mirror of
https://github.com/lynchmarkHQ/lynchmark.com.git
synced 2026-10-08 21:35:23 +00:00
21 lines
694 B
JavaScript
21 lines
694 B
JavaScript
const findConvexHull = async (pts) => {
|
|
const { default: _ } = await import('https://cdn.jsdelivr.net/npm/lodash@4.17.21/+esm');
|
|
const s = _.sortBy(_.uniqWith(pts, _.isEqual), ['x', 'y']);
|
|
if (s.length < 3) return s;
|
|
|
|
const h = [], x = (o, a, b) => (a.x - o.x) * (b.y - o.y) - (a.y - o.y) * (b.x - o.x);
|
|
|
|
for (let i = 0; i < s.length; i++) {
|
|
while (h.length >= 2 && x(h[h.length - 2], h[h.length - 1], s[i]) <= 0) h.pop();
|
|
h.push(s[i]);
|
|
}
|
|
|
|
for (let i = s.length - 2, t = h.length + 1; i >= 0; i--) {
|
|
while (h.length >= t && x(h[h.length - 2], h[h.length - 1], s[i]) <= 0) h.pop();
|
|
h.push(s[i]);
|
|
}
|
|
|
|
h.pop();
|
|
return h;
|
|
};
|
|
export default findConvexHull; |