Method windingLine

src/common/overlay/levelRenderer/Area.js:659–671

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

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

     * @function LevelRenderer.Tool.Areal.prototype.windingLine
     */
    windingLine(x0, y0, x1, y1, x, y) {
        if ((y > y0 && y > y1) || (y < y0 && y < y1)) {
            return 0;
        }
        if (y1 == y0) {
            return 0;
        }
        var dir = y1 < y0 ? 1 : -1;
        var t = (y - y0) / (y1 - y0);
        var x_ = t * (x1 - x0) + x0;

        return x_ > x ? dir : 0;
    }

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