Function isPowerOf2

tutorials/common/scenegraph/texture.cpp:8–13

namespace embree
{
  bool isPowerOf2 (unsigned int x)
  {
    while (((x % 2) == 0) && x > 1)
      x /= 2;
    return (x == 1);
  }

  static std::map<std::string,std::shared_ptr<Texture>> texture_cache;