Abstract: A fully automated filling algorithm for any complex area is designed based on the principle
of grid and equal-spaced parallel lines. Firstly, we turn the whole area filling into grid. Secondly, we
draw a series of equidistant parallel lines and calculate row column ordinal value of each parallel line
going through the polygon grid. Thirdly, each grid cell is filled with the autonomous cycle method,
according to the calculation of the row and column number value of the grid. Finally, the entire area is
automatically filled. The verification of multiple sets of data through an independently designed
application program indicates that the algorithm can realize filling quickly and automatically, and a
detailed analysis is made on the technical difficulties that occur in the experiment.

Key words: grid, parallel lines, area filling, algorithm complexity, automatic filling