Module kernel 

Pure-Rust exact mesh-arrangement CSG kernel — the only CSG kernel, on every target (see docs/architecture/geometry-pipeline.md). Pure-Rust exact mesh-arrangement CSG kernel — predicate foundation.

This layer provides exact, platform-deterministic geometric predicates over a mix of EXPLICIT input points and IMPLICIT intersection points (LPI = line∩plane, TPI = three planes) carried symbolically and never materialised to a float decision.

Determinism: signs are integer parity over deterministic arithmetic. The explicit path goes through geometry-predicates (FMA-free, const error bounds). The EXACT (BigRational) tier is correct by construction and is the oracle for the faster interval/fixed-width tiers, each verified ≡ exact.

Modules

arrangement

Mesh arrangement — the conforming intersection of two operand meshes.

broadphase

Broadphase — a hand-rolled f64 median-split AABB BVH over one operand’s triangles, queried by the other operand’s triangle AABBs to replace the O(|A|·|B|) all-pairs scan.

budget

Deterministic per-boolean exact-predicate budget (issue #1109).

coplanar

Coplanar triangle overlap — the constraints two coplanar overlapping faces impose on each other.

fixed

Fixed-width exact predicate tier — the FAST exact arithmetic between the interval filter and the BigRational fallback.

interner

Symbolic vertex interner — the arrangement’s single source of vertex identity.

interval

Directed-rounding f64 interval tier — the predicate cascade’s fast path.

manifest

Cross-platform sign manifest (G2 L1 slice) — the determinism-bar proof for the predicate layer.

mesh_bridge

Bridge between the pure-Rust kernel (which works on Tri = [[f64;3];3]) and ifc-lite’s Mesh (f32 positions/normals/indices). subtract/union/ intersection here are what the ClippingProcessor seam calls.

predicates

Public predicate dispatch over ImplicitPoint configurations.

rational

Exact (BigRational) predicate tier — the correctness ground truth and the cascade’s last-resort exact fallback. f64 coordinates are exactly representable as BigRational, so every sign here is mathematically exact.

retriangulate

In-plane constrained re-triangulation — phases A–F.

tritri

Triangle–triangle intersection machinery — exact, predicate-driven.

Structs

Lpi

Line–plane implicit point: line through p,q ∩ plane through r,s,t.

Tpi

Three-plane implicit point: planes[i] is a triangle (3 points) defining a plane.

Enums

DropAxis

Which axis to drop when projecting a 3D predicate to 2D (orient2d).

ImplicitPoint

A point that is either an explicit input coordinate or an implicit intersection point carried symbolically over the original input coords.

Sign

Three-valued exact sign.

Functions

assemble_sign

Combine the sign of the homogenised determinant Λ′ with the per-configuration denominator flip.