Method windingQuadratic

src/common/overlay/levelRenderer/Area.js:745–784

* @function LevelRenderer.Tool.Areal.prototype.windingQuadratic

(x0, y0, x1, y1, x2, y2, x, y)

     * @function LevelRenderer.Tool.Areal.prototype.windingQuadratic
     */
    windingQuadratic(x0, y0, x1, y1, x2, y2, x, y) {
        var curve = this.curve;
        var roots = this.roots;

        // Quick reject
        if (
            (y > y0 && y > y1 && y > y2)
            || (y < y0 && y < y1 && y < y2)
        ) {
            return 0;
        }
        var nRoots = curve.quadraticRootAt(y0, y1, y2, y, roots);
        if (nRoots === 0) {
            return 0;
        } else {
            var t = curve.quadraticExtremum(y0, y1, y2);
            if (t >= 0 && t <= 1) {
                var w = 0;
                var y_ = curve.quadraticAt(y0, y1, y2, t);
                for (let i = 0; i < nRoots; i++) {
                    let x_ = curve.quadraticAt(x0, x1, x2, roots[i]);
                    if (x_ > x) {
                        continue;
                    }
                    if (roots[i] < t) {
                        w += y_ < y0 ? 1 : -1;
                    } else {
                        w += y2 < y_ ? 1 : -1;
                    }
                }
                return w;
            } else {
                let x_ = curve.quadraticAt(x0, x1, x2, roots[0]);
                if (x_ > x) {
                    return 0;
                }
                return y2 < y0 ? 1 : -1;
            }
        }
    }

    /**
     * @function LevelRenderer.Tool.Areal.prototype.windingArc