Prism graphics provides optimal rendering of the round rect backgrounds and borders of CSS-styled regions when all 4 sides or corner radii are the same.

But, CSS allows separate radii on each corner of a background and further, separate styles on each side of a background or border. In those cases we instead create a Path (separate radii) or 4 Paths (separate styles), and perform generic path rendering to render their backgrounds and borders.

It would be nice to implement the following methods on Prism Graphics:

fillRoundRect(x, y, w, h, ulw, ulh, urw, urh, lrw, lrh, llw, llh);
drawRoundRect(x, y, w, h, ulw, ulh, urw, urh, lrw, lrh, llw, llh, edgelist);

(where edgelist has bits set for TOP, RIGHT, BOTTOM, LEFT)