Merge pull request #1367 from adrianVmariano/master

anchor fixes

attachments.scad

@@ -3333,7 +3333,7 @@ function _find_anchor(anchor, geom) =
         ) [anchor, pos, vec, oang]
     ) : type == "vnf_isect"? ( //vnf
         let( vnf=geom[1] )
-        approx(anchor,CTR)? [anchor, [0,0,0], UP, 0] :
+        approx(anchor,CTR)? [anchor, cp, UP, 0] :      // CENTER anchors anchor on cp, "origin" anchors on [0,0]
         vnf==EMPTY_VNF? [anchor, [0,0,0], unit(anchor), 0] :
         let(
             eps = 1/2048,
@@ -3383,7 +3383,7 @@ function _find_anchor(anchor, geom) =
         [anchor, pos, n, oang]
     ) : type == "vnf_extent"? ( //vnf
         let( vnf=geom[1] )
-        approx(anchor,CTR)? [anchor, [0,0,0], UP, 0] :
+        approx(anchor,CTR)? [anchor, cp, UP, 0] :      // CENTER anchors anchor on cp, "origin" anchors on [0,0]
         vnf==EMPTY_VNF? [anchor, [0,0,0], unit(anchor,UP), 0] :
         let(
             rpts = apply(rot(from=anchor, to=RIGHT) * move(point3d(-cp)), vnf[0]),
@@ -3432,7 +3432,7 @@ function _find_anchor(anchor, geom) =
             anchor = _force_anchor_2d(anchor),
             rgn = force_region(move(-point2d(cp), p=geom[1]))
         )
-        approx(anchor,[0,0])? [anchor, [0,0,0], BACK, 0] :
+        approx(anchor,[0,0])? [anchor, cp, BACK, 0] :     // CENTER anchors anchor on cp, "origin" anchors on [0,0]
         let(
             isects = [
                 for (path=rgn, t=triplet(path,true)) let(
@@ -3456,7 +3456,7 @@ function _find_anchor(anchor, geom) =
         ) [anchor, pos, vec, 0]
     ) : type == "rgn_extent"? ( //region
         let( anchor = _force_anchor_2d(anchor) )
-        approx(anchor,[0,0])? [anchor, [0,0,0], BACK, 0] :
+        approx(anchor,[0,0])? [anchor, cp, BACK, 0] :   // CENTER anchors anchor on cp, "origin" anchors on [0,0]
         let(
             rgn = force_region(geom[1]),
             rpts = rot(from=anchor, to=RIGHT, p=flatten(rgn)),

rounding.scad

@@ -1365,8 +1365,13 @@ module offset_stroke(path, width=1, rounded=true, start, end, check_valid=true,
 //   anchor = Translate so anchor point is at the origin.  (module only) Default: "origin"
 //   spin = Rotate this many degrees around Z axis after anchor.  (module only) Default: 0
 //   orient = Vector to rotate top towards after spin  (module only)
-//   atype = Select "hull" or "intersect" anchor types.  Default: "hull"
+//   atype = Select "hull", "intersect", "surf_hull" or "surf_intersect" anchor types.  Default: "hull"
 //   cp = Centerpoint for determining "intersect" anchors or centering the shape.  Determintes the base of the anchor vector.  Can be "centroid", "mean", "box" or a 3D point.  Default: "centroid"
+// Anchor Types:
+//   hull = Anchors to the convex hull of the linear sweep of the path, ignoring any end roundings. 
+//   intersect = Anchors to the surface of the linear sweep of the path, ignoring any end roundings.
+//   surf_hull = Anchors to the convex hull of the offset_sweep shape, including end treatments.
+//   surf_intersect = Anchors to the surface of the offset_sweep shape, including any end treatments.
 // Example: Rounding a star shaped prism with postive radius values
 //   star = star(5, r=22, ir=13);
 //   rounded_star = round_corners(star, cut=flatten(repeat([.5,0],5)), $fn=24);
@@ -1641,12 +1646,21 @@ module offset_sweep(path, height,
                     convexity=10,anchor="origin",cp="centroid",
                     spin=0, orient=UP, atype="hull")
 {
-    assert(in_list(atype, _ANCHOR_TYPES), "Anchor type must be \"hull\" or \"intersect\"");
+    assert(in_list(atype, ["intersect","hull","surf_hull","surf_intersect"]), "Anchor type must be \"hull\" or \"intersect\"");
     vnf = offset_sweep(path=path, height=height, h=h, l=l, top=top, bottom=bottom, offset=offset, r=r, steps=steps,
                        quality=quality, check_valid=check_valid, extra=extra, cut=cut, chamfer_width=chamfer_width,
                        chamfer_height=chamfer_height, joint=joint, k=k, angle=angle);
-    vnf_polyhedron(vnf,convexity=convexity,anchor=anchor, spin=spin, orient=orient, atype=atype, cp=cp)
+
-        children();
+    if (in_list(atype,["hull","intersect"])){
+        h=first_defined([h,l,height]);
+        attachable(anchor,spin,orient,region=[path],h=h,extent=atype=="hull",cp=cp){
+            down(h/2)polyhedron(vnf[0],vnf[1],convexity=convexity);
+            children();
+        }
+    }
+    else
+        vnf_polyhedron(vnf,convexity=convexity,anchor=anchor, spin=spin, orient=orient, atype=atype=="surf_hull"?"hull":"intersect", cp=cp)
+            children();
 }   
 
 
@@ -2012,6 +2026,11 @@ function _rp_compute_patches(top, bot, rtop, rsides, ktop, ksides, concave) =
 //   joint_top[1] is negative the shape will flare upward.  At least one value must be non-negative.  The same rules apply for joint_bot.
 //   The joint_sides parameter must be entirely nonnegative.
 //   .
+//   If the roundings at two adjacent side edges exceed the width of the face then the polyhedron will have self-intersecting faces, so it will be invalid.
+//   Similarly, if the roundings on the top or bottom edges cross the top face and intersect with each other, the resulting polyhedron is invalid:
+//   the top face after the roundings are applied must be a valid, non-degenerate polyhedron.  There are two exceptions:  it is permissible to
+//   construct a top that is a single point or two points.  This means you can completely round a cube by setting the joint to half of
+//   the cube's width.  
 //   If you set `debug` to true the module version will display the polyhedron even when it is invalid and it will show the bezier patches at the corners.
 //   This can help troubleshoot problems with your parameters.  With the function form setting debug to true causes it to return [patches,vnf] where
 //   patches is a list of the bezier control points for the corner patches.
@@ -2032,7 +2051,7 @@ function _rp_compute_patches(top, bot, rtop, rsides, ktop, ksides, concave) =
 //   k = continuous curvature rounding parameter for all edges.  Default: 0.5
 //   k_top = continuous curvature rounding parameter for top
 //   k_bot = continuous curvature rounding parameter for bottom
-//   k_bot = continuous curvature rounding parameter for bottom
+//   k_sides = continuous curvature rounding parameter side edges, a number or vector.  
 //   splinesteps = number of segments to use for curved patches.  Default: 16
 //   debug = turn on debug mode which displays illegal polyhedra and shows the bezier corner patches for troubleshooting purposes.  Default: False
 //   convexity = convexity parameter for polyhedron(), only for module version.  Default: 10
@@ -2196,23 +2215,44 @@ function rounded_prism(bottom, top, joint_bot=0, joint_top=0, joint_sides=0, k_b
      bot_patch = _rp_compute_patches(bottom, top, joint_bot, joint_sides_vec, k_bot, k_sides_vec, concave),
 
      vertbad = [for(i=[0:N-1])
-                   if (norm(top[i]-top_patch[i][4][2]) + norm(bottom[i]-bot_patch[i][4][2]) > norm(bottom[i]-top[i])) i],
+                   if (norm(top[i]-top_patch[i][4][2]) + norm(bottom[i]-bot_patch[i][4][2]) > EPSILON + norm(bottom[i]-top[i])) i],
+     // Check that the patch fits on the polygon edge
      topbad = [for(i=[0:N-1])
                    if (norm(top_patch[i][2][4]-top_patch[i][2][2]) + norm(select(top_patch,i+1)[2][0]-select(top_patch,i+1)[2][2])
-                  > norm(top_patch[i][2][2] - select(top_patch,i+1)[2][2]))   [i,(i+1)%N]],
+                  > EPSILON + norm(top_patch[i][2][2] - select(top_patch,i+1)[2][2]))   [i,(i+1)%N]],
      botbad = [for(i=[0:N-1])
                    if (norm(bot_patch[i][2][4]-bot_patch[i][2][2]) + norm(select(bot_patch,i+1)[2][0]-select(bot_patch,i+1)[2][2])
-                  > norm(bot_patch[i][2][2] - select(bot_patch,i+1)[2][2]))   [i,(i+1)%N]],
+                  > EPSILON + norm(bot_patch[i][2][2] - select(bot_patch,i+1)[2][2]))   [i,(i+1)%N]],
-     topinbad = [for(i=[0:N-1])
+     // If top/bot is L-shaped, check that arms of L from adjacent patches don't cross
+     topLbad = [for(i=[0:N-1])
                    if (norm(top_patch[i][0][2]-top_patch[i][0][4]) + norm(select(top_patch,i+1)[0][0]-select(top_patch,i+1)[0][2])
-                          > norm(top_patch[i][0][2]-select(top_patch,i+1)[0][2])) [i,(i+1)%N]],
+                          > EPSILON + norm(top_patch[i][0][2]-select(top_patch,i+1)[0][2])) [i,(i+1)%N]],
-     botinbad = [for(i=[0:N-1])
+     botLbad = [for(i=[0:N-1])
                    if (norm(bot_patch[i][0][2]-bot_patch[i][0][4]) + norm(select(bot_patch,i+1)[0][0]-select(bot_patch,i+1)[0][2])
-                          > norm(bot_patch[i][0][2]-select(bot_patch,i+1)[0][2])) [i,(i+1)%N]]
+                          > EPSILON + norm(bot_patch[i][0][2]-select(bot_patch,i+1)[0][2])) [i,(i+1)%N]],
+     // Check that the inner edges of the patch don't cross
+     topinbad = [for(i=[0:N-1]) 
+                     let(
+                          line1 = project_plane(top,[top_patch[i][2][0],top_patch[i][0][0]]),
+                          line2 = project_plane(top,[select(top_patch,i+1)[2][4],select(top_patch,i+1)[0][4]])
+                     )
+                     if (!approx(line1[0],line1[1]) && !approx(line2[0],line2[1]) &&
+                         line_intersection(line1,line2, SEGMENT,SEGMENT))
+                          [i,(i+1)%N]],
+     botinbad = [for(i=[0:N-1])
+                     let(
+                          line1 = project_plane(bottom,[bot_patch[i][2][0],bot_patch[i][0][0]]),
+                          line2 = project_plane(bottom,[select(bot_patch,i+1)[2][4],select(bot_patch,i+1)[0][4]])
+                     )
+                     if (!approx(line1[0],line1[1]) && !approx(line2[0],line2[1]) &&
+                         line_intersection(line1,line2, SEGMENT,SEGMENT))
+                          [i,(i+1)%N]]
    )
    assert(debug || vertbad==[], str("Top and bottom joint lengths are too large; they interfere with each other at vertices: ",vertbad))
-   assert(debug || topbad==[], str("Joint lengths too large at top edges: ",topbad))
+   assert(debug || topbad==[], str("Joint lengths too large at top or side edges: ",topbad))
-   assert(debug || botbad==[], str("Joint lengths too large at bottom edges: ",botbad))
+   assert(debug || botbad==[], str("Joint lengths too large at bottom or side edges: ",botbad))
+   assert(debug || topLbad==[], str("Joint length too large on the top face or side at edges: ", topLbad))
+   assert(debug || botLbad==[], str("Joint length too large on the bottom face or side at edges: ", botLbad))
    assert(debug || topinbad==[], str("Joint length too large on the top face at edges: ", topinbad))
    assert(debug || botinbad==[], str("Joint length too large on the bottom face at edges: ", botinbad))
    let(
@@ -2242,8 +2282,12 @@ function rounded_prism(bottom, top, joint_bot=0, joint_top=0, joint_sides=0, k_b
                                  top_patch[i][4][4]
                              ]
              ],
-     top_simple = is_path_simple(project_plane(faces[0],faces[0]),closed=true),
+     top_collinear = is_collinear(faces[0]),
-     bot_simple = is_path_simple(project_plane(faces[1],faces[1]),closed=true),
+     bot_collinear = is_collinear(faces[1]),
+     top_degen_ok = top_collinear && len(deduplicate(faces[0]))<=2,
+     bot_degen_ok = bot_collinear && len(deduplicate(faces[1]))<=2,
+     top_simple = top_degen_ok || (!top_collinear && is_path_simple(project_plane(faces[0],faces[0]),closed=true)),
+     bot_simple = bot_degen_ok || (!bot_collinear && is_path_simple(project_plane(faces[1],faces[1]),closed=true)),                                   
      // verify vertical edges
      verify_vert =
        [for(i=[0:N-1],j=[0:4])

shapes3d.scad

@@ -3349,7 +3349,11 @@ module fillet(l=1.0, r, ang=90, overlap=0.01, d, length, h, height, anchor=CENTE
         arc[0] + polar_to_xy(overlap, 90+ang),
         each arc
     ];
-    attachable(anchor,spin,orient, size=[2*maxx,2*maxy,l]) {
+    override = function (anchor)
+        anchor.x>=0 && anchor.y>=0 ? undef
+      : 
+        [[max(0,anchor.x)*maxx, max(0,anchor.y)*maxy, anchor.z*l/2]];
+    attachable(anchor,spin,orient, size=[2*maxx,2*maxy,l],override=override) {      
         if (l > 0) {
             linear_extrude(height=l, convexity=4, center=true) {
                 polygon(path);

tutorials/Attachments.md

@@ -1262,7 +1262,7 @@ module cubic_barbell(s=100, anchor=CENTER, spin=0, orient=UP) {
         children();
     }
 }
-cubic_barbell(100) show_anchors(30);
+cubic_barbell(100) show_anchors(60);
 ```
 
 When the shape is prismoidal, where the top is a different size from the bottom, you can use
@@ -1637,3 +1637,99 @@ sphere_pt = apply(
 ```
 
 
+## Overriding Standard Anchors
+
+Sometimes you may want to use the standard anchors but override some
+of them.  Returning to the square barebell example above, the anchors
+at the right and left sides are on the cubes at each end, but the
+anchors at x=0 are in floating in space.  For prismoidal/cubic anchors
+in 3D and trapezoidal/rectangular anchors in 2D we can override a single anchor by
+specifying the override option and giving the anchor that is being
+overridden, and then the replacement in the form
+`[position, direction, spin]`.  Most often you will only want to
+override the position.  If you omit the other list items then the
+value drived from the standard anchor will be used. Below we override
+position of the FWD anchor:
+
+```
+module cubic_barbell(s=100, anchor=CENTER, spin=0, orient=UP) {
+    override = [
+                 [FWD,  [[0,-s/8,0]]]
+               ];
+    attachable(anchor,spin,orient, size=[s*3,s,s],override=override) {
+        union() {
+            xcopies(2*s) cube(s, center=true);
+            xcyl(h=2*s, d=s/4);
+        }
+        children();
+    }
+}
+cubic_barbell(100) show_anchors(60);
+```
+
+Note how the FWD anchor is now rooted on the cylindrical portion.  If
+you wanted to also change its direction and spin you could do it like
+this:
+
+```
+module cubic_barbell(s=100, anchor=CENTER, spin=0, orient=UP) {
+    override = [
+                 [FWD,  [[0,-s/8,0], FWD+LEFT, 225]]
+               ];
+    attachable(anchor,spin,orient, size=[s*3,s,s],override=override) {
+        union() {
+            xcopies(2*s) cube(s, center=true);
+            xcyl(h=2*s, d=s/4);
+        }
+        children();
+    }
+}
+cubic_barbell(100) show_anchors(60);
+```
+
+In the above example we give three values for the override.  As
+before, the first one places the anchor on the cylinder.  We have
+added the second entry which points the anchor off to the left.
+The third entry gives a spin override, whose effect is shown by the
+position of the red flag on the arrow.  If you want to override all of
+the x=0 anchors to be on the cylinder, with their standard directions,
+you can do that by supplying a list: 
+```
+module cubic_barbell(s=100, anchor=CENTER, spin=0, orient=UP) {
+    override = [
+                 for(j=[-1:1:1], k=[-1:1:1])
+                   if ([j,k]!=[0,0]) [[0,j,k], [s/8*unit([0,j,k])]]
+               ];
+    attachable(anchor,spin,orient, size=[s*3,s,s],override=override) {
+        union() {
+            xcopies(2*s) cube(s, center=true);
+            xcyl(h=2*s, d=s/4);
+        }
+        children();
+    }
+}
+cubic_barbell(100) show_anchors(30);
+```
+
+Now all of the anchors in the middle are all rooted to the cylinder.  Another
+way to do the same thing is to use a function literal for override.
+It will be called with the anchor as its argument and needs to return undef to just use
+the default, or a `[position, direction, spin]` triple to override the
+default.  As before, you can omit values to keep their default.
+Here is the same example using a function literal for the override:
+
+```
+module cubic_barbell(s=100, anchor=CENTER, spin=0, orient=UP) {
+    override = function (anchor) 
+          anchor.x!=0 || anchor==CTR ? undef  // Keep these
+        : [s/8*unit(anchor)];
+    attachable(anchor,spin,orient, size=[s*3,s,s],override=override) {
+        union() {
+            xcopies(2*s) cube(s, center=true);
+            xcyl(h=2*s, d=s/4);
+        }
+        children();
+    }
+}
+cubic_barbell(100) show_anchors(30);
+```

version.scad

@@ -10,7 +10,8 @@
 
 
 
-BOSL_VERSION = [2,0,710];
+BOSL_VERSION = [2,0,714];
+
 
 
 // Section: BOSL Library Version Functions