Trait Predicates

Source

pub trait Predicates {
    // Required methods
    fn orient2d(a: P2, b: P2, c: P2) -> Sign;
    fn orient3d(a: P3, b: P3, c: P3, d: P3) -> Sign;
    fn incircle(a: P2, b: P2, c: P2, d: P2) -> Sign;
    fn insphere(a: P3, b: P3, c: P3, d: P3, e: P3) -> Sign;

    // Provided methods
    fn is_left_of(a: P2, b: P2, c: P2) -> bool { ... }
    fn are_collinear(a: P2, b: P2, c: P2) -> bool { ... }
    fn are_coplanar(a: P3, b: P3, c: P3, d: P3) -> bool { ... }
}

Expand description

Orientation and incircle/insphere tests.

Implementations must agree on sign conventions; only their accuracy and cost may differ.

Required Methods§

Source

fn orient2d(a: P2, b: P2, c: P2) -> Sign

Sign of the area of triangle (a, b, c).

Sign::Positive when the three points are counter-clockwise, Sign::Zero when collinear.

Source

fn orient3d(a: P3, b: P3, c: P3, d: P3) -> Sign

Sign of the volume of tetrahedron (a, b, c, d).

Sign::Positive when d lies below the plane through a, b, c, where “below” is the side from which a, b, c appear clockwise. Sign::Zero when the four points are coplanar.