Merge 9ac540e03d into 53af9121e7

doc fix & screws fix

attachments.scad

@@ -925,7 +925,7 @@ module attach(parent, child, overlap, align, spin=0, norot, inset=0, shiftout=0,
         anchor_data = _find_anchor(anchor, $parent_geom);
         anchor_pos = anchor_data[1];
         anchor_dir = factor*anchor_data[2];
-        anchor_spin = !inside || anchor==TOP || anchor==BOT ? anchor_data[3]
+        anchor_spin = two_d || !inside || anchor==TOP || anchor==BOT ? anchor_data[3]
                     : let(spin_dir = rot(anchor_data[3],from=UP, to=-anchor_dir, p=BACK))
                       _compute_spin(anchor_dir,spin_dir);
         for(align_ind = idx(align_list)){

beziers.scad

@@ -466,12 +466,15 @@ function bezpath_curve(bezpath, splinesteps=16, N=3, endpoint=true) =
     assert(len(bezpath)%N == 1, str("A degree ",N," bezier path should have a multiple of ",N," points in it, plus 1."))
     let(
         segs = (len(bezpath)-1) / N,
-        step = 1 / splinesteps
-    ) [
+        step = 1 / splinesteps,
+        path = [
             for (seg = [0:1:segs-1])
                 each bezier_points(select(bezpath, seg*N, (seg+1)*N), [0:step:1-step/2]),
             if (endpoint) last(bezpath)
-    ];
+        ],
+        is_closed = approx(path[0], last(path)),
+        out = path_merge_collinear(path, closed=is_closed)
+    ) out;
 
 
 // Function: bezpath_closest_point()