@woosh/meep-engine/src/core/geom/3d/plane/orient3d_robust.js

Pure JavaScript game engine. Fully featured and production ready.

import { orient3d } from "robust-predicates";

/**
 *
 * @param {number[]} points
 * @param {number} a index of point a
 * @param {number} b index of point b
 * @param {number} c index of point c
 * @param {number} d index of point d
 * @returns {number}
 */
export function orient3d_robust(
    points,
    a, b, c, d
) {


    const a3 = a * 3;
    const b3 = b * 3;
    const c3 = c * 3;
    const d3 = d * 3;

    const ax = points[a3];
    const ay = points[a3 + 1];
    const az = points[a3 + 2];

    const bx = points[b3];
    const by = points[b3 + 1];
    const bz = points[b3 + 2];

    const cx = points[c3];
    const cy = points[c3 + 1];
    const cz = points[c3 + 2];

    const dx = points[d3];
    const dy = points[d3 + 1];
    const dz = points[d3 + 2];


    return orient3d(ax, ay, az, bx, by, bz, cx, cy, cz, dx, dy, dz);
}