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mapnik/include/geometry.hpp
Artem Pavlenko 72fae1daa1 1. removed dependency on boost_serialization ( we don't really need it) at this time. 
2. coord and envelope operator<< to use 16 digit precision.
3. added 'inside polygon' method impl.
2006-08-20 18:49:22 +00:00

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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: geometry.hpp 39 2005-04-10 20:39:53Z pavlenko $
#ifndef GEOMETRY_HPP
#define GEOMETRY_HPP
#include "vertex_vector.hpp"
#include "vertex_transform.hpp"
#include "ctrans.hpp"
#include "geom_util.hpp"
#include <boost/shared_ptr.hpp>
#include <boost/utility.hpp>
namespace mapnik
{
enum {
Point = 1,
LineString = 2,
Polygon = 3
};
template <typename T>
class geometry : private boost::noncopyable
{
public:
typedef T vertex_type;
typedef typename vertex_type::type value_type;
private:
int srid_;
public:
geometry (int srid=-1)
: srid_(srid) {}
int srid() const
{
return srid_;
}
Envelope<double> envelope()
{
Envelope<double> result;
double x,y;
for (unsigned i=0;i<num_points();++i)
{
vertex(&x,&y);
if (i==0)
{
result.init(x,y,x,y);
}
else
{
result.expand_to_include(x,y);
}
}
return result;
}
virtual int type() const=0;
virtual bool hit_test(value_type x,value_type y) const=0;
virtual void label_position(double *x, double *y) const=0;
virtual void move_to(value_type x,value_type y)=0;
virtual void line_to(value_type x,value_type y)=0;
virtual void transform(const mapnik::CoordTransform& t)=0;
virtual unsigned num_points() const = 0;
virtual unsigned vertex(double* x, double* y)=0;
virtual void rewind(unsigned )=0;
virtual void set_capacity(size_t size)=0;
virtual ~geometry() {}
};
template <typename T>
class point : public geometry<T>
{
typedef geometry<T> geometry_base;
typedef typename geometry<T>::vertex_type vertex_type;
typedef typename geometry<T>::value_type value_type;
private:
vertex_type pt_;
public:
point(int srid)
: geometry<T>(srid)
{}
int type() const
{
return Point;
}
void label_position(double *x, double *y) const
{
*x = pt_.x;
*y = pt_.y;
}
void move_to(value_type x,value_type y)
{
pt_.x = x;
pt_.y = y;
}
void line_to(value_type ,value_type ) {}
void transform(const mapnik::CoordTransform& t)
{
t.forward_x(&pt_.x);
t.forward_y(&pt_.y);
}
unsigned num_points() const
{
return 1;
}
unsigned vertex(double* x, double* y)
{
*x = pt_.x;
*y = pt_.y;
return SEG_LINETO;
}
void rewind(unsigned ) {}
bool hit_test(value_type x,value_type y) const
{
return false;
}
void set_capacity(size_t) {}
virtual ~point() {}
};
template <typename T, template <typename> class Container=vertex_vector2>
class polygon : public geometry<T>
{
typedef geometry<T> geometry_base;
typedef typename geometry<T>::vertex_type vertex_type;
typedef typename geometry_base::value_type value_type;
typedef Container<vertex_type> container_type;
private:
container_type cont_;
mutable unsigned itr_;
public:
polygon(int srid)
: geometry_base(srid),
itr_(0)
{}
int type() const
{
return Polygon;
}
void label_position(double *x, double *y) const
{
unsigned size = cont_.size();
if (size < 3)
{
cont_.get_vertex(0,x,y);
return;
}
double ai;
double atmp = 0;
double xtmp = 0;
double ytmp = 0;
double x0 =0;
double y0 =0;
double x1 =0;
double y1 =0;
unsigned i,j;
for (i = size-1,j = 0; j < size; i = j, ++j)
{
cont_.get_vertex(i,&x0,&y0);
cont_.get_vertex(j,&x1,&y1);
ai = x0 * y1 - x1 * y0;
atmp += ai;
xtmp += (x1 + x0) * ai;
ytmp += (y1 + y0) * ai;
}
if (atmp != 0)
{
*x = xtmp/(3*atmp);
*y = ytmp /(3*atmp);
return;
}
*x=x0;
*y=y0;
}
void line_to(value_type x,value_type y)
{
cont_.push_back(x,y,SEG_LINETO);
}
void move_to(value_type x,value_type y)
{
cont_.push_back(x,y,SEG_MOVETO);
}
void transform(mapnik::CoordTransform const& t)
{
unsigned size = cont_.size();
for (unsigned pos=0; pos < size; ++pos)
{
cont_.transform_at(pos,t);
}
}
unsigned num_points() const
{
return cont_.size();
}
unsigned vertex(double* x, double* y)
{
return cont_.get_vertex(itr_++,x,y);
}
void rewind(unsigned )
{
itr_=0;
}
bool hit_test(value_type x,value_type y) const
{
return point_inside_path(x,y,cont_.begin(),cont_.end());
}
void set_capacity(size_t size)
{
cont_.set_capacity(size);
}
virtual ~polygon() {}
};
template <typename T, template <typename> class Container=vertex_vector>
class line_string : public geometry<T>
{
typedef geometry<T> geometry_base;
typedef typename geometry_base::value_type value_type;
typedef typename geometry<T>::vertex_type vertex_type;
typedef Container<vertex_type> container_type;
private:
container_type cont_;
mutable unsigned itr_;
public:
line_string(int srid)
: geometry_base(srid),
itr_(0)
{}
int type() const
{
return LineString;
}
void label_position(double *x, double *y) const
{
// calculate mid point on line string
double x0=0;
double y0=0;
double x1=0;
double y1=0;
unsigned size = cont_.size();
if (size == 1)
{
cont_.get_vertex(0,x,y);
}
else if (size == 2)
{
cont_.get_vertex(0,&x0,&y0);
cont_.get_vertex(1,&x1,&y1);
*x = 0.5 * (x1 + x0);
*y = 0.5 * (y1 + y0);
}
else
{
double len=0.0;
for (unsigned pos = 1; pos < size; ++pos)
{
cont_.get_vertex(pos-1,&x0,&y0);
cont_.get_vertex(pos,&x1,&y1);
double dx = x1 - x0;
double dy = y1 - y0;
len += sqrt(dx * dx + dy * dy);
}
double midlen = 0.5 * len;
double dist = 0.0;
for (unsigned pos = 1; pos < size;++pos)
{
cont_.get_vertex(pos-1,&x0,&y0);
cont_.get_vertex(pos,&x1,&y1);
double dx = x1 - x0;
double dy = y1 - y0;
double seg_len = sqrt(dx * dx + dy * dy);
if (( dist + seg_len) >= midlen)
{
double r = (midlen - dist)/seg_len;
*x = x0 + (x1 - x0) * r;
*y = y0 + (y1 - y0) * r;
break;
}
dist += seg_len;
}
}
}
void line_to(value_type x,value_type y)
{
cont_.push_back(x,y,SEG_LINETO);
}
void move_to(value_type x,value_type y)
{
cont_.push_back(x,y,SEG_MOVETO);
}
void transform(mapnik::CoordTransform const& t)
{
unsigned size = cont_.size();
for (unsigned pos=0; pos < size; ++pos)
{
cont_.transform_at(pos,t);
}
}
unsigned num_points() const
{
return cont_.size();
}
unsigned vertex(double* x, double* y)
{
return cont_.get_vertex(itr_++,x,y);
}
void rewind(unsigned )
{
itr_=0;
}
bool hit_test(value_type x,value_type y) const
{
return false;
}
void set_capacity(size_t size)
{
cont_.set_capacity(size);
}
virtual ~line_string() {}
};
typedef point<vertex2d> point_impl;
typedef line_string<vertex2d,vertex_vector2> line_string_impl;
typedef polygon<vertex2d,vertex_vector2> polygon_impl;
typedef geometry<vertex2d> geometry_type;
typedef boost::shared_ptr<geometry_type> geometry_ptr;
}
#endif //GEOMETRY_HPP
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