Struct Arrangement 

pub struct Arrangement {
    pub interner: Interner,
    pub tris_a: Vec<[Vid; 3]>,
    pub tris_b: Vec<[Vid; 3]>,
    pub unrecovered: usize,
    pub coplanar_a: Vec<bool>,
    pub coplanar_b: Vec<bool>,
    /* private fields */
}

The conforming arrangement of two operand meshes over a shared interner.

Fields

interner: Interner

tris_a: Vec<[Vid; 3]>

Operand A’s conforming sub-triangles (interned Vids).

tris_b: Vec<[Vid; 3]>

Operand B’s conforming sub-triangles.

unrecovered: usize

Total constraint sub-segments the per-triangle re-triangulations could not force as edges (Mesh2d::unrecovered). Non-zero ⇒ the operands do not fully conform along their intersection; centroid classification of straddling sub-triangles is unreliable. The N-ary batched difference treats this as a hard reject; the binary boolean keeps its historical graceful-degrade behavior.

coplanar_a: Vec<bool>

Per-sub-triangle (parallel to tris_a) flag: this sub-triangle’s PARENT face had a COPLANAR overlap with the other operand — so a sub-triangle on it may lie on a shared interface plane and needs the [solid_side] regime-2 classification (boolean_vids). false ⇒ the parent face is transversal to the other operand, so the plain centroid ray-cast suffices (the common case; keeps box−box etc. on the fast single-cast path).

coplanar_b: Vec<bool>

Per-sub-triangle (parallel to tris_b) coplanar-parent flag.