From 43e8b03494ffb3a7340dd04e5fa542ca964ce698 Mon Sep 17 00:00:00 2001
From: jyviko <2501648+jyviko@users.noreply.github.com>
Date: Thu, 22 Oct 2026 01:01:49 -0400
Subject: [PATCH] kernel: a point path's polyline is swept as the lines it is,
 however smooth

The SMLib point sweep refused a polyline whose points turn gently (a smooth run
of more than two points), a branch on the shape of the input: a polyline is
the path its points make, and SMLib's cornered sweep mitres it at each point.
Curves with an exact form no longer reach the kernel as points (previous
commit); what still does (curves projected onto a face, intersection and iso
curves, sweep_path's point lists) is followed as those points.

(not built: base in progress)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017itGh5fpMEousnZ91cYcVt
---
 crates/kernel/src/sweep_path.rs | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/crates/kernel/src/sweep_path.rs b/crates/kernel/src/sweep_path.rs
index 3047fe872e..ded2bb094a 100644
--- a/crates/kernel/src/sweep_path.rs
+++ b/crates/kernel/src/sweep_path.rs
@@ -518,20 +518,12 @@ pub fn sweep_path_with(plane: &Plane, region: &Region2, path: &[Vec3], ctl: &Swe
     smlib_sweep_points(plane, region, &crate::PointPath::polyline(path.to_vec()), ctl)
 }
 
-/// [`crate::sweep_point_path_with`] through SMLib: each drawn 3D spline exactly (its spans), each
-/// polyline as the lines between its points ([`crate::PointPath::segs`]), swept by
-/// [`crate::sweep_with`], which mitres the corners. A smooth polyline of more points stands for a
-/// curve that reaches the kernel only as points (a projected, linked or included 3D curve), which
-/// SMLib has no path for yet.
+/// [`crate::sweep_point_path_with`] through SMLib: each curve held exactly as its segments (a
+/// drawn 3D spline's spans, a sketch curve's or an edge's curve), each polyline as the lines
+/// between its points ([`crate::PointPath::segs`]), swept by [`crate::sweep_with`], which mitres
+/// the corners. A polyline is the path its points make, however smooth they run: a curve that
+/// reaches the kernel only as points is followed as those points.
 pub(crate) fn smlib_sweep_points(plane: &Plane, region: &Region2, path: &crate::PointPath, ctl: &SweepControl) -> Result<Body> {
-    for piece in &path.pieces {
-        if let crate::PathPiece::Polyline(pts) = piece {
-            let pts = clean(pts)?;
-            if pts.len() > 2 && !pts.windows(3).any(|w| turn(w[1] - w[0], w[2] - w[1]) > CORNER) {
-                return Err(crate::smlib_sweeps::refuse("sweep along a smooth path of points (a projected or linked 3D curve)"));
-            }
-        }
-    }
     let segs = path.segs()?;
     if segs.is_empty() || segs.len() > 1000 {
         return Err(KernelError::Invalid("the path needs 1…1000 segments".into()));