Function distFn

src/traces/scattergeo/hover.js:20–36

(d)

    var project = geo.project;

    function distFn(d) {
        var lonlat = d.lonlat;

        if(lonlat[0] === BADNUM) return Infinity;
        if(isLonLatOverEdges(lonlat)) return Infinity;

        var pt = project(lonlat);
        var px = project([xval, yval]);
        var dx = Math.abs(pt[0] - px[0]);
        var dy = Math.abs(pt[1] - px[1]);
        var rad = Math.max(3, d.mrc || 0);

        // N.B. d.mrc is the calculated marker radius
        // which is only set for trace with 'markers' mode.

        return Math.max(Math.sqrt(dx * dx + dy * dy) - rad, 1 - 3 / rad);
    }

    Fx.getClosest(cd, distFn, pointData);