🤖 AI Summary
This work addresses the unmodeled semantic constraints—namely, group continuity and partial ordering—in boundary labeling, aiming to automatically generate non-overlapping, semantically compliant label layouts under geometric and connectivity constraints. We provide the first formal proof that this problem is NP-hard under multiple hard constraints, including fixed endpoints, orthogonal edges, and minimum inter-label spacing. To tackle it, we propose a novel hybrid algorithmic framework with theoretical guarantees (a constant-factor approximation ratio) and practical efficiency, integrating integer linear programming, computational geometry optimization, greedy heuristics, and dynamic programming-based pruning. Evaluated on standard benchmarks, our method reduces crossing edges by 37% compared to state-of-the-art approaches, achieves a label placement success rate of 98.2%, and maintains an average runtime below 10 milliseconds.