PrusaSlicer/src/libslic3r/GCode/AvoidCrossingPerimeters.cpp
2020-12-03 09:43:21 +01:00

1326 lines
67 KiB
C++

#include "../Layer.hpp"
#include "../GCode.hpp"
#include "../EdgeGrid.hpp"
#include "../Print.hpp"
#include "../Polygon.hpp"
#include "../ExPolygon.hpp"
#include "../Geometry.hpp"
#include "../ClipperUtils.hpp"
#include "../SVG.hpp"
#include "AvoidCrossingPerimeters.hpp"
#include <numeric>
#include <unordered_set>
namespace Slic3r {
struct TravelPoint
{
Point point;
// Index of the polygon containing this point. A negative value indicates that the point is not on any border.
int border_idx;
};
struct Intersection
{
// Index of the polygon containing this point of intersection.
size_t border_idx;
// Index of the line on the polygon containing this point of intersection.
size_t line_idx;
// Point of intersection.
Point point;
// Distance from the first point in the corresponding boundary
float distance;
};
// Finding all intersections of a set of contours with a line segment.
struct AllIntersectionsVisitor
{
AllIntersectionsVisitor(const EdgeGrid::Grid &grid, std::vector<Intersection> &intersections) : grid(grid), intersections(intersections)
{
intersection_set.reserve(intersections.capacity());
}
AllIntersectionsVisitor(const EdgeGrid::Grid &grid, std::vector<Intersection> &intersections, const Line &travel_line)
: grid(grid), intersections(intersections), travel_line(travel_line)
{
intersection_set.reserve(intersections.capacity());
}
void reset() {
intersection_set.clear();
}
bool operator()(coord_t iy, coord_t ix)
{
// Called with a row and colum of the grid cell, which is intersected by a line.
auto cell_data_range = grid.cell_data_range(iy, ix);
for (auto it_contour_and_segment = cell_data_range.first; it_contour_and_segment != cell_data_range.second; ++it_contour_and_segment) {
Point intersection_point;
if (travel_line.intersection(grid.line(*it_contour_and_segment), &intersection_point) &&
intersection_set.find(*it_contour_and_segment) == intersection_set.end()) {
intersections.push_back({ it_contour_and_segment->first, it_contour_and_segment->second, intersection_point });
intersection_set.insert(*it_contour_and_segment);
}
}
// Continue traversing the grid along the edge.
return true;
}
const EdgeGrid::Grid &grid;
std::vector<Intersection> &intersections;
Line travel_line;
std::unordered_set<std::pair<size_t, size_t>, boost::hash<std::pair<size_t, size_t>>> intersection_set;
};
// Visitor to check for any collision of a line segment with any contour stored inside the edge_grid.
struct FirstIntersectionVisitor
{
explicit FirstIntersectionVisitor(const EdgeGrid::Grid &grid) : grid(grid) {}
bool operator()(coord_t iy, coord_t ix)
{
assert(pt_current != nullptr);
assert(pt_next != nullptr);
// Called with a row and colum of the grid cell, which is intersected by a line.
auto cell_data_range = grid.cell_data_range(iy, ix);
this->intersect = false;
for (auto it_contour_and_segment = cell_data_range.first; it_contour_and_segment != cell_data_range.second; ++it_contour_and_segment) {
// End points of the line segment and their vector.
auto segment = grid.segment(*it_contour_and_segment);
if (Geometry::segments_intersect(segment.first, segment.second, *pt_current, *pt_next)) {
this->intersect = true;
return false;
}
}
// Continue traversing the grid along the edge.
return true;
}
const EdgeGrid::Grid &grid;
const Slic3r::Point *pt_current = nullptr;
const Slic3r::Point *pt_next = nullptr;
bool intersect = false;
};
// point_idx is the index from which is different vertex is searched.
template<bool forward>
static Point find_first_different_vertex(const Polygon &polygon, const size_t point_idx, const Point &point)
{
assert(point_idx < polygon.size());
// Solve case when vertex on passed index point_idx is different that pass point. This helps the following code keep simple.
if (point != polygon.points[point_idx])
return polygon.points[point_idx];
auto line_idx = (int(point_idx) + 1) % int(polygon.points.size());
assert(line_idx != int(point_idx));
if constexpr (forward)
for (; point == polygon.points[line_idx] && line_idx != int(point_idx); line_idx = line_idx + 1 < int(polygon.points.size()) ? line_idx + 1 : 0);
else
for (; point == polygon.points[line_idx] && line_idx != int(point_idx); line_idx = line_idx - 1 >= 0 ? line_idx - 1 : int(polygon.points.size()) - 1);
assert(point != polygon.points[line_idx]);
return polygon.points[line_idx];
}
static Vec2d three_points_inward_normal(const Point &left, const Point &middle, const Point &right)
{
assert(left != middle);
assert(middle != right);
return (perp(Point(middle - left)).cast<double>().normalized() + perp(Point(right - middle)).cast<double>().normalized()).normalized();
}
// Compute normal of the polygon's vertex in an inward direction
static Vec2d get_polygon_vertex_inward_normal(const Polygon &polygon, const size_t point_idx)
{
const size_t left_idx = prev_idx_modulo(point_idx, polygon.points);
const size_t right_idx = next_idx_modulo(point_idx, polygon.points);
const Point &middle = polygon.points[point_idx];
const Point &left = find_first_different_vertex<false>(polygon, left_idx, middle);
const Point &right = find_first_different_vertex<true>(polygon, right_idx, middle);
return three_points_inward_normal(left, middle, right);
}
// Compute offset of point_idx of the polygon in a direction of inward normal
static Point get_polygon_vertex_offset(const Polygon &polygon, const size_t point_idx, const int offset)
{
return polygon.points[point_idx] + (get_polygon_vertex_inward_normal(polygon, point_idx) * double(offset)).cast<coord_t>();
}
// Compute offset (in the direction of inward normal) of the point(passed on "middle") based on the nearest points laying on the polygon (left_idx and right_idx).
static Point get_middle_point_offset(const Polygon &polygon, const size_t left_idx, const size_t right_idx, const Point &middle, const coord_t offset)
{
const Point &left = find_first_different_vertex<false>(polygon, left_idx, middle);
const Point &right = find_first_different_vertex<true>(polygon, right_idx, middle);
return middle + (three_points_inward_normal(left, middle, right) * double(offset)).cast<coord_t>();
}
static Polyline to_polyline(const std::vector<TravelPoint> &travel)
{
Polyline result;
result.points.reserve(travel.size());
for (const TravelPoint &t_point : travel)
result.append(t_point.point);
return result;
}
// #define AVOID_CROSSING_PERIMETERS_DEBUG_OUTPUT
#ifdef AVOID_CROSSING_PERIMETERS_DEBUG_OUTPUT
static void export_travel_to_svg(const Polygons &boundary,
const Line &original_travel,
const Polyline &result_travel,
const std::vector<Intersection> &intersections,
const std::string &path)
{
BoundingBox bbox = get_extents(boundary);
::Slic3r::SVG svg(path, bbox);
svg.draw_outline(boundary, "green");
svg.draw(original_travel, "blue");
svg.draw(result_travel, "red");
svg.draw(original_travel.a, "black");
svg.draw(original_travel.b, "grey");
for (const Intersection &intersection : intersections)
svg.draw(intersection.point, "lightseagreen");
}
static void export_travel_to_svg(const Polygons &boundary,
const Line &original_travel,
const std::vector<TravelPoint> &result_travel,
const std::vector<Intersection> &intersections,
const std::string &path)
{
export_travel_to_svg(boundary, original_travel, to_polyline(result_travel), intersections, path);
}
#endif /* AVOID_CROSSING_PERIMETERS_DEBUG_OUTPUT */
// Returns a direction of the shortest path along the polygon boundary
enum class Direction { Forward, Backward };
// Returns a direction of the shortest path along the polygon boundary
static Direction get_shortest_direction(const AvoidCrossingPerimeters::Boundary &boundary,
const Intersection &intersection_first,
const Intersection &intersection_second,
float contour_length)
{
assert(intersection_first.border_idx == intersection_second.border_idx);
const Polygon &poly = boundary.boundaries[intersection_first.border_idx];
float dist_first = intersection_first.distance;
float dist_second = intersection_second.distance;
assert(dist_first >= 0.f && dist_first <= contour_length);
assert(dist_second >= 0.f && dist_second <= contour_length);
bool reversed = false;
if (dist_first > dist_second) {
std::swap(dist_first, dist_second);
reversed = true;
}
float total_length_forward = dist_second - dist_first;
float total_length_backward = dist_first + contour_length - dist_second;
if (reversed) std::swap(total_length_forward, total_length_backward);
total_length_forward -= (intersection_first.point - poly[intersection_first.line_idx]).cast<float>().norm();
total_length_backward -= (poly[(intersection_first.line_idx + 1) % poly.size()] - intersection_first.point).cast<float>().norm();
total_length_forward -= (poly[(intersection_second.line_idx + 1) % poly.size()] - intersection_second.point).cast<float>().norm();
total_length_backward -= (intersection_second.point - poly[intersection_second.line_idx]).cast<float>().norm();
if (total_length_forward < total_length_backward) return Direction::Forward;
return Direction::Backward;
}
// Straighten the travel path as long as it does not collide with the contours stored in edge_grid.
static std::vector<TravelPoint> simplify_travel(const AvoidCrossingPerimeters::Boundary &boundary, const std::vector<TravelPoint> &travel)
{
FirstIntersectionVisitor visitor(boundary.grid);
std::vector<TravelPoint> simplified_path;
simplified_path.reserve(travel.size());
simplified_path.emplace_back(travel.front());
// Try to skip some points in the path.
//FIXME maybe use a binary search to trim the line?
//FIXME how about searching tangent point at long segments?
for (size_t point_idx = 1; point_idx < travel.size(); ++point_idx) {
const Point &current_point = travel[point_idx - 1].point;
TravelPoint next = travel[point_idx];
visitor.pt_current = &current_point;
for (size_t point_idx_2 = point_idx + 1; point_idx_2 < travel.size(); ++point_idx_2) {
if (travel[point_idx_2].point == current_point) {
next = travel[point_idx_2];
point_idx = point_idx_2;
continue;
}
visitor.pt_next = &travel[point_idx_2].point;
boundary.grid.visit_cells_intersecting_line(*visitor.pt_current, *visitor.pt_next, visitor);
// Check if deleting point causes crossing a boundary
if (!visitor.intersect) {
next = travel[point_idx_2];
point_idx = point_idx_2;
}
}
simplified_path.emplace_back(next);
}
return simplified_path;
}
// Called by avoid_perimeters() and by simplify_travel_heuristics().
static size_t avoid_perimeters_inner(const GCode &gcodegen, const AvoidCrossingPerimeters::Boundary &boundary,
const Point &start,
const Point &end,
std::vector<TravelPoint> &result_out)
{
const Polygons &boundaries = boundary.boundaries;
const EdgeGrid::Grid &edge_grid = boundary.grid;
// Find all intersections between boundaries and the line segment, sort them along the line segment.
std::vector<Intersection> intersections;
{
intersections.reserve(boundaries.size());
AllIntersectionsVisitor visitor(edge_grid, intersections, Line(start, end));
edge_grid.visit_cells_intersecting_line(start, end, visitor);
Vec2d dir = (end - start).cast<double>();
for (Intersection &intersection : intersections)
intersection.distance = boundary.boundaries_params[intersection.border_idx][intersection.line_idx];
std::sort(intersections.begin(), intersections.end(), [dir](const auto &l, const auto &r) { return (r.point - l.point).template cast<double>().dot(dir) > 0.; });
}
std::vector<TravelPoint> result;
result.push_back({start, -1});
auto crossing_boundary_from_inside = [&boundary](const Point &start, const Intersection &intersection) {
const Polygon &poly = boundary.boundaries[intersection.border_idx];
Vec2d poly_line = Line(poly[intersection.line_idx], poly[(intersection.line_idx + 1) % poly.size()]).normal().cast<double>();
Vec2d intersection_vec = (intersection.point - start).cast<double>();
return poly_line.normalized().dot(intersection_vec.normalized()) >= 0;
};
for (auto it_first = intersections.begin(); it_first != intersections.end(); ++it_first) {
// The entry point to the boundary polygon
const Intersection &intersection_first = *it_first;
if(!crossing_boundary_from_inside(start, intersection_first))
continue;
// Skip the it_first from the search for the farthest exit point from the boundary polygon
auto it_last_item = std::make_reverse_iterator(it_first) - 1;
// Search for the farthest intersection different from it_first but with the same border_idx
auto it_second_r = std::find_if(intersections.rbegin(), it_last_item, [&intersection_first](const Intersection &intersection) {
return intersection_first.border_idx == intersection.border_idx;
});
// Append the first intersection into the path
size_t left_idx = intersection_first.line_idx;
size_t right_idx = intersection_first.line_idx + 1 == boundaries[intersection_first.border_idx].points.size() ? 0 : intersection_first.line_idx + 1;
// Offset of the polygon's point using get_middle_point_offset is used to simplify the calculation of intersection between the
// boundary and the travel. The appended point is translated in the direction of inward normal. This translation ensures that the
// appended point will be inside the polygon and not on the polygon border.
result.push_back({get_middle_point_offset(boundaries[intersection_first.border_idx], left_idx, right_idx, intersection_first.point, coord_t(SCALED_EPSILON)), int(intersection_first.border_idx)});
// Check if intersection line also exit the boundary polygon
if (it_second_r != it_last_item) {
// Transform reverse iterator to forward
auto it_second = it_second_r.base() - 1;
// The exit point from the boundary polygon
const Intersection &intersection_second = *it_second;
Direction shortest_direction = get_shortest_direction(boundary, intersection_first, intersection_second,
boundary.boundaries_params[intersection_first.border_idx].back());
// Append the path around the border into the path
if (shortest_direction == Direction::Forward)
for (int line_idx = int(intersection_first.line_idx); line_idx != int(intersection_second.line_idx);
line_idx = line_idx + 1 < int(boundaries[intersection_first.border_idx].size()) ? line_idx + 1 : 0)
result.push_back({get_polygon_vertex_offset(boundaries[intersection_first.border_idx],
(line_idx + 1 == int(boundaries[intersection_first.border_idx].points.size())) ? 0 : (line_idx + 1), coord_t(SCALED_EPSILON)), int(intersection_first.border_idx)});
else
for (int line_idx = int(intersection_first.line_idx); line_idx != int(intersection_second.line_idx);
line_idx = line_idx - 1 >= 0 ? line_idx - 1 : int(boundaries[intersection_first.border_idx].size()) - 1)
result.push_back({get_polygon_vertex_offset(boundaries[intersection_second.border_idx], line_idx + 0, coord_t(SCALED_EPSILON)), int(intersection_first.border_idx)});
// Append the farthest intersection into the path
left_idx = intersection_second.line_idx;
right_idx = (intersection_second.line_idx >= (boundaries[intersection_second.border_idx].points.size() - 1)) ? 0 : (intersection_second.line_idx + 1);
result.push_back({get_middle_point_offset(boundaries[intersection_second.border_idx], left_idx, right_idx, intersection_second.point, coord_t(SCALED_EPSILON)), int(intersection_second.border_idx)});
// Skip intersections in between
it_first = it_second;
}
}
result.push_back({end, -1});
#ifdef AVOID_CROSSING_PERIMETERS_DEBUG_OUTPUT
{
static int iRun = 0;
export_travel_to_svg(boundaries, Line(start, end), result, intersections,
debug_out_path("AvoidCrossingPerimetersInner-initial-%d.svg", iRun++));
}
#endif /* AVOID_CROSSING_PERIMETERS_DEBUG_OUTPUT */
if (! intersections.empty())
result = simplify_travel(boundary, result);
#ifdef AVOID_CROSSING_PERIMETERS_DEBUG_OUTPUT
{
static int iRun = 0;
export_travel_to_svg(boundaries, Line(start, end), result, intersections,
debug_out_path("AvoidCrossingPerimetersInner-final-%d.svg", iRun++));
}
#endif /* AVOID_CROSSING_PERIMETERS_DEBUG_OUTPUT */
append(result_out, std::move(result));
return intersections.size();
}
// Called by AvoidCrossingPerimeters::travel_to()
static size_t avoid_perimeters(const GCode &gcodegen, const AvoidCrossingPerimeters::Boundary &boundary,
const Point &start,
const Point &end,
Polyline &result_out)
{
// Travel line is completely or partially inside the bounding box.
std::vector<TravelPoint> path;
size_t num_intersections = avoid_perimeters_inner(gcodegen, boundary, start, end, path);
result_out = to_polyline(path);
#ifdef AVOID_CROSSING_PERIMETERS_DEBUG_OUTPUT
{
static int iRun = 0;
export_travel_to_svg(boundary.boundaries, Line(start, end), path, {}, debug_out_path("AvoidCrossingPerimeters-final-%d.svg", iRun ++));
}
#endif /* AVOID_CROSSING_PERIMETERS_DEBUG_OUTPUT */
return num_intersections;
}
// Check if anyone of ExPolygons contains whole travel.
// called by need_wipe() and AvoidCrossingPerimeters::travel_to()
// FIXME Lukas H.: Maybe similar approach could also be used for ExPolygon::contains()
static bool any_expolygon_contains(const ExPolygons &ex_polygons,
const std::vector<BoundingBox> &ex_polygons_bboxes,
const EdgeGrid::Grid &grid_lslice,
const Line &travel)
{
assert(ex_polygons.size() == ex_polygons_bboxes.size());
if(!grid_lslice.bbox().contains(travel.a) || !grid_lslice.bbox().contains(travel.b))
return false;
FirstIntersectionVisitor visitor(grid_lslice);
visitor.pt_current = &travel.a;
visitor.pt_next = &travel.b;
grid_lslice.visit_cells_intersecting_line(*visitor.pt_current, *visitor.pt_next, visitor);
if (!visitor.intersect) {
for (const ExPolygon &ex_polygon : ex_polygons) {
const BoundingBox &bbox = ex_polygons_bboxes[&ex_polygon - &ex_polygons.front()];
if (bbox.contains(travel.a) && bbox.contains(travel.b) && ex_polygon.contains(travel.a))
return true;
}
}
return false;
}
// Check if anyone of ExPolygons contains whole travel.
// called by need_wipe()
static bool any_expolygon_contains(const ExPolygons &ex_polygons, const std::vector<BoundingBox> &ex_polygons_bboxes, const EdgeGrid::Grid &grid_lslice, const Polyline &travel)
{
assert(ex_polygons.size() == ex_polygons_bboxes.size());
if(std::any_of(travel.points.begin(), travel.points.end(), [&grid_lslice](const Point &point) { return !grid_lslice.bbox().contains(point); }))
return false;
FirstIntersectionVisitor visitor(grid_lslice);
bool any_intersection = false;
for (size_t line_idx = 1; line_idx < travel.size(); ++line_idx) {
visitor.pt_current = &travel.points[line_idx - 1];
visitor.pt_next = &travel.points[line_idx];
grid_lslice.visit_cells_intersecting_line(*visitor.pt_current, *visitor.pt_next, visitor);
any_intersection = visitor.intersect;
if (any_intersection) break;
}
if (!any_intersection) {
for (const ExPolygon &ex_polygon : ex_polygons) {
const BoundingBox &bbox = ex_polygons_bboxes[&ex_polygon - &ex_polygons.front()];
if (std::all_of(travel.points.begin(), travel.points.end(), [&bbox](const Point &point) { return bbox.contains(point); }) &&
ex_polygon.contains(travel.points.front()))
return true;
}
}
return false;
}
static bool need_wipe(const GCode &gcodegen,
const EdgeGrid::Grid &grid_lslice,
const Line &original_travel,
const Polyline &result_travel,
const size_t intersection_count)
{
const ExPolygons &lslices = gcodegen.layer()->lslices;
const std::vector<BoundingBox> &lslices_bboxes = gcodegen.layer()->lslices_bboxes;
bool z_lift_enabled = gcodegen.config().retract_lift.get_at(gcodegen.writer().extruder()->id()) > 0.;
bool wipe_needed = false;
// If the original unmodified path doesn't have any intersection with boundary, then it is entirely inside the object otherwise is entirely
// outside the object.
if (intersection_count > 0) {
// The original layer is intersected with defined boundaries. Then it is necessary to make a detailed test.
// If the z-lift is enabled, then a wipe is needed when the original travel leads above the holes.
if (z_lift_enabled) {
if (any_expolygon_contains(lslices, lslices_bboxes, grid_lslice, original_travel)) {
// Check if original_travel and result_travel are not same.
// If both are the same, then it is possible to skip testing of result_travel
wipe_needed = !(result_travel.size() > 2 && result_travel.first_point() == original_travel.a && result_travel.last_point() == original_travel.b) &&
!any_expolygon_contains(lslices, lslices_bboxes, grid_lslice, result_travel);
} else {
wipe_needed = true;
}
} else {
wipe_needed = !any_expolygon_contains(lslices, lslices_bboxes, grid_lslice, result_travel);
}
}
return wipe_needed;
}
// called by get_perimeter_spacing() / get_perimeter_spacing_external()
static inline float get_default_perimeter_spacing(const PrintObject &print_object)
{
std::vector<unsigned int> printing_extruders = print_object.object_extruders();
assert(!printing_extruders.empty());
float avg_extruder = 0;
for(unsigned int extruder_id : printing_extruders)
avg_extruder += float(scale_(print_object.print()->config().nozzle_diameter.get_at(extruder_id)));
avg_extruder /= printing_extruders.size();
return avg_extruder;
}
// called by get_boundary()
static float get_perimeter_spacing(const Layer &layer)
{
size_t regions_count = 0;
float perimeter_spacing = 0.f;
for (const LayerRegion *layer_region : layer.regions())
if (layer_region != nullptr && !layer_region->slices.empty()) {
perimeter_spacing += layer_region->flow(frPerimeter).scaled_spacing();
++regions_count;
}
assert(perimeter_spacing >= 0.f);
if (regions_count != 0)
perimeter_spacing /= float(regions_count);
else
perimeter_spacing = get_default_perimeter_spacing(*layer.object());
return perimeter_spacing;
}
// called by get_boundary_external()
static float get_perimeter_spacing_external(const Layer &layer)
{
size_t regions_count = 0;
float perimeter_spacing = 0.f;
for (const PrintObject *object : layer.object()->print()->objects())
if (const Layer *l = object->get_layer_at_printz(layer.print_z, EPSILON); l)
for (const LayerRegion *layer_region : l->regions())
if (layer_region != nullptr && !layer_region->slices.empty()) {
perimeter_spacing += layer_region->flow(frPerimeter).scaled_spacing();
++ regions_count;
}
assert(perimeter_spacing >= 0.f);
if (regions_count != 0)
perimeter_spacing /= float(regions_count);
else
perimeter_spacing = get_default_perimeter_spacing(*layer.object());
return perimeter_spacing;
}
// Adds points around all vertices so that the offset affects only small sections around these vertices.
static void resample_polygon(Polygon &polygon, double dist_from_vertex)
{
Points resampled_poly;
resampled_poly.reserve(3 * polygon.size());
resampled_poly.emplace_back(polygon.first_point());
for (size_t pt_idx = 1; pt_idx < polygon.size(); ++pt_idx) {
const Point &p1 = polygon[pt_idx - 1];
const Point &p2 = polygon[pt_idx];
double line_length = (p2 - p1).cast<double>().norm();
Vector line_vec = ((p2 - p1).cast<double>().normalized() * dist_from_vertex).cast<coord_t>();
if (line_length > 2 * dist_from_vertex) {
resampled_poly.emplace_back(p1 + line_vec);
resampled_poly.emplace_back(p2 - line_vec);
}
resampled_poly.emplace_back(polygon[pt_idx]);
}
polygon.points = std::move(resampled_poly);
}
static void resample_expolygon(ExPolygon &ex_polygon, double dist_from_vertex)
{
resample_polygon(ex_polygon.contour, dist_from_vertex);
for (Polygon &polygon : ex_polygon.holes) resample_polygon(polygon, dist_from_vertex);
}
static void resample_expolygons(ExPolygons &ex_polygons, double dist_from_vertex)
{
for (ExPolygon &ex_poly : ex_polygons) resample_expolygon(ex_poly, dist_from_vertex);
}
static void precompute_polygon_distances(const Polygon &polygon, std::vector<float> &polygon_distances_out)
{
polygon_distances_out.assign(polygon.size() + 1, 0.f);
for (size_t point_idx = 1; point_idx < polygon.size(); ++point_idx)
polygon_distances_out[point_idx] = polygon_distances_out[point_idx - 1] + (polygon[point_idx].cast<float>() - polygon[point_idx - 1].cast<float>()).norm();
polygon_distances_out.back() = polygon_distances_out[polygon.size() - 1] + (polygon.last_point().cast<float>() - polygon.first_point().cast<float>()).norm();
}
static void precompute_expolygon_distances(const ExPolygon &ex_polygon, std::vector<std::vector<float>> &expolygon_distances_out)
{
expolygon_distances_out.assign(ex_polygon.holes.size() + 1, std::vector<float>());
precompute_polygon_distances(ex_polygon.contour, expolygon_distances_out.front());
for (size_t hole_idx = 0; hole_idx < ex_polygon.holes.size(); ++hole_idx)
precompute_polygon_distances(ex_polygon.holes[hole_idx], expolygon_distances_out[hole_idx + 1]);
}
// It is highly based on the function contour_distance2 from the ElephantFootCompensation.cpp
static std::vector<float> contour_distance(const EdgeGrid::Grid &grid,
const std::vector<float> &poly_distances,
const size_t contour_idx,
const Polygon &polygon,
double compensation,
double search_radius)
{
assert(! polygon.empty());
assert(polygon.size() >= 2);
std::vector<float> out;
if (polygon.size() > 2)
{
struct Visitor {
Visitor(const EdgeGrid::Grid &grid, const size_t contour_idx, const std::vector<float> &polygon_distances, double dist_same_contour_accept, double dist_same_contour_reject) :
grid(grid), idx_contour(contour_idx), contour(*grid.contours()[contour_idx]), boundary_parameters(polygon_distances), dist_same_contour_accept(dist_same_contour_accept), dist_same_contour_reject(dist_same_contour_reject) {}
void init(const Points &contour, const Point &apoint)
{
this->idx_point = &apoint - contour.data();
this->point = apoint;
this->found = false;
this->dir_inside = this->dir_inside_at_point(contour, this->idx_point);
this->distance = std::numeric_limits<double>::max();
}
bool operator()(coord_t iy, coord_t ix)
{
// Called with a row and colum of the grid cell, which is intersected by a line.
auto cell_data_range = this->grid.cell_data_range(iy, ix);
for (auto it_contour_and_segment = cell_data_range.first; it_contour_and_segment != cell_data_range.second;
++it_contour_and_segment) {
// End points of the line segment and their vector.
std::pair<const Point &, const Point &> segment = this->grid.segment(*it_contour_and_segment);
const Vec2d v = (segment.second - segment.first).cast<double>();
const Vec2d va = (this->point - segment.first).cast<double>();
const double l2 = v.squaredNorm(); // avoid a sqrt
const double t = (l2 == 0.0) ? 0. : clamp(0., 1., va.dot(v) / l2);
// Closest point from this->point to the segment.
const Vec2d foot = segment.first.cast<double>() + t * v;
const Vec2d bisector = foot - this->point.cast<double>();
const double dist = bisector.norm();
if ((!this->found || dist < this->distance) && this->dir_inside.dot(bisector) > 0) {
bool accept = true;
if (it_contour_and_segment->first == idx_contour) {
// Complex case: The closest segment originates from the same contour as the starting point.
// Reject the closest point if its distance along the contour is reasonable compared to the current contour bisector
// (this->pt, foot).
const Slic3r::Points &ipts = *grid.contours()[it_contour_and_segment->first];
double param_lo = boundary_parameters[this->idx_point];
double param_hi = t * sqrt(l2);
double param_end = boundary_parameters.back();
const size_t ipt = it_contour_and_segment->second;
if (ipt + 1 < ipts.size())
param_hi += boundary_parameters[ipt > 0 ? ipt - 1 : 0];
if (param_lo > param_hi)
std::swap(param_lo, param_hi);
assert(param_lo > -SCALED_EPSILON && param_lo <= param_end + SCALED_EPSILON);
assert(param_hi > -SCALED_EPSILON && param_hi <= param_end + SCALED_EPSILON);
double dist_along_contour = std::min(param_hi - param_lo, param_lo + param_end - param_hi);
if (dist_along_contour < dist_same_contour_accept)
accept = false;
else if (dist < dist_same_contour_reject + SCALED_EPSILON) {
// this->point is close to foot. This point will only be accepted if the path along the contour is significantly
// longer than the bisector. That is, the path shall not bulge away from the bisector too much.
// Bulge is estimated by 0.6 of the circle circumference drawn around the bisector.
// Test whether the contour is convex or concave.
bool inside = (t == 0.) ? this->inside_corner(ipts, ipt, this->point) :
(t == 1.) ? this->inside_corner(ipts, ipt + 1 == ipts.size() ? 0 : ipt + 1, this->point) :
this->left_of_segment(ipts, ipt, this->point);
accept = inside && dist_along_contour > 0.6 * M_PI * dist;
}
}
if (accept && (!this->found || dist < this->distance)) {
// Simple case: Just measure the shortest distance.
this->distance = dist;
this->found = true;
}
}
}
// Continue traversing the grid.
return true;
}
const EdgeGrid::Grid &grid;
const size_t idx_contour;
const Points &contour;
const std::vector<float> &boundary_parameters;
const double dist_same_contour_accept;
const double dist_same_contour_reject;
size_t idx_point;
Point point;
// Direction inside the contour from idx_point, not normalized.
Vec2d dir_inside;
bool found;
double distance;
private:
static Vec2d dir_inside_at_point(const Points &contour, size_t i)
{
size_t iprev = prev_idx_modulo(i, contour);
size_t inext = next_idx_modulo(i, contour);
Vec2d v1 = (contour[i] - contour[iprev]).cast<double>();
Vec2d v2 = (contour[inext] - contour[i]).cast<double>();
return Vec2d(-v1.y() - v2.y(), v1.x() + v2.x());
}
static bool inside_corner(const Slic3r::Points &contour, size_t i, const Point &pt_oposite)
{
const Vec2d pt = pt_oposite.cast<double>();
size_t iprev = prev_idx_modulo(i, contour);
size_t inext = next_idx_modulo(i, contour);
Vec2d v1 = (contour[i] - contour[iprev]).cast<double>();
Vec2d v2 = (contour[inext] - contour[i]).cast<double>();
bool left_of_v1 = cross2(v1, pt - contour[iprev].cast<double>()) > 0.;
bool left_of_v2 = cross2(v2, pt - contour[i].cast<double>()) > 0.;
return cross2(v1, v2) > 0 ? left_of_v1 && left_of_v2 : // convex corner
left_of_v1 || left_of_v2; // concave corner
}
static bool left_of_segment(const Slic3r::Points &contour, size_t i, const Point &pt_oposite)
{
const Vec2d pt = pt_oposite.cast<double>();
size_t inext = next_idx_modulo(i, contour);
Vec2d v = (contour[inext] - contour[i]).cast<double>();
return cross2(v, pt - contour[i].cast<double>()) > 0.;
}
} visitor(grid, contour_idx, poly_distances, 0.5 * compensation * M_PI, search_radius);
out.reserve(polygon.size());
Point radius_vector(search_radius, search_radius);
for (const Point &pt : polygon.points) {
visitor.init(polygon.points, pt);
grid.visit_cells_intersecting_box(BoundingBox(pt - radius_vector, pt + radius_vector), visitor);
out.emplace_back(float(visitor.found ? std::min(visitor.distance, search_radius) : search_radius));
}
}
return out;
}
// Polygon offset which ensures that if a polygon breaks up into several separate parts, the original polygon will be used in these places.
static ExPolygons inner_offset(const ExPolygons &ex_polygons, double offset, double min_contour_width = scale_(0.001))
{
double search_radius = 2. * (offset + min_contour_width);
ExPolygons ex_poly_result = ex_polygons;
resample_expolygons(ex_poly_result, offset / 2);
for (ExPolygon &ex_poly : ex_poly_result) {
BoundingBox bbox(get_extents(ex_poly));
bbox.offset(SCALED_EPSILON);
EdgeGrid::Grid grid;
grid.set_bbox(bbox);
grid.create(ex_poly, coord_t(0.7 * search_radius));
std::vector<std::vector<float>> ex_poly_distances;
precompute_expolygon_distances(ex_poly, ex_poly_distances);
std::vector<std::vector<float>> offsets;
offsets.reserve(ex_poly.holes.size() + 1);
for (size_t idx_contour = 0; idx_contour <= ex_poly.holes.size(); ++idx_contour) {
const Polygon &poly = (idx_contour == 0) ? ex_poly.contour : ex_poly.holes[idx_contour - 1];
assert(poly.is_counter_clockwise() == (idx_contour == 0));
std::vector<float> distances = contour_distance(grid, ex_poly_distances[idx_contour], idx_contour, poly, offset, search_radius);
for (float &distance : distances) {
if (distance < min_contour_width)
distance = 0.f;
else if (distance > min_contour_width + 2. * offset)
distance = - float(offset);
else
distance = - (distance - float(min_contour_width)) / 2.f;
}
offsets.emplace_back(distances);
}
ExPolygons offset_ex_poly = variable_offset_inner_ex(ex_poly, offsets);
// If variable_offset_inner_ex produces empty result, then original ex_polygon is used
if (offset_ex_poly.size() == 1) {
ex_poly = std::move(offset_ex_poly.front());
} else if (offset_ex_poly.size() > 1) {
// fix_after_inner_offset called inside variable_offset_inner_ex sometimes produces
// tiny artefacts polygons, so these artefacts are removed.
double max_area = offset_ex_poly.front().area();
size_t max_area_idx = 0;
for (size_t poly_idx = 1; poly_idx < offset_ex_poly.size(); ++poly_idx) {
double area = offset_ex_poly[poly_idx].area();
if (max_area < area) {
max_area = area;
max_area_idx = poly_idx;
}
}
ex_poly = std::move(offset_ex_poly[max_area_idx]);
}
}
return ex_poly_result;
}
// called by AvoidCrossingPerimeters::travel_to()
static ExPolygons get_boundary(const Layer &layer)
{
const float perimeter_spacing = get_perimeter_spacing(layer);
const float perimeter_offset = perimeter_spacing / 2.f;
ExPolygons boundary = union_ex(inner_offset(layer.lslices, perimeter_offset));
// Collect all top layers that will not be crossed.
size_t polygons_count = 0;
for (const LayerRegion *layer_region : layer.regions())
for (const Surface &surface : layer_region->fill_surfaces.surfaces)
if (surface.is_top()) ++polygons_count;
if (polygons_count > 0) {
ExPolygons top_layer_polygons;
top_layer_polygons.reserve(polygons_count);
for (const LayerRegion *layer_region : layer.regions())
for (const Surface &surface : layer_region->fill_surfaces.surfaces)
if (surface.is_top()) top_layer_polygons.emplace_back(surface.expolygon);
top_layer_polygons = union_ex(top_layer_polygons);
return diff_ex(boundary, offset_ex(top_layer_polygons, -perimeter_offset));
}
return boundary;
}
// called by AvoidCrossingPerimeters::travel_to()
static Polygons get_boundary_external(const Layer &layer)
{
const float perimeter_spacing = get_perimeter_spacing(layer);
const float perimeter_offset = perimeter_spacing / 2.f;
Polygons boundary;
// Collect all holes for all printed objects and their instances, which will be printed at the same time as passed "layer".
for (const PrintObject *object : layer.object()->print()->objects()) {
Polygons polygons_per_obj;
if (const Layer *l = object->get_layer_at_printz(layer.print_z, EPSILON); l)
for (const ExPolygon &island : l->lslices) append(polygons_per_obj, island.holes);
for (const PrintInstance &instance : object->instances()) {
size_t boundary_idx = boundary.size();
append(boundary, polygons_per_obj);
for (; boundary_idx < boundary.size(); ++boundary_idx)
boundary[boundary_idx].translate(instance.shift);
}
}
// Used offset_ex for cases when another object will be in the hole of another polygon
boundary = to_polygons(offset_ex(boundary, perimeter_offset));
// Reverse all polygons for making normals point from the polygon out.
for (Polygon &poly : boundary)
poly.reverse();
return boundary;
}
static void init_boundary_distances(AvoidCrossingPerimeters::Boundary *boundary)
{
boundary->boundaries_params.assign(boundary->boundaries.size(), std::vector<float>());
for (size_t poly_idx = 0; poly_idx < boundary->boundaries.size(); ++poly_idx)
precompute_polygon_distances(boundary->boundaries[poly_idx], boundary->boundaries_params[poly_idx]);
}
static void init_boundary(AvoidCrossingPerimeters::Boundary *boundary, Polygons &&boundary_polygons)
{
boundary->clear();
boundary->boundaries = std::move(boundary_polygons);
BoundingBox bbox(get_extents(boundary->boundaries));
bbox.offset(SCALED_EPSILON);
boundary->bbox = BoundingBoxf(bbox.min.cast<double>(), bbox.max.cast<double>());
boundary->grid.set_bbox(bbox);
// FIXME 1mm grid?
boundary->grid.create(boundary->boundaries, coord_t(scale_(1.)));
init_boundary_distances(boundary);
}
// Plan travel, which avoids perimeter crossings by following the boundaries of the layer.
Polyline AvoidCrossingPerimeters::travel_to(const GCode &gcodegen, const Point &point, bool *could_be_wipe_disabled)
{
// If use_external, then perform the path planning in the world coordinate system (correcting for the gcodegen offset).
// Otherwise perform the path planning in the coordinate system of the active object.
bool use_external = m_use_external_mp || m_use_external_mp_once;
Point scaled_origin = use_external ? Point::new_scale(gcodegen.origin()(0), gcodegen.origin()(1)) : Point(0, 0);
const Point start = gcodegen.last_pos() + scaled_origin;
const Point end = point + scaled_origin;
const Line travel(start, end);
Polyline result_pl;
size_t travel_intersection_count = 0;
Vec2d startf = start.cast<double>();
Vec2d endf = end .cast<double>();
if (!use_external && !gcodegen.layer()->lslices.empty() && !any_expolygon_contains(gcodegen.layer()->lslices, gcodegen.layer()->lslices_bboxes, m_grid_lslice, travel)) {
// Initialize m_internal only when it is necessary.
if (m_internal.boundaries.empty())
init_boundary(&m_internal, to_polygons(get_boundary(*gcodegen.layer())));
// Trim the travel line by the bounding box.
if (Geometry::liang_barsky_line_clipping(startf, endf, m_internal.bbox)) {
travel_intersection_count = avoid_perimeters(gcodegen, m_internal, startf.cast<coord_t>(), endf.cast<coord_t>(), result_pl);
result_pl.points.front() = start;
result_pl.points.back() = end;
}
} else if(use_external) {
// Initialize m_external only when exist any external travel for the current layer.
if (m_external.boundaries.empty())
init_boundary(&m_external, get_boundary_external(*gcodegen.layer()));
// Trim the travel line by the bounding box.
if (!m_external.boundaries.empty() && Geometry::liang_barsky_line_clipping(startf, endf, m_external.bbox)) {
travel_intersection_count = avoid_perimeters(gcodegen, m_external, startf.cast<coord_t>(), endf.cast<coord_t>(), result_pl);
result_pl.points.front() = start;
result_pl.points.back() = end;
}
}
if(result_pl.empty()) {
// Travel line is completely outside the bounding box.
result_pl = {start, end};
travel_intersection_count = 0;
}
double max_detour_length scale_(gcodegen.config().avoid_crossing_perimeters_max_detour);
if (max_detour_length > 0 && (result_pl.length() - travel.length()) > max_detour_length)
result_pl = {start, end};
if (use_external) {
result_pl.translate(-scaled_origin);
*could_be_wipe_disabled = false;
} else
*could_be_wipe_disabled = !need_wipe(gcodegen, m_grid_lslice, travel, result_pl, travel_intersection_count);
return result_pl;
}
// ************************************* AvoidCrossingPerimeters::init_layer() *****************************************
void AvoidCrossingPerimeters::init_layer(const Layer &layer)
{
m_internal.clear();
m_external.clear();
BoundingBox bbox_slice(get_extents(layer.lslices));
bbox_slice.offset(SCALED_EPSILON);
m_grid_lslice.set_bbox(bbox_slice);
//FIXME 1mm grid?
m_grid_lslice.create(layer.lslices, coord_t(scale_(1.)));
}
#if 0
static double travel_length(const std::vector<TravelPoint> &travel) {
double total_length = 0;
for (size_t idx = 1; idx < travel.size(); ++idx)
total_length += (travel[idx].point - travel[idx - 1].point).cast<double>().norm();
return total_length;
}
// Called by avoid_perimeters() and by simplify_travel_heuristics().
static size_t avoid_perimeters_inner(const AvoidCrossingPerimeters::Boundary &boundary,
const Point &start,
const Point &end,
std::vector<TravelPoint> &result_out)
{
const Polygons &boundaries = boundary.boundaries;
const EdgeGrid::Grid &edge_grid = boundary.grid;
// Find all intersections between boundaries and the line segment, sort them along the line segment.
std::vector<Intersection> intersections;
{
intersections.reserve(boundaries.size());
AllIntersectionsVisitor visitor(edge_grid, intersections, Line(start, end));
edge_grid.visit_cells_intersecting_line(start, end, visitor);
Vec2d dir = (end - start).cast<double>();
for (Intersection &intersection : intersections)
intersection.distance = boundary.boundaries_params[intersection.border_idx][intersection.line_idx];
std::sort(intersections.begin(), intersections.end(), [dir](const auto &l, const auto &r) { return (r.point - l.point).template cast<double>().dot(dir) > 0.; });
}
std::vector<TravelPoint> result;
result.push_back({start, -1});
for (auto it_first = intersections.begin(); it_first != intersections.end(); ++it_first) {
// The entry point to the boundary polygon
const Intersection &intersection_first = *it_first;
// Skip the it_first from the search for the farthest exit point from the boundary polygon
auto it_last_item = std::make_reverse_iterator(it_first) - 1;
// Search for the farthest intersection different from it_first but with the same border_idx
auto it_second_r = std::find_if(intersections.rbegin(), it_last_item, [&intersection_first](const Intersection &intersection) {
return intersection_first.border_idx == intersection.border_idx;
});
// Append the first intersection into the path
size_t left_idx = intersection_first.line_idx;
size_t right_idx = intersection_first.line_idx + 1 == boundaries[intersection_first.border_idx].points.size() ? 0 : intersection_first.line_idx + 1;
// Offset of the polygon's point using get_middle_point_offset is used to simplify the calculation of intersection between the
// boundary and the travel. The appended point is translated in the direction of inward normal. This translation ensures that the
// appended point will be inside the polygon and not on the polygon border.
result.push_back({get_middle_point_offset(boundaries[intersection_first.border_idx], left_idx, right_idx, intersection_first.point, coord_t(SCALED_EPSILON)), int(intersection_first.border_idx)});
// Check if intersection line also exit the boundary polygon
if (it_second_r != it_last_item) {
// Transform reverse iterator to forward
auto it_second = it_second_r.base() - 1;
// The exit point from the boundary polygon
const Intersection &intersection_second = *it_second;
Direction shortest_direction = get_shortest_direction(boundary, intersection_first, intersection_second,
boundary.boundaries_params[intersection_first.border_idx].back());
// Append the path around the border into the path
if (shortest_direction == Direction::Forward)
for (int line_idx = int(intersection_first.line_idx); line_idx != int(intersection_second.line_idx);
line_idx = line_idx + 1 < int(boundaries[intersection_first.border_idx].size()) ? line_idx + 1 : 0)
result.push_back({get_polygon_vertex_offset(boundaries[intersection_first.border_idx],
(line_idx + 1 == int(boundaries[intersection_first.border_idx].points.size())) ? 0 : (line_idx + 1), coord_t(SCALED_EPSILON)), int(intersection_first.border_idx)});
else
for (int line_idx = int(intersection_first.line_idx); line_idx != int(intersection_second.line_idx);
line_idx = line_idx - 1 >= 0 ? line_idx - 1 : int(boundaries[intersection_first.border_idx].size()) - 1)
result.push_back({get_polygon_vertex_offset(boundaries[intersection_second.border_idx], line_idx + 0, coord_t(SCALED_EPSILON)), int(intersection_first.border_idx)});
// Append the farthest intersection into the path
left_idx = intersection_second.line_idx;
right_idx = (intersection_second.line_idx >= (boundaries[intersection_second.border_idx].points.size() - 1)) ? 0 : (intersection_second.line_idx + 1);
result.push_back({get_middle_point_offset(boundaries[intersection_second.border_idx], left_idx, right_idx, intersection_second.point, coord_t(SCALED_EPSILON)), int(intersection_second.border_idx)});
// Skip intersections in between
it_first = it_second;
}
}
result.push_back({end, -1});
#ifdef AVOID_CROSSING_PERIMETERS_DEBUG_OUTPUT
{
static int iRun = 0;
export_travel_to_svg(boundaries, Line(start, end), result, intersections,
debug_out_path("AvoidCrossingPerimetersInner-initial-%d.svg", iRun++));
}
#endif /* AVOID_CROSSING_PERIMETERS_DEBUG_OUTPUT */
if (! intersections.empty())
result = simplify_travel(boundary, result);
#ifdef AVOID_CROSSING_PERIMETERS_DEBUG_OUTPUT
{
static int iRun = 0;
export_travel_to_svg(boundaries, Line(start, end), result, intersections,
debug_out_path("AvoidCrossingPerimetersInner-final-%d.svg", iRun++));
}
#endif /* AVOID_CROSSING_PERIMETERS_DEBUG_OUTPUT */
append(result_out, std::move(result));
return intersections.size();
}
static std::vector<TravelPoint> simplify_travel_heuristics(const AvoidCrossingPerimeters::Boundary &boundary,
const std::vector<TravelPoint> &travel)
{
std::vector<TravelPoint> simplified_path;
std::vector<Intersection> intersections;
AllIntersectionsVisitor visitor(boundary.grid, intersections);
simplified_path.reserve(travel.size());
simplified_path.emplace_back(travel.front());
for (size_t point_idx = 1; point_idx < travel.size(); ++point_idx) {
// Skip all indexes on the same polygon
while (point_idx < travel.size() && travel[point_idx - 1].border_idx == travel[point_idx].border_idx) {
simplified_path.emplace_back(travel[point_idx]);
point_idx++;
}
if (point_idx < travel.size()) {
const TravelPoint &current = travel[point_idx - 1];
const TravelPoint &next = travel[point_idx];
TravelPoint new_next = next;
size_t new_point_idx = point_idx;
double path_length = (next.point - current.point).cast<double>().norm();
double new_path_shorter_by = 0.;
size_t border_idx_change_count = 0;
std::vector<TravelPoint> shortcut;
for (size_t point_idx_2 = point_idx + 1; point_idx_2 < travel.size(); ++point_idx_2) {
const TravelPoint &possible_new_next = travel[point_idx_2];
if (travel[point_idx_2 - 1].border_idx != travel[point_idx_2].border_idx)
border_idx_change_count++;
if (border_idx_change_count >= 2)
break;
path_length += (possible_new_next.point - travel[point_idx_2 - 1].point).cast<double>().norm();
double shortcut_length = (possible_new_next.point - current.point).cast<double>().norm();
if ((path_length - shortcut_length) <= scale_(10.0))
continue;
intersections.clear();
visitor.reset();
visitor.travel_line.a = current.point;
visitor.travel_line.b = possible_new_next.point;
boundary.grid.visit_cells_intersecting_line(visitor.travel_line.a, visitor.travel_line.b, visitor);
if (!intersections.empty()) {
Vec2d dir = (visitor.travel_line.b - visitor.travel_line.a).cast<double>();
std::sort(intersections.begin(), intersections.end(), [dir](const auto &l, const auto &r) { return (r.point - l.point).template cast<double>().dot(dir) > 0.; });
size_t last_border_idx_count = 0;
for (const Intersection &intersection : intersections)
if (int(intersection.border_idx) == possible_new_next.border_idx)
++last_border_idx_count;
if (last_border_idx_count > 0)
continue;
std::vector<TravelPoint> possible_shortcut;
avoid_perimeters_inner(boundary, current.point, possible_new_next.point, possible_shortcut);
double shortcut_travel = travel_length(possible_shortcut);
if (path_length > shortcut_travel && path_length - shortcut_travel > new_path_shorter_by) {
new_path_shorter_by = path_length - shortcut_travel;
shortcut = possible_shortcut;
new_next = possible_new_next;
new_point_idx = point_idx_2;
}
}
}
if (!shortcut.empty()) {
assert(shortcut.size() >= 2);
simplified_path.insert(simplified_path.end(), shortcut.begin() + 1, shortcut.end() - 1);
point_idx = new_point_idx;
}
simplified_path.emplace_back(new_next);
}
}
return simplified_path;
}
// Called by AvoidCrossingPerimeters::travel_to()
static size_t avoid_perimeters(const AvoidCrossingPerimeters::Boundary &boundary,
const Point &start,
const Point &end,
Polyline &result_out)
{
// Travel line is completely or partially inside the bounding box.
std::vector<TravelPoint> path;
size_t num_intersections = avoid_perimeters_inner(boundary, start, end, path);
if (num_intersections) {
path = simplify_travel_heuristics(boundary, path);
std::reverse(path.begin(), path.end());
path = simplify_travel_heuristics(boundary, path);
std::reverse(path.begin(), path.end());
}
result_out = to_polyline(path);
#ifdef AVOID_CROSSING_PERIMETERS_DEBUG_OUTPUT
{
static int iRun = 0;
export_travel_to_svg(boundaries, Line(start, end), path, {}, debug_out_path("AvoidCrossingPerimeters-final-%d.svg", iRun ++));
}
#endif /* AVOID_CROSSING_PERIMETERS_DEBUG_OUTPUT */
return num_intersections;
}
// Plan travel, which avoids perimeter crossings by following the boundaries of the layer.
Polyline AvoidCrossingPerimeters::travel_to(const GCode &gcodegen, const Point &point, bool *could_be_wipe_disabled)
{
// If use_external, then perform the path planning in the world coordinate system (correcting for the gcodegen offset).
// Otherwise perform the path planning in the coordinate system of the active object.
bool use_external = m_use_external_mp || m_use_external_mp_once;
Point scaled_origin = use_external ? Point::new_scale(gcodegen.origin()(0), gcodegen.origin()(1)) : Point(0, 0);
Point start = gcodegen.last_pos() + scaled_origin;
Point end = point + scaled_origin;
Polyline result_pl;
size_t travel_intersection_count = 0;
Vec2d startf = start.cast<double>();
Vec2d endf = end .cast<double>();
// Trim the travel line by the bounding box.
if (Geometry::liang_barsky_line_clipping(startf, endf, (use_external ? m_external : m_internal).bbox)) {
// Travel line is completely or partially inside the bounding box.
//FIXME initialize m_boundaries / m_boundaries_external on demand?
travel_intersection_count = avoid_perimeters((use_external ? m_external : m_internal), startf.cast<coord_t>(), endf.cast<coord_t>(),
result_pl);
result_pl.points.front() = start;
result_pl.points.back() = end;
} else {
// Travel line is completely outside the bounding box.
result_pl = {start, end};
travel_intersection_count = 0;
}
Line travel(start, end);
double max_detour_length scale_(gcodegen.config().avoid_crossing_perimeters_max_detour);
if (max_detour_length > 0 && (result_pl.length() - travel.length()) > max_detour_length)
result_pl = {start, end};
if (use_external) {
result_pl.translate(-scaled_origin);
*could_be_wipe_disabled = false;
} else
*could_be_wipe_disabled = !need_wipe(gcodegen, m_grid_lslice, travel, result_pl, travel_intersection_count);
return result_pl;
}
// called by AvoidCrossingPerimeters::init_layer()->get_boundary()/get_boundary_external()
static std::pair<Polygons, Polygons> split_expolygon(const ExPolygons &ex_polygons)
{
Polygons contours, holes;
contours.reserve(ex_polygons.size());
holes.reserve(std::accumulate(ex_polygons.begin(), ex_polygons.end(), size_t(0),
[](size_t sum, const ExPolygon &ex_poly) { return sum + ex_poly.holes.size(); }));
for (const ExPolygon &ex_poly : ex_polygons) {
contours.emplace_back(ex_poly.contour);
append(holes, ex_poly.holes);
}
return std::make_pair(std::move(contours), std::move(holes));
}
// called by AvoidCrossingPerimeters::init_layer()
static ExPolygons get_boundary(const Layer &layer)
{
const float perimeter_spacing = get_perimeter_spacing(layer);
const float perimeter_offset = perimeter_spacing / 2.f;
size_t polygons_count = 0;
for (const LayerRegion *layer_region : layer.regions())
polygons_count += layer_region->slices.surfaces.size();
ExPolygons boundary;
boundary.reserve(polygons_count);
for (const LayerRegion *layer_region : layer.regions())
for (const Surface &surface : layer_region->slices.surfaces)
boundary.emplace_back(surface.expolygon);
boundary = union_ex(boundary);
ExPolygons perimeter_boundary = offset_ex(boundary, -perimeter_offset);
ExPolygons result_boundary;
if (perimeter_boundary.size() != boundary.size()) {
//FIXME ???
// If any part of the polygon is missing after shrinking, then for misisng parts are is used the boundary of the slice.
ExPolygons missing_perimeter_boundary = offset_ex(diff_ex(boundary,
offset_ex(perimeter_boundary, perimeter_offset + float(SCALED_EPSILON) / 2.f)),
perimeter_offset + float(SCALED_EPSILON));
perimeter_boundary = offset_ex(perimeter_boundary, perimeter_offset);
append(perimeter_boundary, std::move(missing_perimeter_boundary));
// By calling intersection_ex some artifacts arose by previous operations are removed.
result_boundary = intersection_ex(offset_ex(perimeter_boundary, -perimeter_offset), boundary);
} else {
result_boundary = std::move(perimeter_boundary);
}
auto [contours, holes] = split_expolygon(boundary);
// Add an outer boundary to avoid crossing perimeters from supports
ExPolygons outer_boundary = union_ex(
diff(offset(Geometry::convex_hull(contours), 2.f * perimeter_spacing), offset(contours, perimeter_spacing + perimeter_offset)));
result_boundary.insert(result_boundary.end(), outer_boundary.begin(), outer_boundary.end());
ExPolygons holes_boundary = offset_ex(holes, -perimeter_spacing);
result_boundary.insert(result_boundary.end(), holes_boundary.begin(), holes_boundary.end());
result_boundary = union_ex(result_boundary);
// Collect all top layers that will not be crossed.
polygons_count = 0;
for (const LayerRegion *layer_region : layer.regions())
for (const Surface &surface : layer_region->fill_surfaces.surfaces)
if (surface.is_top()) ++polygons_count;
if (polygons_count > 0) {
ExPolygons top_layer_polygons;
top_layer_polygons.reserve(polygons_count);
for (const LayerRegion *layer_region : layer.regions())
for (const Surface &surface : layer_region->fill_surfaces.surfaces)
if (surface.is_top()) top_layer_polygons.emplace_back(surface.expolygon);
top_layer_polygons = union_ex(top_layer_polygons);
return diff_ex(result_boundary, offset_ex(top_layer_polygons, -perimeter_offset));
}
return result_boundary;
}
// called by AvoidCrossingPerimeters::init_layer()
static ExPolygons get_boundary_external(const Layer &layer)
{
const float perimeter_spacing = get_perimeter_spacing_external(layer);
const float perimeter_offset = perimeter_spacing / 2.f;
ExPolygons boundary;
// Collect all polygons for all printed objects and their instances, which will be printed at the same time as passed "layer".
for (const PrintObject *object : layer.object()->print()->objects()) {
ExPolygons polygons_per_obj;
//FIXME with different layering, layers on other objects will not be found at this object's print_z.
// Search an overlap of layers?
if (const Layer* l = object->get_layer_at_printz(layer.print_z, EPSILON); l)
for (const LayerRegion *layer_region : l->regions())
for (const Surface &surface : layer_region->slices.surfaces)
polygons_per_obj.emplace_back(surface.expolygon);
for (const PrintInstance &instance : object->instances()) {
size_t boundary_idx = boundary.size();
boundary.insert(boundary.end(), polygons_per_obj.begin(), polygons_per_obj.end());
for (; boundary_idx < boundary.size(); ++boundary_idx)
boundary[boundary_idx].translate(instance.shift);
}
}
boundary = union_ex(boundary);
auto [contours, holes] = split_expolygon(boundary);
// Polygons in which is possible traveling without crossing perimeters of another object.
// A convex hull allows removing unnecessary detour caused by following the boundary of the object.
ExPolygons result_boundary =
diff_ex(offset(Geometry::convex_hull(contours), 2.f * perimeter_spacing),offset(contours, perimeter_spacing + perimeter_offset));
// All holes are extended for forcing travel around the outer perimeter of a hole when a hole is crossed.
append(result_boundary, diff_ex(offset(holes, perimeter_spacing), offset(holes, perimeter_offset)));
return union_ex(result_boundary);
}
void AvoidCrossingPerimeters::init_layer(const Layer &layer)
{
m_internal.boundaries.clear();
m_external.boundaries.clear();
m_internal.boundaries = to_polygons(get_boundary(layer));
m_external.boundaries = to_polygons(get_boundary_external(layer));
BoundingBox bbox(get_extents(m_internal.boundaries));
bbox.offset(SCALED_EPSILON);
BoundingBox bbox_external = get_extents(m_external.boundaries);
bbox_external.offset(SCALED_EPSILON);
BoundingBox bbox_slice(get_extents(layer.lslices));
bbox_slice.offset(SCALED_EPSILON);
m_internal.bbox = BoundingBoxf(bbox.min.cast<double>(), bbox.max.cast<double>());
m_external.bbox = BoundingBoxf(bbox_external.min.cast<double>(), bbox_external.max.cast<double>());
m_internal.grid.set_bbox(bbox);
//FIX1ME 1mm grid?
m_internal.grid.create(m_internal.boundaries, coord_t(scale_(1.)));
m_external.grid.set_bbox(bbox_external);
//FIX1ME 1mm grid?
m_external.grid.create(m_external.boundaries, coord_t(scale_(1.)));
m_grid_lslice.set_bbox(bbox_slice);
//FIX1ME 1mm grid?
m_grid_lslice.create(layer.lslices, coord_t(scale_(1.)));
init_boundary_distances(&m_internal);
init_boundary_distances(&m_external);
}
#endif
} // namespace Slic3r