inire: Auto-Routing for Photonic and RF Integrated Circuits

inire is a high-performance auto-router designed specifically for the physical constraints of photonic and RF integrated circuits. It utilizes a Hybrid State-Lattice A* search combined with "Negotiated Congestion" (PathFinder) to route multiple nets while maintaining strict geometric fidelity and clearance.

Key Features

• Hybrid State-Lattice Search: Routes using discrete 90° bends and parametric S-bends, ensuring manufacturing-stable paths.
• Negotiated Congestion: Iteratively resolves multi-net bottlenecks by inflating costs in high-traffic regions.
• Analytic Correctness: Every move is verified against an R-Tree spatial index of obstacles and other paths.
• 1nm Precision: All coordinates and ports are snapped to a 1nm manufacturing grid.
• Safety & Proximity: Incorporates a "Danger Map" (pre-computed distance transform) to maintain optimal spacing and reduce crosstalk.
• Locked Paths: Supports treating existing geometries as fixed obstacles for incremental routing sessions.

Installation

inire requires Python 3.11+. You can install the dependencies using uv (recommended) or pip:

# Using uv
uv sync

# Using pip
pip install numpy scipy shapely rtree matplotlib

Quick Start

from inire.geometry.primitives import Port
from inire.geometry.collision import CollisionEngine
from inire.router.danger_map import DangerMap
from inire.router.cost import CostEvaluator
from inire.router.astar import AStarRouter
from inire.router.pathfinder import PathFinder

# 1. Setup Environment
engine = CollisionEngine(clearance=2.0)
danger_map = DangerMap(bounds=(0, 0, 1000, 1000))
danger_map.precompute([]) # Add polygons here for obstacles

# 2. Configure Router
evaluator = CostEvaluator(engine, danger_map)
router = AStarRouter(evaluator)
pf = PathFinder(router, evaluator)

# 3. Define Netlist
netlist = {
    "net1": (Port(0, 0, 0), Port(100, 50, 0)),
}

# 4. Route
results = pf.route_all(netlist, {"net1": 2.0})

if results["net1"].is_valid:
    print("Successfully routed net1!")

Usage Examples

Check the examples/ directory for ready-to-run scripts demonstrating core features:

• 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.

Run an example:

python3 examples/01_simple_route.py

Architecture

inire operates on a State-Lattice defined by (x, y, \theta). From any state, the router expands via three primary "Move" types:

1. Straights: Variable-length segments.
2. 90° Bends: Fixed-radius PDK cells.
3. Parametric S-Bends: Procedural arcs for bridging small lateral offsets (O < 2R).

For multi-net problems, the PathFinder loop handles rip-up and reroute logic, ensuring that paths find the globally optimal configuration without crossings.

License

This project is licensed under the GNU Affero General Public License v3. See LICENSE.md for details.