm
    outline and literature references.
  - tiling_copy / tiling_neighbourhood for universal cover visualisation.

  Tests: 121 → 158 (+37 Phase 7 tests covering all new features).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-13 07:57:13 +02:00
Tarik Moussa
4fc48b39f0 feat(phase6): exact hyperbolic layout, Gauss–Bonnet, cut graph, normalisation — 121 tests
New files:
- gauss_bonnet.hpp: euler_characteristic, genus, Σ(2π-Θ_v) sum/rhs/deficit,
  check_gauss_bonnet (throws), enforce_gauss_bonnet (correct sign: Δ=(lhs-rhs)/V)
- cut_graph.hpp: CutGraph struct + compute_cut_graph (tree-cotree, Erickson–Whittlesey
  2005); boundary edges correctly excluded from cut set
- test_phase6.cpp: 26 new tests (GaussBonnet ×8, CutGraph ×6, HyperbolicTrilateration
  ×4, Normalisation ×4 — all pass)

layout.hpp (Phase 6 rewrite):
- detail::trilaterate_hyp: exact Möbius + hyperbolic law of cosines replacing old tanh(d/2)
- detail::center_poincare_disk: Möbius centering for hyperbolic normalisation
- normalise_euclidean: centroid → origin + PCA major-axis rotation
- normalise_hyperbolic: Möbius centering in the Poincaré disk
- normalise_spherical: Rodrigues rotation → north pole
- euclidean_layout / hyper_ideal_layout: optional CutGraph* + HolonomyData* + normalise

Bug fixes caught by new tests:
- gauss_bonnet.hpp: enforce_gauss_bonnet had wrong sign for delta
- cut_graph.hpp: boundary edges were incorrectly marked as cut edges

121 tests pass, 2 skipped (Hessian stubs).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-13 01:15:41 +02:00
Tarik Moussa
b7593e3f6d feat(phase5): Layout, CLI, JSON/XML serialisation — 95 tests
Phase 5 complete:

layout.hpp
  - euclidean_layout(): BFS unfolding in ℝ² using trilaterate_2d
  - spherical_layout(): BFS on S² using trilaterate_sph (spherical law of cosines)
  - hyper_ideal_layout(): BFS in Poincaré disk (tanh(d/2) Euclidean approx)
  - save_layout_off(): convenience OFF writer for 2-D and 3-D layouts

serialization.hpp
  - save/load_result_json(): nlohmann/json; stores DOF vector + uv/pos layout
  - save/load_result_xml(): hand-written writer/parser; same schema

conformallab_cli.cpp (rewritten)
  - CLI11 interface: -i/-o/-g/-j/-x/-s/-v
  - Dispatches to euclidean / spherical / hyper_ideal pipeline
  - Runs Newton, computes layout, saves OFF + JSON + XML

examples/example_layout.cpp
  - Full round-trip demo: solve → layout → JSON/XML → reload → verify

tests/cgal/test_layout.cpp (8 tests)
  - Euclidean_PreservesEdgeLengths, CorrectVertexCount, TriangleIsNonDegenerate
  - Spherical_PreservesArcLengths, PositionsOnUnitSphere
  - HyperIdeal_SuccessAndFinitePositions
  - Serialization.JSON_RoundTrip, XML_RoundTrip

All 95 CGAL tests pass (2 skipped — Hessian stubs unchanged).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-13 00:53:47 +02:00
Tarik Moussa
3f124eb071 feat(phase4): HyperIdeal Newton solver, SparseQR fallback, examples, docs
Phase 4 complete — 87 CGAL tests pass, 2 skipped.

Newton solver (phase4a):
- hyper_ideal_hessian.hpp: symmetric FD Hessian (O(ε²), PSD by convexity)
- newton_hyper_ideal(): Newton + backtracking for the HyperIdeal functional
- detail::solve_with_fallback(): optional bool* fallback_used parameter
- solve_linear_system(): public API exposing LDLT→SparseQR fallback

SparseQR fallback tests (SparseQRFallback.*):
- FullRankSystem_CorrectSolution: LDLT path, fallback_used=false
- SingularMatrix_FallbackActivated: zero-pivot → QR activated, fallback_used=true
- Euclidean_ClosedMeshNoPinConverges: gauge-mode null space handled via QR

HyperIdeal Newton tests (NewtonSolver.HyperIdeal_*):
- ConvergesTriangleAllVariable, ResultFieldsConsistent,
  ConvergesTetrahedron, SparseQRFallbackNoCrash
- Natural-target base point (b=1.0, a=0.5) — x=0 is degenerate in log-space

Pipeline tests (test_pipeline.cpp):
- End-to-end: all three geometries, mesh I/O round-trip, solve+export

Example programs (code/examples/):
- example_euclidean.cpp:   headless Euclidean pipeline
- example_hyper_ideal.cpp: headless HyperIdeal pipeline
- example_viewer.cpp:      interactive libigl viewer with jet colour map

README:
- Mathematical scope table: C++ vs Java original (18 rows)
- "For mathematicians" section: mental model, step-by-step new-functional
  guide, half-edge traversal snippets, recommended reading

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-13 00:11:25 +02:00
Tarik Moussa
e70689d29f feat(phase4a+4b): Newton solver + CGAL mesh I/O
Phase 4a — newton_solver.hpp:
  - newton_euclidean(): SimplicialLDLT on H (PSD); solves H·Δx = −G
  - newton_spherical(): SimplicialLDLT on −H (NSD→PSD); solves (−H)·Δx = G
  - Backtracking line search (halving α up to 20×) for global convergence
  - NewtonResult struct: x, iterations, grad_inf_norm, converged
  - 7 tests: 4 spherical (convergence, few iters, large perturbation,
    field consistency) + 3 Euclidean (triangle pinned, quad pinned,
    mixed pinned — all with natural-theta equilibrium at x=0)

Phase 4b — mesh_io.hpp:
  - read_mesh() / write_mesh(): CGAL::IO::read/write_polygon_mesh wrappers
  - load_mesh() / save_mesh(): throwing convenience versions
  - Supports OFF, OBJ, PLY (format detected by file extension)
  - 6 tests: OFF round-trip (tet + quad), OBJ round-trip, missing-file throw,
    vertex-position preservation, save/load convenience wrappers

All 75 cgal tests pass (3 skipped as before).

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
2026-05-12 17:35:00 +02:00
Tarik Moussa
194effba97 feat(phase3f+3g): analytical Hessians + PI consolidation
Phase 3g — constants.hpp:
  - Introduce conformallab::PI and TWO_PI in a single constants.hpp
  - Remove scattered local PI/pi definitions from hyper_ideal_geometry.hpp,
    hyper_ideal_utility.hpp, euclidean_functional.hpp, mesh_builder.hpp,
    spherical_geometry.hpp (backward-compatible PI_SPHER alias kept)

Phase 3f — Euclidean Hessian (euclidean_hessian.hpp):
  - Cotangent-Laplace operator (Pinkall–Polthier 1993)
  - euclidean_cot_weights() helper + euclidean_hessian() + hessian_check_euclidean()
  - Correct Pinkall–Polthier 1/2 normalization factor
  - 8 tests: cot weights, symmetry, null-space (H·1=0), PSD, FD × 4 meshes

Phase 3f — Spherical Hessian (spherical_hessian.hpp):
  - Derives ∂α_i/∂u_j directly from the spherical law of cosines:
      ∂α1/∂l_opp  = sin(l_opp) / [sin(l_a)·sin(l_b)·sin(α1)]
      ∂α1/∂l_adj  = [cot(l_adj)·cos(α1) − cot(l_other)] / sin(α1)
    then chains with ∂l/∂λ = tan(l/2)
  - spherical_cot_weights() kept as a standalone helper (tested separately)
  - 8 tests: cot weights, symmetry, correct null-space & sign-convention
    (H·1 ≠ 0; H is NSD at equilibrium), FD × 3 meshes

All 62 cgal tests pass (3 skipped as before).

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
2026-05-12 17:22:28 +02:00
Tarik Moussa
8c353bb884 feat(phase3d+3e): port EuclideanCyclicFunctional + add SphericalFunctional gauge-fix
Phase 3d — EuclideanCyclicFunctional:
  • euclidean_geometry.hpp: t-value / atan2 corner-angle formula with
    centering trick (μ = (Λ̃₁₂+Λ̃₂₃+Λ̃₃₁)/6) for numerical stability
  • euclidean_functional.hpp: EuclideanMaps bundle, gradient (G_v = Θ_v − Σα_v,
    G_e = α_opp⁺ + α_opp⁻ − φ_e), 10-point GL path-integral energy,
    gradient_check_euclidean — identical halfedge convention to SphericalFunctional
  • test_euclidean_functional.cpp: 11 tests (1 skip) covering angle formula,
    right-isosceles triangle, angle sum = π, degenerate detection, gradient
    checks on triangle/quad-strip/tetrahedron/fan-5/mixed-pinned, NaN check

Phase 3e — Spherical gauge-fix:
  • spherical_gauge_shift(): Newton + backtracking line search to find t*
    where ΣG_v(x + t·1) = 0 (maximises E along the global scale direction);
    bisection used when sign change is detectable, Newton+backtrack otherwise
  • apply_spherical_gauge(): in-place wrapper
  • 3 new tests: GaugeFix_SpherTetVertexZerosSumGv, GaugeFix_ApplyInPlace,
    GaugeFix_AlreadyAtGaugeReturnsTNearZero

Total: 45 cgal tests pass, 3 skipped (@Ignore Hessian stubs, one per functional)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-12 07:39:14 +02:00
Tarik Moussa
a4c2a89e7e feat(phase3c): port SphericalFunctional onto ConformalMesh; update README
New headers:
- spherical_geometry.hpp: spherical arc length l(λ) and half-angle formula
  for interior angles of a spherical triangle (SphericalFaceAngles struct)
- spherical_functional.hpp: SphericalMaps bundle, setup/assign DOF helpers,
  compute_lambda0_from_mesh(), gradient (Θ_v − Σα_v; Schläfli edge formula),
  energy via 10-point Gauss-Legendre path integral, gradient_check_spherical()

Updated:
- mesh_builder.hpp: add make_spherical_tetrahedron() (vertices on unit sphere)
  and make_octahedron_face() (single right-angled spherical triangle)
- tests/cgal/CMakeLists.txt: enable test_spherical_functional.cpp
- README.md: rewrite for CGAL-package goal, two test targets, all headers,
  updated project tree, Phase progress table, key design decisions

Tests (cgal.SphericalFunctional.*): 8 active + 1 skip
- OctaFaceAnglesAreRightAngles, SpherTetAngleSumExceedsPi
- GradientCheck_{OctaFaceVertex, SpherTetVertex, SpherTetAllDofs,
  SpherFan4Vertex, MixedPinnedVertices}
- AnglesFiniteAtKnownPoint
All 30 cgal.* tests pass (2 @Ignore skips).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-12 00:01:24 +02:00
Tarik Moussa
516ac89bd8 feat(phase3b): port HyperIdealFunctional energy + gradient onto ConformalMesh
Implements the hyper-ideal discrete conformal map functional on
CGAL::Surface_mesh. The energy and analytic gradient are ported directly
from HyperIdealFunctional.java; correctness is verified via a
finite-difference gradient check (same eps=1E-5 / tol=1E-4 as Java).

New files:
  include/hyper_ideal_geometry.hpp    — ζ, ζ₁₃, ζ₁₄, ζ₁₅, lij, αij, σi, σij
  include/hyper_ideal_functional.hpp  — HyperIdealMaps, evaluate_hyper_ideal,
                                        gradient_check
  tests/cgal/test_hyper_ideal_functional.cpp  — 6 tests (1 skipped @Ignore)

Test results (local, -DWITH_CGAL=ON):
  conformallab_cgal_tests: 21 registered | 20 passed | 1 skipped | 0 failed
    - GradientCheck_AllHyperIdealTriangle   ✓
    - GradientCheck_ExtendedDomain          ✓
    - GradientCheck_TetrahedronAllVariable  ✓
    - EnergyFiniteAtTestPoint               ✓
    - GradientCheck_MixedIdealHyperIdeal    ✓
    - GradientCheck_Fan6AllVariable         ✓

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-11 23:10:23 +02:00
Tarik Moussa
bf9c323d60 feat(phase3a): introduce CGAL Surface_mesh as ConformalMesh foundation
Replaces the Java CoHDS with CGAL::Surface_mesh<Point3> (Simple_cartesian
kernel). Adds domain-specific property maps for lambda/theta/idx/alpha and
face geometry type — the direct C++ equivalent of CoVertex/CoEdge adapters.

New files:
  include/conformal_mesh.hpp   — ConformalMesh type + property-map helpers
  include/mesh_builder.hpp     — mesh factories (triangle, tetrahedron,
                                 quad-strip, fan) for tests and examples
  tests/cgal/                  — second test executable (conformallab_cgal_tests)
                                 built only with -DWITH_CGAL=ON

Test results (local, -DWITH_CGAL=ON):
  conformallab_tests:      36 registered | 23 passed | 13 skipped | 0 failed
  conformallab_cgal_tests: 14 registered | 14 passed |  0 skipped | 0 failed

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-11 18:36:21 +02:00
Tarik Moussa
ae5db7216e tests: port HyperIdealVisualizationPlugin circle-projection tests
All checks were successful
C++ Tests / test (push) Successful in 2m29s
Mirror to Codeberg / mirror (push) Successful in 26s
Implements getEuclideanCircleFromHyperbolic() in C++ (hyperboloid model
→ Poincaré disk via Lorentz boost + circumcircle). Ports the 2 Java tests
that were the only remaining candidates not requiring HDS or a solver.

All other unported tests (DataTypesTest, SchottkyIOTest,
UniformizationDataTest, BranchedCoverTorusTest) are blocked by XML
serialization or HDS – stubs remain for Phase 4.

Test totals: 36 registered | 23 passed | 13 skipped | 0 failed.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-11 17:23:15 +02:00
Tarik Moussa
c5a86cb30a tests: port DiscreteEllipticUtility + P2 tests; stub HDS-blocked tests
All checks were successful
C++ Tests / test (push) Successful in 2m39s
Mirror to Codeberg / mirror (push) Successful in 24s
Fully ported (pure math, no HDS required):
  test_discrete_elliptic_utility.cpp  – 2 tests
    normalizeModulus: move tau into SL(2,Z) fundamental domain
  test_p2_utility.cpp                 – 3 tests
    P2 projective geometry (perpendicularBisector, pointFromLines,
    makeDirectIsometryFromFrames double vs long double precision)

New headers:
  include/discrete_elliptic_utility.hpp  – normalizeModulus
  include/p2_utility.hpp                 – P2 Euclidean geometry (templated
    on scalar type so double and long double share one implementation)

Stubs (GTEST_SKIP, blocked until HDS port – Phase 4):
  test_hyper_ideal_functional.cpp          – 5 tests (1 @Ignore in Java)
  test_hyper_ideal_hyperelliptic_utility.cpp – 3 tests
  test_spherical_functional.cpp            – 5 tests
  All use CoHDS + HalfEdgeUtils which are not yet ported to C++.

Result: 34 tests total | 21 passed | 13 skipped | 0 failed

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-11 17:15:18 +02:00
Tarik Moussa
a2876b9cbf port MatrixUtility and SurfaceCurveUtility tests to C++
- include/matrix_utility.hpp: 4x4 mapping matrix R·from=to (Eigen)
- include/projective_math.hpp: dehomogenize, hyperbolicDistance,
  isOnSegment (collinearity + betweenness via 3D cross/dot),
  getPointOnCorrespondingSegment (parameter by arc-length ratio)
- test_matrix_utility.cpp: port of MatrixUtilityTest (1 test)
- test_surface_curve_utility.cpp: port of SurfaceCurveUtilityTest
  testIsBetween and testGetPointOnSegment_SegmentEdge (2 tests)
- tolerance adjusted to 1e-12 for matrix inversion (2.7e-15 rounding
  from Eigen vs jReality's LU; both well within meaningful accuracy)

Total: 16/16 tests pass

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-09 01:15:35 +02:00
Tarik Moussa
c30d540521 add GTest infrastructure and port first mathematical tests from Java
- Add Google Test via CMake FetchContent (v1.14.0)
- Add clausen.hpp: Clausen integral, Lobachevsky function, Im(Li2)
- Add hyper_ideal_utility.hpp: generalized and ideal-vertex hyperbolic
  tetrahedron volume formulas using Eigen for the 4x4 Gram determinant
- Port ClausenTest (5 tests) and HyperIdealUtilityTest (8 tests) from
  Java/JUnit — all 13 pass with same tolerances as the Java originals
- Fix pre-existing VIEWER/viewer case mismatch in CMakeLists.txt

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-09 01:07:19 +02:00
Tarik Moussa
e150cf6ef3 add new compile target for viewer 2026-03-17 21:18:59 +02:00
Tarik Moussa
2479aedeee ad simple visualization 2026-03-16 17:47:48 +02:00
Tarik Moussa
1ce993f296 ad simple visualization 2026-03-16 17:20:15 +02:00
Tarik Moussa
f3b7453a45 add CMake dependency handling for portability 2026-02-16 18:18:39 +02:00