Function is_ear

utils/algorithms.cpp:20–54

}

static bool is_ear(const size_t i, const std::vector<Vec3> &points, const std::vector<size_t> &indices, const Vec3 &normal)
{
    const size_t prev = indices[(i + indices.size() - 1) % indices.size()];
    const size_t curr = indices[i];
    const size_t next = indices[(i + 1) % indices.size()];

    const Vec3 &v1 = points[prev];
    const Vec3 &v2 = points[curr];
    const Vec3 &v3 = points[next];

    // check if angle is convex
    const Vec3 d1 = v2 - v1;
    const Vec3 d2 = v3 - v2;

    if (Vec3::dot(Vec3::cross(d1, d2), normal) <= 0.0f)
    {
        return false; // not convex
    }

    // check for no other points inside triangle
    for (size_t j = 0; j < indices.size(); j++)
    {
        if (j == (i - 1 + indices.size()) % indices.size() || j == i || j == (i + 1) % indices.size())
        {
            continue;
        }

        if (is_in_triangle(points[indices[j]], v1, v2, v3, normal))
        {
            return false; // point inside triangle
        }
    }

    return true; // ear found
}

// main functions