private void updateHull()

in commons-geometry-hull/src/main/java/org/apache/commons/geometry/hull/euclidean/twod/MonotoneChain.java [117:161]

37 lines of code
11 McCabe index (conditional complexity)


    private void updateHull(final Vector2D point, final List<Vector2D> hull) {
        final Precision.DoubleEquivalence precision = getPrecision();

        if (hull.size() == 1) {
            // ensure that we do not add an identical point
            final Vector2D p1 = hull.get(0);
            if (p1.eq(point, precision)) {
                return;
            }
        }

        while (hull.size() >= 2) {
            final int size = hull.size();
            final Vector2D p1 = hull.get(size - 2);
            final Vector2D p2 = hull.get(size - 1);

            final double offset = Lines.fromPoints(p1, p2, precision).offset(point);
            if (precision.eqZero(offset)) {
                // the point is collinear to the line (p1, p2)

                final double distanceToCurrent = p1.distance(point);
                if (precision.eqZero(distanceToCurrent) || precision.eqZero(p2.distance(point))) {
                    // the point is assumed to be identical to either p1 or p2
                    return;
                }

                final double distanceToLast = p1.distance(p2);
                if (isIncludeCollinearPoints()) {
                    final int index = distanceToCurrent < distanceToLast ? size - 1 : size;
                    hull.add(index, point);
                } else {
                    if (distanceToCurrent > distanceToLast) {
                        hull.remove(size - 1);
                        hull.add(point);
                    }
                }
                return;
            } else if (offset > 0) {
                hull.remove(size - 1);
            } else {
                break;
            }
        }
        hull.add(point);
    }