// Aqsis
// Copyright (C) 2001, Paul C. Gregory and the other authors and contributors
// All rights reserved.
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// (This is the New BSD license)

/** \file
 *
 * \brief Functions to get magic numbers and match them against the possible
 * file types.
 *
 * \author Chris Foster
 */

#ifndef MAGICNUMBER_H_INCLUDED
#define MAGICNUMBER_H_INCLUDED

#include <aqsis/aqsis.h>

#include <iosfwd>

#include <aqsis/util/file.h>
#include <aqsis/tex/io/imagefiletype.h>

namespace Aqsis {

//------------------------------------------------------------------------------
/** \brief Determine the type of a file using a "magic number"
 *
 * Many file formats have a distinctive pattern in the first few bytes which
 * can be matched to guess the file type.  This is rather more reliable than a
 * file suffix naming convention, but can still become confused.
 *
 * \throw XqInvalidFile if the file cannot be opened.
 *
 * \param fileName - file name to read from.
 * \return a guess at the file type based on the first few bytes.
 */
AQSIS_TEX_SHARE EqImageFileType guessFileType(const boostfs::path& fileName);

/** \brief Determine the type of an open file stream by using a "magic number"
 *
 * \see guessFileType(const boostfs::path& fileName)
 *
 * \param inStream - The first few bytes of this stream are read
 */
AQSIS_TEX_SHARE EqImageFileType guessFileType(std::istream& inStream);


//------------------------------------------------------------------------------
} // namespace Aqsis

#endif // MAGICNUMBER_H_INCLUDED
