PrusaSlicer-NonPlainar/xs/src/libslic3r/Polyline.cpp
2018-01-17 10:39:05 +01:00

296 lines
7.9 KiB
C++

#include "BoundingBox.hpp"
#include "Polyline.hpp"
#include "ExPolygon.hpp"
#include "ExPolygonCollection.hpp"
#include "Line.hpp"
#include "Polygon.hpp"
#include <iostream>
#include <utility>
namespace Slic3r {
Polyline::operator Polylines() const
{
Polylines polylines;
polylines.push_back(*this);
return polylines;
}
Polyline::operator Line() const
{
if (this->points.size() > 2) CONFESS("Can't convert polyline with more than two points to a line");
return Line(this->points.front(), this->points.back());
}
Point
Polyline::last_point() const
{
return this->points.back();
}
Point
Polyline::leftmost_point() const
{
Point p = this->points.front();
for (Points::const_iterator it = this->points.begin() + 1; it != this->points.end(); ++it) {
if (it->x < p.x) p = *it;
}
return p;
}
Lines
Polyline::lines() const
{
Lines lines;
if (this->points.size() >= 2) {
lines.reserve(this->points.size() - 1);
for (Points::const_iterator it = this->points.begin(); it != this->points.end()-1; ++it) {
lines.push_back(Line(*it, *(it + 1)));
}
}
return lines;
}
// removes the given distance from the end of the polyline
void
Polyline::clip_end(double distance)
{
while (distance > 0) {
Point last_point = this->last_point();
this->points.pop_back();
if (this->points.empty()) break;
double last_segment_length = last_point.distance_to(this->last_point());
if (last_segment_length <= distance) {
distance -= last_segment_length;
continue;
}
Line segment(last_point, this->last_point());
this->points.push_back(segment.point_at(distance));
distance = 0;
}
}
// removes the given distance from the start of the polyline
void
Polyline::clip_start(double distance)
{
this->reverse();
this->clip_end(distance);
if (this->points.size() >= 2) this->reverse();
}
void
Polyline::extend_end(double distance)
{
// relocate last point by extending the last segment by the specified length
Line line(
this->points.back(),
*(this->points.end() - 2)
);
this->points.back() = line.point_at(-distance);
}
void
Polyline::extend_start(double distance)
{
// relocate first point by extending the first segment by the specified length
this->points.front() = Line(this->points.front(), this->points[1]).point_at(-distance);
}
/* this method returns a collection of points picked on the polygon contour
so that they are evenly spaced according to the input distance */
Points
Polyline::equally_spaced_points(double distance) const
{
Points points;
points.push_back(this->first_point());
double len = 0;
for (Points::const_iterator it = this->points.begin() + 1; it != this->points.end(); ++it) {
double segment_length = it->distance_to(*(it-1));
len += segment_length;
if (len < distance) continue;
if (len == distance) {
points.push_back(*it);
len = 0;
continue;
}
double take = segment_length - (len - distance); // how much we take of this segment
Line segment(*(it-1), *it);
points.push_back(segment.point_at(take));
--it;
len = -take;
}
return points;
}
void
Polyline::simplify(double tolerance)
{
this->points = MultiPoint::_douglas_peucker(this->points, tolerance);
}
/* This method simplifies all *lines* contained in the supplied area */
template <class T>
void
Polyline::simplify_by_visibility(const T &area)
{
Points &pp = this->points;
size_t s = 0;
bool did_erase = false;
for (size_t i = s+2; i < pp.size(); i = s + 2) {
if (area.contains(Line(pp[s], pp[i]))) {
pp.erase(pp.begin() + s + 1, pp.begin() + i);
did_erase = true;
} else {
++s;
}
}
if (did_erase)
this->simplify_by_visibility(area);
}
template void Polyline::simplify_by_visibility<ExPolygon>(const ExPolygon &area);
template void Polyline::simplify_by_visibility<ExPolygonCollection>(const ExPolygonCollection &area);
void
Polyline::split_at(const Point &point, Polyline* p1, Polyline* p2) const
{
if (this->points.empty()) return;
// find the line to split at
size_t line_idx = 0;
Point p = this->first_point();
double min = point.distance_to(p);
Lines lines = this->lines();
for (Lines::const_iterator line = lines.begin(); line != lines.end(); ++line) {
Point p_tmp = point.projection_onto(*line);
if (point.distance_to(p_tmp) < min) {
p = p_tmp;
min = point.distance_to(p);
line_idx = line - lines.begin();
}
}
// create first half
p1->points.clear();
for (Lines::const_iterator line = lines.begin(); line != lines.begin() + line_idx + 1; ++line) {
if (!line->a.coincides_with(p)) p1->points.push_back(line->a);
}
// we add point instead of p because they might differ because of numerical issues
// and caller might want to rely on point belonging to result polylines
p1->points.push_back(point);
// create second half
p2->points.clear();
p2->points.push_back(point);
for (Lines::const_iterator line = lines.begin() + line_idx; line != lines.end(); ++line) {
p2->points.push_back(line->b);
}
}
bool
Polyline::is_straight() const
{
/* Check that each segment's direction is equal to the line connecting
first point and last point. (Checking each line against the previous
one would cause the error to accumulate.) */
double dir = Line(this->first_point(), this->last_point()).direction();
Lines lines = this->lines();
for (Lines::const_iterator line = lines.begin(); line != lines.end(); ++line) {
if (!line->parallel_to(dir)) return false;
}
return true;
}
std::string
Polyline::wkt() const
{
std::ostringstream wkt;
wkt << "LINESTRING((";
for (Points::const_iterator p = this->points.begin(); p != this->points.end(); ++p) {
wkt << p->x << " " << p->y;
if (p != this->points.end()-1) wkt << ",";
}
wkt << "))";
return wkt.str();
}
BoundingBox get_extents(const Polyline &polyline)
{
return polyline.bounding_box();
}
BoundingBox get_extents(const Polylines &polylines)
{
BoundingBox bb;
if (! polylines.empty()) {
bb = polylines.front().bounding_box();
for (size_t i = 1; i < polylines.size(); ++ i)
bb.merge(polylines[i]);
}
return bb;
}
bool remove_degenerate(Polylines &polylines)
{
bool modified = false;
size_t j = 0;
for (size_t i = 0; i < polylines.size(); ++ i) {
if (polylines[i].points.size() >= 2) {
if (j < i)
std::swap(polylines[i].points, polylines[j].points);
++ j;
} else
modified = true;
}
if (j < polylines.size())
polylines.erase(polylines.begin() + j, polylines.end());
return modified;
}
ThickLines
ThickPolyline::thicklines() const
{
ThickLines lines;
if (this->points.size() >= 2) {
lines.reserve(this->points.size() - 1);
for (size_t i = 0; i < this->points.size()-1; ++i) {
ThickLine line(this->points[i], this->points[i+1]);
line.a_width = this->width[2*i];
line.b_width = this->width[2*i+1];
lines.push_back(line);
}
}
return lines;
}
void
ThickPolyline::reverse()
{
Polyline::reverse();
std::reverse(this->width.begin(), this->width.end());
std::swap(this->endpoints.first, this->endpoints.second);
}
Lines3 Polyline3::lines() const
{
Lines3 lines;
if (points.size() >= 2)
{
lines.reserve(points.size() - 1);
for (Points3::const_iterator it = points.begin(); it != points.end() - 1; ++it)
{
lines.emplace_back(*it, *(it + 1));
}
}
return lines;
}
}