initial pass on examples

examples/02_congestion_resolution.py

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+
+from inire.geometry.collision import CollisionEngine
+from inire.geometry.primitives import Port
+from inire.router.astar import AStarRouter
+from inire.router.cost import CostEvaluator
+from inire.router.danger_map import DangerMap
+from inire.router.pathfinder import PathFinder
+from inire.utils.visualization import plot_routing_results
+
+
+def main() -> None:
+    print("Running Example 02: Congestion Resolution (Crossing)...")
+
+    # 1. Setup Environment (Open space)
+    bounds = (0, 0, 100, 100)
+    engine = CollisionEngine(clearance=2.0)
+    danger_map = DangerMap(bounds=bounds)
+    danger_map.precompute([])
+
+    evaluator = CostEvaluator(engine, danger_map)
+    router = AStarRouter(evaluator)
+    pf = PathFinder(router, evaluator)
+
+    # 2. Define Netlist
+    # Two nets that MUST cross.
+    # Since crossings are illegal in single-layer routing, one net must detour around the other.
+    netlist = {
+        "horizontal": (Port(10, 50, 0), Port(90, 50, 0)),
+        "vertical": (Port(50, 10, 90), Port(50, 90, 90)),
+    }
+    net_widths = {"horizontal": 2.0, "vertical": 2.0}
+
+    # 3. Route with Negotiated Congestion
+    # We increase the base penalty to encourage faster divergence
+    pf.base_congestion_penalty = 500.0
+    results = pf.route_all(netlist, net_widths)
+
+    # 4. Check Results
+    all_valid = all(r.is_valid for r in results.values())
+    if all_valid:
+        print("Success! Congestion resolved (one net detoured).")
+    else:
+        print("Some nets failed or have collisions.")
+        for nid, res in results.items():
+            print(f"  {nid}: valid={res.is_valid}, collisions={res.collisions}")
+
+    # 5. Visualize
+    fig, ax = plot_routing_results(results, [], bounds)
+    fig.savefig("examples/congestion.png")
+    print("Saved plot to examples/congestion.png")
+
+
+if __name__ == "__main__":
+    main()