Function isPtInsidePolygon

src/plots/polar/helpers.js:22–39

* is pt (r,a) inside polygon made up vertices at angles 'vangles' * inside a given polar sector * * @param {number} r : pt's radial coordinate * @param {number} a : pt's angular coordinate in *radians* * @param {2-item array} rBnds : sector's radial bounds * @param {2-item array} aBnds : secto

(r, a, rBnds, aBnds, vangles)

 * @return {boolean}
 */
function isPtInsidePolygon(r, a, rBnds, aBnds, vangles) {
    if(!isAngleInsideSector(a, aBnds)) return false;

    var r0, r1;

    if(rBnds[0] < rBnds[1]) {
        r0 = rBnds[0];
        r1 = rBnds[1];
    } else {
        r0 = rBnds[1];
        r1 = rBnds[0];
    }

    var polygonIn = polygonTester(makePolygon(r0, aBnds[0], aBnds[1], vangles));
    var polygonOut = polygonTester(makePolygon(r1, aBnds[0], aBnds[1], vangles));
    var xy = [r * Math.cos(a), r * Math.sin(a)];
    return polygonOut.contains(xy) && !polygonIn.contains(xy);
}

// find intersection of 'v0' <-> 'v1' edge with a ray at angle 'a'
// (i.e. a line that starts from the origin at angle 'a')