edgeMarker

also paint a small rounded marker in one page margin, level with this highlight. It tells a reader a note lives on this page without them having to find the highlighted words. Every dimension is a fraction of the rendered page width, so it keeps its proportions in a thumbnail and at deep zoom alike, and its inner edge is clamped past the highlighted quads so it never paints over the words. On a page whose text reaches into that margin, leaving no room, nothing is drawn.