add various direction examples

README.md

@@ -62,6 +62,8 @@ Check the `examples/` directory for ready-to-run scripts demonstrating core feat
 *   **`examples/01_simple_route.py`**: Basic single-net routing with visualization.
 *   **`examples/02_congestion_resolution.py`**: Multi-net routing resolving bottlenecks using Negotiated Congestion.
 *   **`examples/03_locked_paths.py`**: Incremental workflow using `lock_net()` to route around previously fixed paths.
+*   **`examples/04_sbends_and_radii.py`**: Complex paths using parametric S-bends and multiple bend radii.
+*   **`examples/05_orientation_stress.py`**: Stress test for various port orientation combinations (U-turns, opposite directions).
 
 Run an example:
 ```bash

examples/05_orientation_stress.py

@@ -0,0 +1,56 @@
+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 05: Orientation Stress Test...")
+
+    # 1. Setup Environment
+    # Give some breathing room (-20 to 120) for U-turns and flips (R=10)
+    bounds = (-20, -20, 120, 120)
+    engine = CollisionEngine(clearance=2.0)
+    danger_map = DangerMap(bounds=bounds)
+    danger_map.precompute([])
+    
+    evaluator = CostEvaluator(engine, danger_map, greedy_h_weight=1.1)
+    router = AStarRouter(evaluator, node_limit=100000)
+    pf = PathFinder(router, evaluator)
+    
+    # 2. Define Netlist with various orientation challenges
+    netlist = {
+        # Opposite directions: requires two 90-degree bends to flip orientation
+        "opposite": (Port(10, 80, 0), Port(90, 80, 180)),
+        
+        # 90-degree turn: standard L-shape
+        "turn_90": (Port(10, 60, 0), Port(40, 90, 90)),
+        
+        # Output behind input: requires a full U-turn
+        "behind": (Port(80, 40, 0), Port(20, 40, 0)),
+        
+        # Sharp return: output is behind and oriented towards the input
+        "return_loop": (Port(80, 20, 0), Port(40, 10, 180)),
+    }
+    net_widths = {nid: 2.0 for nid in netlist}
+
+    # 3. Route
+    results = pf.route_all(netlist, net_widths)
+
+    # 4. Check Results
+    for nid, res in results.items():
+        status = "Success" if res.is_valid else "Failed"
+        total_len = sum(comp.length for comp in res.path) if res.path else 0
+        print(f"  {nid:12}: {status}, total_length={total_len:.1f}")
+
+    # 5. Visualize
+    fig, ax = plot_routing_results(results, [], bounds, netlist=netlist)
+    fig.savefig("examples/orientation_stress.png")
+    print("Saved plot to examples/orientation_stress.png")
+
+
+if __name__ == "__main__":
+    main()

inire/router/danger_map.py

@@ -70,6 +70,10 @@ class DangerMap:
         safe_distances = np.maximum(distances, 0.1)
         self.grid = np.where(distances < self.safety_threshold, self.k / (safe_distances**2), 0.0).astype(np.float32)
 
+    def is_within_bounds(self, x: float, y: float) -> bool:
+        """Check if a coordinate is within the design bounds."""
+        return self.minx <= x <= self.maxx and self.miny <= y <= self.maxy
+
     def get_cost(self, x: float, y: float) -> float:
         """Get the proximity cost at a specific coordinate."""
         ix = int((x - self.minx) / self.resolution)
@@ -77,4 +81,4 @@ class DangerMap:
 
         if 0 <= ix < self.width_cells and 0 <= iy < self.height_cells:
             return float(self.grid[ix, iy])
-        return 1e6  # Outside bounds is expensive
+        return 1e15  # Outside bounds is impossible