get_fn() and quant() is already in BOSL2. Fix round_path, add chamfer…

…_path, lerp_index, rpath and path_sweep2d_fill

box.scad

@@ -24,16 +24,62 @@ $box_inside_overlap = 0.0001;
 
 $box_wall = undef;
 
-function quant(val, q) = round(val/q)*q;
-
-function get_fn(r, q=1) = $fn > 0 ? $fn : quant(max(min(360/$fa,r*2*PI/$fs),5),q);
-
 // for any non-zero element b[i], return b[i] else a[i]
 function v_replace_nonzero(a,b) =
     assert( is_list(a) && is_list(b) && len(a)==len(b), "Incompatible input")
     [for (i = [0:1:len(a)-1]) b[i] != 0 ? b[i] : a[i]];
 
-function round_path(path, r, closed=true) = r==0 ? path : offset(offset(path,r,closed=closed),-r,closed=closed);
+function round_path(path, r, or, ir, closed=true) =
+    let(
+        or = get_radius(r1=or, r=r, dflt=0),
+        ir = get_radius(r1=ir, r=r, dflt=0),
+    ) or==0 && ir==0 ? path : offset(offset(offset(path,delta=ir,chamfer=true,closed=closed),-or-ir,closed=closed),or,closed=closed);
+
+function chamfer_path(path, r, or, ir, closed=true) =
+    let(
+        or = get_radius(r1=or, r=r, dflt=0),
+        ir = get_radius(r1=ir, r=r, dflt=0),
+    ) or==0 && ir==0 ? path : offset(offset(offset(path,delta=ir,chamfer=true,closed=closed),delta=-or-ir,chamfer=true,closed=closed),delta=or,chamfer=true,closed=closed);
+
+function lerp_index(v,x) = let(i=floor(x), a = v[i], b = v[min(i+1,len(v)-1)], f = x-i) lerp(a,b,f);
+
+// takes a list of [x,y,R] or [x,y,z,R] points and returns a rounded/chamfered path.
+// where R is positive for circular and negative for chamfer.
+function rpath(points, closed=true) =
+    let(
+        path = [for(p = points) slice(p,0,-2)],
+        r = [for(p = points) last(p)],
+    ) [
+        for(i = idx(path)) each
+            let(
+                rr = r[i],
+                ra = abs(rr),
+                pt = select(path,i-1,i+1),
+                angle = vector_angle(pt)/2,
+                prev = unit(pt[0]-pt[1]),
+                next = unit(pt[2]-pt[1])
+            ) rr < 0 ? [pt[1]+prev*ra, pt[1]+next*ra]
+            : rr > 0 ?
+            let(
+                d = ra/tan(angle),
+                center = ra/sin(angle) * unit(prev+next)+pt[1],
+                start = pt[1]+prev*d,
+                end = pt[1]+next*d
+            ) (approx(angle,90) ? [start,end] : arc(max(3,ceil((90-angle)/180*segs(ra))), cp=center, points=[start,end]))
+            : [path[i]]
+    ];
+
+// like path_sweep2d for closed path, that fills the hole (bottom). for easy creation of boxes from side profile and top path.
+module path_sweep2d_fill(profile, path) {
+    path_sweep2d(profile,path,closed=true) children();
+
+    fill = [
+        for(p=[profile[0],last(profile)])
+            up(p.y,path3d(offset(path,delta=p.x+0.001,closed=true)))
+    ];
+    //skin(bot,slices=0);
+    vnf_polyhedron(vnf_vertex_array(fill,caps=true,col_wrap=true));
+}
 
 function vector_name(v) =
     assert(is_vector(v))

examples/laserbox.scad

@@ -31,7 +31,7 @@ module toggle_switch(anchor=BOTTOM,spin) {
 
 //cut_inspect(LEFT,ofs=[-21.1,0,0]) // inspect only laser mount
 //cut_inspect(BACK)
-box_make(print=false, explode=0.1)
+box_make(print=true, explode=30.1)
 box_shell_base_lid(box_sz,rsides=6,wall_sides=1.6,wall_top=2,base_height=3,rim_height=2,rbot_inside=1,rtop_inside=1)
 {
     size = $parent_size;

examples/snap_fit_test.scad

@@ -4,6 +4,8 @@ include <jl_scad/utils.scad>
 
 $slop = 0.1;
 $fn = $preview?16:48;
+$attachable_dump_tree = true;
+
 
 sz = [30,30,10];
 

parts.scad

@@ -119,13 +119,13 @@ module box_screw_clamp(h=2,od=8,od2,id=3,id2,head_d=6,head_depth=3,idepth=0,gap=
 }
 
 function keyhole(d1=3,d2=6,l,r) =
-    let(r=default(r,d1/2),l=d2,$fn=get_fn(d2/2,4)) // fn must be even by 4 for this to work!
+    let(r=default(r,d1/2),l=d2,$fn=quant(segs(d2/2),4)) // fn must be even by 4 for this to work!
     assert(r<d1)
     force_path(round_path(union([
         circle(d=d1),
         rect([d1,l],anchor=TOP),
         move([0,-l],circle(d=d2)),
-    ]),r));
+    ]),-r));
 
 module box_hole(d=1, rounding, chamfer, teardrop=false, teardrop_cap=true, depth=0, anchor=CENTER) {
     p = teardrop ? teardrop2d(d=d,cap_h=teardrop_cap==true?d/2:teardrop_cap,spin=$box_half==TOP?180:0) : circle(d=d);