Sinusoid shape and grid cell size based on the resolution, which is a
rez of >=10 px, based on the number of rows from pole to pole. We split the
difference and put the remainder at the poles. Each cell is a quad with four
corners, unless, at the poles the top or bottom edge collapses to zero. But
the corners from adjacent rows show up in the top or bottom edges so the quads
are up to six sided...
I have made an array of quads and redrew the 100th cell in brown.