vn-verdnaturachat/ios/Pods/boost-for-react-native/boost/polygon/detail/minkowski.hpp

132 lines
5.0 KiB
C++

/*
Copyright 2008 Intel Corporation
Use, modification and distribution are subject to the Boost Software License,
Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
http://www.boost.org/LICENSE_1_0.txt).
*/
namespace boost { namespace polygon { namespace detail {
template <typename coordinate_type>
struct minkowski_offset {
typedef point_data<coordinate_type> point;
typedef polygon_set_data<coordinate_type> polygon_set;
typedef polygon_with_holes_data<coordinate_type> polygon;
typedef std::pair<point, point> edge;
static void convolve_two_segments(std::vector<point>& figure, const edge& a, const edge& b) {
figure.clear();
figure.push_back(point(a.first));
figure.push_back(point(a.first));
figure.push_back(point(a.second));
figure.push_back(point(a.second));
convolve(figure[0], b.second);
convolve(figure[1], b.first);
convolve(figure[2], b.first);
convolve(figure[3], b.second);
}
template <typename itrT1, typename itrT2>
static void convolve_two_point_sequences(polygon_set& result, itrT1 ab, itrT1 ae, itrT2 bb, itrT2 be) {
if(ab == ae || bb == be)
return;
point first_a = *ab;
point prev_a = *ab;
std::vector<point> vec;
polygon poly;
++ab;
for( ; ab != ae; ++ab) {
point first_b = *bb;
point prev_b = *bb;
itrT2 tmpb = bb;
++tmpb;
for( ; tmpb != be; ++tmpb) {
convolve_two_segments(vec, std::make_pair(prev_b, *tmpb), std::make_pair(prev_a, *ab));
set_points(poly, vec.begin(), vec.end());
result.insert(poly);
prev_b = *tmpb;
}
prev_a = *ab;
}
}
template <typename itrT>
static void convolve_point_sequence_with_polygons(polygon_set& result, itrT b, itrT e, const std::vector<polygon>& polygons) {
for(std::size_t i = 0; i < polygons.size(); ++i) {
convolve_two_point_sequences(result, b, e, begin_points(polygons[i]), end_points(polygons[i]));
for(typename polygon_with_holes_traits<polygon>::iterator_holes_type itrh = begin_holes(polygons[i]);
itrh != end_holes(polygons[i]); ++itrh) {
convolve_two_point_sequences(result, b, e, begin_points(*itrh), end_points(*itrh));
}
}
}
static void convolve_two_polygon_sets(polygon_set& result, const polygon_set& a, const polygon_set& b) {
result.clear();
std::vector<polygon> a_polygons;
std::vector<polygon> b_polygons;
a.get(a_polygons);
b.get(b_polygons);
for(std::size_t ai = 0; ai < a_polygons.size(); ++ai) {
convolve_point_sequence_with_polygons(result, begin_points(a_polygons[ai]),
end_points(a_polygons[ai]), b_polygons);
for(typename polygon_with_holes_traits<polygon>::iterator_holes_type itrh = begin_holes(a_polygons[ai]);
itrh != end_holes(a_polygons[ai]); ++itrh) {
convolve_point_sequence_with_polygons(result, begin_points(*itrh),
end_points(*itrh), b_polygons);
}
for(std::size_t bi = 0; bi < b_polygons.size(); ++bi) {
polygon tmp_poly = a_polygons[ai];
result.insert(convolve(tmp_poly, *(begin_points(b_polygons[bi]))));
tmp_poly = b_polygons[bi];
result.insert(convolve(tmp_poly, *(begin_points(a_polygons[ai]))));
}
}
}
};
}
template<typename T>
inline polygon_set_data<T>&
polygon_set_data<T>::resize(coordinate_type resizing, bool corner_fill_arc, unsigned int num_circle_segments) {
using namespace ::boost::polygon::operators;
if(!corner_fill_arc) {
if(resizing < 0)
return shrink(-resizing);
if(resizing > 0)
return bloat(resizing);
return *this;
}
if(resizing == 0) return *this;
if(empty()) return *this;
if(num_circle_segments < 3) num_circle_segments = 4;
rectangle_data<coordinate_type> rect;
extents(rect);
if(resizing < 0) {
::boost::polygon::bloat(rect, 10);
(*this) = rect - (*this); //invert
}
//make_arc(std::vector<point_data< T> >& return_points,
//point_data< double> start, point_data< double> end,
//point_data< double> center, double r, unsigned int num_circle_segments)
std::vector<point_data<coordinate_type> > circle;
point_data<double> center(0.0, 0.0), start(0.0, (double)resizing);
make_arc(circle, start, start, center, std::abs((double)resizing),
num_circle_segments);
polygon_data<coordinate_type> poly;
set_points(poly, circle.begin(), circle.end());
polygon_set_data<coordinate_type> offset_set;
offset_set += poly;
polygon_set_data<coordinate_type> result;
detail::minkowski_offset<coordinate_type>::convolve_two_polygon_sets
(result, *this, offset_set);
if(resizing < 0) {
result = result & rect;//eliminate overhang
result = result ^ rect;//invert
}
*this = result;
return *this;
}
}}