DOI 10.1007/0-387-29555-0_13 is Ushijima (sole author) —
"A Volume Formula for Generalised Hyperbolic Tetrahedra",
in: Prékopa & Molnár (eds.), Non-Euclidean Geometries,
Springer 2006. arXiv: math/0309216.
The references.md entry was wrong on all three counts:
- Author: "Meyerhoff, Ushijima" → Ushijima only
- Title: "A Note on the Dirichlet Domain" → entirely different title
- Book: "The Epstein Birthday Schrift" → Non-Euclidean Geometries
Same error pattern as the Kolpakov-Mednykh fix: the Java source
links only to a DOI without naming authors; a wrong name was
invented during the C++ port.
Files corrected: hyper_ideal_utility.hpp, hyper_ideal_functional.hpp,
references.md, tests.md, project-structure.md, finding-orchestration.md,
math-derivation-citation-audit.md, MANUAL-DOWNLOAD.md
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
arXiv:math/0603097 is Springborn 2008 ("A variational principle for weighted
Delaunay triangulations and hyperideal polyhedra"), not a Kolpakov-Mednykh paper.
The author pair Kolpakov & Mednykh has no joint publication from 2006; their
earliest collaboration is arXiv:1008.0312 (2010, on torus knots, unrelated).
The wrong author name was introduced during the Java→C++ port — the Java source
correctly links to math/0603097 without naming the authors; whoever ported it
invented "Kolpakov-Mednykh". The S1 citation audit (2026-05-31) then cemented
the error by adding the incorrect row to references.md.
Files corrected (7):
- code/include/hyper_ideal_utility.hpp
- code/include/hyper_ideal_functional.hpp
- code/tests/cgal/test_hyper_ideal_functional.cpp
- doc/math/references.md
- doc/roadmap/research-track.md
- doc/architecture/project-structure.md
- doc/api/tests.md
Also:
- doc/reviewer/math-derivation-citation-audit-2026-05-31.md: M1 post-correction noted
- doc/reviewer/finding-orchestration.md: lesson-learned section added (AI citation
audits can introduce plausible-but-wrong attributions; human expert review required
before CGAL submission)
- papers/MANUAL-DOWNLOAD.md: overview of papers requiring manual download (paywalled
journals, TU Berlin theses, books)
- .gitignore: papers/*.pdf excluded (downloaded arXiv PDFs, not tracked)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
The hyper-ideal vertex scale b is floored to keep the geometry valid. The
original clamp `b<0 → 0.01` mirrors the Java oracle but is only C⁰ (in fact
value-discontinuous at b=0): a Newton step crossing the feasibility boundary
hits a kink that can stall convergence (numerical-stability audit N3).
Rather than replace the Java-faithful behaviour (which would break the golden
parity tests), make the floor a selectable mode so BOTH the Java standpoint
and the clean mathematics are available:
- HyperIdealScaleClamp::HardJava (DEFAULT) — the original snap, bit-for-bit
faithful to HyperIdealFunctional.java → all parity tests unchanged.
- HyperIdealScaleClamp::SmoothBarrier — C¹ softplus floor
b ↦ floor + softplus_β(b−floor), β = HYPER_IDEAL_SCALE_SHARPNESS (=100);
≈ identity away from the floor, smooth across b=0. Opt-in.
clamp_hyper_ideal_scale centralises the logic (also folds in the N4 nachzügler:
compute_face_angles used a bare 0.01). The mode threads with a defaulted
trailing parameter through compute_face_angles, face_angles_from_local_dofs,
evaluate_hyper_ideal, the four hyper_ideal_hessian* variants and
newton_hyper_ideal — so every existing call site keeps HardJava behaviour.
Tests (+4): clamp-function C¹/floor/identity contract, mode-equivalence away
from the boundary, and end-to-end SmoothBarrier convergence to the same Java
golden vector (LawsonHyperIdeal). 296/296 CGAL tests pass.
Documented in doc/math/geometry-modes.md.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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>
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>
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>
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>
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>
