Проблема текстурирования в OpenGL 3.2

Эта тема пригодилась. Я полностью переписал предыдущее решение на Java и стал более удобным для пользователя. Кроме того, для большей гибкости я использую коллекции и дженерики:

/**
 * Combines several collections of elements and create permutations of all of them, taking one element from each
 * collection, and keeping the same order in resultant lists as the one in original list of collections.
 * 
 * <ul>Example
 * <li>Input  = { {a,b,c} , {1,2,3,4} }</li>
 * <li>Output = { {a,1} , {a,2} , {a,3} , {a,4} , {b,1} , {b,2} , {b,3} , {b,4} , {c,1} , {c,2} , {c,3} , {c,4} }</li>
 * </ul>
 * 
 * @param collections Original list of collections which elements have to be combined.
 * @return Resultant collection of lists with all permutations of original list.
 */
public static <T> Collection<List<T>> permutations(List<Collection<T>> collections) {
  if (collections == null || collections.isEmpty()) {
    return Collections.emptyList();
  } else {
    Collection<List<T>> res = Lists.newLinkedList();
    permutationsImpl(collections, res, 0, new LinkedList<T>());
    return res;
  }
}

/** Recursive implementation for {@link #permutations(List, Collection)} */
private static <T> void permutationsImpl(List<Collection<T>> ori, Collection<List<T>> res, int d, List<T> current) {
  // if depth equals number of original collections, final reached, add and return
  if (d == ori.size()) {
    res.add(current);
    return;
  }

  // iterate from current collection and copy 'current' element N times, one for each element
  Collection<T> currentCollection = ori.get(d);
  for (T element : currentCollection) {
    List<T> copy = Lists.newLinkedList(current);
    copy.add(element);
    permutationsImpl(ori, res, d + 1, copy);
  }
}

Я использую библиотеку guava для создания коллекций.