Merge 289d6afb3e into 53af9121e7

doc fix & screws fix

attachments.scad

@@ -3755,7 +3755,7 @@ function _find_anchor(anchor, geom) =
                                              direction= unit(mean([for(face=edgefaces) polygon_normal(select(vnf[0],vnf[1][face]))])),
                                              edgedir = edge[1]-edge[0],
                                              nz = [for(i=[0:2]) if (!approx(edgedir[i],0)) i],
-                                             flip = last(nz) < 0 ? -1 : 1, 
+                                             flip = edgedir[last(nz)] < 0 ? -1 : 1,
                                              spin = _compute_spin(direction, flip*edgedir)
                                         )
                                         [direction,spin]

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()