get_light_normal_matrix_y (gint n)
{
    static const FactorAndMatrix matrix_list[] = {
        {
         {0, 0, 0,
          0, -2, -1,
          0, 2, 1},
         2.0 / 3.0},
        {
         {0, 0, 0,
          -1, -2, -1,
          1, 2, 1},
         1.0 / 3.0},
        {
         {0, 0, 0,
          -1, -2, 0,
          1, 2, 0},
         2.0 / 3.0},
        {

         {0, -2, -1,
          0, 0, 0,
          0, 2, 1},
         1.0 / 2.0},
        {
         {-1, -2, -1,
          0, 0, 0,
          1, 2, 1},
         1.0 / 4.0},
        {
         {-1, -2, 0,
          0, 0, 0,
          1, 2, 0},
         1.0 / 2.0},
        {

         {0, -2, -1,
          0, 2, 1,
          0, 0, 0},
         2.0 / 3.0},
        {
         {0, -2, -1,
          1, 2, 1,
          0, 0, 0},
         1.0 / 3.0},
        {
         {-1, -2, 0,
          1, 2, 0,
          0, 0, 0},
         2.0 / 3.0}
    };

    return matrix_list[n];
}
get_light_normal_matrix_y (gint n)
{
    static const FactorAndMatrix matrix_list[] = {
        {
         {0, 0, 0,
          0, -2, -1,
          0, 2, 1},
         2.0 / 3.0},
        {
         {0, 0, 0,
          -1, -2, -1,
          1, 2, 1},
         1.0 / 3.0},
        {
         {0, 0, 0,
          -1, -2, 0,
          1, 2, 0},
         2.0 / 3.0},
        {

         {0, -2, -1,
          0, 0, 0,
          0, 2, 1},
         1.0 / 2.0},
        {
         {-1, -2, -1,
          0, 0, 0,
          1, 2, 1},
         1.0 / 4.0},
        {
         {-1, -2, 0,
          0, 0, 0,
          1, 2, 0},
         1.0 / 2.0},
        {

         {0, -2, -1,
          0, 2, 1,
          0, 0, 0},
         2.0 / 3.0},
        {
         {0, -2, -1,
          1, 2, 1,
          0, 0, 0},
         1.0 / 3.0},
        {
         {-1, -2, 0,
          1, 2, 0,
          0, 0, 0},
         2.0 / 3.0}
    };

    return matrix_list[n];
}