Added rounding and chamfering to trapezoid()

paths.scad

@@ -407,6 +407,158 @@ function path_torsion(path, closed=false) =
     ];
 
 
+// Function: path_chamfer_and_rounding()
+// Usage:
+//   path2 = path_chamfer_and_rounding(path, [closed], [chamfer], [rounding]);
+// Description:
+//   Rounds or chamfers corners in the given path.
+// Arguments:
+//   path = The path to chamfer and/or round.
+//   closed = If true, treat path like a closed polygon.  Default: true
+//   chamfer = The length of the chamfer faces at the corners.  If given as a list of numbers, gives individual chamfers for each corner, from first to last.  Default: 0 (no chamfer)
+//   rounding = The rounding radius for the corners.  If given as a list of numbers, gives individual radii for each corner, from first to last.  Default: 0 (no rounding)
+// Example(2D): Chamfering a Path
+//   path = star(5, step=2, d=100);
+//   path2 = path_chamfer_and_rounding(path, closed=true, chamfer=5);
+//   stroke(path2, closed=true);
+// Example(2D): Per-Corner Chamfering
+//   path = star(5, step=2, d=100);
+//   chamfs = [for (i=[0:1:4]) each 3*[i,i]];
+//   path2 = path_chamfer_and_rounding(path, closed=true, chamfer=chamfs);
+//   stroke(path2, closed=true);
+// Example(2D): Rounding a Path
+//   path = star(5, step=2, d=100);
+//   path2 = path_chamfer_and_rounding(path, closed=true, rounding=5);
+//   stroke(path2, closed=true);
+// Example(2D): Per-Corner Chamfering
+//   path = star(5, step=2, d=100);
+//   rs = [for (i=[0:1:4]) each 3*[i,i]];
+//   path2 = path_chamfer_and_rounding(path, closed=true, rounding=rs);
+//   stroke(path2, closed=true);
+// Example(2D): Mixing Chamfers and Roundings
+//   path = star(5, step=2, d=100);
+//   chamfs = [for (i=[0:4]) each [5,0]];
+//   rs = [for (i=[0:4]) each [0,10]];
+//   path2 = path_chamfer_and_rounding(path, closed=true, chamfer=chamfs, rounding=rs);
+//   stroke(path2, closed=true);
+function path_chamfer_and_rounding(path, closed, chamfer, rounding) =
+	let (
+		path = deduplicate(path,closed=true),
+		lp = len(path),
+		chamfer = is_undef(chamfer)? repeat(0,lp) :
+			is_vector(chamfer)? list_pad(chamfer,lp,0) :
+			is_num(chamfer)? repeat(chamfer,lp) :
+			assert(false, "Bad chamfer value."),
+		rounding = is_undef(rounding)? repeat(0,lp) :
+			is_vector(rounding)? list_pad(rounding,lp,0) :
+			is_num(rounding)? repeat(rounding,lp) :
+			assert(false, "Bad rounding value."),
+		corner_paths = [
+			for (i=(closed? [0:1:lp-1] : [1:1:lp-2])) let(
+				p1 = select(path,i-1),
+				p2 = select(path,i),
+				p3 = select(path,i+1)
+			)
+			chamfer[i]  > 0? _corner_chamfer_path(p1, p2, p3, side=chamfer[i]) :
+			rounding[i] > 0? _corner_roundover_path(p1, p2, p3, r=rounding[i]) :
+			[p2]
+		],
+		out = [
+			if (!closed) path[0],
+			for (i=(closed? [0:1:lp-1] : [1:1:lp-2])) let(
+				p1 = select(path,i-1),
+				p2 = select(path,i),
+				crn1 = select(corner_paths,i-1),
+				crn2 = corner_paths[i],
+				l1 = norm(select(crn1,-1)-p1),
+				l2 = norm(crn2[0]-p2),
+				needed = l1 + l2,
+				seglen = norm(p2-p1),
+				check = assert(seglen >= needed, str("Path segment ",i," is too short to fulfill rounding/chamfering for the adjacent corners."))
+			) each crn2,
+			if (!closed) select(path,-1)
+		]
+	) deduplicate(out);
+
+
+function _corner_chamfer_path(p1, p2, p3, dist1, dist2, side, angle) = 
+	let(
+		v1 = unit(p1 - p2),
+		v2 = unit(p3 - p2),
+		n = vector_axis(v1,v2),
+		ang = vector_angle(v1,v2),
+		path = (is_num(dist1) && is_undef(dist2) && is_undef(side))? (
+			// dist1 & optional angle
+			assert(dist1 > 0)
+			let(angle = default(angle,(180-ang)/2))
+			assert(is_num(angle))
+			assert(angle > 0 && angle < 180)
+			let(
+				pta = p2 + dist1*v1,
+				a3 = 180 - angle - ang
+			) assert(a3>0, "Angle too extreme.")
+			let(
+				side = sin(angle) * dist1/sin(a3),
+				ptb = p2 + side*v2
+			) [pta, ptb]
+		) : (is_undef(dist1) && is_num(dist2) && is_undef(side))? (
+			// dist2 & optional angle
+			assert(dist2 > 0)
+			let(angle = default(angle,(180-ang)/2))
+			assert(is_num(angle))
+			assert(angle > 0 && angle < 180)
+			let(
+				ptb = p2 + dist2*v2,
+				a3 = 180 - angle - ang
+			) assert(a3>0, "Angle too extreme.")
+			let(
+				side = sin(angle) * dist2/sin(a3),
+				pta = p2 + side*v1
+			) [pta, ptb]
+		) : (is_undef(dist1) && is_undef(dist2) && is_num(side))? (
+			// side & optional angle
+			assert(side > 0)
+			let(angle = default(angle,(180-ang)/2))
+			assert(is_num(angle))
+			assert(angle > 0 && angle < 180)
+			let(
+				a3 = 180 - angle - ang
+			) assert(a3>0, "Angle too extreme.")
+			let(
+				dist1 = sin(a3) * side/sin(ang),
+				dist2 = sin(angle) * side/sin(ang),
+				pta = p2 + dist1*v1,
+				ptb = p2 + dist2*v2
+			) [pta, ptb]
+		) : (is_num(dist1) && is_num(dist2) && is_undef(side) && is_undef(side))? (
+			// dist1 & dist2
+			assert(dist1 > 0)
+			assert(dist2 > 0)
+			let(
+				pta = p2 + dist1*v1,
+				ptb = p2 + dist2*v2
+			) [pta, ptb]
+		) : (
+			assert(false,"Bad arguments.")
+		)
+	) path;
+
+
+function _corner_roundover_path(p1, p2, p3, r, d) = 
+	let(
+		r = get_radius(r=r,d=d,dflt=undef),
+		res = circle_2tangents(p1, p2, p3, r=r, tangents=true),
+		cp = res[0],
+		n = res[1],
+		tp1 = res[2],
+		ang = res[4]+res[5],
+		steps = floor(segs(r)*ang/360+0.5),
+		step = ang / steps,
+		path = [for (i=[0:1:steps]) move(cp, p=rot(a=-i*step, v=n, p=tp1-cp))]
+	) path;
+
+
+
 // Function: path3d_spiral()
 // Description:
 //   Returns a 3D spiral path.

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):
@@ -1217,43 +1219,69 @@ 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),
+        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]]
     )
     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) {
+module trapezoid(h, w1, w2, angle, shift=0, chamfer=0, rounding=0, anchor=CENTER, spin=0) {
-    assert(is_undef(h) || is_finite(h));
+	path = trapezoid(h=h, w1=w1, w2=w2, angle=angle, shift=shift, chamfer=chamfer, rounding=rounding);
-    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));
     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.");
+        if (simple) {
-        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();
             }
+        } else {
+            attachable(anchor,spin, two_d=true, path=path) {
+                polygon(path);
+                children();
+            }
+        }
     }
 }
 

version.scad

@@ -8,7 +8,7 @@
 //////////////////////////////////////////////////////////////////////
 
 
-BOSL_VERSION = [2,0,496];
+BOSL_VERSION = [2,0,497];
 
 
 // Section: BOSL Library Version Functions