openmesh/src/OpenMesh/Core/IO/BinaryHelper.cc

/*===========================================================================*\
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 *                               OpenMesh                                    *
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/*===========================================================================*\
 *                                                                           *
 *   $Revision$                                                         *
 *   $Date$                   *
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\*===========================================================================*/


//=============================================================================
//
//  Helper Functions for binary reading / writing
//
//=============================================================================


//== INCLUDES =================================================================


#include <OpenMesh/Core/System/config.h>
// -------------------- STL
#include <algorithm>
// -------------------- OpenMesh
#include <OpenMesh/Core/IO/BinaryHelper.hh>


//== NAMESPACES ===============================================================


namespace OpenMesh {
namespace IO {

#ifndef DOXY_IGNORE_THIS

//== IMPLEMENTATION ===========================================================

//-----------------------------------------------------------------------------

short int read_short(FILE* _in, bool _swap)
{
  union u1 { short int s; unsigned char c[2]; }  sc;
  fread((char*)sc.c, 1, 2, _in);
  if (_swap) std::swap(sc.c[0], sc.c[1]);
  return sc.s;
}


//-----------------------------------------------------------------------------


int read_int(FILE* _in, bool _swap)
{
  union u2 { int i; unsigned char c[4]; } ic;
  fread((char*)ic.c, 1, 4, _in);
  if (_swap) {
    std::swap(ic.c[0], ic.c[3]);
    std::swap(ic.c[1], ic.c[2]);
  }
  return ic.i;
}


//-----------------------------------------------------------------------------


float read_float(FILE* _in, bool _swap)
{
  union u3 { float f; unsigned char c[4]; } fc;
  fread((char*)fc.c, 1, 4, _in);
  if (_swap) {
    std::swap(fc.c[0], fc.c[3]);
    std::swap(fc.c[1], fc.c[2]);
  }
  return fc.f;
}


//-----------------------------------------------------------------------------


double read_double(FILE* _in, bool _swap)
{
  union u4 { double d; unsigned char c[8]; } dc;
  fread((char*)dc.c, 1, 8, _in);
  if (_swap) {
    std::swap(dc.c[0], dc.c[7]);
    std::swap(dc.c[1], dc.c[6]);
    std::swap(dc.c[2], dc.c[5]);
    std::swap(dc.c[3], dc.c[4]);
  }
  return dc.d;
}

//-----------------------------------------------------------------------------

short int read_short(std::istream& _in, bool _swap)
{
  union u1 { short int s; unsigned char c[2]; }  sc;
  _in.read((char*)sc.c, 2);
  if (_swap) std::swap(sc.c[0], sc.c[1]);
  return sc.s;
}


//-----------------------------------------------------------------------------


int read_int(std::istream& _in, bool _swap)
{
  union u2 { int i; unsigned char c[4]; } ic;
  _in.read((char*)ic.c, 4);
  if (_swap) {
    std::swap(ic.c[0], ic.c[3]);
    std::swap(ic.c[1], ic.c[2]);
  }
  return ic.i;
}


//-----------------------------------------------------------------------------


float read_float(std::istream& _in, bool _swap)
{
  union u3 { float f; unsigned char c[4]; } fc;
  _in.read((char*)fc.c, 4);
  if (_swap) {
    std::swap(fc.c[0], fc.c[3]);
    std::swap(fc.c[1], fc.c[2]);
  }
  return fc.f;
}


//-----------------------------------------------------------------------------


double read_double(std::istream& _in, bool _swap)
{
  union u4 { double d; unsigned char c[8]; } dc;
  _in.read((char*)dc.c, 8);
  if (_swap) {
    std::swap(dc.c[0], dc.c[7]);
    std::swap(dc.c[1], dc.c[6]);
    std::swap(dc.c[2], dc.c[5]);
    std::swap(dc.c[3], dc.c[4]);
  }
  return dc.d;
}


//-----------------------------------------------------------------------------


void write_short(short int _i, FILE* _out, bool _swap)
{
  union u1 { short int s; unsigned char c[2]; } sc;
  sc.s = _i;
  if (_swap) std::swap(sc.c[0], sc.c[1]);
  fwrite((char*)sc.c, 1, 2, _out);
}


//-----------------------------------------------------------------------------


void write_int(int _i, FILE* _out, bool _swap)
{
  union u2 { int i; unsigned char c[4]; } ic;
  ic.i = _i;
  if (_swap) {
    std::swap(ic.c[0], ic.c[3]);
    std::swap(ic.c[1], ic.c[2]);
  }
  fwrite((char*)ic.c, 1, 4, _out);
}


//-----------------------------------------------------------------------------


void write_float(float _f, FILE* _out, bool _swap)
{
  union u3 { float f; unsigned char c[4]; } fc;
  fc.f = _f;
  if (_swap) {
    std::swap(fc.c[0], fc.c[3]);
    std::swap(fc.c[1], fc.c[2]);
  }
  fwrite((char*)fc.c, 1, 4, _out);
}


//-----------------------------------------------------------------------------


void write_double(double _d, FILE* _out, bool _swap)
{
  union u4 { double d; unsigned char c[8]; } dc;
  dc.d = _d;
  if (_swap) {
    std::swap(dc.c[0], dc.c[7]);
    std::swap(dc.c[1], dc.c[6]);
    std::swap(dc.c[2], dc.c[5]);
    std::swap(dc.c[3], dc.c[4]);
  }
  fwrite((char*)dc.c, 1, 8, _out);
}

#endif

//=============================================================================
} // namespace IO
} // namespace OpenMesh
//=============================================================================