PrusaSlicer-NonPlainar/src/libslic3r/PolylineCollection.cpp
2019-06-25 16:04:29 +02:00

93 lines
2.7 KiB
C++

#include "PolylineCollection.hpp"
namespace Slic3r {
struct Chaining
{
Point first;
Point last;
size_t idx;
};
template<typename T>
inline int nearest_point_index(const std::vector<Chaining> &pairs, const Point &start_near, bool no_reverse)
{
T dmin = std::numeric_limits<T>::max();
int idx = 0;
for (std::vector<Chaining>::const_iterator it = pairs.begin(); it != pairs.end(); ++it) {
T d = sqr(T(start_near(0) - it->first(0)));
if (d <= dmin) {
d += sqr(T(start_near(1) - it->first(1)));
if (d < dmin) {
idx = (it - pairs.begin()) * 2;
dmin = d;
if (dmin < EPSILON)
break;
}
}
if (! no_reverse) {
d = sqr(T(start_near(0) - it->last(0)));
if (d <= dmin) {
d += sqr(T(start_near(1) - it->last(1)));
if (d < dmin) {
idx = (it - pairs.begin()) * 2 + 1;
dmin = d;
if (dmin < EPSILON)
break;
}
}
}
}
return idx;
}
Polylines PolylineCollection::_chained_path_from(
const Polylines &src,
Point start_near,
bool no_reverse,
bool move_from_src)
{
std::vector<Chaining> endpoints;
endpoints.reserve(src.size());
for (size_t i = 0; i < src.size(); ++ i) {
Chaining c;
c.first = src[i].first_point();
if (! no_reverse)
c.last = src[i].last_point();
c.idx = i;
endpoints.push_back(c);
}
Polylines retval;
while (! endpoints.empty()) {
// find nearest point
int endpoint_index = nearest_point_index<double>(endpoints, start_near, no_reverse);
assert(endpoint_index >= 0 && size_t(endpoint_index) < endpoints.size() * 2);
if (move_from_src) {
retval.push_back(std::move(src[endpoints[endpoint_index/2].idx]));
} else {
retval.push_back(src[endpoints[endpoint_index/2].idx]);
}
if (endpoint_index & 1)
retval.back().reverse();
endpoints.erase(endpoints.begin() + endpoint_index/2);
start_near = retval.back().last_point();
}
return retval;
}
Point PolylineCollection::leftmost_point(const Polylines &polylines)
{
if (polylines.empty())
throw std::invalid_argument("leftmost_point() called on empty PolylineCollection");
Polylines::const_iterator it = polylines.begin();
Point p = it->leftmost_point();
for (++ it; it != polylines.end(); ++it) {
Point p2 = it->leftmost_point();
if (p2(0) < p(0))
p = p2;
}
return p;
}
} // namespace Slic3r