mirror of
https://github.com/multipleof4/lynchmark.git
synced 2026-01-14 16:47:55 +00:00
19 lines
595 B
JavaScript
19 lines
595 B
JavaScript
async function findConvexHull(points){
|
|
const {default:_}=await import('https://cdn.skypack.dev/lodash-es');
|
|
const pts=_.uniqWith(_.sortBy(points,['x','y']),(a,b)=>a.x===b.x&&a.y===b.y);
|
|
if(pts.length<3) return pts.slice();
|
|
const c=(o,a,b)=>(a.x-o.x)*(b.y-o.y)-(a.y-o.y)*(b.x-o.x);
|
|
const l=[],u=[];
|
|
for(const p of pts){
|
|
while(l.length>1&&c(l.at(-2),l.at(-1),p)<=0)l.pop();
|
|
l.push(p);
|
|
}
|
|
for(let i=pts.length;i--;){
|
|
const p=pts[i];
|
|
while(u.length>1&&c(u.at(-2),u.at(-1),p)<=0)u.pop();
|
|
u.push(p);
|
|
}
|
|
l.pop();u.pop();
|
|
return [...l,...u].reverse();
|
|
}
|
|
export default findConvexHull; |