Added rounding and chamfering to trapezoid()

shapes2d.scad

@@ -1206,6 +1206,8 @@ module octagon(r, d, or, od, ir, id, side, rounding=0, realign=false, align_tip,
 //   w2 = The X axis width of the back end of the trapezoid.
 //   angle = If given in place of `h`, `w1`, or `w2`, then the missing value is calculated such that the right side has that angle away from the Y axis.
 //   shift = Scalar value to shift the back of the trapezoid along the X axis by.  Default: 0
+//   rounding = The rounding radius for the corners.  If given as a list of four numbers, gives individual radii for each corner, in the order [X+Y+,X-Y+,X-Y-,X+Y-]. Default: 0 (no rounding)
+//   chamfer = The Length of the chamfer faces at the corners.  If given as a list of four numbers, gives individual chamfers for each corner, in the order [X+Y+,X-Y+,X-Y-,X+Y-].  Default: 0 (no chamfer)
 //   anchor = Translate so anchor point is at origin (0,0,0).  See [anchor](attachments.scad#anchor).  Default: `CENTER`
 //   spin = Rotate this many degrees around the Z axis after anchor.  See [spin](attachments.scad#spin).  Default: `0`
 // Examples(2D):
@@ -1217,42 +1219,68 @@ module octagon(r, d, or, od, ir, id, side, rounding=0, realign=false, align_tip,
 //   trapezoid(h=20, w2=10, angle=30);
 //   trapezoid(h=20, w2=30, angle=-30);
 //   trapezoid(w1=30, w2=10, angle=30);
+// Example(2D): Chamferred Trapezoid
+//   trapezoid(h=30, w1=60, w2=40, chamfer=5);
+// Example(2D): Rounded Trapezoid
+//   trapezoid(h=30, w1=60, w2=40, rounding=5);
+// Example(2D): Mixed Chamfering and Rounding
+//   trapezoid(h=30, w1=60, w2=40, rounding=[5,0,10,0],chamfer=[0,8,0,15],$fa=1,$fs=1);
 // Example(2D): Called as Function
 //   stroke(closed=true, trapezoid(h=30, w1=40, w2=20));
-function trapezoid(h, w1, w2, angle, shift=0, anchor=CENTER, spin=0) =
+function trapezoid(h, w1, w2, angle, shift=0, chamfer=0, rounding=0, anchor=CENTER, spin=0) =
     assert(is_undef(h) || is_finite(h))
     assert(is_undef(w1) || is_finite(w1))
     assert(is_undef(w2) || is_finite(w2))
     assert(is_undef(angle) || is_finite(angle))
     assert(num_defined([h, w1, w2, angle]) == 3, "Must give exactly 3 of the arguments h, w1, w2, and angle.")
     assert(is_finite(shift))
+	assert(is_finite(chamfer)  || is_vector(chamfer,4))
+	assert(is_finite(rounding) || is_vector(rounding,4))
     let(
+		simple = chamfer==0 && rounding==0,
         h  = !is_undef(h)?  h  : opp_ang_to_adj(abs(w2-w1)/2, abs(angle)),
         w1 = !is_undef(w1)? w1 : w2 + 2*(adj_ang_to_opp(h, angle) + shift),
-        w2 = !is_undef(w2)? w2 : w1 - 2*(adj_ang_to_opp(h, angle) + shift),
-        path = [[w1/2,-h/2], [-w1/2,-h/2], [-w2/2+shift,h/2], [w2/2+shift,h/2]]
+        w2 = !is_undef(w2)? w2 : w1 - 2*(adj_ang_to_opp(h, angle) + shift)
     )
     assert(w1>=0 && w2>=0 && h>0, "Degenerate trapezoid geometry.")
-    reorient(anchor,spin, two_d=true, size=[w1,h], size2=w2, p=path);
+    assert(w1+w2>0, "Degenerate trapezoid geometry.")
+    let(
+        base_path = [
+            [w2/2+shift,h/2],
+            [-w2/2+shift,h/2],
+            [-w1/2,-h/2],
+            [w1/2,-h/2],
+        ],
+		cpath = simple? base_path :
+			path_chamfer_and_rounding(
+				base_path, closed=true,
+				chamfer=chamfer,
+				rounding=rounding
+			),
+		path = reverse(cpath)
+	) simple?
+		reorient(anchor,spin, two_d=true, size=[w1,h], size2=w2, shift=shift, p=path) :
+		reorient(anchor,spin, two_d=true, path=path, p=path);
 
 
 
-module trapezoid(h, w1, w2, angle, shift=0, anchor=CENTER, spin=0) {
-    assert(is_undef(h) || is_finite(h));
-    assert(is_undef(w1) || is_finite(w1));
-    assert(is_undef(w2) || is_finite(w2));
-    assert(is_undef(angle) || is_finite(angle));
-    assert(num_defined([h, w1, w2, angle]) == 3, "Must give exactly 3 of the arguments h, w1, w2, and angle.");
-    assert(is_finite(shift));
+module trapezoid(h, w1, w2, angle, shift=0, chamfer=0, rounding=0, anchor=CENTER, spin=0) {
+	path = trapezoid(h=h, w1=w1, w2=w2, angle=angle, shift=shift, chamfer=chamfer, rounding=rounding);
     union() {
+		simple = chamfer==0 && rounding==0;
         h  = !is_undef(h)?  h  : opp_ang_to_adj(abs(w2-w1)/2, abs(angle));
         w1 = !is_undef(w1)? w1 : w2 + 2*(adj_ang_to_opp(h, angle) + shift);
         w2 = !is_undef(w2)? w2 : w1 - 2*(adj_ang_to_opp(h, angle) + shift);
-        assert(w1>=0 && w2>=0 && h>0, "Degenerate trapezoid geometry.");
-        path = [[w1/2,-h/2], [-w1/2,-h/2], [-w2/2+shift,h/2], [w2/2+shift,h/2]];
-        attachable(anchor,spin, two_d=true, size=[w1,h], size2=w2, shift=shift) {
-            polygon(path);
-            children();
+        if (simple) {
+            attachable(anchor,spin, two_d=true, size=[w1,h], size2=w2, shift=shift) {
+                polygon(path);
+                children();
+            }
+        } else {
+            attachable(anchor,spin, two_d=true, path=path) {
+                polygon(path);
+                children();
+            }
         }
     }
 }