Function orient3d_in 

pub fn orient3d_in(
    scratch: &mut Scratch<'_>,
    a: &impl Point,
    b: &impl Point,
    c: &impl Point,
    d: &impl Point,
) -> Result<Option<Sign>, ScratchExhausted>

orient3d with the arena scratch for the exact coordinates of implicit points, instead of the arena of the thread: the same result, or an error if scratch runs out of room. Available without std.

scratch is left as it was, on success and on error. It is not used when the filter decides, nor when every point is explicit. With implicit points the exact stages may need several thousand f64; an arena made with Scratch::growable (with the alloc feature of implicit-predicates-core) never runs out.

Errors

ScratchExhausted if scratch runs out of room; a larger arena then gives the result.

Examples

use implicit_predicates::{Lnc, Scratch, Sign, orient3d_in};

let (a, b, c) = ([1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]);
let m = Lnc::new(a, b, 0.1)?;
let mut buf = vec![0.0; 4096];
let mut scratch = Scratch::borrowed(&mut buf);
assert_eq!(orient3d_in(&mut scratch, &a, &b, &c, &m), Ok(Some(Sign::Zero)));
assert_eq!(scratch.used(), 0);

// An arena too small is reported.
let mut small = [0.0; 8];
assert!(orient3d_in(&mut Scratch::borrowed(&mut small), &a, &b, &c, &m).is_err());