mapnik/src/projection.cpp
2010-06-02 11:03:30 +00:00

142 lines
3.1 KiB
C++

/*****************************************************************************
*
* 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
*
*****************************************************************************/
//$Id$
// mapnik
#include <mapnik/projection.hpp>
#include <mapnik/utils.hpp>
// proj4
#include <proj_api.h>
namespace mapnik {
#ifdef MAPNIK_THREADSAFE
boost::mutex projection::mutex_;
#endif
projection::projection(std::string params)
: params_(params)
{
init(); //
}
projection::projection(projection const& rhs)
: params_(rhs.params_)
{
init(); //
}
projection& projection::operator=(projection const& rhs)
{
projection tmp(rhs);
swap(tmp);
return *this;
}
bool projection::operator==(const projection& other) const
{
return (params_ == other.params_);
}
bool projection::operator!=(const projection& other) const
{
return !(*this == other);
}
bool projection::is_initialized() const
{
return proj_ ? true : false;
}
bool projection::is_geographic() const
{
#ifdef MAPNIK_THREADSAFE
mutex::scoped_lock lock(mutex_);
#endif
return pj_is_latlong(proj_) ? true : false;
}
std::string const& projection::params() const
{
return params_;
}
void projection::forward(double & x, double &y ) const
{
#ifdef MAPNIK_THREADSAFE
mutex::scoped_lock lock(mutex_);
#endif
projUV p;
p.u = x * DEG_TO_RAD;
p.v = y * DEG_TO_RAD;
p = pj_fwd(p,proj_);
x = p.u;
y = p.v;
if (pj_is_latlong(proj_))
{
x *=RAD_TO_DEG;
y *=RAD_TO_DEG;
}
}
void projection::inverse(double & x,double & y) const
{
#ifdef MAPNIK_THREADSAFE
mutex::scoped_lock lock(mutex_);
#endif
if (pj_is_latlong(proj_))
{
x *=DEG_TO_RAD;
y *=DEG_TO_RAD;
}
projUV p;
p.u = x;
p.v = y;
p = pj_inv(p,proj_);
x = RAD_TO_DEG * p.u;
y = RAD_TO_DEG * p.v;
}
projection::~projection()
{
#ifdef MAPNIK_THREADSAFE
mutex::scoped_lock lock(mutex_);
#endif
if (proj_) pj_free(proj_);
}
void projection::init()
{
#ifdef MAPNIK_THREADSAFE
mutex::scoped_lock lock(mutex_);
#endif
proj_=pj_init_plus(params_.c_str());
if (!proj_) throw proj_init_error(params_);
}
void projection::swap (projection& rhs)
{
std::swap(params_,rhs.params_);
init ();
}
}