Fills shape into a copy of raster. Edge pixels get the fraction of the pixel the shape covers
(4 x 4 samples). Adding combines with max; subtracting removes the shape's coverage (max(0, m - v)),
so adding and then subtracting the same shape is a no-op, like the wand and the eraser.
Polygons use the even-odd rule; fewer than three points, or a flat box, fill nothing.
Fills
shapeinto a copy ofraster. Edge pixels get the fraction of the pixel the shape covers (4 x 4 samples). Adding combines with max; subtracting removes the shape's coverage (max(0, m - v)), so adding and then subtracting the same shape is a no-op, like the wand and the eraser. Polygons use the even-odd rule; fewer than three points, or a flat box, fill nothing.