protected RegionSizeProperties computeRegionSizeProperties()

in commons-geometry-euclidean/src/main/java/org/apache/commons/geometry/euclidean/twod/RegionBSPTree2D.java [202:258]

34 lines of code
8 McCabe index (conditional complexity)


    protected RegionSizeProperties<Vector2D> computeRegionSizeProperties() {
        // handle simple cases
        if (isFull()) {
            return new RegionSizeProperties<>(Double.POSITIVE_INFINITY, null);
        } else if (isEmpty()) {
            return new RegionSizeProperties<>(0, null);
        }

        // compute the size based on the boundary line subsets
        double quadrilateralAreaSum = 0.0;

        double scaledSumX = 0.0;
        double scaledSumY = 0.0;

        Vector2D startPoint;
        Vector2D endPoint;
        double signedArea;

        for (final LineConvexSubset boundary : boundaries()) {

            if (boundary.isInfinite()) {
                // at least on boundary is infinite, meaning that
                // the size is also infinite
                quadrilateralAreaSum = Double.POSITIVE_INFINITY;

                break;
            }

            startPoint = boundary.getStartPoint();
            endPoint = boundary.getEndPoint();

            // compute the area
            signedArea = startPoint.signedArea(endPoint);

            quadrilateralAreaSum += signedArea;

            // compute scaled coordinate values for the centroid
            scaledSumX += signedArea * (startPoint.getX() + endPoint.getX());
            scaledSumY += signedArea * (startPoint.getY() + endPoint.getY());
        }

        double size = Double.POSITIVE_INFINITY;
        Vector2D centroid = null;

        // The area is finite only if the computed quadrilateral area is finite and non-negative.
        // Negative areas indicate that the region is inside-out, with a finite outside surrounded
        // by an infinite inside.
        if (quadrilateralAreaSum >= 0 && Double.isFinite(quadrilateralAreaSum)) {
            size = 0.5 * quadrilateralAreaSum;

            if (quadrilateralAreaSum > 0) {
                centroid = Vector2D.of(scaledSumX, scaledSumY).multiply(1.0 / (3.0 * quadrilateralAreaSum));
            }
        }

        return new RegionSizeProperties<>(size, centroid);
    }