589 lines
14 KiB
C++
589 lines
14 KiB
C++
/*****************************************************************************
|
|
*
|
|
* This file is part of Mapnik (c++ mapping toolkit)
|
|
*
|
|
* Copyright (C) 2015 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_GEOM_UTIL_HPP
|
|
#define MAPNIK_GEOM_UTIL_HPP
|
|
|
|
// mapnik
|
|
#include <mapnik/box2d.hpp>
|
|
#include <mapnik/coord.hpp>
|
|
#include <mapnik/vertex.hpp>
|
|
#include <mapnik/geometry_types.hpp>
|
|
// stl
|
|
#include <cmath>
|
|
#include <vector>
|
|
#include <algorithm>
|
|
|
|
namespace mapnik
|
|
{
|
|
template <typename T>
|
|
bool clip_test(T p,T q,double& tmin,double& tmax)
|
|
{
|
|
double r = 0;
|
|
bool result=true;
|
|
if (p<0.0)
|
|
{
|
|
r=q/p;
|
|
if (r>tmax) result=false;
|
|
else if (r>tmin) tmin=r;
|
|
}
|
|
else if (p>0.0)
|
|
{
|
|
r=q/p;
|
|
if (r<tmin) result=false;
|
|
else if (r<tmax) tmax=r;
|
|
} else if (q<0.0) result=false;
|
|
return result;
|
|
}
|
|
|
|
template <typename T,typename Image>
|
|
bool clip_line(T& x0,T& y0,T& x1,T& y1,box2d<T> const& box)
|
|
{
|
|
double tmin=0.0;
|
|
double tmax=1.0;
|
|
double dx=x1-x0;
|
|
if (clip_test<double>(-dx,x0,tmin,tmax))
|
|
{
|
|
if (clip_test<double>(dx,box.width()-x0,tmin,tmax))
|
|
{
|
|
double dy=y1-y0;
|
|
if (clip_test<double>(-dy,y0,tmin,tmax))
|
|
{
|
|
if (clip_test<double>(dy,box.height()-y0,tmin,tmax))
|
|
{
|
|
if (tmax<1.0)
|
|
{
|
|
x1=static_cast<T>(x0+tmax*dx);
|
|
y1=static_cast<T>(y0+tmax*dy);
|
|
}
|
|
if (tmin>0.0)
|
|
{
|
|
x0+=static_cast<T>(tmin*dx);
|
|
y0+=static_cast<T>(tmin*dy);
|
|
}
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
template <typename Iter>
|
|
inline bool point_inside_path(double x,double y,Iter start,Iter end)
|
|
{
|
|
bool inside=false;
|
|
double x0=std::get<0>(*start);
|
|
double y0=std::get<1>(*start);
|
|
|
|
double x1 = 0;
|
|
double y1 = 0;
|
|
while (++start!=end)
|
|
{
|
|
if ( std::get<2>(*start) == SEG_MOVETO)
|
|
{
|
|
x0 = std::get<0>(*start);
|
|
y0 = std::get<1>(*start);
|
|
continue;
|
|
}
|
|
x1=std::get<0>(*start);
|
|
y1=std::get<1>(*start);
|
|
|
|
if ((((y1 <= y) && (y < y0)) ||
|
|
((y0 <= y) && (y < y1))) &&
|
|
( x < (x0 - x1) * (y - y1)/ (y0 - y1) + x1))
|
|
inside=!inside;
|
|
x0=x1;
|
|
y0=y1;
|
|
}
|
|
return inside;
|
|
}
|
|
|
|
inline bool point_in_circle(double x,double y,double cx,double cy,double r)
|
|
{
|
|
double dx = x - cx;
|
|
double dy = y - cy;
|
|
double d2 = dx * dx + dy * dy;
|
|
return (d2 <= r * r);
|
|
}
|
|
|
|
template <typename T>
|
|
inline T sqr(T x)
|
|
{
|
|
return x * x;
|
|
}
|
|
|
|
inline double distance2(double x0,double y0,double x1,double y1)
|
|
{
|
|
double dx = x1 - x0;
|
|
double dy = y1 - y0;
|
|
return sqr(dx) + sqr(dy);
|
|
}
|
|
|
|
inline double distance(double x0,double y0, double x1,double y1)
|
|
{
|
|
return std::sqrt(distance2(x0,y0,x1,y1));
|
|
}
|
|
|
|
inline double point_to_segment_distance(double x, double y,
|
|
double ax, double ay,
|
|
double bx, double by)
|
|
{
|
|
double len2 = distance2(ax,ay,bx,by);
|
|
|
|
if (len2 < 1e-14)
|
|
{
|
|
return distance(x,y,ax,ay);
|
|
}
|
|
|
|
double r = ((x - ax)*(bx - ax) + (y - ay)*(by -ay))/len2;
|
|
if ( r < 0 )
|
|
{
|
|
return distance(x,y,ax,ay);
|
|
}
|
|
else if (r > 1)
|
|
{
|
|
return distance(x,y,bx,by);
|
|
}
|
|
double s = ((ay - y)*(bx - ax) - (ax - x)*(by - ay))/len2;
|
|
return std::fabs(s) * std::sqrt(len2);
|
|
}
|
|
|
|
template <typename Iter>
|
|
inline bool point_on_path(double x,double y,Iter start,Iter end, double tol)
|
|
{
|
|
double x0=std::get<0>(*start);
|
|
double y0=std::get<1>(*start);
|
|
double x1 = 0;
|
|
double y1 = 0;
|
|
while (++start != end)
|
|
{
|
|
if ( std::get<2>(*start) == SEG_MOVETO)
|
|
{
|
|
x0 = std::get<0>(*start);
|
|
y0 = std::get<1>(*start);
|
|
continue;
|
|
}
|
|
x1=std::get<0>(*start);
|
|
y1=std::get<1>(*start);
|
|
|
|
double distance = point_to_segment_distance(x,y,x0,y0,x1,y1);
|
|
if (distance < tol)
|
|
return true;
|
|
x0=x1;
|
|
y0=y1;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// filters
|
|
struct filter_in_box
|
|
{
|
|
box2d<double> box_;
|
|
explicit filter_in_box(box2d<double> const& box)
|
|
: box_(box) {}
|
|
|
|
bool pass(box2d<double> const& extent) const
|
|
{
|
|
return extent.intersects(box_);
|
|
}
|
|
};
|
|
|
|
struct filter_at_point
|
|
{
|
|
box2d<double> box_;
|
|
explicit filter_at_point(coord2d const& pt, double tol=0)
|
|
: box_(pt,pt)
|
|
{
|
|
box_.pad(tol);
|
|
}
|
|
|
|
bool pass(box2d<double> const& extent) const
|
|
{
|
|
return extent.intersects(box_);
|
|
}
|
|
};
|
|
|
|
////////////////////////////////////////////////////////////////////////////
|
|
template <typename PathType>
|
|
double path_length(PathType & path)
|
|
{
|
|
double x0 = 0;
|
|
double y0 = 0;
|
|
double x1 = 0;
|
|
double y1 = 0;
|
|
path.rewind(0);
|
|
unsigned command = path.vertex(&x0,&y0);
|
|
if (command == SEG_END) return 0;
|
|
double length = 0;
|
|
while (SEG_END != (command = path.vertex(&x1, &y1)))
|
|
{
|
|
if (command == SEG_CLOSE) continue;
|
|
length += distance(x0,y0,x1,y1);
|
|
x0 = x1;
|
|
y0 = y1;
|
|
}
|
|
return length;
|
|
}
|
|
|
|
template <typename PathType>
|
|
bool hit_test_first(PathType & path, double x, double y)
|
|
{
|
|
bool inside=false;
|
|
double x0 = 0;
|
|
double y0 = 0;
|
|
double x1 = 0;
|
|
double y1 = 0;
|
|
path.rewind(0);
|
|
unsigned command = path.vertex(&x0, &y0);
|
|
if (command == SEG_END)
|
|
{
|
|
return false;
|
|
}
|
|
unsigned count = 0;
|
|
while (SEG_END != (command = path.vertex(&x1, &y1)))
|
|
{
|
|
if (command == SEG_CLOSE)
|
|
{
|
|
break;
|
|
}
|
|
++count;
|
|
if (command == SEG_MOVETO)
|
|
{
|
|
x0 = x1;
|
|
y0 = y1;
|
|
continue;
|
|
}
|
|
|
|
if ((((y1 <= y) && (y < y0)) ||
|
|
((y0 <= y) && (y < y1))) &&
|
|
(x < (x0 - x1) * (y - y1)/ (y0 - y1) + x1))
|
|
inside=!inside;
|
|
|
|
x0 = x1;
|
|
y0 = y1;
|
|
}
|
|
return inside;
|
|
}
|
|
|
|
namespace label {
|
|
|
|
template <typename PathType>
|
|
bool middle_point(PathType & path, double & x, double & y)
|
|
{
|
|
double x0 = 0;
|
|
double y0 = 0;
|
|
double x1 = 0;
|
|
double y1 = 0;
|
|
double mid_length = 0.5 * path_length(path);
|
|
path.rewind(0);
|
|
unsigned command = path.vertex(&x0,&y0);
|
|
if (command == SEG_END) return false;
|
|
double dist = 0.0;
|
|
while (SEG_END != (command = path.vertex(&x1, &y1)))
|
|
{
|
|
if (command == SEG_CLOSE) continue;
|
|
double seg_length = distance(x0, y0, x1, y1);
|
|
|
|
if ( dist + seg_length >= mid_length)
|
|
{
|
|
double r = (mid_length - dist)/seg_length;
|
|
x = x0 + (x1 - x0) * r;
|
|
y = y0 + (y1 - y0) * r;
|
|
break;
|
|
}
|
|
dist += seg_length;
|
|
x0 = x1;
|
|
y0 = y1;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
template <typename PathType>
|
|
bool centroid(PathType & path, double & x, double & y)
|
|
{
|
|
double x0 = 0.0;
|
|
double y0 = 0.0;
|
|
double x1 = 0.0;
|
|
double y1 = 0.0;
|
|
double start_x;
|
|
double start_y;
|
|
|
|
path.rewind(0);
|
|
unsigned command = path.vertex(&x0, &y0);
|
|
if (command == SEG_END) return false;
|
|
|
|
start_x = x0;
|
|
start_y = y0;
|
|
|
|
double atmp = 0.0;
|
|
double xtmp = 0.0;
|
|
double ytmp = 0.0;
|
|
unsigned count = 1;
|
|
while (SEG_END != (command = path.vertex(&x1, &y1)))
|
|
{
|
|
if (command == SEG_CLOSE) continue;
|
|
double dx0 = x0 - start_x;
|
|
double dy0 = y0 - start_y;
|
|
double dx1 = x1 - start_x;
|
|
double dy1 = y1 - start_y;
|
|
|
|
double ai = dx0 * dy1 - dx1 * dy0;
|
|
atmp += ai;
|
|
xtmp += (dx1 + dx0) * ai;
|
|
ytmp += (dy1 + dy0) * ai;
|
|
x0 = x1;
|
|
y0 = y1;
|
|
++count;
|
|
}
|
|
|
|
if (count <= 2) {
|
|
x = (start_x + x0) * 0.5;
|
|
y = (start_y + y0) * 0.5;
|
|
return true;
|
|
}
|
|
|
|
if (atmp != 0)
|
|
{
|
|
x = (xtmp/(3*atmp)) + start_x;
|
|
y = (ytmp/(3*atmp)) + start_y;
|
|
}
|
|
else
|
|
{
|
|
x = x0;
|
|
y = y0;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// Compute centroid over a set of paths
|
|
#if 0
|
|
template <typename Iter>
|
|
bool centroid_geoms(Iter start, Iter end, double & x, double & y)
|
|
{
|
|
double x0 = 0.0;
|
|
double y0 = 0.0;
|
|
double x1 = 0.0;
|
|
double y1 = 0.0;
|
|
double start_x = x0;
|
|
double start_y = y0;
|
|
|
|
double atmp = 0.0;
|
|
double xtmp = 0.0;
|
|
double ytmp = 0.0;
|
|
unsigned count = 0;
|
|
|
|
while (start != end)
|
|
{
|
|
typename Iter::value_type const& geom = *start++;
|
|
vertex_adapter path(geom);
|
|
path.rewind(0);
|
|
unsigned command = path.vertex(&x0, &y0);
|
|
if (command == SEG_END) continue;
|
|
|
|
if ( ! count++ ) {
|
|
start_x = x0;
|
|
start_y = y0;
|
|
}
|
|
|
|
while (SEG_END != (command = path.vertex(&x1, &y1)))
|
|
{
|
|
if (command == SEG_CLOSE) continue;
|
|
double dx0 = x0 - start_x;
|
|
double dy0 = y0 - start_y;
|
|
double dx1 = x1 - start_x;
|
|
double dy1 = y1 - start_y;
|
|
double ai = dx0 * dy1 - dx1 * dy0;
|
|
atmp += ai;
|
|
xtmp += (dx1 + dx0) * ai;
|
|
ytmp += (dy1 + dy0) * ai;
|
|
x0 = x1;
|
|
y0 = y1;
|
|
++count;
|
|
}
|
|
|
|
}
|
|
|
|
if (count == 0) return false;
|
|
|
|
if (count <= 2) {
|
|
x = (start_x + x0) * 0.5;
|
|
y = (start_y + y0) * 0.5;
|
|
return true;
|
|
}
|
|
|
|
if (atmp != 0)
|
|
{
|
|
x = (xtmp/(3*atmp)) + start_x;
|
|
y = (ytmp/(3*atmp)) + start_y;
|
|
}
|
|
else
|
|
{
|
|
x = x0;
|
|
y = y0;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
#endif
|
|
|
|
template <typename PathType>
|
|
bool hit_test(PathType & path, double x, double y, double tol)
|
|
{
|
|
bool inside=false;
|
|
double x0 = 0;
|
|
double y0 = 0;
|
|
double x1 = 0;
|
|
double y1 = 0;
|
|
double start_x = 0;
|
|
double start_y = 0;
|
|
path.rewind(0);
|
|
unsigned command = path.vertex(&x0, &y0);
|
|
if (command == SEG_END)
|
|
{
|
|
return false;
|
|
}
|
|
unsigned count = 0;
|
|
mapnik::geometry::geometry_types geom_type = static_cast<mapnik::geometry::geometry_types>(path.type());
|
|
while (SEG_END != (command = path.vertex(&x1, &y1)))
|
|
{
|
|
++count;
|
|
if (command == SEG_MOVETO)
|
|
{
|
|
x0 = x1;
|
|
y0 = y1;
|
|
start_x = x0;
|
|
start_y = y0;
|
|
continue;
|
|
}
|
|
else if (command == SEG_CLOSE)
|
|
{
|
|
x1 = start_x;
|
|
y1 = start_y;
|
|
}
|
|
switch(geom_type)
|
|
{
|
|
case mapnik::geometry::geometry_types::Polygon:
|
|
{
|
|
if ((((y1 <= y) && (y < y0)) ||
|
|
((y0 <= y) && (y < y1))) &&
|
|
(x < (x0 - x1) * (y - y1)/ (y0 - y1) + x1))
|
|
inside=!inside;
|
|
break;
|
|
}
|
|
case mapnik::geometry::geometry_types::LineString:
|
|
{
|
|
double distance = point_to_segment_distance(x,y,x0,y0,x1,y1);
|
|
if (distance < tol)
|
|
return true;
|
|
break;
|
|
}
|
|
default:
|
|
break;
|
|
}
|
|
x0 = x1;
|
|
y0 = y1;
|
|
}
|
|
|
|
// TODO - handle multi-point?
|
|
if (count == 0) // one vertex
|
|
{
|
|
return distance(x, y, x0, y0) <= tol;
|
|
}
|
|
return inside;
|
|
}
|
|
|
|
template <typename PathType>
|
|
bool interior_position(PathType & path, double & x, double & y)
|
|
{
|
|
// start with the centroid
|
|
if (!label::centroid(path, x,y))
|
|
return false;
|
|
|
|
// otherwise we find a horizontal line across the polygon and then return the
|
|
// center of the widest intersection between the polygon and the line.
|
|
|
|
std::vector<double> intersections; // only need to store the X as we know the y
|
|
|
|
double x0 = 0;
|
|
double y0 = 0;
|
|
path.rewind(0);
|
|
unsigned command = path.vertex(&x0, &y0);
|
|
double x1 = 0;
|
|
double y1 = 0;
|
|
while (SEG_END != (command = path.vertex(&x1, &y1)))
|
|
{
|
|
if (command == SEG_CLOSE)
|
|
continue;
|
|
if (command != SEG_MOVETO)
|
|
{
|
|
// if the segments overlap
|
|
if (y0==y1)
|
|
{
|
|
if (y0==y)
|
|
{
|
|
double xi = (x0+x1)/2.0;
|
|
intersections.push_back(xi);
|
|
}
|
|
}
|
|
// if the path segment crosses the bisector
|
|
else if ((y0 <= y && y1 >= y) ||
|
|
(y0 >= y && y1 <= y))
|
|
{
|
|
// then calculate the intersection
|
|
double xi = x0;
|
|
if (x0 != x1)
|
|
{
|
|
double m = (y1-y0)/(x1-x0);
|
|
double c = y0 - m*x0;
|
|
xi = (y-c)/m;
|
|
}
|
|
|
|
intersections.push_back(xi);
|
|
}
|
|
}
|
|
x0 = x1;
|
|
y0 = y1;
|
|
}
|
|
// no intersections we just return the default
|
|
if (intersections.empty())
|
|
return true;
|
|
std::sort(intersections.begin(), intersections.end());
|
|
double max_width = 0;
|
|
for (unsigned ii = 1; ii < intersections.size(); ii += 2)
|
|
{
|
|
double xlow = intersections[ii-1];
|
|
double xhigh = intersections[ii];
|
|
double width = xhigh - xlow;
|
|
if (width > max_width)
|
|
{
|
|
x = (xlow + xhigh) / 2.0;
|
|
max_width = width;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
}}
|
|
|
|
#endif // MAPNIK_GEOM_UTIL_HPP
|