ABSTRACT
In non-Manhattan geometry layout extraction, polygon to trapezoid decomposition is an indispensable step. Its efficiency and the organization of generated trapezoids significantly affect the performance of layout extractors. We present a new polygon to trapezoid decomposition algorithm used in our layout extractor iLEX. The concept of edge pair and scanline interval are introduced to provide improved efficiency over conventional scanline algorithms. Definitions for trapezoid corner stitches are provided as well as integrated algorithms on corner stitching trapezoids generated. Complexity analysis shows that our scanline algorithm has an expected computation time of Ο(n log n), and an expected space of Ο(√n), where n is the number of non-vertical edges in the given layout.
- 1.J. L. Bentley and T. A. Ottmann. Algorithms for reporting and counting geometric intersections. IEEE Transactions on Computing, 6-28(9):643-647, September 1979.Google ScholarDigital Library
- 2.K. W. Chiang, S. Nahar, and C. Y. Lo. Time-efficient vlsi artwork analysis algorithms in goalie2. IEEE Transactions on Computer-Aided Design, 8(6):640-648, June 1989.Google ScholarCross Ref
- 3.U. Lauther. An o(nlogn) algorithm for boolean mask operations. In 18th Design Automation Conference, pages 555-562, 1981. Google ScholarDigital Library
- 4.D. Marple, M. Smulders, and H. Hegen. Tailor: A layout system based on trapezoidal corner stitching. IEEE Transaction on Computer-Aided Design, 9(1):66- 90, January 1990.Google ScholarDigital Library
- 5.J. K. Ousterhout. Corner stitching: A data-structuring technique for vlsi layout tools. IEEE Transactions on Computer-Aided Design, CAD-3(1):87-100, January 1984.Google Scholar
- 6.W. S. Scott and J. K. Ousterhout. Magic's circuit extractor. In 22nd Design Automation Conference, pages 286-292, 1985. Google ScholarDigital Library
- 7.N. P. van der Meijs and A. J. van Genderen. An efficient algorithm for analysis of non-orthogonal layout. In IEEE International Symposium on Circuits and Systems, pages 47-52, 1989.Google ScholarCross Ref
Index Terms
- Efficient algorithms for polygon to trapezoid decomposition and trapezoid corner stitching
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