feat(geometry): pn_geometry.hpp — Pn projective-metric substrate (jReality port) #31

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user2595 merged 2 commits from feat/pn-geometry-substrate into main 2026-05-30 15:26:26 +00:00

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user2595 commented 2026-05-30 15:00:58 +00:00

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Summary

Ports the de.jreality.math.Pn surface that the Java algorithmic core uses across every not-yet-ported geometric phase (27 files, ≈106 imports). Porting it once unblocks all downstream consumers.

What it unblocks

Phase	Consumer
9c	HyperbolicLayout, FundamentalPolygon
10c′	KoebePolyhedron
10e	quasi-isothermic / SphericalLayout
11c	CircleDomain
—	hyperelliptic θ

pn_geometry.hpp (header-only, Eigen, ~120 LOC)

• PnMetric { EUCLIDEAN=0, ELLIPTIC=+1, HYPERBOLIC=-1 } — matches jReality.
• pn_inner_product / pn_norm / pn_dehomogenize / pn_set_to_length / pn_normalize.
• pn_distance_between — Euclidean, elliptic (acos), hyperbolic (acosh).
• pn_linear_interpolation — affine (E) + geodesic slerp (S/H).

HYPERBOLIC timelike-positive, anchored against projective_math.hpp::hyperbolicDistance.

Tests — 6/6 GREEN (246/246 cgal)

InnerProductSignatures · EuclideanDistance · EllipticDistanceIsAngle · HyperbolicDistanceClosedFormAndAnchor · NormAndScaling · LinearInterpolationGeodesic.

java-parity.md — Infrastructure table + Phase 9c dependency notes

Infrastructure / support layers (new section):

Layer	Status
Pn	⚠️ partial → pn_geometry.hpp
Rn	⚠️ partial → Eigen inline
Matrix	✅ → Eigen::Matrix4d
P2	⚠️ port inline with Phase 9c (see below)
MatrixBuilder	❌ on demand (hyperelliptic θ only)
XML types	❌ not planned (GUI persistence)

Phase 9c rows annotated with ⚠️: FundamentalPolygonUtility and CanonicalFormUtility depend on P2.makeDirectIsometryFromFrames, P2.projectP3ToP2, P2.imbedMatrixP2InP3 + the high-precision P2Big / cpp_dec_float_50 substrate. A future Phase 9c session should start by writing p2_geometry.hpp (~5 functions, ~80 LOC) before tackling the utility classes.

🤖 Generated with Claude Code

## Summary Ports the `de.jreality.math.Pn` surface that the Java algorithmic core uses across every not-yet-ported geometric phase (27 files, ≈106 imports). Porting it once unblocks all downstream consumers. ## What it unblocks | Phase | Consumer | |---|---| | 9c | HyperbolicLayout, FundamentalPolygon | | 10c′ | KoebePolyhedron | | 10e | quasi-isothermic / SphericalLayout | | 11c | CircleDomain | | — | hyperelliptic θ | ## `pn_geometry.hpp` (header-only, Eigen, ~120 LOC) - `PnMetric { EUCLIDEAN=0, ELLIPTIC=+1, HYPERBOLIC=-1 }` — matches jReality. - `pn_inner_product` / `pn_norm` / `pn_dehomogenize` / `pn_set_to_length` / `pn_normalize`. - `pn_distance_between` — Euclidean, elliptic (acos), hyperbolic (acosh). - `pn_linear_interpolation` — affine (E) + geodesic slerp (S/H). HYPERBOLIC timelike-positive, anchored against `projective_math.hpp::hyperbolicDistance`. ## Tests — 6/6 GREEN (246/246 cgal) `InnerProductSignatures` · `EuclideanDistance` · `EllipticDistanceIsAngle` · `HyperbolicDistanceClosedFormAndAnchor` · `NormAndScaling` · `LinearInterpolationGeodesic`. ## `java-parity.md` — Infrastructure table + Phase 9c dependency notes **Infrastructure / support layers** (new section): | Layer | Status | |---|---| | `Pn` | ⚠️ partial → `pn_geometry.hpp` | | `Rn` | ⚠️ partial → Eigen inline | | `Matrix` | ✅ → `Eigen::Matrix4d` | | `P2` | ⚠️ **port inline with Phase 9c** (see below) | | `MatrixBuilder` | ❌ on demand (hyperelliptic θ only) | | XML types | ❌ not planned (GUI persistence) | **Phase 9c rows** annotated with ⚠️: `FundamentalPolygonUtility` and `CanonicalFormUtility` depend on `P2.makeDirectIsometryFromFrames`, `P2.projectP3ToP2`, `P2.imbedMatrixP2InP3` + the high-precision `P2Big` / `cpp_dec_float_50` substrate. A future Phase 9c session should start by writing `p2_geometry.hpp` (~5 functions, ~80 LOC) before tackling the utility classes. 🤖 Generated with [Claude Code](https://claude.com/claude-code)

user2595 added 1 commit 2026-05-30 15:00:58 +00:00

feat(geometry): pn_geometry.hpp — Pn projective-metric substrate (jReality port) ... f79d0b79dc

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>

user2595 added 1 commit 2026-05-30 15:16:01 +00:00

docs(java-parity): P2/Matrix jReality notes + Phase 9c dependency warning ... 87ec7b76b0

- Infrastructure table: add Matrix (→ Eigen inline, done) and P2 rows.
  P2 marked "port inline with Phase 9c" — almost exclusively consumed by
  FundamentalPolygon/CanonicalForm/SurfaceCurve (all Phase 9c), so building
  p2_geometry.hpp as a standalone ahead of 9c would be dead weight.
- Phase 9c rows in the utility table: ⚠️ annotation listing the exact P2.*
  methods needed (makeDirectIsometryFromFrames, projectP3ToP2,
  imbedMatrixP2InP3) plus the P2Big/cpp_dec_float_50 high-precision
  prerequisite for the group-relation product ∏gᵢ = Id.

Ensures a future Phase 9c session starts with full context and does not
discover the jReality/precision dependencies mid-port.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

user2595 added 2 commits 2026-05-30 15:21:21 +00:00

docs(java-parity): P2/Matrix jReality notes + Phase 9c dependency warning ... 87ec7b76b0

- Infrastructure table: add Matrix (→ Eigen inline, done) and P2 rows.
  P2 marked "port inline with Phase 9c" — almost exclusively consumed by
  FundamentalPolygon/CanonicalForm/SurfaceCurve (all Phase 9c), so building
  p2_geometry.hpp as a standalone ahead of 9c would be dead weight.
- Phase 9c rows in the utility table: ⚠️ annotation listing the exact P2.*
  methods needed (makeDirectIsometryFromFrames, projectP3ToP2,
  imbedMatrixP2InP3) plus the P2Big/cpp_dec_float_50 high-precision
  prerequisite for the group-relation product ∏gᵢ = Id.

Ensures a future Phase 9c session starts with full context and does not
discover the jReality/precision dependencies mid-port.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs(java-parity): P2/Matrix jReality notes + Phase 9c dependency warning ... 330515ea90

- Infrastructure table: add Matrix (→ Eigen inline, done) and P2 rows.
  P2 marked "port inline with Phase 9c" — almost exclusively consumed by
  FundamentalPolygon/CanonicalForm/SurfaceCurve (all Phase 9c), so building
  p2_geometry.hpp as a standalone ahead of 9c would be dead weight.
- Phase 9c rows in the utility table: ⚠️ annotation listing the exact P2.*
  methods needed (makeDirectIsometryFromFrames, projectP3ToP2,
  imbedMatrixP2InP3) plus the P2Big/cpp_dec_float_50 high-precision
  prerequisite for the group-relation product ∏gᵢ = Id.

Ensures a future Phase 9c session starts with full context and does not
discover the jReality/precision dependencies mid-port.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

user2595 merged commit adfcb7b931 into main 2026-05-30 15:26:26 +00:00

user2595 referenced this issue from a commit 2026-05-30 15:26:28 +00:00

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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Reference: conformallab/ConformalLabpp#31

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