allsegs level0segs level1segs List of all the polygon segments for all the levels For contour lines lenallsegs == lenlevels and for filled contour regions lenallsegs

The allsegs list contains all the polygon segments for all the levels. If we have contour lines, the length of allsegs will be the same as the length of the levels list. If we have filled contour regions, the length of allsegs will be one less than the length of the levels list.

Each level segment list, such as level0segs, contains a list of polygons. Each polygon is represented as a list of coordinate pairs, where each pair represents a vertex of the polygon.

Here is an example of how the level0segs list should look like:

level0segs = [
    [[x0, y0], [x1, y1], ...],  # polygon0
    [[x2, y2], [x3, y3], ...],  # polygon1
    ...
]

Each polygon list contains the coordinates of the vertices of the polygon. For example, polygon0 is represented by the list [[x0, y0], [x1, y1], ...], where [x0, y0], [x1, y1], etc. are the coordinate pairs of the polygon's vertices