Defines the x and y coordinates of a point. Note that both are defined as gint16 values, so the coordinates are limited to between -32,768 and 32,767. The fill rule is only relevant for polygons which overlap themselves. This is all pixels in either of source1 or source2 . This is a region containing the pixels that are in one of the source regions, but which are not in both.
Positive values shrink the region.
Negative values expand it.