Merge pull request #1070 from revarbat/revarbat_dev

Added point attachment geometry.

attachments.scad

@@ -2080,6 +2080,8 @@ function named_anchor(name, pos, orient=UP, spin=0) = [name, pos, orient, spin];
 
 // Function: attach_geom()
 //
+// Usage: Null/Point Geometry
+//   geom = attach_geom(...);
 // Usage: Square/Trapezoid Geometry
 //   geom = attach_geom(two_d=true, size=, [size2=], [shift=], ...);
 // Usage: Circle/Oval Geometry
@@ -2129,6 +2131,9 @@ function named_anchor(name, pos, orient=UP, spin=0) = [name, pos, orient, spin];
 //   two_d = If true, the attachable shape is 2D.  If false, 3D.  Default: false (3D)
 //   axis = The vector pointing along the axis of a geometry.  Default: UP
 //
+// Example(NORENDER): Null/Point Shape
+//   geom = attach_geom();
+//
 // Example(NORENDER): Cubical Shape
 //   geom = attach_geom(size=size);
 //
@@ -2281,7 +2286,7 @@ function attach_geom(
             )
         )
     ) :
-    assert(false, "Unrecognizable geometry description.");
+    ["point", cp, offset, anchors];
 
 
 
@@ -2315,6 +2320,7 @@ function _attach_geom_2d(geom) =
 //   Returns the `[X,Y,Z]` bounding size for the given attachment geometry description.
 function _attach_geom_size(geom) =
     let( type = geom[0] )
+    type == "point"? [0,0,0] :
     type == "prismoid"? ( //size, size2, shift, axis
         let(
             size=geom[1], size2=geom[2], shift=point2d(geom[3]),
@@ -2555,6 +2561,12 @@ function _find_anchor(anchor, geom) =
             pos2 = rot(from=UP, to=axis, p=pos),
             vec2 = anch==CENTER? UP : rot(from=UP, to=axis, p=vec)
         ) [anchor, pos2, vec2, oang]
+    ) : type == "point"? (
+        let(
+            anchor = unit(point3d(anchor),CENTER),
+            pos = point3d(cp) + point3d(offset),
+            vec = unit(anchor,UP)
+        ) [anchor, pos, vec, oang]
     ) : type == "spheroid"? ( //r
         let(
             rr = geom[1],

skin.scad

@@ -3685,8 +3685,13 @@ function _textured_revolution(
     assert(in_list(atype, _ANCHOR_TYPES), "Anchor type must be \"hull\" or \"intersect\"")
     let(
         regions = !is_path(shape,2)? region_parts(shape) :
-            shape[0].y <= last(shape).y? [[reverse(shape)]] :
+            closed? region_parts([shape]) :
-            [[shape]],
+            let(
+                clpoly = [[0,shape[0].y], each shape, [0,last(shape).y]],
+                dpoly = deduplicate(clpoly),
+                cwpoly = is_polygon_clockwise(dpoly) ? dpoly : reverse(dpoly)
+            )
+            [[ select(cwpoly,1,-2) ]],
         checks = [
             for (rgn=regions, path=rgn)
             assert(all(path, function(pt) pt.x>=0))
@@ -3747,7 +3752,7 @@ function _textured_revolution(
             is_path(taper,2)? let(
                 retaper = [
                     for (t=taper)
-                    assert(t[0]>=0 && t[0]<=100, "taper lookup indices must be betweem 0 and 100 inclusive.")
+                    assert(t[0]>=0 && t[0]<=100, "taper lookup indices must be between 0 and 100 inclusive.")
                     [t[0]/100, t[1]]
                 ],
                 taperout = [[-1,retaper[0][1]], each retaper, [2,last(retaper)[1]]]