Function pathCornerForPolygons

src/plots/polar/polar.js:897–929

(r, va0, va1)

    // ... we could eventually add another mode for cursor
    // angles 'close to' enough to a particular vertex.
    function pathCornerForPolygons(r, va0, va1) {
        if(r === 0) return _this.pathSector(2 * chw);

        var xy0 = ra2xy(r, va0);
        var xy1 = ra2xy(r, va1);
        var x = clampTiny((xy0[0] + xy1[0]) / 2);
        var y = clampTiny((xy0[1] + xy1[1]) / 2);
        var innerPts, outerPts;

        if(x && y) {
            var m = y / x;
            var mperp = -1 / m;
            var midPts = findXYatLength(chw, m, x, y);
            innerPts = findXYatLength(chl, mperp, midPts[0][0], midPts[0][1]);
            outerPts = findXYatLength(chl, mperp, midPts[1][0], midPts[1][1]);
        } else {
            var dx, dy;
            if(y) {
                // horizontal handles
                dx = chl;
                dy = chw;
            } else {
                // vertical handles
                dx = chw;
                dy = chl;
            }
            innerPts = [[x - dx, y - dy], [x + dx, y - dy]];
            outerPts = [[x - dx, y + dy], [x + dx, y + dy]];
        }

        return 'M' + innerPts.join('L') +
            'L' + outerPts.reverse().join('L') + 'Z';
    }

    function zoomPrep() {
        r0 = null;