Radial Menu

a file on a stage. press it and pull, and a wheel of five formats opens around where it was. let go over one and the file converts.

key insight: which wedge is under the hand is arithmetic and not a hit test. the file is what the pointer is over, so the wedges could never see it: wedgeAt maps the hand's angle onto five slices and returns null inside the dead zone, and the same maths serves a mouse, a finger and the arrow keys.

the wedge under the hand previews its format on the file itself, drawn once and reused through <use> under an SVG filter. jpg blocks up, gif dithers to six levels, avif softens a touch and pdf sets it small on a white page, so the wheel demos what the names mean.