Acta Geodaetica et Cartographica Sinica ›› 2025, Vol. 54 ›› Issue (2): 345-355.doi: 10.11947/j.AGCS.2025.20230369

• Cartography and Geoinformation • Previous Articles    

CPU-GPU hybrid parallel overlay analysis method for GIS vector polygons based on improved Vatti algorithm using even-odd sorting

Shanshan WANG1(), Junfu FAN2(), Zhikun ZHANG2,3, Jianyun HAN1   

  1. 1.China Aero Geophysical Survey and Remote Sensing Center for Natural Resources, Beijing 100083, China
    2.School of Civil Engineering and Geomatics, Shandong University of Technology, Zibo 255000, China
    3.Fourth Geological Brigade of Shandong Province Geological and Mineral Exploration and Development Bureau (Fourth Geological and Mineral Exploration Institute of Shandong Province), Weifang 261021, China
  • Received:2023-08-28 Published:2025-03-11
  • Contact: Junfu FAN E-mail:wangss1028@126.com;fanjf@sdut.edu.cn
  • About author:WANG Shanshan (1985—), female, PhD, senior engineer, majors in remote sensing geology and spatial analysis. E-mail: wangss1028@126.com
  • Supported by:
    The National Natural Science Foundation of China(42171413);The Cooperation Pilot Project for Ministry of Natural Resources and Provinces(2023ZRBSHZ048);A Grant from the State Key Laboratory of Resources and Environmental Information System

Abstract:

Vector polygon clipping is one of the important and commonly used basic functions in the field of GIS. The explosive growth of geographic spatial data scale has put higher demands on the computational efficiency of traditional clipping algorithms. Currently, vector polygon clipping algorithms are increasingly showing characteristics of computation intensive and data intensive. In response to this phenomenon, this article optimizes the data structure of the vector polygon clipping Vatti algorithm and applies GPU multi-core parallel technology to the construction of ordered scanning beams. When the block size is 128 and the number of clipped polygon vertices reaches 3 276 800, the acceleration ratio of the polygon clipping Vatti algorithm reaches 2.55 times under the intersection operator operation. On this basis, this article further utilizes computing resources based on CPU multi-threaded parallel technology and proposes an optimization method called vertex segmentation hybrid parallel (VSHP) that divides the dataset by the number of vertices and achieves hybrid parallel acceleration. For a large-scale dataset, the main thread reads the data and divides the raw data based on the number of vertices and threads, and then hands it over to each thread for calculation. During this process, the GPU is sequentially called to filter the minimum bounding rectangle and accelerate the construction of ordered scanning beam segments. Finally, when all data tasks are calculated, the main thread completes the merging and output of the results. Experiments have shown that ideal acceleration can be achieved when calling 4 threads, and a maximum acceleration ratio of 19.15 times can be achieved when enabling 16 threads under dynamic scheduling strategy. This article attempts to achieve desktop supercomputing with low energy consumption through mixed parallel computing of CPU-GPU, aiming to provide some reference value for traditional vector polygon clipping algorithms to achieve high-performance acceleration optimization on low-cost consumer hardware platforms and reduce the cost of large-scale applications of geographic information data.

Key words: overlay analysis, vector polygon clipping, hybrid parallel, odd-even sort, OpenMP, algorithm optimization, high performance computing, GIS

CLC Number: