layer priority operation

gdsfactory/geometry/__init__.py

@@ -11,6 +11,7 @@
 from gdsfactory.geometry.check_space import check_space
 from gdsfactory.geometry.check_width import check_width
 from gdsfactory.geometry.invert import invert
+from gdsfactory.geometry.layer_priority import layer_priority
 from gdsfactory.geometry.offset import offset
 from gdsfactory.geometry.outline import outline
 from gdsfactory.geometry.trim import trim
@@ -32,4 +33,5 @@
     "xor_diff",
     "functions",
     "trim",
+    "layer_priority",
 )

gdsfactory/geometry/layer_priority.py

@@ -0,0 +1,119 @@
+import gdsfactory as gf
+from gdsfactory.typings import LayerSpec, ComponentSpec
+import numpy as np
+
+
+def layer_priority(
+    component: ComponentSpec,
+    layer_high_order: LayerSpec,
+    layer_low_order: LayerSpec,
+    remove_high_order: bool = False,
+    **kwargs,
+):
+    """Returns a new component where a specified layer is removed from another.
+
+    Arguments:
+        layer_high_order: layer used to etch
+        layer_low_order: layer etched into
+        remove_high_order: whether to also remove the high order layer polygons. Useful if the higher order layer is purely logical.
+        kwargs: leyword arguments for boolean difference operation
+    """
+    c = gf.Component()
+
+    # Obtain component subsets
+    layers_to_remove = (
+        [gf.get_layer(layer_low_order), gf.get_layer(layer_high_order)]
+        if remove_high_order
+        else [gf.get_layer(layer_low_order)]
+    )
+    component_minus_layers = component.extract(
+        [
+            gf.get_layer(layer)
+            for layer in component.get_layers()
+            if gf.get_layer(layer) not in layers_to_remove
+        ]
+    )
+    component_high_order = component.extract([layer_high_order])
+    component_low_order = component.extract([layer_low_order])
+
+    # Remove high priority from low priority
+    component_high_order_removed_from_low_order = gf.geometry.boolean(
+        A=component_low_order,
+        B=component_high_order,
+        operation="A-B",
+        layer=layer_low_order,
+        **kwargs,
+    )
+
+    # Place all the other layers
+    c << component_minus_layers
+    c << component_high_order_removed_from_low_order
+
+    c.add_ports(ports=component.ports)
+
+    return c
+
+
+def test_layer_priority() -> None:
+    funky_cross_section = gf.cross_section.cross_section(
+        width=0.5,
+        layer="WG",
+        sections=[
+            gf.cross_section.Section(width=2, layer="N"),
+            gf.cross_section.Section(width=2, layer="SLAB150"),
+        ],
+    )
+
+    c = gf.components.coupler(cross_section=funky_cross_section)
+
+    c_WG_before = c.extract([gf.get_layer("WG")])
+    c_SLAB150_before = c.extract([gf.get_layer("SLAB150")])
+    c_N_before = c.extract([gf.get_layer("N")])
+
+    c_processed = layer_priority(
+        component=c,
+        layer_high_order="WG",
+        layer_low_order="SLAB150",
+        remove_high_order=False,
+    )
+
+    c_WG_after = c_processed.extract([gf.get_layer("WG")])
+    c_SLAB150_after = c_processed.extract([gf.get_layer("SLAB150")])
+    c_N_after = c_processed.extract([gf.get_layer("N")])
+
+    assert np.isclose(c_WG_before.area(), c_WG_after.area(), atol=1e-3)
+    assert np.isclose(c_N_before.area(), c_N_after.area(), atol=1e-3)
+    assert c_SLAB150_before.area() > c_SLAB150_after.area()
+
+    c_processed = layer_priority(
+        component=c,
+        layer_high_order="WG",
+        layer_low_order="SLAB150",
+        remove_high_order=True,
+    )
+    c_WG_after = c_processed.extract([gf.get_layer("WG")])
+
+    assert c_WG_after.area() == 0
+
+
+if __name__ == "__main__":
+    funky_cross_section = gf.cross_section.cross_section(
+        width=0.5,
+        layer="WG",
+        sections=[
+            gf.cross_section.Section(width=2, layer="N"),
+            gf.cross_section.Section(width=2, layer="SLAB150"),
+        ],
+    )
+
+    c = gf.components.coupler(cross_section=funky_cross_section)
+
+    c_processed = layer_priority(
+        component=c,
+        layer_high_order="WG",
+        layer_low_order="SLAB150",
+        remove_high_order=False,
+    )
+    c_processed.show(show_ports=True)
+
+    # test_layer_priority()