glm::vec3 Landscape::calculateNormal(const glm::vec2& position)
    {
        float height_l = getHeightAtXZ(glm::dvec2(position.x - 1, position.y));
        float height_r = getHeightAtXZ(glm::dvec2(position.x + 1, position.y));
        float height_d = getHeightAtXZ(glm::dvec2(position.x, position.y + 1));
        float height_u = getHeightAtXZ(glm::dvec2(position.x, position.y - 1));

        return glm::normalize(glm::dvec3(height_l - height_r, 0.1f, height_d - height_u));
    }