imfheader.h

对gif

    //-------------------------------------------------------------
    // Sanity check -- examines the header, and throws an exception
    // if it finds something wrong (empty display window, negative
    // pixel aspect ratio, unknown compression sceme etc.)
    //
    // set isTiled to true if you are checking a tiled/multi-res
    // header
    //-------------------------------------------------------------

    void			sanityCheck (bool isTiled = false) const;


    //----------------------------------------------------------------
    // Maximum image size and maximim tile size:
    //
    // sanityCheck() will throw an exception if the width or height of
    // the data window exceeds the maximum image width or height, or
    // if the size of a tile exceeds the maximum tile width or height.
    // 
    // At program startup the maximum image and tile width and height
    // are set to zero, meaning that width and height are unlimited.
    //
    // Limiting image and tile width and height limits how much memory
    // will be allocated when a file is opened.  This can help protect
    // applications from running out of memory while trying to read
    // a damaged image file.
    //----------------------------------------------------------------

    static void			setMaxImageSize (int maxWidth, int maxHeight);
    static void			setMaxTileSize (int maxWidth, int maxHeight);


    //------------------------------------------------------------------
    // Input and output:
    //
    // If the header contains a preview image attribute, then writeTo()
    // returns the position of that attribute in the output stream; this
    // information is used by OutputFile::updatePreviewImage().
    // If the header contains no preview image attribute, then writeTo()
    // returns 0.
    //------------------------------------------------------------------


    Int64			writeTo (OStream &os,
					 bool isTiled = false) const;

    void			readFrom (IStream &is, int &version);

  private:

    AttributeMap		_map;
};


//----------
// Iterators
//----------

class Header::Iterator
{
  public:

    Iterator ();
    Iterator (const Header::AttributeMap::iterator &i);

    Iterator &			operator ++ ();
    Iterator 			operator ++ (int);

    const char *		name () const;
    Attribute &			attribute () const;

  private:

    friend class Header::ConstIterator;

    Header::AttributeMap::iterator _i;
};


class Header::ConstIterator
{
  public:

    ConstIterator ();
    ConstIterator (const Header::AttributeMap::const_iterator &i);
    ConstIterator (const Header::Iterator &other);

    ConstIterator &		operator ++ ();
    ConstIterator 		operator ++ (int);

    const char *		name () const;
    const Attribute &		attribute () const;

  private:

    friend bool operator == (const ConstIterator &, const ConstIterator &);
    friend bool operator != (const ConstIterator &, const ConstIterator &);

    Header::AttributeMap::const_iterator _i;
};


//------------------------------------------------------------------------
// Library initialization:
//
// In a multithreaded program, staticInitialize() must be called once
// during startup, before the program accesses any other functions or
// classes in the IlmImf library.  Calling staticInitialize() in this
// way avoids races during initialization of the library's global
// variables.
//
// Single-threaded programs are not required to call staticInitialize();
// initialization of the library's global variables happens automatically.
//
//------------------------------------------------------------------------

void staticInitialize ();


//-----------------
// Inline Functions
//-----------------


inline
Header::Iterator::Iterator (): _i()
{
    // empty
}


inline
Header::Iterator::Iterator (const Header::AttributeMap::iterator &i): _i (i)
{
    // empty
}


inline Header::Iterator &		
Header::Iterator::operator ++ ()
{
    ++_i;
    return *this;
}


inline Header::Iterator 	
Header::Iterator::operator ++ (int)
{
    Iterator tmp = *this;
    ++_i;
    return tmp;
}


inline const char *
Header::Iterator::name () const
{
    return *_i->first;
}


inline Attribute &	
Header::Iterator::attribute () const
{
    return *_i->second;
}


inline
Header::ConstIterator::ConstIterator (): _i()
{
    // empty
}

inline
Header::ConstIterator::ConstIterator
    (const Header::AttributeMap::const_iterator &i): _i (i)
{
    // empty
}


inline
Header::ConstIterator::ConstIterator (const Header::Iterator &other):
    _i (other._i)
{
    // empty
}

inline Header::ConstIterator &
Header::ConstIterator::operator ++ ()
{
    ++_i;
    return *this;
}


inline Header::ConstIterator 		
Header::ConstIterator::operator ++ (int)
{
    ConstIterator tmp = *this;
    ++_i;
    return tmp;
}


inline const char *
Header::ConstIterator::name () const
{
    return *_i->first;
}


inline const Attribute &	
Header::ConstIterator::attribute () const
{
    return *_i->second;
}


inline bool
operator == (const Header::ConstIterator &x, const Header::ConstIterator &y)
{
    return x._i == y._i;
}


inline bool
operator != (const Header::ConstIterator &x, const Header::ConstIterator &y)
{
    return !(x == y);
}


//---------------------
// Template definitions
//---------------------

template <class T>
T &
Header::typedAttribute (const char name[])
{
    Attribute *attr = &(*this)[name];
    T *tattr = dynamic_cast <T*> (attr);

    if (tattr == 0)
	throw Iex::TypeExc ("Unexpected attribute type.");

    return *tattr;
}


template <class T>
const T &
Header::typedAttribute (const char name[]) const
{
    const Attribute *attr = &(*this)[name];
    const T *tattr = dynamic_cast <const T*> (attr);

    if (tattr == 0)
	throw Iex::TypeExc ("Unexpected attribute type.");

    return *tattr;
}


template <class T>
T *
Header::findTypedAttribute (const char name[])
{
    AttributeMap::iterator i = _map.find (name);
    return (i == _map.end())? 0: dynamic_cast <T*> (i->second);
}


template <class T>
const T *
Header::findTypedAttribute (const char name[]) const
{
    AttributeMap::const_iterator i = _map.find (name);
    return (i == _map.end())? 0: dynamic_cast <const T*> (i->second);
}


} // namespace Imf

#endif