Alternative approach works but looks bad

package.py

@@ -111,7 +111,7 @@ def do_release(dry_run):
 
     if not dry_run:
         print('Create git commit')
-        subprocess.run(['git', 'commit', '-m', f'Version {version}', '--no-edit'], check=True, capture_output=True)
+        subprocess.run(['git', 'commit', '-m', f'KiCad package version {version}', '--no-edit'], check=True, capture_output=True)
         res = subprocess.run('git rev-parse --short HEAD'.split(), check=True, capture_output=True, text=True)
         print(f'Created commit {res.stdout.strip()}')
         print(f'Creating and signing version tag v{version}')

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "kicoil"
-version = "0.9.0"
+version = "0.10.0"
 description = "Planar Inductor Generator"
 readme = "README.rst"
 license = "Apache-2.0"

src/kicoil/geometry.py

@@ -142,6 +142,8 @@ class CircleShape(Shape):
     def project_point(self, r, a, r_ref=None):
         return cos(a) * r, sin(a) * r
 
+    def map_angle(self, a):
+        return a
 
     def offset_exterior(self, margin):
         r = self.outer_radius + margin
@@ -180,6 +182,12 @@ class OffsetShape(Shape):
         return points, arm_length, angle_refs
 
 
+    def map_angle(self, a):
+        a_new = self.sk.map_angle(a / (2*pi), self.outer_radius, self.inner_radius)
+        print(f'NEW MAPPED {a:.3f} to {a_new:.3f}')
+        return a_new * 2 * pi
+
+
     def project_point(self, r, a, r_ref=None):
         # Skeletonator uses a t coordinate from 0 - 1 per revolution instead of a radian angle.
         return self.sk.project_point(a/(2*pi) % 1, r, r_ref=r_ref)
@@ -518,6 +526,7 @@ class PlanarInductor():
             fold_angle = start_angle + self.sweeping_angle
             end_angle = fold_angle + self.sweeping_angle
 
+            print(f'### TWIST {i} INWARD ###')
             # Handle the spiral arm
             points_layer0, arm_length, angle_refs_layer0 = self.shape.compute_spiral(a1=start_angle, a2=fold_angle, fn=circle_segments)
             x0, y0 = points_layer0[0]
@@ -533,6 +542,7 @@ class PlanarInductor():
                 footprint.lines.extend(kicad.make_line(*p1, *p2, self.trace_width, self.layer_pair[0]) for p1, p2 in zip(points_layer0, points_layer0[1:]))
 
             if self.layers > 1:
+                print(f'### TWIST {i} OUTWARD ###')
                 # Handle the returning arm on the bottom layer
                 points_layer1, _, angle_refs_layer1 = self.shape.compute_spiral(a1=end_angle, a2=fold_angle, fn=circle_segments)
                 points_layer1 = points_layer1[::-1]
@@ -568,8 +578,8 @@ class PlanarInductor():
 
             xv, yv = self.shape.project_point(r, fold_angle, r_ref=refs_layer0[-1])
 
-            footprint.lines.append(kicad.make_line(*points_layer0[-1], xv, yv, self.trace_width, self.layer_pair[0]))
-            footprint.lines.append(kicad.make_line(xv, yv, *points_layer1[0], self.trace_width, self.layer_pair[1]))
+            #footprint.lines.append(kicad.make_line(*points_layer0[-1], xv, yv, self.trace_width, self.layer_pair[0]))
+            #footprint.lines.append(kicad.make_line(xv, yv, *points_layer1[0], self.trace_width, self.layer_pair[1]))
 
             footprint.pads.append(kicad.make_via(xv, yv,
                                                  self.via_diameter, self.via_drill, self.clearance,
@@ -586,7 +596,7 @@ class PlanarInductor():
             points_layer0, refs_layer0 = arms_layers[0][i]
             points_layer1, refs_layer1 = arms_layers[1][(i - self.turns) % self.twists]
             
-            xv, yv = self.shape.project_point(r, start_angle, r_ref=refs_layer0[0])
+            xv, yv = self.shape.project_point(r, self.shape.map_angle(start_angle), r_ref=refs_layer0[0])
 
             footprint.lines.append(kicad.make_line(*points_layer0[0], xv, yv, self.trace_width, self.layer_pair[0]))
             footprint.lines.append(kicad.make_line(*points_layer1[-1], xv, yv, self.trace_width, self.layer_pair[1]))

src/kicoil/skeletonator.py

@@ -31,6 +31,14 @@ def interpolate(p1, p2, t, t_start=0, t_end=1):
     return (x1 + t*dx, y1 + t*dy)
 
 
+def interpolate_1d(a, b, t, t_start=0, t_end=1):
+    if math.isclose(t_start, t_end):
+        return a
+    t_range = t_end - t_start
+    t = (t - t_start) / t_range
+    return a + (b-a) * t
+
+
 def approx_in_range(value, lower, upper):
     """ Approximate range check """
     if math.isclose(value, lower) or math.isclose(value, upper):
@@ -245,8 +253,43 @@ class Skeletonator:
             arcs.append(arc)
             points.append(pt)
         return arcs, points
-    
+
+    def map_angle(self, t, r1, r2):
+        r_ref = min(r1, r2)
+        _ic_arcs, inner_circumference = self.map_circumference(r_ref)
+        inner_circumference_sum = sum(math.dist(p1, p2) for p1, p2 in edge_cycle(inner_circumference))
+
+        angle = 0
+        point_angles = [0]
+        for p1, p2 in edge_cycle(inner_circumference):
+            edge_angle = math.dist(p1, p2) / inner_circumference_sum
+            angle += edge_angle
+            point_angles.append(angle)
+
+        _oc_arcs, outer_circumference = self.map_circumference(max(r1, r2))
+        outer_circumference_sum = sum(math.dist(p1, p2) for p1, p2 in edge_cycle(outer_circumference))
+
+        angle = 0
+        point_angles_outer = [0]
+        for p1, p2 in edge_cycle(outer_circumference):
+            edge_angle = math.dist(p1, p2) / outer_circumference_sum
+            angle += edge_angle
+            point_angles_outer.append(angle)
+
+        t_map_int = math.floor(t)
+        t %= 1.0
+           
+        for ia1, ia2, oa1, oa2 in zip(point_angles, point_angles[1:] + [1], point_angles_outer, point_angles_outer[1:] + [1]):
+           
+            if approx_in_range(t, oa1, oa2):
+                if oa1 == oa2:
+                    return t_map_int + ia2
+                else:
+                    return t_map_int + ia1 + (ia2 - ia1) * ((t - oa1) / (oa2 - oa1))
+
+
     def do_spiral(self, t1, t2, r1=None, r2=None):
+        print(f'  {t1=:.5f} {t2=:.5f} {r1=:.2f} {r2=:.2f}')
         if r1 is None:
             r1 = self.radius
         if r2 is None:
@@ -256,48 +299,38 @@ class Skeletonator:
             t1, t2 = t2, t1
             r1, r2 = r2, r1
 
-        def r_interpolate(t):
-            t = max(t1, min(t2, t)) # Clip to start/end of spiral
-            f = (t - t1) / (t2 - t1)
-            return r1 + (r2 - r1) * f
+        angle_map = []
+        circumferences = []
+        n = 100
+        radius_steps = [r1 + (r2 - r1) * i/(n-1) for i in range(n)]
+        angle_steps = [t1 + (t2 - t1) * i/(n-1) for i in range(n)]
+        for r in radius_steps:
+            _ic_arcs, circumference = self.map_circumference(r)
+            circumference_sum = sum(math.dist(p1, p2) for p1, p2 in edge_cycle(circumference))
+            circumferences.append(circumference_sum)
 
-        for t_start in range(math.floor(t1), math.ceil(t2)):
-            t_end = t_start + 1
-            r_outer = r_interpolate(t_start)
-            r_inner = r_interpolate(t_end)
-            r_ref = min(r_inner, r_outer) # Handle outward spirals where the radii are swapped
-            _ic_arcs, inner_circumference = self.map_circumference(r_ref)
-
-            angle = t_start
-            circumference_angles = []
-            inner_circumference_sum = sum(math.dist(p1, p2) for p1, p2 in edge_cycle(inner_circumference))
-            point_angles = []
-            for p1, p2 in edge_cycle(inner_circumference):
-                edge_angle = math.dist(p1, p2) / inner_circumference_sum
-                point_angles.append(angle)
+            angle = 0
+            point_angles = [0]
+            for p1, p2 in edge_cycle(circumference):
+                edge_angle = math.dist(p1, p2) / circumference_sum
                 angle += edge_angle
-            point_angles.append(t_end)
+                point_angles.append(angle)
+            
+            angle_map.append(point_angles)
 
-            for (p1, p2), (tp1, tp2) in zip(self.poly_edges, itertools.pairwise(point_angles)):
-                rp1 = r_interpolate(tp1)
-                rp2 = r_interpolate(tp2)
-                _arc, p1_proj = self.project_arc(p1, rp1)
-                _arc, p2_proj = self.project_arc(p2, rp2)
+        for r, t, point_angles in zip(radius_steps, angle_steps, angle_map):
+            for (p1, p2), (tp1, tp2) in zip(self.poly_edges, itertools.pairwise(point_angles + point_angles[:1])):
+                _arc, p1_proj = self.project_arc(p1, r)
+                _arc, p2_proj = self.project_arc(p2, r)
                 
-                if approx_in_range(t1, tp1, tp2):
-                    _arc, p2_proj_r1 = self.project_arc(p2, r1)
-                    yield interpolate(p1_proj, p2_proj_r1, t1, tp1, tp2), r_ref
-                if approx_in_range(t2, tp1, tp2):
-                    _arc, p1_proj_r2 = self.project_arc(p1, r2)
-                    yield interpolate(p1_proj_r2, p2_proj, t2, tp1, tp2), r_ref
-                elif approx_in_range(tp2, t1, t2):
-                    yield p2_proj, r_ref
+                if approx_in_range(t%1, tp1, tp2):
+                    yield interpolate(p1_proj, p2_proj, t%1, tp1, tp2), r
 
     def dump_to_pdf(self, filename):
         with PdfPages(filename) as pdf:
             fig, ax = plt.subplots(figsize=(10, 10))
 
-            # polygon outline
+            # polygon outliner
             poly_x = [p[0] for p in self.poly] + [self.poly[0][0]]
             poly_y = [p[1] for p in self.poly] + [self.poly[0][1]]
             ax.plot(poly_x, poly_y, 'b-', linewidth=2, label='Polygon')

uv.lock

@@ -569,7 +569,7 @@ wheels = [
 
 [[package]]
 name = "kicoil"
-version = "0.9.0"
+version = "0.10.0"
 source = { editable = "." }
 dependencies = [
     { name = "beautifulsoup4" },