FillRule
GskFillRule
is used to select how paths are filled.
Whether or not a point is included in the fill is determined by taking a ray from that point to infinity and looking at intersections with the path. The ray can be in any direction, as long as it doesn't pass through the end point of a segment or have a tricky intersection such as intersecting tangent to the path.
(Note that filling is not actually implemented in this way. This is just a description of the rule that is applied.)
New entries may be added in future versions.
Since
4.14
Entries
If the path crosses the ray from left-to-right, counts +1. If the path crosses the ray from right to left, counts -1. (Left and right are determined from the perspective of looking along the ray from the starting point.) If the total count is non-zero, the point will be filled.