Keep hole-to-hole spacing between every two vias, one net's included

Every pin of a supply drops its own via to the plane, and nothing kept
two of them apart: the flight controller came back with 199 co-located
holes and 109 hole-to-hole errors, nearly all VDD_3V3 and GND. A via now
keeps its drill plus --hole-to-hole (default 0.25 mm, KiCad's) from
every via centre, fixed ones included, except an own-net via at the same
cell, which it reuses; such a via is written once, and none is written
on top of a via already on the board.

src/freeroute/route/pipeline.py

@@ -12,6 +12,8 @@ to DSN units (dividing by the resolution) for the SES ``(wire (path ...))`` and
 
 from __future__ import annotations
 
+import re
+
 from freeroute.board import build_board
 from freeroute.dsn import DsnBoard, parse_dsn
 from freeroute.ses import RoutedVia, RoutedWire, RoutingResult, write_ses
@@ -72,6 +74,20 @@ def _mm_to_board(dsn: DsnBoard, scale: int, value_mm: float | None) -> int | Non
     return round(value_mm / unit_mm * scale)
 
 
+def _via_drill_board(dsn: DsnBoard, scale: int) -> int | None:
+    """The via's drill in board units, from KiCad's padstack name
+    (``Via[0-1]_600:300_um`` is a 600 um pad with a 300 um drill); None when
+    the name does not say, and the pad size stands in for it."""
+    match = re.search(r"_([\d.]+):([\d.]+)_um", _via_padstack(dsn))
+    if not match:
+        return None
+    return round(float(match.group(2)) * _dsn_units_per_um(dsn) * scale)
+
+
+def _dsn_units_per_um(dsn: DsnBoard) -> float:
+    return {"um": 1.0, "mm": 0.001, "mil": 1 / 25.4, "inch": 1 / 25400}.get(dsn.unit, 1.0)
+
+
 def _via_half_board(dsn: DsnBoard, scale: int) -> int | None:
     """Half the via pad's size in board units, from the DSN's via padstack.
 
@@ -102,6 +118,7 @@ def route_dsn_board(
     seed: int | None = None,
     route_first: frozenset | None = None,
     access_cost: float = 0.0,
+    hole_to_hole_mm: float = 0.25,
     rollback: bool = True,
 ) -> tuple[RouteResult, int, list[str]]:
     """Route a parsed :class:`DsnBoard`; return the board-unit result, the scale,
@@ -128,6 +145,8 @@ def route_dsn_board(
         access_cost=access_cost,
         rollback=rollback,
         net_widths=_net_widths_board(dsn, scale),
+        via_drill=_via_drill_board(dsn, scale),
+        hole_to_hole=_mm_to_board(dsn, scale, hole_to_hole_mm) or 0,
     )
     return result, scale, [layer.name for layer in dsn.layers]
 
@@ -177,6 +196,7 @@ def build_routing_result(
     seed: int | None = None,
     route_first: frozenset | None = None,
     access_cost: float = 0.0,
+    hole_to_hole_mm: float = 0.25,
     rollback: bool = True,
 ) -> RoutingResult:
     """Route ``dsn`` (grid track) and convert to a DSN-unit RoutingResult."""
@@ -185,6 +205,7 @@ def build_routing_result(
         edge_clearance_mm=edge_clearance_mm, resolution=resolution, seed=seed,
         route_first=route_first,
         access_cost=access_cost,
+        hole_to_hole_mm=hole_to_hole_mm,
         rollback=rollback,
     )
     return _to_routing_result(route, dsn, scale, layer_names)
@@ -204,6 +225,7 @@ def route_dsn_board_exact(
     seed: int | None = None,
     route_first: frozenset | None = None,
     access_cost: float = 0.0,
+    hole_to_hole_mm: float = 0.25,
     rollback: bool = True,
 ) -> tuple[ExactRouteResult, int, list[str]]:
     """Route a parsed :class:`DsnBoard` with the exact-geometry (orthogonal,
@@ -234,6 +256,8 @@ def route_dsn_board_exact(
         access_cost=access_cost,
         rollback=rollback,
         net_widths=_net_widths_board(dsn, scale),
+        via_drill=_via_drill_board(dsn, scale),
+        hole_to_hole=_mm_to_board(dsn, scale, hole_to_hole_mm) or 0,
     )
     return exact, scale, [layer.name for layer in dsn.layers]
 
@@ -252,6 +276,7 @@ def build_exact_routing_result(
     seed: int | None = None,
     route_first: frozenset | None = None,
     access_cost: float = 0.0,
+    hole_to_hole_mm: float = 0.25,
     rollback: bool = True,
 ) -> RoutingResult:
     """Route ``dsn`` (exact track) and convert to a DSN-unit RoutingResult."""
@@ -268,6 +293,7 @@ def build_exact_routing_result(
         seed=seed,
         route_first=route_first,
         access_cost=access_cost,
+        hole_to_hole_mm=hole_to_hole_mm,
         rollback=rollback,
     )
     return _to_routing_result(exact.result, dsn, scale, layer_names)