public static List convexPolygonToTriangleFan()

in commons-geometry-euclidean/src/main/java/org/apache/commons/geometry/euclidean/internal/EuclideanUtils.java [52:82]

• 24 lines of code
• 4 McCabe index (conditional complexity)

    public static <T> List<T> convexPolygonToTriangleFan(final List<Vector3D> vertices,
           final Function<List<Vector3D>, T> fn) {
        final int size = vertices.size();
        if (size < TRIANGLE_VERTEX_COUNT) {
            throw new IllegalArgumentException("Cannot create triangle fan: " + TRIANGLE_VERTEX_COUNT +
                    " or more vertices are required but found only " + vertices.size());
        } else if (size == TRIANGLE_VERTEX_COUNT) {
            return Collections.singletonList(fn.apply(vertices));
        }

        final List<T> triangles = new ArrayList<>(size - 2);

        final int fanIdx = findBestTriangleFanIndex(vertices);
        int vertexIdx = (fanIdx + 1) % size;

        final Vector3D fanBase = vertices.get(fanIdx);
        Vector3D vertexA = vertices.get(vertexIdx);
        Vector3D vertexB;

        vertexIdx = (vertexIdx + 1) % size;
        while (vertexIdx != fanIdx) {
            vertexB = vertices.get(vertexIdx);

            triangles.add(fn.apply(Arrays.asList(fanBase, vertexA, vertexB)));

            vertexA = vertexB;
            vertexIdx = (vertexIdx + 1) % size;
        }

        return triangles;
    }