mapnik/src/projection.cpp
Tom Hughes 05ab656b57 The upcoming 4.8.0 release of PROJ.4 is supposed to be threadsafe, so
lets believe them and not use any locks if we are building against
version 4.8.0 or later.

Instead we use the new proj_ctx_alloc routine to create a context and
pass that when initialising the projection structure.
2010-09-24 15:26:50 +00:00

148 lines
3.4 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 {
#if defined(MAPNIK_THREADSAFE) && PJ_VERSION < 480
boost::mutex projection::mutex_;
#endif
projection::projection(std::string const& 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
{
return is_geographic_;
}
std::string const& projection::params() const
{
return params_;
}
void projection::forward(double & x, double &y ) const
{
#if defined(MAPNIK_THREADSAFE) && PJ_VERSION < 480
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 (is_geographic_)
{
x *=RAD_TO_DEG;
y *=RAD_TO_DEG;
}
}
void projection::inverse(double & x,double & y) const
{
#if defined(MAPNIK_THREADSAFE) && PJ_VERSION < 480
mutex::scoped_lock lock(mutex_);
#endif
if (is_geographic_)
{
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()
{
#if defined(MAPNIK_THREADSAFE) && PJ_VERSION < 480
mutex::scoped_lock lock(mutex_);
#endif
if (proj_) pj_free(proj_);
#if PJ_VERSION >= 480
if (proj_ctx_) pj_ctx_free(proj_ctx_);
#endif
}
void projection::init()
{
#if defined(MAPNIK_THREADSAFE) && PJ_VERSION < 480
mutex::scoped_lock lock(mutex_);
#endif
#if PJ_VERSION >= 480
proj_ctx_=pj_ctx_alloc();
proj_=pj_init_plus_ctx(proj_ctx_, params_.c_str());
#else
proj_=pj_init_plus(params_.c_str());
#endif
if (!proj_) throw proj_init_error(params_);
is_geographic_ = pj_is_latlong(proj_) ? true : false;
}
void projection::swap (projection& rhs)
{
std::swap(params_,rhs.params_);
init ();
}
}