private static boolean insideQuadrilateral()

in commons-geometry-hull/src/main/java/org/apache/commons/geometry/hull/euclidean/twod/AklToussaintHeuristic.java [120:150]

• 21 lines of code
• 7 McCabe index (conditional complexity)

    private static boolean insideQuadrilateral(final Vector2D point,
                                               final List<? extends Vector2D> quadrilateralPoints) {

        Vector2D v1 = quadrilateralPoints.get(0);
        Vector2D v2 = quadrilateralPoints.get(1);

        if (point.equals(v1) || point.equals(v2)) {
            return true;
        }

        // get the location of the point relative to the first two vertices
        final double last = signedAreaPoints(v1, v2, point);
        final int size = quadrilateralPoints.size();
        // loop through the rest of the vertices
        for (int i = 1; i < size; i++) {
            v1 = v2;
            v2 = quadrilateralPoints.get((i + 1) == size ? 0 : i + 1);

            if (point.equals(v2)) {
                return true;
            }

            // do side of line test: multiply the last location with this location
            // if they are the same sign then the operation will yield a positive result
            // -x * -y = +xy, x * y = +xy, -x * y = -xy, x * -y = -xy
            if (last * signedAreaPoints(v1, v2, point) < 0) {
                return false;
            }
        }
        return true;
    }