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17 lines
600 B
JavaScript
17 lines
600 B
JavaScript
const findConvexHull = async (pts) => {
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const { default: _ } = await import('https://cdn.jsdelivr.net/npm/lodash@4.17.21/+esm')
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const s = _.sortBy(_.uniqWith(pts, _.isEqual), ['x', 'y'])
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if (s.length < 3) return s
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const k = (o, a, b) => (a.x - o.x) * (b.y - o.y) - (a.y - o.y) * (b.x - o.x)
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const m = (v) => {
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const h = []
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for (const p of v) {
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while (h.length >= 2 && k(h[h.length - 2], h[h.length - 1], p) <= 0) h.pop()
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h.push(p)
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}
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return h
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}
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const l = m(s), u = m(s.reverse())
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return l.slice(0, -1).concat(u.slice(0, -1))
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}
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export default findConvexHull; |