Optional
radius: numberCount of how many rings around the center to include. defaults to 1.
Optional
includeSelf: booleanShould this include the center pixel? Defaults to false.
A hitbox where all pixels fit within a circle of the given
radius, where the precise euclidean distance is <=
the radias.
Makes a euclidean neighborhood.
Area is not quite that of a circle. TODO find math for exact value.