Improve probepoint export according to current standards

* single-reference support
* assign "west" and "east" probers
* unit tests
* macro to visualise exported probepoints for visual inspection

klayout_package/python/kqcircuits/defaults.py

@@ -106,11 +106,24 @@
 default_bar_format = '{l_bar}{bar}| {n_fmt}/{total_fmt} [Elapsed: {elapsed}, Left (eta): {remaining}, {rate_inv_fmt}' \
                      '{postfix}]'
 
-# dictionary of probepoint types for probepoint export
-# key is the refpoint name prefix for a type of probepoints, value is a text representation of the probepoint type
-default_probe_types = {"testarray": "testarrays", "qb": "qubits"}
-# tuple of refpoint name suffixes that are used (together with probe_types) to identify refpoints as probepoints
-default_probe_suffixes = ("_c", "_l")
+# refpoint is extracted as probepoint if it contains some string from default_probe_types and
+# ends with some substring from default_probe_suffixes
+
+default_probe_types = ["testarray", "qb"]
+default_probe_suffixes = [
+    "_l", "_r", "_top", # Test array probepoints
+    # Single island qubit probepoints
+    "_probe_ground", "_probe_island",
+    # Double island qubit probepoints
+    "_probe_island_1", "_probe_island_2"
+]
+# for probepoint pair, one is assigned to west and other to east prober based on their x coordinate
+# but we also want to set a standard where ground is consistently probed from one side and island
+# from the other. This dict defines such rules
+recommended_probe_suffix_mapping = {
+    "_probe_ground": "east",
+    "_probe_island": "west"
+}
 
 # Library names in dependency order. Every library should have its dependencies before its own entry.
 kqc_library_names = (

klayout_package/python/kqcircuits/qubits/double_pads.py

@@ -126,6 +126,13 @@ def build(self):
         self.add_port("drive", pya.DPoint(float(self.drive_position[0]), float(self.drive_position[1])),
                       direction=pya.DVector(float(self.drive_position[0]), float(self.drive_position[1])))
 
+        # Probepoints
+        self.refpoints["probe_island_1"] = pya.DPoint(0,
+            self.squid_offset + squid_height / 2 + taper_height + float(self.island1_extent[1]) / 2)
+        self.refpoints["probe_island_2"] = pya.DPoint(0,
+            self.squid_offset - squid_height / 2 - taper_height - float(self.island2_extent[1]) / 2)
+
+
     def _build_coupler(self, first_island_top_edge):
         coupler_top_edge = first_island_top_edge + self.coupler_offset + float(self.coupler_extent[1])
         coupler_polygon = pya.DPolygon([

klayout_package/python/kqcircuits/qubits/qubit.py

@@ -39,6 +39,19 @@ class Qubit(Element):
     * possible fluxlines
     * e-beam layers for SQUIDs
     * SQUID name parameter
+
+    It is customary to also define probepoints for a qubit. Simply define two refpoints as appropriate probepoints.
+    For single island qubits::
+
+        self.refpoints["probe_ground"] = pya.DPoint(...)
+        self.refpoints["probe_island"] = pya.DPoint(...)
+        self.cell.shapes(self.get_layer("ground_grid_avoidance")).insert(
+            pya.DBox(-20.0, -20.0, 20.0, 20.0).moved(self.refpoints["probe_ground"]))
+
+    For double island qubits::
+
+        self.refpoints["probe_island_1"] = pya.DPoint(...)
+        self.refpoints["probe_island_2"] = pya.DPoint(...)
     """
 
     LIBRARY_NAME = "Qubit Library"

klayout_package/python/scripts/macros/export/export_probepoints_json.lym

@@ -8,6 +8,7 @@
  <doc/>
  <autorun>false</autorun>
  <autorun-early>false</autorun-early>
+ <priority>0</priority>
  <shortcut/>
  <show-in-menu>false</show-in-menu>
  <group-name/>
@@ -34,13 +35,26 @@
 
 """Prints the probepoints of a chip as JSON. Assumes that a single chip exists in the top cell."""
 
+import json
 from kqcircuits.klayout_view import KLayoutView
 from kqcircuits.util.export_helper import generate_probepoints_json
 
 top_cell = KLayoutView(current=True).active_cell
 
+### Set file location, or leave empty to get probepoint JSON empty
+FILE_LOCATION = ""
 ### Action
-# Note that this works on the bottom face by default. For the top, specify a second 't' argument.
-print(generate_probepoints_json(top_cell))
+# See API docs on how to best call generate_probepoints_json for your purposes
+probepoint_json = generate_probepoints_json(top_cell,
+    face='1t1',
+    references=['nw'],
+    contact=None)
+json_str = json.dumps(probepoint_json, indent=2)
+
+if FILE_LOCATION:
+    with open(FILE_LOCATION, 'w') as file:
+        file.write(json_str)
+else:
+    print(json_str)
 </text>
 </klayout-macro>

klayout_package/python/scripts/macros/generate/visualise_probepoints.lym

@@ -0,0 +1,93 @@
+<?xml version="1.0" encoding="utf-8"?>
+<klayout-macro>
+ <description>Visualise probepoints from json file to layout</description>
+ <version/>
+ <category>pymacros</category>
+ <prolog/>
+ <epilog/>
+ <doc/>
+ <autorun>false</autorun>
+ <autorun-early>false</autorun-early>
+ <priority>0</priority>
+ <shortcut/>
+ <show-in-menu>false</show-in-menu>
+ <group-name/>
+ <menu-path/>
+ <interpreter>python</interpreter>
+ <dsl-interpreter-name/>
+ <text># This code is part of KQCircuits
+# Copyright (C) 2023 IQM Finland Oy
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public
+# License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later
+# version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with this program. If not, see
+# https://www.gnu.org/licenses/gpl-3.0.html.
+#
+# The software distribution should follow IQM trademark policy for open-source software
+# (meetiqm.com/developers/osstmpolicy). IQM welcomes contributions to the code. Please see our contribution agreements
+# for individuals (meetiqm.com/developers/clas/individual) and organizations (meetiqm.com/developers/clas/organization).
+
+
+"""Visualises the probepoints in external JSON file.
+Open or generate chip geometry then run this macro with specified filename
+to compare that the probepoints align with chip components.
+After running this macro, right click the Layers panel (on the right by default)
+and choose "Add Other Layer Entries".
+"""
+
+import json
+from kqcircuits.klayout_view import KLayoutView
+from kqcircuits.pya_resolver import pya
+from kqcircuits.util.export_helper import generate_probepoints_json
+
+# SPECIFY ARGUMENTS
+FILENAME = ""     # Probepoint JSON file to visualise
+FLIP_FACE = False # Mirrors points wrt Y-axis. Recommended for flipchips
+FACE = '1t1'      # Specify substrate face to probe
+
+cell = KLayoutView(current=True).active_cell
+
+with open(FILENAME) as f:
+    probepoint_json = json.load(f)
+
+bbox_for_face = cell.dbbox_per_layer(
+    cell.layout().layer(
+        [l for l in cell.layout().layer_infos() if l.name == f"{FACE}_base_metal_gap_wo_grid"][0]
+    )
+)
+
+def to_dtext(text_string, json_object):
+    x = json_object["x"] * 1e3
+    y = json_object["y"] * 1e3
+    if FLIP_FACE:
+        x = bbox_for_face.p2.x - x
+    else:
+        x += bbox_for_face.p1.x
+    y += bbox_for_face.p1.y
+    return pya.DText(text_string, x, y)
+
+def visualise_point(group, layer_string, text_string, json_object):
+    layer_name = layer_string if not group else f"{group}_{layer_string}"
+    cell.shapes(cell.layout().layer(layer_name)).insert(to_dtext(text_string, json_object))
+
+def visualise_group(group):
+    visualise_point(group.get("id"), "alignment", "alignment", probepoint_json["alignment"])
+    for site in probepoint_json["sites"]:
+        visualise_point(group.get("id"), "east", site["id"], site["east"])
+        visualise_point(group.get("id"), "west", site["id"], site["west"])
+
+for layer in cell.layout().layer_infos():
+    if "alignment" in layer.name or "west" in layer.name or "east" in layer.name:
+        cell.shapes(cell.layout().layer(layer)).clear()
+
+if "groups" in probepoint_json:
+    for group in groups:
+        visualise_group(group)
+else:
+    visualise_group(probepoint_json)</text>
+</klayout-macro>