mapnik/include/mapnik/ctrans.hpp

520 lines
15 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2011 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
*
*****************************************************************************/
#ifndef MAPNIK_CTRANS_HPP
#define MAPNIK_CTRANS_HPP
// mapnik
#include <mapnik/box2d.hpp>
#include <mapnik/vertex.hpp>
#include <mapnik/coord_array.hpp>
#include <mapnik/proj_transform.hpp>
// boost
#include <boost/math/constants/constants.hpp>
// stl
#include <algorithm>
const double pi = boost::math::constants::pi<double>();
const double pi_by_2 = pi/2.0;
namespace mapnik
{
typedef coord_array<coord2d> CoordinateArray;
template <typename Transform, typename Geometry>
struct MAPNIK_DECL coord_transform
{
coord_transform(Transform const& t, Geometry& geom)
: t_(t), geom_(geom) {}
unsigned vertex(double *x, double *y) const
{
unsigned command = geom_.vertex(x, y);
t_.forward(x, y);
return command;
}
void rewind(unsigned pos)
{
geom_.rewind(pos);
}
private:
Transform const& t_;
Geometry& geom_;
};
template <typename Transform, typename Geometry>
struct MAPNIK_DECL coord_transform2
{
typedef std::size_t size_type;
typedef typename Geometry::value_type value_type;
coord_transform2(Transform const& t,
Geometry const& geom,
proj_transform const& prj_trans)
: t_(t),
geom_(geom),
prj_trans_(prj_trans) {}
unsigned vertex(double *x, double *y) const
{
unsigned command = SEG_MOVETO;
bool ok = false;
bool skipped_points = false;
double z = 0;
while (!ok && command != SEG_END)
{
command = geom_.vertex(x, y);
ok = prj_trans_.backward(*x, *y, z);
if (!ok) {
skipped_points = true;
}
}
if (skipped_points && (command == SEG_LINETO))
{
command = SEG_MOVETO;
}
t_.forward(x, y);
return command;
}
void rewind(unsigned pos)
{
geom_.rewind(pos);
}
Geometry const& geom() const
{
return geom_;
}
private:
Transform const& t_;
Geometry const& geom_;
proj_transform const& prj_trans_;
};
template <typename Transform, typename Geometry>
struct MAPNIK_DECL coord_transform3
{
coord_transform3(Transform const& t,
Geometry const& geom,
proj_transform const& prj_trans,
int dx, int dy)
: t_(t),
geom_(geom),
prj_trans_(prj_trans),
dx_(dx), dy_(dy) {}
unsigned vertex(double *x, double *y) const
{
unsigned command = geom_.vertex(x, y);
double z = 0;
prj_trans_.backward(*x, *y, z);
t_.forward(x, y);
*x += dx_;
*y += dy_;
return command;
}
void rewind(unsigned pos)
{
geom_.rewind(pos);
}
private:
Transform const& t_;
Geometry const& geom_;
proj_transform const& prj_trans_;
int dx_;
int dy_;
};
// TODO - expose this and make chainable
template <typename Transform,typename Geometry>
struct MAPNIK_DECL coord_transform_parallel
{
typedef std::size_t size_type;
typedef typename Geometry::value_type value_type;
coord_transform_parallel(Transform const& t,
Geometry const& geom,
proj_transform const& prj_trans )
: t_(t),
geom_(geom),
prj_trans_(prj_trans),
offset_(0.0),
threshold_(10),
m_status(initial) {}
enum status
{
initial,
start,
first,
process,
last_vertex,
angle_joint,
end
};
double get_offset() const
{
return offset_;
}
void set_offset(double offset)
{
offset_ = offset;
}
unsigned int get_threshold() const
{
return threshold_;
}
void set_threshold(unsigned int t)
{
threshold_ = t;
}
unsigned vertex(double * x , double * y)
{
double z=0;
if (offset_==0.0)
{
unsigned command = geom_.vertex(x,y);
prj_trans_.backward(*x,*y,z);
t_.forward(x,y);
return command;
}
else
{
while(true){
switch(m_status)
{
case end:
return SEG_END;
break;
case initial:
m_pre_cmd = geom_.vertex(x,y);
prj_trans_.backward(*x,*y,z);
t_.forward(x,y);
m_pre_x = *x;
m_pre_y = *y;
//m_status = (m_pre_cmd!=SEG_END)?start:end; //
case start:
m_cur_cmd = geom_.vertex(&m_cur_x, &m_cur_y);
prj_trans_.backward(m_cur_x,m_cur_y,z);
t_.forward(&m_cur_x,&m_cur_y);
case first:
angle_a = atan2((m_pre_y-m_cur_y),(m_pre_x-m_cur_x));
dx_pre = cos(angle_a + pi_by_2);
dy_pre = sin(angle_a + pi_by_2);
#ifdef MAPNIK_DEBUG
std::clog << "offsetting line by: " << offset_ << "\n";
std::clog << "initial dx=" << (dx_pre * offset_) << " dy=" << (dy_pre * offset_) << "\n";
#endif
*x = m_pre_x + (dx_pre * offset_);
*y = m_pre_y + (dy_pre * offset_);
m_status = process;
return SEG_MOVETO;
case process:
switch(m_cur_cmd)
{
case SEG_LINETO:
m_next_cmd = geom_.vertex(&m_next_x, &m_next_y);
prj_trans_.backward(m_next_x,m_next_y,z);
t_.forward(&m_next_x,&m_next_y);
switch(m_next_cmd)
{
case SEG_LINETO:
m_status = angle_joint;
break;
default:
m_status = last_vertex;
break;
}
break;
case SEG_END:
m_status = end;
return SEG_END;
}
break;
case last_vertex:
dx_curr = cos(angle_a + pi_by_2);
dy_curr = sin(angle_a + pi_by_2);
*x = m_cur_x + (dx_curr * offset_);
*y = m_cur_y + (dy_curr * offset_);
m_status = end;
return m_cur_cmd;
case angle_joint:
angle_b = atan2((m_cur_y-m_next_y),(m_cur_x-m_next_x));
h = tan((angle_b - angle_a)/2.0);
if (fabs(h) < threshold_)
{
dx_curr = cos(angle_a + pi_by_2);
dy_curr = sin(angle_a + pi_by_2);
*x = m_cur_x + (dx_curr * offset_) - h * (dy_curr * offset_);
*y = m_cur_y + (dy_curr * offset_) + h * (dx_curr * offset_);
}
else // skip sharp spikes
{
#ifdef MAPNIK_DEBUG
dx_curr = cos(angle_a + pi_by_2);
dy_curr = sin(angle_a + pi_by_2);
sin_curve = dx_curr*dy_pre-dy_curr*dx_pre;
std::clog << "angle a: " << angle_a << "\n";
std::clog << "angle b: " << angle_b << "\n";
std::clog << "h: " << h << "\n";
std::clog << "sin_curve: " << sin_curve << "\n";
#endif
m_status = process;
break;
}
// alternate sharp spike fix, but suboptimal...
/*
sin_curve = dx_curr*dy_pre-dy_curr*dx_pre;
cos_curve = -dx_pre*dx_curr-dy_pre*dy_curr;
#ifdef MAPNIK_DEBUG
std::clog << "sin_curve value: " << sin_curve << "\n";
#endif
if(sin_curve > -0.3 && sin_curve < 0.3) {
angle_b = atan2((m_cur_y-m_next_y),(m_cur_x-m_next_x));
h = tan((angle_b - angle_a)/2.0);
*x = m_cur_x + (dx_curr * offset_) - h * (dy_curr * offset_);
*y = m_cur_y + (dy_curr * offset_) + h * (dx_curr * offset_);
} else {
if (angle_b - angle_a > 0)
h = -1.0*(1.0+cos_curve)/sin_curve;
else
h = (1.0+cos_curve)/sin_curve;
*x = m_cur_x + (dx_curr + base_shift*dy_curr)*offset_;
*y = m_cur_y + (dy_curr - base_shift*dx_curr)*offset_;
}
*/
m_pre_x = *x;
m_pre_x = *y;
m_cur_x = m_next_x;
m_cur_y = m_next_y;
angle_a = angle_b;
m_pre_cmd = m_cur_cmd;
m_cur_cmd = m_next_cmd;
m_status = process;
return m_pre_cmd;
}
}
}
}
void rewind (unsigned pos)
{
geom_.rewind(pos);
m_status = initial;
}
private:
Transform const& t_;
Geometry const& geom_;
proj_transform const& prj_trans_;
int offset_;
unsigned int threshold_;
status m_status;
double dx_pre;
double dy_pre;
double dx_curr;
double dy_curr;
double sin_curve;
double cos_curve;
double angle_a;
double angle_b;
double h;
unsigned m_pre_cmd;
double m_pre_x;
double m_pre_y;
unsigned m_cur_cmd;
double m_cur_x;
double m_cur_y;
unsigned m_next_cmd;
double m_next_x;
double m_next_y;
};
class CoordTransform
{
private:
int width_;
int height_;
double sx_;
double sy_;
box2d<double> extent_;
double offset_x_;
double offset_y_;
public:
CoordTransform(int width, int height, const box2d<double>& extent,
double offset_x = 0, double offset_y = 0)
: width_(width), height_(height), extent_(extent),
offset_x_(offset_x), offset_y_(offset_y)
{
sx_ = static_cast<double>(width_) / extent_.width();
sy_ = static_cast<double>(height_) / extent_.height();
}
inline int width() const
{
return width_;
}
inline int height() const
{
return height_;
}
inline double scale_x() const
{
return sx_;
}
inline double scale_y() const
{
return sy_;
}
inline void forward(double *x, double *y) const
{
*x = (*x - extent_.minx()) * sx_ - offset_x_;
*y = (extent_.maxy() - *y) * sy_ - offset_y_;
}
inline void backward(double *x, double *y) const
{
*x = extent_.minx() + (*x + offset_x_) / sx_;
*y = extent_.maxy() - (*y + offset_y_) / sy_;
}
inline coord2d& forward(coord2d& c) const
{
forward(&c.x, &c.y);
return c;
}
inline coord2d& backward(coord2d& c) const
{
backward(&c.x, &c.y);
return c;
}
inline box2d<double> forward(const box2d<double>& e,
proj_transform const& prj_trans) const
{
double x0 = e.minx();
double y0 = e.miny();
double x1 = e.maxx();
double y1 = e.maxy();
double z = 0.0;
prj_trans.backward(x0, y0, z);
forward(&x0, &y0);
prj_trans.backward(x1, y1, z);
forward(&x1, &y1);
return box2d<double>(x0, y0, x1, y1);
}
inline box2d<double> forward(const box2d<double>& e) const
{
double x0 = e.minx();
double y0 = e.miny();
double x1 = e.maxx();
double y1 = e.maxy();
forward(&x0, &y0);
forward(&x1, &y1);
return box2d<double>(x0, y0, x1, y1);
}
inline box2d<double> backward(const box2d<double>& e,
proj_transform const& prj_trans) const
{
double x0 = e.minx();
double y0 = e.miny();
double x1 = e.maxx();
double y1 = e.maxy();
double z = 0.0;
backward(&x0, &y0);
prj_trans.forward(x0, y0, z);
backward(&x1, &y1);
prj_trans.forward(x1, y1, z);
return box2d<double>(x0, y0, x1, y1);
}
inline box2d<double> backward(const box2d<double>& e) const
{
double x0 = e.minx();
double y0 = e.miny();
double x1 = e.maxx();
double y1 = e.maxy();
backward(&x0, &y0);
backward(&x1, &y1);
return box2d<double>(x0, y0, x1, y1);
}
inline CoordinateArray& forward(CoordinateArray& coords) const
{
for (unsigned i = 0; i < coords.size(); ++i)
{
forward(coords[i]);
}
return coords;
}
inline CoordinateArray& backward(CoordinateArray& coords) const
{
for (unsigned i = 0; i < coords.size(); ++i)
{
backward(coords[i]);
}
return coords;
}
inline box2d<double> const& extent() const
{
return extent_;
}
};
}
#endif // MAPNIK_CTRANS_HPP