// Copyright (c) 2020 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

#ifndef _Image_DDSParser_HeaderFile
#define _Image_DDSParser_HeaderFile

#include <Image_CompressedPixMap.hxx>
#include <NCollection_Buffer.hxx>

class Image_SupportedFormats;

//! Auxiliary tool for parsing DDS file structure (without decoding).
class Image_DDSParser
{
public:

  //! Load the face from DDS file.
  //! @param theSupported [in] list of supported image formats
  //! @param theFile      [in] file path
  //! @param theFaceIndex [in] face index, within [0, Image_CompressedPixMap::NbFaces()) range;
  //!                          use -1 to skip reading the face data
  //! @param theFileOffset [in] offset to the DDS data
  //! @return loaded face or NULL if file cannot be read or not valid DDS file
  Standard_EXPORT static Handle(Image_CompressedPixMap) Load (const Handle(Image_SupportedFormats)& theSupported,
                                                              const TCollection_AsciiString& theFile,
                                                              const Standard_Integer theFaceIndex,
                                                              const int64_t theFileOffset = 0);

  //! Load the face from DDS file.
  //! @param theSupported [in] list of supported image formats
  //! @param theBuffer    [in] pre-loaded file data, should be at least of 128 bytes long defining DDS header.
  //! @param theFaceIndex [in] face index, within [0, Image_CompressedPixMap::NbFaces()) range;
  //!                          use -1 to skip reading the face data
  //! @return loaded face or NULL if file cannot be read or not valid DDS file
  Standard_EXPORT static Handle(Image_CompressedPixMap) Load (const Handle(Image_SupportedFormats)& theSupported,
                                                              const Handle(NCollection_Buffer)& theBuffer,
                                                              const Standard_Integer theFaceIndex);

  
private:

  struct DDSPixelFormat;
  struct DDSFileHeader;

private:

  //! Parse DDS header.
  static Handle(Image_CompressedPixMap) parseHeader (const DDSFileHeader& theHeader);

};

#endif // _Image_DDSParser_HeaderFile
