[utils.curves.euler_bend] add num_point arg and improve naming

masque/builder/utils.py

@@ -21,7 +21,7 @@ def ell(
         *,
         spacing: float | ArrayLike | None = None,
         set_rotation: float | None = None,
-        ) -> dict[str, float]:
+        ) -> dict[str, numpy.float64]:
     """
     Calculate extension for each port in order to build a 90-degree bend with the provided
     channel spacing:

masque/shapes/arc.py

@@ -233,7 +233,7 @@ class Arc(Shape):
         r0, r1 = self.radii
 
         # Convert from polar angle to ellipse parameter (for [rx*cos(t), ry*sin(t)] representation)
-        a_ranges = cast(tuple[tuple[float, float], tuple[float, float]], self._angles_to_parameters())
+        a_ranges = cast(_array2x2_t, self._angles_to_parameters())
 
         # Approximate perimeter via numerical integration
 
@@ -246,13 +246,13 @@ class Arc(Shape):
 
         def get_arclens(n_pts: int, a0: float, a1: float, dr: float) -> tuple[NDArray[numpy.float64], NDArray[numpy.float64]]:
             """ Get `n_pts` arclengths """
-            t, dt = numpy.linspace(a0, a1, n_pts, retstep=True)  # NOTE: could probably use an adaptive number of points
-            r0sin = (r0 + dr) * numpy.sin(t)
-            r1cos = (r1 + dr) * numpy.cos(t)
+            tt, dt = numpy.linspace(a0, a1, n_pts, retstep=True)  # NOTE: could probably use an adaptive number of points
+            r0sin = (r0 + dr) * numpy.sin(tt)
+            r1cos = (r1 + dr) * numpy.cos(tt)
             arc_dl = numpy.sqrt(r0sin * r0sin + r1cos * r1cos)
-            #arc_lengths = numpy.diff(t) * (arc_dl[1:] + arc_dl[:-1]) / 2
+            #arc_lengths = numpy.diff(tt) * (arc_dl[1:] + arc_dl[:-1]) / 2
             arc_lengths = (arc_dl[1:] + arc_dl[:-1]) * numpy.abs(dt) / 2
-            return arc_lengths, t
+            return arc_lengths, tt
 
         wh = self.width / 2.0
         if num_vertices is not None:
@@ -286,6 +286,7 @@ class Arc(Shape):
                 thetas = thetas[::-1]
             return thetas
 
+        thetas_inner: NDArray[numpy.float64]
         if wh in (r0, r1):
             thetas_inner = numpy.zeros(1)      # Don't generate multiple vertices if we're at the origin
         else:
@@ -320,11 +321,11 @@ class Arc(Shape):
 
         If the extrema are innaccessible due to arc constraints, check the arc endpoints instead.
         """
-        a_ranges = self._angles_to_parameters()
+        a_ranges = cast(_array2x2_t, self._angles_to_parameters())
 
         mins = []
         maxs = []
-        for a, sgn in zip(a_ranges, (-1, +1), strict=True):
+        for aa, sgn in zip(a_ranges, (-1, +1), strict=True):
             wh = sgn * self.width / 2
             rx = self.radius_x + wh
             ry = self.radius_y + wh
@@ -335,13 +336,13 @@ class Arc(Shape):
                 maxs.append([0, 0])
                 continue
 
-            a0, a1 = a
+            a0, a1 = aa
             a0_offset = a0 - (a0 % (2 * pi))
 
             sin_r = numpy.sin(self.rotation)
             cos_r = numpy.cos(self.rotation)
-            sin_a = numpy.sin(a)
-            cos_a = numpy.cos(a)
+            sin_a = numpy.sin(aa)
+            cos_a = numpy.cos(aa)
 
             # Cutoff angles
             xpt = (-self.rotation) % (2 * pi) + a0_offset
@@ -431,19 +432,19 @@ class Arc(Shape):
              [[x2, y2], [x3, y3]]],    would create this arc from its corresponding ellipse.
             ```
         """
-        a_ranges = self._angles_to_parameters()
+        a_ranges = cast(_array2x2_t, self._angles_to_parameters())
 
         mins = []
         maxs = []
-        for a, sgn in zip(a_ranges, (-1, +1), strict=True):
+        for aa, sgn in zip(a_ranges, (-1, +1), strict=True):
             wh = sgn * self.width / 2
             rx = self.radius_x + wh
             ry = self.radius_y + wh
 
             sin_r = numpy.sin(self.rotation)
             cos_r = numpy.cos(self.rotation)
-            sin_a = numpy.sin(a)
-            cos_a = numpy.cos(a)
+            sin_a = numpy.sin(aa)
+            cos_a = numpy.cos(aa)
 
             # arc endpoints
             xn, xp = sorted(rx * cos_r * cos_a - ry * sin_r * sin_a)
@@ -461,21 +462,23 @@ class Arc(Shape):
             "Eccentric anomaly" parameter ranges for the inner and outer edges, in the form
                    `[[a_min_inner, a_max_inner], [a_min_outer, a_max_outer]]`
         """
-        a = []
+        aa = []
         for sgn in (-1, +1):
             wh = sgn * self.width / 2.0
             rx = self.radius_x + wh
             ry = self.radius_y + wh
 
-            a0, a1 = (numpy.arctan2(rx * numpy.sin(a), ry * numpy.cos(a)) for a in self.angles)
+            a0, a1 = (numpy.arctan2(rx * numpy.sin(ai), ry * numpy.cos(ai)) for ai in self.angles)
             sign = numpy.sign(self.angles[1] - self.angles[0])
             if sign != numpy.sign(a1 - a0):
                 a1 += sign * 2 * pi
 
-            a.append((a0, a1))
-        return numpy.array(a, dtype=float)
+            aa.append((a0, a1))
+        return numpy.array(aa, dtype=float)
 
     def __repr__(self) -> str:
         angles = f' a°{numpy.rad2deg(self.angles)}'
         rotation = f' r°{numpy.rad2deg(self.rotation):g}' if self.rotation != 0 else ''
         return f'<Arc o{self.offset} r{self.radii}{angles} w{self.width:g}{rotation}>'
+
+_array2x2_t = tuple[tuple[float, float], tuple[float, float]]

masque/shapes/path.py

@@ -271,7 +271,7 @@ class Path(Shape):
         # TODO: Path.travel() needs testing
         direction = numpy.array([1, 0])
 
-        verts = [numpy.zeros(2)]
+        verts: list[NDArray[numpy.float64]] = [numpy.zeros(2)]
         for angle, distance in travel_pairs:
             direction = numpy.dot(rotation_matrix_2d(angle), direction.T).T
             verts.append(verts[-1] + direction * distance)

masque/utils/curves.py

@@ -22,9 +22,10 @@ def bezier(
     Returns:
         `[[x0, y0], [x1, y1], ...]` corresponding to `[tt0, tt1, ...]`
     """
+    nodes = numpy.asarray(nodes)
+    tt = numpy.asarray(tt)
     nn = nodes.shape[0]
-    if weights is None:
-        weights = numpy.ones(nn)
+    weights = numpy.ones(nn) if weights is None else numpy.asarray(weights)
 
     t_half0 = tt <= 0.5
     umul = tt / (1 - tt)
@@ -43,7 +44,10 @@ def bezier(
 
 
 
-def euler_bend(switchover_angle: float) -> NDArray[numpy.float64]:
+def euler_bend(
+        switchover_angle: float,
+        num_points: int = 200,
+        ) -> NDArray[numpy.float64]:
     """
     Generate a 90 degree Euler bend (AKA Clothoid bend or Cornu spiral).
 
@@ -51,42 +55,44 @@ def euler_bend(switchover_angle: float) -> NDArray[numpy.float64]:
         switchover_angle: After this angle, the bend will transition into a circular arc
             (and transition back to an Euler spiral on the far side). If this is set to
             `>= pi / 4`, no circular arc will be added.
+        num_points: Number of points in the curve
 
     Returns:
         `[[x0, y0], ...]` for the curve
     """
-    # Switchover angle
-    # AKA: Clothoid bend, Cornu spiral
-    theta_max = numpy.sqrt(2 * switchover_angle)
+    ll_max = numpy.sqrt(2 * switchover_angle)        # total length of (one) spiral portion
+    ll_tot = 2 * ll_max + (pi / 2 - 2 * switchover_angle)
+    num_points_spiral = numpy.floor(ll_max / ll_tot * num_points).astype(int)
+    num_points_arc = num_points - 2 * num_points_spiral
 
-    def gen_curve(theta_max: float):
+    def gen_spiral(ll_max: float):
         xx = []
         yy = []
-        for theta in numpy.linspace(0, theta_max, 100):
-            qq = numpy.linspace(0, theta, 1000)
+        for ll in numpy.linspace(0, ll_max, num_points_spiral):
+            qq = numpy.linspace(0, ll, 1000)        # integrate to current arclength
             xx.append(numpy.trapz( numpy.cos(qq * qq / 2), qq))
             yy.append(numpy.trapz(-numpy.sin(qq * qq / 2), qq))
         xy_part = numpy.stack((xx, yy), axis=1)
         return xy_part
 
-    xy_part = gen_curve(theta_max)
-    xy_parts = [xy_part]
+    xy_spiral = gen_spiral(ll_max)
+    xy_parts = [xy_spiral]
 
     if switchover_angle < pi / 4:
         # Build a circular segment to join the two euler portions
-        rmin = 1.0 / theta_max
+        rmin = 1.0 / ll_max
         half_angle = pi / 4 - switchover_angle
-        qq = numpy.linspace(half_angle * 2, 0, 10) + switchover_angle
+        qq = numpy.linspace(half_angle * 2, 0, num_points_arc + 1) + switchover_angle
         xc = rmin * numpy.cos(qq)
-        yc = rmin * numpy.sin(qq) + xy_part[-1, 1]
-        xc += xy_part[-1, 0] - xc[0]
-        yc += xy_part[-1, 1] - yc[0]
-        xy_parts.append(numpy.stack((xc, yc), axis=1))
+        yc = rmin * numpy.sin(qq) + xy_spiral[-1, 1]
+        xc += xy_spiral[-1, 0] - xc[0]
+        yc += xy_spiral[-1, 1] - yc[0]
+        xy_parts.append(numpy.stack((xc[1:], yc[1:]), axis=1))
 
     endpoint_xy = xy_parts[-1][-1, :]
-    second_curve = xy_part[::-1, ::-1] + endpoint_xy - xy_part[-1, ::-1]
+    second_spiral = xy_spiral[::-1, ::-1] + endpoint_xy - xy_spiral[-1, ::-1]
 
-    xy_parts.append(second_curve)
+    xy_parts.append(second_spiral)
     xy = numpy.concatenate(xy_parts)
 
     # Remove any 2x-duplicate points