[AutoTool] enable custom sbend endpoint_at

masque/builder/__init__.py

@@ -48,9 +48,11 @@ from .tools import (
     PathTool as PathTool,
     RenderStep as RenderStep,
     PrimitiveKind as PrimitiveKind,
+    GeneratedEndpointFn as GeneratedEndpointFn,
     PrimitiveOffer as PrimitiveOffer,
     StraightOffer as StraightOffer,
     BendOffer as BendOffer,
     SOffer as SOffer,
     UOffer as UOffer,
+    circular_arc_sbend_endpoint as circular_arc_sbend_endpoint,
 )

masque/builder/tools.py

@@ -39,7 +39,7 @@ from collections import ChainMap
 from collections.abc import Sequence, Callable, Mapping
 from abc import ABC, abstractmethod
 from dataclasses import dataclass, field
-from math import isclose as scalar_isclose, isfinite as scalar_isfinite, isnan as scalar_isnan
+from math import isclose as scalar_isclose, isfinite as scalar_isfinite, isnan as scalar_isnan, sqrt
 
 import numpy
 from numpy.typing import NDArray
@@ -706,6 +706,32 @@ class Tool(ABC):
 
 
 GeneratedPrimitiveFn = Callable[..., Pattern | Library]
+GeneratedEndpointFn = Callable[[float], Port]
+
+
+def circular_arc_sbend_endpoint(radius: float, ptype: str) -> GeneratedEndpointFn:
+    """
+    Return an S-bend endpoint planner for two abutting circular arcs.
+
+    The returned callback assumes a pure generated S-bend made from two equal
+    circular arcs with no attached straight or non-circular pieces. Positive
+    and negative jogs are supported; the output rotation is always `pi`.
+    """
+    rr = float(radius)
+    if not scalar_isfinite(rr) or rr <= 0:
+        raise BuildError(f'S-bend radius must be positive and finite, got {rr:g}')
+
+    def endpoint(jog: float) -> Port:
+        jj = float(jog)
+        jog_magnitude = abs(jj)
+        if scalar_isclose(jog_magnitude, 0.0, rel_tol=1e-9, abs_tol=1e-12):
+            return Port((0, 0), rotation=pi, ptype=ptype)
+        if jog_magnitude > 2 * rr and not scalar_isclose(jog_magnitude, 2 * rr, rel_tol=1e-9, abs_tol=1e-12):
+            raise BuildError(f'S-bend jog magnitude {jog_magnitude:g} exceeds diameter {2 * rr:g}')
+        dx = sqrt(max(0.0, 4 * rr * jog_magnitude - jog_magnitude ** 2))
+        return Port((dx, jj), rotation=pi, ptype=ptype)
+
+    return endpoint
 
 
 @dataclass
@@ -853,23 +879,29 @@ class AutoTool(Tool):
             out_port_name: str,
             *,
             jog_range: tuple[float, float] = (0, numpy.inf),
+            endpoint: GeneratedEndpointFn | None = None,
             ) -> Self:
         """
         Register a generated S-bend primitive.
-        """
-        for jog_domain in self._signed_jog_domains(jog_range):
-            priority_bias = len(self._s_offers) * BUILTIN_PRIORITY_STEP
 
-            def endpoint_s(
-                    jog: float,
-                    *,
-                    fn: GeneratedPrimitiveFn = fn,
-                    in_port_name: str = in_port_name,
-                    out_port_name: str = out_port_name,
-                    ) -> Port:
+        `endpoint`, when supplied, describes the generated S-bend output port
+        directly during planning and avoids instantiating `fn()` inside
+        `endpoint_at()`.
+        """
+        if endpoint is None:
+            def endpoint_at(jog: float) -> Port:
                 jog_magnitude = abs(jog)
                 sbend_dxy = self._sbend2dxy(fn, in_port_name, out_port_name, jog_magnitude)
                 return Port((float(sbend_dxy[0]), float(jog)), rotation=pi, ptype=ptype)
+        else:
+            def endpoint_at(jog: float) -> Port:
+                out_port = endpoint(jog)
+                if not ptypes_compatible(out_port.ptype, ptype):
+                    raise BuildError('S-bend endpoint ptype does not match registered ptype')
+                return out_port
+
+        for jog_domain in self._signed_jog_domains(jog_range):
+            priority_bias = len(self._s_offers) * BUILTIN_PRIORITY_STEP
 
             def data_at(jog: float) -> AutoTool.GeneratedData:
                 return self.GeneratedData(
@@ -881,7 +913,7 @@ class AutoTool(Tool):
 
             self._s_offers.append(SOffer.generated(
                 ptype,
-                endpoint_s,
+                endpoint_at,
                 data_at,
                 priority_bias = priority_bias,
                 bbox_for_data = self._bbox_for_data,

masque/test/test_autotool_planning.py

@@ -5,7 +5,7 @@ import pytest
 from numpy import pi
 from numpy.testing import assert_allclose
 
-from masque.builder.tools import AutoTool, PrimitiveOffer, RenderStep, UOffer
+from masque.builder.tools import AutoTool, PrimitiveOffer, RenderStep, UOffer, circular_arc_sbend_endpoint
 from masque.builder.pather import Pather
 from masque.library import Library
 from masque.pattern import Pattern
@@ -368,6 +368,60 @@ def make_sbend_tool(jog_range: tuple[float, float]) -> AutoTool:
         )
 
 
+def test_autotool_sbend_custom_endpoint_avoids_generator_during_planning() -> None:
+    calls = 0
+
+    def make_counted_sbend(jog: float) -> Pattern:
+        nonlocal calls
+        calls += 1
+        return make_sbend(jog, ptype="core")
+
+    def endpoint(jog: float) -> Port:
+        return Port((20, jog), rotation=pi, ptype="core")
+
+    tool = AutoTool().add_sbend(
+        "core",
+        make_counted_sbend,
+        "A",
+        "B",
+        jog_range=(0, 1e8),
+        endpoint=endpoint,
+    )
+
+    offer = tool.primitive_offers("s", in_ptype="core")[0]
+    out_port = offer.endpoint_at(4)
+
+    assert calls == 0
+    assert_allclose(out_port.offset, [20, 4])
+    assert out_port.rotation == pi
+    assert out_port.ptype == "core"
+
+    data = offer.commit(4)
+    assert data.parameter == 4
+    assert data.mirrored is False
+
+
+def test_circular_arc_sbend_endpoint() -> None:
+    endpoint = circular_arc_sbend_endpoint(radius=5, ptype="core")
+
+    out_port = endpoint(4)
+    assert_allclose(out_port.offset, [8, 4])
+    assert out_port.rotation == pi
+    assert out_port.ptype == "core"
+
+    mirrored_port = endpoint(-4)
+    assert_allclose(mirrored_port.offset, [8, -4])
+    assert mirrored_port.rotation == pi
+    assert mirrored_port.ptype == "core"
+
+    zero_port = endpoint(0)
+    assert_allclose(zero_port.offset, [0, 0])
+    assert zero_port.rotation == pi
+
+    with pytest.raises(BuildError, match="exceeds diameter"):
+        endpoint(11)
+
+
 def make_uturn_pattern(length: float = 10, jog: float = 4, ptype: str = "core") -> Pattern:
     pat = Pattern()
     y0, y1 = sorted((0, jog))