BambuStudio/libslic3r/Polygon.cpp

686 lines
22 KiB
C++

#include "BoundingBox.hpp"
#include "ClipperUtils.hpp"
#include "Exception.hpp"
#include "Polygon.hpp"
#include "Polyline.hpp"
namespace Slic3r {
double Polygon::length() const
{
double l = 0;
if (this->points.size() > 1) {
l = (this->points.back() - this->points.front()).cast<double>().norm();
for (size_t i = 1; i < this->points.size(); ++ i)
l += (this->points[i] - this->points[i - 1]).cast<double>().norm();
}
return l;
}
Lines Polygon::lines() const
{
return to_lines(*this);
}
Polyline Polygon::split_at_vertex(const Point &point) const
{
// find index of point
for (const Point &pt : this->points)
if (pt == point)
return this->split_at_index(int(&pt - &this->points.front()));
throw Slic3r::InvalidArgument("Point not found");
return Polyline();
}
// Split a closed polygon into an open polyline, with the split point duplicated at both ends.
Polyline Polygon::split_at_index(int index) const
{
Polyline polyline;
polyline.points.reserve(this->points.size() + 1);
for (Points::const_iterator it = this->points.begin() + index; it != this->points.end(); ++it)
polyline.points.push_back(*it);
for (Points::const_iterator it = this->points.begin(); it != this->points.begin() + index + 1; ++it)
polyline.points.push_back(*it);
return polyline;
}
double Polygon::area(const Points &points)
{
double a = 0.;
if (points.size() >= 3) {
Vec2d p1 = points.back().cast<double>();
for (const Point &p : points) {
Vec2d p2 = p.cast<double>();
a += cross2(p1, p2);
p1 = p2;
}
}
return 0.5 * a;
}
double Polygon::area() const
{
return Polygon::area(points);
}
bool Polygon::is_counter_clockwise() const
{
return ClipperLib::Orientation(this->points);
}
bool Polygon::is_clockwise() const
{
return !this->is_counter_clockwise();
}
bool Polygon::make_counter_clockwise()
{
if (!this->is_counter_clockwise()) {
this->reverse();
return true;
}
return false;
}
bool Polygon::make_clockwise()
{
if (this->is_counter_clockwise()) {
this->reverse();
return true;
}
return false;
}
void Polygon::douglas_peucker(double tolerance)
{
this->points.push_back(this->points.front());
Points p = MultiPoint::_douglas_peucker(this->points, tolerance);
p.pop_back();
this->points = std::move(p);
}
Polygons Polygon::simplify(double tolerance) const
{
// Works on CCW polygons only, CW contour will be reoriented to CCW by Clipper's simplify_polygons()!
assert(this->is_counter_clockwise());
// repeat first point at the end in order to apply Douglas-Peucker
// on the whole polygon
Points points = this->points;
points.push_back(points.front());
Polygon p(MultiPoint::_douglas_peucker(points, tolerance));
p.points.pop_back();
Polygons pp;
pp.push_back(p);
return simplify_polygons(pp);
}
// Only call this on convex polygons or it will return invalid results
void Polygon::triangulate_convex(Polygons* polygons) const
{
for (Points::const_iterator it = this->points.begin() + 2; it != this->points.end(); ++it) {
Polygon p;
p.points.reserve(3);
p.points.push_back(this->points.front());
p.points.push_back(*(it-1));
p.points.push_back(*it);
// this should be replaced with a more efficient call to a merge_collinear_segments() method
if (p.area() > 0) polygons->push_back(p);
}
}
// center of mass
// source: https://en.wikipedia.org/wiki/Centroid
Point Polygon::centroid() const
{
double area_sum = 0.;
Vec2d c(0., 0.);
if (points.size() >= 3) {
Vec2d p1 = points.back().cast<double>();
for (const Point &p : points) {
Vec2d p2 = p.cast<double>();
double a = cross2(p1, p2);
area_sum += a;
c += (p1 + p2) * a;
p1 = p2;
}
}
return Point(Vec2d(c / (3. * area_sum)));
}
bool Polygon::intersection(const Line &line, Point *intersection) const
{
if (this->points.size() < 2)
return false;
if (Line(this->points.front(), this->points.back()).intersection(line, intersection))
return true;
for (size_t i = 1; i < this->points.size(); ++ i)
if (Line(this->points[i - 1], this->points[i]).intersection(line, intersection))
return true;
return false;
}
bool Polygon::first_intersection(const Line& line, Point* intersection) const
{
if (this->points.size() < 2)
return false;
bool found = false;
double dmin = 0.;
Line l(this->points.back(), this->points.front());
for (size_t i = 0; i < this->points.size(); ++ i) {
l.b = this->points[i];
Point ip;
if (l.intersection(line, &ip)) {
if (! found) {
found = true;
dmin = (line.a - ip).cast<double>().squaredNorm();
*intersection = ip;
} else {
double d = (line.a - ip).cast<double>().squaredNorm();
if (d < dmin) {
dmin = d;
*intersection = ip;
}
}
}
l.a = l.b;
}
return found;
}
bool Polygon::intersections(const Line &line, Points *intersections) const
{
if (this->points.size() < 2)
return false;
size_t intersections_size = intersections->size();
Line l(this->points.back(), this->points.front());
for (size_t i = 0; i < this->points.size(); ++ i) {
l.b = this->points[i];
Point intersection;
if (l.intersection(line, &intersection))
intersections->emplace_back(std::move(intersection));
l.a = l.b;
}
return intersections->size() > intersections_size;
}
bool Polygon::overlaps(const Polygons& other) const
{
if (this->empty() || other.empty())
return false;
Polylines pl_out = intersection_pl(to_polylines(other), *this);
// See unit test SCENARIO("Clipper diff with polyline", "[Clipper]")
// for in which case the intersection_pl produces any intersection.
return !pl_out.empty() ||
// If *this is completely inside other, then pl_out is empty, but the expolygons overlap. Test for that situation.
std::any_of(other.begin(), other.end(), [this](auto& poly) {return poly.contains(this->points.front()); });
}
// Filter points from poly to the output with the help of FilterFn.
// filter function receives two vectors:
// v1: this_point - previous_point
// v2: next_point - this_point
// and returns true if the point is to be copied to the output.
template<typename FilterFn>
Points filter_points_by_vectors(const Points &poly, FilterFn filter)
{
// Last point is the first point visited.
Point p1 = poly.back();
// Previous vector to p1.
Vec2d v1 = (p1 - *(poly.end() - 2)).cast<double>();
Points out;
for (Point p2 : poly) {
// p2 is next point to the currently visited point p1.
Vec2d v2 = (p2 - p1).cast<double>();
if (filter(v1, v2))
out.emplace_back(p2);
v1 = v2;
p1 = p2;
}
return out;
}
template<typename ConvexConcaveFilterFn>
Points filter_convex_concave_points_by_angle_threshold(const Points &poly, double angle_threshold, ConvexConcaveFilterFn convex_concave_filter)
{
assert(angle_threshold >= 0.);
if (angle_threshold < EPSILON) {
double cos_angle = cos(angle_threshold);
return filter_points_by_vectors(poly, [convex_concave_filter, cos_angle](const Vec2d &v1, const Vec2d &v2){
return convex_concave_filter(v1, v2) && v1.normalized().dot(v2.normalized()) < cos_angle;
});
} else {
return filter_points_by_vectors(poly, [convex_concave_filter](const Vec2d &v1, const Vec2d &v2){
return convex_concave_filter(v1, v2);
});
}
}
Points Polygon::convex_points(double angle_threshold) const
{
return filter_convex_concave_points_by_angle_threshold(this->points, angle_threshold, [](const Vec2d &v1, const Vec2d &v2){ return cross2(v1, v2) > 0.; });
}
Points Polygon::concave_points(double angle_threshold) const
{
return filter_convex_concave_points_by_angle_threshold(this->points, angle_threshold, [](const Vec2d &v1, const Vec2d &v2){ return cross2(v1, v2) < 0.; });
}
// Projection of a point onto the polygon.
Point Polygon::point_projection(const Point &point) const
{
Point proj = point;
double dmin = std::numeric_limits<double>::max();
if (! this->points.empty()) {
for (size_t i = 0; i < this->points.size(); ++ i) {
const Point &pt0 = this->points[i];
const Point &pt1 = this->points[(i + 1 == this->points.size()) ? 0 : i + 1];
double d = (point - pt0).cast<double>().norm();
if (d < dmin) {
dmin = d;
proj = pt0;
}
d = (point - pt1).cast<double>().norm();
if (d < dmin) {
dmin = d;
proj = pt1;
}
Vec2d v1(coordf_t(pt1(0) - pt0(0)), coordf_t(pt1(1) - pt0(1)));
coordf_t div = v1.squaredNorm();
if (div > 0.) {
Vec2d v2(coordf_t(point(0) - pt0(0)), coordf_t(point(1) - pt0(1)));
coordf_t t = v1.dot(v2) / div;
if (t > 0. && t < 1.) {
Point foot(coord_t(floor(coordf_t(pt0(0)) + t * v1(0) + 0.5)), coord_t(floor(coordf_t(pt0(1)) + t * v1(1) + 0.5)));
d = (point - foot).cast<double>().norm();
if (d < dmin) {
dmin = d;
proj = foot;
}
}
}
}
}
return proj;
}
std::vector<float> Polygon::parameter_by_length() const
{
// Parametrize the polygon by its length.
std::vector<float> lengths(points.size()+1, 0.);
for (size_t i = 1; i < points.size(); ++ i)
lengths[i] = lengths[i-1] + (points[i] - points[i-1]).cast<float>().norm();
lengths.back() = lengths[lengths.size()-2] + (points.front() - points.back()).cast<float>().norm();
return lengths;
}
void Polygon::densify(float min_length, std::vector<float>* lengths_ptr)
{
std::vector<float> lengths_local;
std::vector<float>& lengths = lengths_ptr ? *lengths_ptr : lengths_local;
if (! lengths_ptr) {
// Length parametrization has not been provided. Calculate our own.
lengths = this->parameter_by_length();
}
assert(points.size() == lengths.size() - 1);
for (size_t j=1; j<=points.size(); ++j) {
bool last = j == points.size();
int i = last ? 0 : j;
if (lengths[j] - lengths[j-1] > min_length) {
Point diff = points[i] - points[j-1];
float diff_len = lengths[j] - lengths[j-1];
float r = (min_length/diff_len);
Point new_pt = points[j-1] + Point(r*diff[0], r*diff[1]);
points.insert(points.begin() + j, new_pt);
lengths.insert(lengths.begin() + j, lengths[j-1] + min_length);
}
}
assert(points.size() == lengths.size() - 1);
}
Polygon Polygon::transform(const Transform3d& trafo) const
{
unsigned int vertices_count = (unsigned int)points.size();
Polygon dstpoly;
dstpoly.points.resize(vertices_count);
if (vertices_count == 0)
return dstpoly;
unsigned int data_size = 3 * vertices_count * sizeof(float);
Eigen::MatrixXd src(3, vertices_count);
for (size_t i = 0; i < vertices_count; i++)
{
src.col(i) = Vec3d{ double(points[i].x()), double(points[i].y()),0. };
}
Eigen::MatrixXd dst(3, vertices_count);
dst = trafo * src.colwise().homogeneous();
for (size_t i = 0; i < vertices_count; i++)
{
dstpoly.points[i] = { dst(0,i),dst(1,i) };
}
return dstpoly;
}
BoundingBox get_extents(const Polygon &poly)
{
return poly.bounding_box();
}
BoundingBox get_extents(const Polygons &polygons)
{
BoundingBox bb;
if (! polygons.empty()) {
bb = get_extents(polygons.front());
for (size_t i = 1; i < polygons.size(); ++ i)
bb.merge(get_extents(polygons[i]));
}
return bb;
}
BoundingBox get_extents_rotated(const Polygon &poly, double angle)
{
return get_extents_rotated(poly.points, angle);
}
BoundingBox get_extents_rotated(const Polygons &polygons, double angle)
{
BoundingBox bb;
if (! polygons.empty()) {
bb = get_extents_rotated(polygons.front().points, angle);
for (size_t i = 1; i < polygons.size(); ++ i)
bb.merge(get_extents_rotated(polygons[i].points, angle));
}
return bb;
}
extern std::vector<BoundingBox> get_extents_vector(const Polygons &polygons)
{
std::vector<BoundingBox> out;
out.reserve(polygons.size());
for (Polygons::const_iterator it = polygons.begin(); it != polygons.end(); ++ it)
out.push_back(get_extents(*it));
return out;
}
// Polygon must be valid (at least three points), collinear points and duplicate points removed.
bool polygon_is_convex(const Points &poly)
{
if (poly.size() < 3)
return false;
Point p0 = poly[poly.size() - 2];
Point p1 = poly[poly.size() - 1];
for (size_t i = 0; i < poly.size(); ++ i) {
Point p2 = poly[i];
auto det = cross2((p1 - p0).cast<int64_t>(), (p2 - p1).cast<int64_t>());
if (det < 0)
return false;
p0 = p1;
p1 = p2;
}
return true;
}
bool has_duplicate_points(const Polygons &polys)
{
#if 1
// Check globally.
size_t cnt = 0;
for (const Polygon &poly : polys)
cnt += poly.points.size();
std::vector<Point> allpts;
allpts.reserve(cnt);
for (const Polygon &poly : polys)
allpts.insert(allpts.end(), poly.points.begin(), poly.points.end());
return has_duplicate_points(std::move(allpts));
#else
// Check per contour.
for (const Polygon &poly : polys)
if (has_duplicate_points(poly))
return true;
return false;
#endif
}
static inline bool is_stick(const Point &p1, const Point &p2, const Point &p3)
{
Point v1 = p2 - p1;
Point v2 = p3 - p2;
int64_t dir = int64_t(v1(0)) * int64_t(v2(0)) + int64_t(v1(1)) * int64_t(v2(1));
if (dir > 0)
// p3 does not turn back to p1. Do not remove p2.
return false;
double l2_1 = double(v1(0)) * double(v1(0)) + double(v1(1)) * double(v1(1));
double l2_2 = double(v2(0)) * double(v2(0)) + double(v2(1)) * double(v2(1));
if (dir == 0)
// p1, p2, p3 may make a perpendicular corner, or there is a zero edge length.
// Remove p2 if it is coincident with p1 or p2.
return l2_1 == 0 || l2_2 == 0;
// p3 turns back to p1 after p2. Are p1, p2, p3 collinear?
// Calculate distance from p3 to a segment (p1, p2) or from p1 to a segment(p2, p3),
// whichever segment is longer
double cross = double(v1(0)) * double(v2(1)) - double(v2(0)) * double(v1(1));
double dist2 = cross * cross / std::max(l2_1, l2_2);
return dist2 < EPSILON * EPSILON;
}
bool remove_sticks(Polygon &poly)
{
bool modified = false;
size_t j = 1;
for (size_t i = 1; i + 1 < poly.points.size(); ++ i) {
if (! is_stick(poly[j-1], poly[i], poly[i+1])) {
// Keep the point.
if (j < i)
poly.points[j] = poly.points[i];
++ j;
}
}
if (++ j < poly.points.size()) {
poly.points[j-1] = poly.points.back();
poly.points.erase(poly.points.begin() + j, poly.points.end());
modified = true;
}
while (poly.points.size() >= 3 && is_stick(poly.points[poly.points.size()-2], poly.points.back(), poly.points.front())) {
poly.points.pop_back();
modified = true;
}
while (poly.points.size() >= 3 && is_stick(poly.points.back(), poly.points.front(), poly.points[1]))
poly.points.erase(poly.points.begin());
return modified;
}
bool remove_sticks(Polygons &polys)
{
bool modified = false;
size_t j = 0;
for (size_t i = 0; i < polys.size(); ++ i) {
modified |= remove_sticks(polys[i]);
if (polys[i].points.size() >= 3) {
if (j < i)
std::swap(polys[i].points, polys[j].points);
++ j;
}
}
if (j < polys.size())
polys.erase(polys.begin() + j, polys.end());
return modified;
}
bool remove_degenerate(Polygons &polys)
{
bool modified = false;
size_t j = 0;
for (size_t i = 0; i < polys.size(); ++ i) {
if (polys[i].points.size() >= 3) {
if (j < i)
std::swap(polys[i].points, polys[j].points);
++ j;
} else
modified = true;
}
if (j < polys.size())
polys.erase(polys.begin() + j, polys.end());
return modified;
}
bool remove_small(Polygons &polys, double min_area)
{
bool modified = false;
size_t j = 0;
for (size_t i = 0; i < polys.size(); ++ i) {
if (std::abs(polys[i].area()) >= min_area) {
if (j < i)
std::swap(polys[i].points, polys[j].points);
++ j;
} else
modified = true;
}
if (j < polys.size())
polys.erase(polys.begin() + j, polys.end());
return modified;
}
void remove_collinear(Polygon &poly)
{
if (poly.points.size() > 2) {
// copy points and append both 1 and last point in place to cover the boundaries
Points pp;
pp.reserve(poly.points.size()+2);
pp.push_back(poly.points.back());
pp.insert(pp.begin()+1, poly.points.begin(), poly.points.end());
pp.push_back(poly.points.front());
// delete old points vector. Will be re-filled in the loop
poly.points.clear();
size_t i = 0;
size_t k = 0;
while (i < pp.size()-2) {
k = i+1;
const Point &p1 = pp[i];
while (k < pp.size()-1) {
const Point &p2 = pp[k];
const Point &p3 = pp[k+1];
Line l(p1, p3);
if(l.distance_to(p2) < SCALED_EPSILON) {
k++;
} else {
if(i > 0) poly.points.push_back(p1); // implicitly removes the first point we appended above
i = k;
break;
}
}
if(k > pp.size()-2) break; // all remaining points are collinear and can be skipped
}
poly.points.push_back(pp[i]);
}
}
void remove_collinear(Polygons &polys)
{
for (Polygon &poly : polys)
remove_collinear(poly);
}
Polygons polygons_simplify(const Polygons &source_polygons, double tolerance)
{
Polygons out;
out.reserve(source_polygons.size());
for (const Polygon &source_polygon : source_polygons) {
// Run Douglas / Peucker simplification algorithm on an open polyline (by repeating the first point at the end of the polyline),
Points simplified = MultiPoint::_douglas_peucker(to_polyline(source_polygon).points, tolerance);
// then remove the last (repeated) point.
simplified.pop_back();
// Simplify the decimated contour by ClipperLib.
bool ccw = ClipperLib::Area(simplified) > 0.;
for (Points &path : ClipperLib::SimplifyPolygons(ClipperUtils::SinglePathProvider(simplified), ClipperLib::pftNonZero)) {
if (! ccw)
// ClipperLib likely reoriented negative area contours to become positive. Reverse holes back to CW.
std::reverse(path.begin(), path.end());
out.emplace_back(std::move(path));
}
}
return out;
}
// Do polygons match? If they match, they must have the same topology,
// however their contours may be rotated.
bool polygons_match(const Polygon &l, const Polygon &r)
{
if (l.size() != r.size())
return false;
auto it_l = std::find(l.points.begin(), l.points.end(), r.points.front());
if (it_l == l.points.end())
return false;
auto it_r = r.points.begin();
for (; it_l != l.points.end(); ++ it_l, ++ it_r)
if (*it_l != *it_r)
return false;
it_l = l.points.begin();
for (; it_r != r.points.end(); ++ it_l, ++ it_r)
if (*it_l != *it_r)
return false;
return true;
}
bool overlaps(const Polygons& polys1, const Polygons& polys2)
{
for (const Polygon& poly1 : polys1) {
if (poly1.overlaps(polys2))
return true;
}
return false;
}
bool contains(const Polygon &polygon, const Point &p, bool border_result)
{
if (const int poly_count_inside = ClipperLib::PointInPolygon(p, polygon.points);
poly_count_inside == -1)
return border_result;
else
return (poly_count_inside % 2) == 1;
}
bool contains(const Polygons &polygons, const Point &p, bool border_result)
{
int poly_count_inside = 0;
for (const Polygon &poly : polygons) {
const int is_inside_this_poly = ClipperLib::PointInPolygon(p, poly.points);
if (is_inside_this_poly == -1)
return border_result;
poly_count_inside += is_inside_this_poly;
}
return (poly_count_inside % 2) == 1;
}
Polygon make_circle(double radius, double error)
{
double angle = 2. * acos(1. - error / radius);
size_t num_segments = size_t(ceil(2. * M_PI / angle));
return make_circle_num_segments(radius, num_segments);
}
Polygon make_circle_num_segments(double radius, size_t num_segments)
{
Polygon out;
out.points.reserve(num_segments);
double angle_inc = 2.0 * M_PI / num_segments;
for (size_t i = 0; i < num_segments; ++ i) {
const double angle = angle_inc * i;
out.points.emplace_back(coord_t(cos(angle) * radius), coord_t(sin(angle) * radius));
}
return out;
}
}