The CGAL WASM build crashes for some simple n-gons

src/kicoil/cli.py

@@ -26,7 +26,7 @@ import math
 import click
 from gerbonara.layers import LayerStack
 
-from .geometry import PlanarInductor, divisors, CircleShape, SectorShape, StarShape, SVGShape
+from .geometry import PlanarInductor, divisors, CircleShape, SectorShape, StarShape, SVGShape, RectangleShape, RegularPolygonShape
 from .kicad import footprint_to_board
 from .svg import make_transparent_svg
 
@@ -170,6 +170,28 @@ def trapezoid(ctx, outfile, **kwargs):
     ctx.obj['write'](shape, outfile)
 
 
+@cli.command()
+@click.option('--width', type=float, default=50, help='Width [mm]')
+@click.option('--height', type=float, default=40, help='Height [mm]')
+@click.option('--annular-width', type=float, default=10, help='Width of the trace area on the outside of the shape [mm]')
+@click.argument('outfile', required=False, type=click.Path(writable=True, dir_okay=False, path_type=Path))
+@click.pass_context
+def rectangle(ctx, outfile, **kwargs):
+    shape = RectangleShape(**kwargs)
+    ctx.obj['write'](shape, outfile)
+
+
+@cli.command()
+@click.option('--diameter', type=float, default=50, help='Width [mm]')
+@click.option('-n', '--corners', type=int, default=8, help='Number of corners')
+@click.option('--annular-width', type=float, default=10, help='Width of the trace area on the outside of the shape [mm]')
+@click.argument('outfile', required=False, type=click.Path(writable=True, dir_okay=False, path_type=Path))
+@click.pass_context
+def regular_polygon(ctx, outfile, **kwargs):
+    shape = RegularPolygonShape(**kwargs)
+    ctx.obj['write'](shape, outfile)
+
+
 @cli.command()
 @click.option('--inner-diameter', type=float, default=25, help='Inner diameter [mm]')
 @click.option('--outer-diameter', type=float, default=50, help='Outer diameter [mm]')

src/kicoil/geometry.py

@@ -195,11 +195,12 @@ class TrapezoidShape(OffsetShape):
     height: float
     offset: float
     annular_width: float
+    arc_tolerance: float = 0.05 # mm
     polygon: list = field(init=False)
 
     def __post_init__(self):
         w, h, d = self.width, self.height, self.offset
-        self.polygon = [(w/2-d, 0), (w/2, h), (-w/2, h), (-w/2+d, 0)]
+        self.polygon = [(w/2-d, -h/2), (w/2, h/2), (-w/2, h/2), (-w/2+d, -h/2)]
         super().__post_init__()
     
     @property
@@ -211,6 +212,27 @@ class TrapezoidShape(OffsetShape):
         return f'{self.width:.2f} x {self.height:.2f} mm, {self.offset:.2f} mm offset isosceles trapezoidal'
 
 
+@dataclass
+class RectangleShape(OffsetShape):
+    width: float
+    height: float
+    annular_width: float
+    arc_tolerance: float = 0.05 # mm
+    polygon: list = field(init=False)
+
+    def __post_init__(self):
+        w, h = self.width, self.height
+        self.polygon = [(w/2, -h/2), (w/2, h/2), (-w/2, h/2), (-w/2, -h/2)]
+        super().__post_init__()
+    
+    @property
+    def slug(self):
+        return f'rectangle_{self.width:.2f}x{self.height:.2f}'
+    
+    @property
+    def desc(self):
+        return f'{self.width:.2f} x {self.height:.2f} mm rectangle'
+
 @dataclass
 class SectorShape(OffsetShape):
     inner_diameter: float
@@ -265,6 +287,32 @@ class StarShape(OffsetShape):
         purpose = ', for demonic purposes' if self.points == 5 else ''
         return f'{self.outer_diameter:.2f} x {self.inner_diameter:.2f} mm star shape{purpose}'
 
+
+@dataclass
+class RegularPolygonShape(OffsetShape):
+    diameter: float
+    annular_width: float
+    corners: int = 8
+    arc_tolerance: float = 0.05 # mm
+    polygon: list = field(init=False)
+
+    def __post_init__(self):
+        # center on y axis
+        pt = lambda r, a: (-r*sin(a), r*cos(a))
+        circle = lambda r, n, phase: [pt(r, (i + phase)*2*pi/n) for i in range(n)]
+        self.polygon  = list(circle(self.diameter/2, self.corners, 0))
+        print(self.polygon)
+        super().__post_init__()
+    
+    @property
+    def slug(self):
+        return f'regular_{self.corners}gon_{self.diameter:.2f}'
+    
+    @property
+    def desc(self):
+        return f'{self.diameter:.2f} mm diameter {self.corners} corner regular polygon'
+
+
 @dataclass
 class SVGShape(OffsetShape):
     filename: str
@@ -282,6 +330,16 @@ class SVGShape(OffsetShape):
             d = d.strip('MmZ ').replace(',', 'L')
             coord_pairs = d.split('L')
             coords = list(reversed([tuple(map(float, pair.split())) for pair in coord_pairs]))
+            # Calculate bounding box
+            min_x = min(x for x, _y in coords)
+            min_y = max(x for x, _y in coords)
+            max_x = min(y for _x, y in coords)
+            max_y = max(y for _x, y in coords)
+            if max_x < 0 or max_y < 0 or min_x > 0 or min_y > 0:
+                # (0, 0) is not within the polygon's axis-aligned bounding box, recenter.
+                ox, oy = skeletonator.polygon_center_of_mass(coords)
+                warnings.warn(f'Polygon looks not centered, bounds are ({min_x:.2f}, {min_y:.2f}), ({max_x:.2f}, {max_y:.2f}). Aligning (0, 0) with polygon centroid at ({ox:.2f}, {oy:.2f})')
+                coords = [(x-ox, y-oy) for x, y in coords]
         self.polygon  = coords
         super().__post_init__()
     
@@ -331,7 +389,6 @@ class PlanarInductor():
         alpha2 = atan((self.shape.outer_radius - self.shape.inner_radius) / self.sweeping_angle / c2)
         alpha = (alpha1+alpha2)/2
         self.projected_spiral_pitch = self.spiral_pitch*cos(alpha)
-        print(self.shape.inner_radius, self.shape.outer_radius, self.spiral_pitch, self.turns_per_layer)
 
         if self.layers == 1 and self.twists > 1:
             warnings.warn('Warning: Twists set to a value other than 1, but single-layer mode is enabled. The twists value will be ignored.')

src/kicoil/skeletonator.py

@@ -45,6 +45,29 @@ def edge_cycle(points):
     return itertools.pairwise(itertools.chain(points, points[:1]))
 
 
+def polygon_is_clockwise(points):
+    (x1, y1, i), *_rest = sorted((x, y, i) for i, (x, y) in enumerate(points))
+    x0, y0 = points[(i-1)%len(points)]
+    x2, y2 = points[(i+1)%len(points)]
+    det = (x0*y1 + x1*y2 + x2*y0) - (x2*y1 + x1*y0 + x0*y2)
+    return det < 0
+
+
+def polygon_center_of_mass(polygon):
+    # https://en.wikipedia.org/wiki/Centroid
+    total_x, total_y = 0, 0
+    area = 0
+    for (x1, y1), (x2, y2) in edge_cycle(polygon):
+        diff = (x1*y2 - x2*y1)
+        total_x += (x1 + x2) * diff
+        total_y += (y1 + y2) * diff
+        area += diff
+    area /= 2
+    total_x /= 6*area
+    total_y /= 6*area
+    return total_x, total_y
+
+
 class WasmApp:
     def __init__(self, wasm_filename, cachedir="kicoil"):
         module_binary = importlib.resources.read_binary(__package__, wasm_filename)
@@ -103,14 +126,6 @@ class SkeletonNode:
         return self.x, self.y
 
 
-def polygon_is_clockwise(points):
-    x1, y1, i = sorted((x, y, i) for x, y in points)
-    x0, y0 = points[(i-1)%len(points)]
-    x2, y2 = points[(i+1)%len(points)]
-    det = (x1*y2 + x2*y3 + x3*y1) - (x3*y2 + x2*y1 + x1*y3)
-    return det < 0
-
-
 skeleton_wasm = WasmApp('skeleton.wasm')
 
 def compute_skeleton(exterior):
@@ -119,6 +134,7 @@ def compute_skeleton(exterior):
         if p2 != p1:
             points_deduplicated.append(p1)
     input_data = '\n'.join(f'{x} {y}' for x, y in points_deduplicated)
+    Path('/tmp/debug.txt').write_text(input_data)
     
     rc, data = skeleton_wasm.run(input_data)