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/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2006 Artem Pavlenko
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*****************************************************************************/
//$Id: shapefile.hpp 33 2005-04-04 13:01:03Z pavlenko $
#ifndef SHAPEFILE_HPP
#define SHAPEFILE_HPP
#include <mapnik/envelope.hpp>
// boost
#include <boost/utility.hpp>
#include <boost/iostreams/stream.hpp>
#include <boost/iostreams/device/file.hpp>
#include <boost/iostreams/device/mapped_file.hpp>
#include <cstring>
using mapnik::Envelope;
struct shape_record
{
const char* data;
size_t size;
mutable size_t pos;
explicit shape_record(size_t size)
: size(size),
pos(0) {}
void set_data(const char * data_)
{
data = data_;
}
void skip(unsigned n)
{
pos+=n;
}
int read_ndr_integer()
{
int val=(data[pos] & 0xff) |
(data[pos+1] & 0xff) << 8 |
(data[pos+2] & 0xff) << 16 |
(data[pos+3] & 0xff) << 24;
pos+=4;
return val;
}
int read_xdr_integer()
{
int val=(data[pos] & 0xff) << 24 |
(data[pos+1] & 0xff) << 16 |
(data[pos+2] & 0xff) << 8 |
(data[pos+3] & 0xff);
pos+=4;
return val;
}
double read_double()
{
double val;
#ifndef WORDS_BIGENDIAN
std::memcpy(&val,&data[pos],8);
#else
long long bits = ((long long)data[pos] & 0xff) |
((long long)data[pos+1] & 0xff) << 8 |
((long long)data[pos+2] & 0xff) << 16 |
((long long)data[pos+3] & 0xff) << 24 |
((long long)data[pos+4] & 0xff) << 32 |
((long long)data[pos+5] & 0xff) << 40 |
((long long)data[pos+6] & 0xff) << 48 |
((long long)data[pos+7] & 0xff) << 56 ;
std::memcpy(&val,&bits,8);
#endif
pos+=8;
return val;
}
long remains()
{
return (size-pos);
}
~shape_record() {}
};
using namespace boost::iostreams;
class shape_file : boost::noncopyable
{
stream<mapped_file_source> file_;
public:
shape_file();
shape_file(const std::string& file_name);
~shape_file();
bool is_open();
void close();
inline void read_record(shape_record& rec)
{
rec.set_data(file_->data() + file_.tellg());
file_.seekg(rec.size,std::ios::cur);
}
inline int read_xdr_integer()
{
char b[4];
file_.read(b, 4);
return b[3] & 0xffu | (b[2] & 0xffu) << 8 |
(b[1] & 0xffu) << 16 | (b[0] & 0xffu) << 24;
}
inline int read_ndr_integer()
{
char b[4];
file_.read(b,4);
return b[0]&0xffu | (b[1]&0xffu) << 8 |
(b[2]&0xffu) << 16 | (b[3]&0xffu) << 24;
}
inline double read_double()
{
double val;
#ifndef WORDS_BIGENDIAN
file_.read(reinterpret_cast<char*>(&val),8);
#else
char b[8];
file_.read(b,8);
long long bits = ((long long)b[0] & 0xff) |
((long long)b[1] & 0xff) << 8 |
((long long)b[2] & 0xff) << 16 |
((long long)b[3] & 0xff) << 24 |
((long long)b[4] & 0xff) << 32 |
((long long)b[5] & 0xff) << 40 |
((long long)b[6] & 0xff) << 48 |
((long long)b[7] & 0xff) << 56 ;
memcpy(&val,&bits,8);
#endif
return val;
}
inline void read_envelope(Envelope<double>& envelope)
{
#ifndef WORDS_BIGENDIAN
file_.read(reinterpret_cast<char*>(&envelope),sizeof(envelope));
#else
double minx=read_double();
double miny=read_double();
double maxx=read_double();
double maxy=read_double();
envelope.init(minx,miny,maxx,maxy);
#endif
}
inline void skip(std::streampos bytes)
{
file_.seekg(bytes,std::ios::cur);
}
inline void rewind()
{
seek(100);
}
inline void seek(std::streampos pos)
{
file_.seekg(pos,std::ios::beg);
}
inline std::streampos pos()
{
return file_.tellg();
}
inline bool is_eof()
{
return file_.eof();
}
};
#endif //SHAPEFILE_HPP
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