#include "clipper/clipper_z.hpp"
#include "ClipperUtils.hpp"
#include "EdgeGrid.hpp"
#include "Layer.hpp"
#include "Print.hpp"
#include "ShortestPath.hpp"
#include "libslic3r.h"
#include <algorithm>
#include <numeric>
#include <unordered_set>
#include <tbb/parallel_for.h>
#ifndef NDEBUG
// #define BRIM_DEBUG_TO_SVG
#endif
namespace Slic3r {
static void append_and_translate(ExPolygons &dst, const ExPolygons &src, const PrintInstance &instance) {
size_t dst_idx = dst.size();
expolygons_append(dst, src);
for (; dst_idx < dst.size(); ++dst_idx)
dst[dst_idx].translate(instance.shift.x(), instance.shift.y());
}
static void append_and_translate(Polygons &dst, const Polygons &src, const PrintInstance &instance) {
size_t dst_idx = dst.size();
polygons_append(dst, src);
for (; dst_idx < dst.size(); ++dst_idx)
dst[dst_idx].translate(instance.shift.x(), instance.shift.y());
}
static float max_brim_width(const ConstPrintObjectPtrsAdaptor &objects)
{
assert(!objects.empty());
return float(std::accumulate(objects.begin(), objects.end(), 0.,
[](double partial_result, const PrintObject *object) {
return std::max(partial_result, object->config().brim_type == btNoBrim ? 0. : object->config().brim_width.value);
}));
}
static ConstPrintObjectPtrs get_top_level_objects_with_brim(const Print &print)
{
Polygons islands;
ConstPrintObjectPtrs island_to_object;
for (const PrintObject *object : print.objects()) {
Polygons islands_object;
islands_object.reserve(object->layers().front()->lslices.size());
for (const ExPolygon &ex_poly : object->layers().front()->lslices)
islands_object.emplace_back(ex_poly.contour);
islands.reserve(islands.size() + object->instances().size() * islands_object.size());
for (const PrintInstance &instance : object->instances())
for (Polygon &poly : islands_object) {
islands.emplace_back(poly);
islands.back().translate(instance.shift);
island_to_object.emplace_back(object);
}
}
assert(islands.size() == island_to_object.size());
ClipperLib_Z::Paths islands_clip;
islands_clip.reserve(islands.size());
for (const Polygon &poly : islands) {
islands_clip.emplace_back();
ClipperLib_Z::Path &island_clip = islands_clip.back();
island_clip.reserve(poly.points.size());
int island_idx = int(&poly - &islands.front());
// The Z coordinate carries index of the island used to get the pointer to the object.
for (const Point &pt : poly.points)
island_clip.emplace_back(pt.x(), pt.y(), island_idx + 1);
}
// Init Clipper
ClipperLib_Z::Clipper clipper;
// Assign the maximum Z from four points. This values is valid index of the island
clipper.ZFillFunction([](const ClipperLib_Z::IntPoint &e1bot, const ClipperLib_Z::IntPoint &e1top, const ClipperLib_Z::IntPoint &e2bot,
const ClipperLib_Z::IntPoint &e2top, ClipperLib_Z::IntPoint &pt) {
pt.z() = std::max(std::max(e1bot.z(), e1top.z()), std::max(e2bot.z(), e2top.z()));
});
// Add islands
clipper.AddPaths(islands_clip, ClipperLib_Z::ptSubject, true);
// Execute union operation to construct polytree
ClipperLib_Z::PolyTree islands_polytree;
clipper.Execute(ClipperLib_Z::ctUnion, islands_polytree, ClipperLib_Z::pftEvenOdd, ClipperLib_Z::pftEvenOdd);
std::unordered_set<size_t> processed_objects_idx;
ConstPrintObjectPtrs top_level_objects_with_brim;
for (int i = 0; i < islands_polytree.ChildCount(); ++i) {
for (const ClipperLib_Z::IntPoint &point : islands_polytree.Childs[i]->Contour) {
if (point.z() != 0 && processed_objects_idx.find(island_to_object[point.z() - 1]->id().id) == processed_objects_idx.end()) {
top_level_objects_with_brim.emplace_back(island_to_object[point.z() - 1]);
processed_objects_idx.insert(island_to_object[point.z() - 1]->id().id);
}
}
}
return top_level_objects_with_brim;
}
static Polygons top_level_outer_brim_islands(const ConstPrintObjectPtrs &top_level_objects_with_brim)
{
Polygons islands;
for (const PrintObject *object : top_level_objects_with_brim) {
//FIXME how about the brim type?
float brim_offset = float(scale_(object->config().brim_offset.value));
Polygons islands_object;
for (const ExPolygon &ex_poly : object->layers().front()->lslices) {
Polygons contour_offset = offset(ex_poly.contour, brim_offset);
for (Polygon &poly : contour_offset)
poly.douglas_peucker(SCALED_RESOLUTION);
polygons_append(islands_object, std::move(contour_offset));
}
for (const PrintInstance &instance : object->instances())
append_and_translate(islands, islands_object, instance);
}
return islands;
}
static ExPolygons top_level_outer_brim_area(const Print &print, const ConstPrintObjectPtrs &top_level_objects_with_brim, const float no_brim_offset)
{
std::unordered_set<size_t> top_level_objects_idx;
top_level_objects_idx.reserve(top_level_objects_with_brim.size());
for (const PrintObject *object : top_level_objects_with_brim)
top_level_objects_idx.insert(object->id().id);
ExPolygons brim_area;
Polygons no_brim_area;
for (const PrintObject *object : print.objects()) {
const BrimType brim_type = object->config().brim_type.value;
const float brim_offset = scale_(object->config().brim_offset.value);
const float brim_width = scale_(object->config().brim_width.value);
const bool is_top_outer_brim = top_level_objects_idx.find(object->id().id) != top_level_objects_idx.end();
ExPolygons brim_area_object;
Polygons no_brim_area_object;
for (const ExPolygon &ex_poly : object->layers().front()->lslices) {
if ((brim_type == BrimType::btOuterOnly || brim_type == BrimType::btOuterAndInner) && is_top_outer_brim)
append(brim_area_object, diff_ex(offset(ex_poly.contour, brim_width + brim_offset), offset(ex_poly.contour, brim_offset)));
if (brim_type == BrimType::btOuterOnly || brim_type == BrimType::btNoBrim)
append(no_brim_area_object, offset(ex_poly.holes, -no_brim_offset));
if (brim_type != BrimType::btNoBrim)
append(no_brim_area_object, offset(ex_poly.contour, brim_offset));
no_brim_area_object.emplace_back(ex_poly.contour);
}
for (const PrintInstance &instance : object->instances()) {
append_and_translate(brim_area, brim_area_object, instance);
append_and_translate(no_brim_area, no_brim_area_object, instance);
}
}
return diff_ex(brim_area, no_brim_area);
}
static ExPolygons inner_brim_area(const Print &print, const ConstPrintObjectPtrs &top_level_objects_with_brim, const float no_brim_offset)
{
std::unordered_set<size_t> top_level_objects_idx;
top_level_objects_idx.reserve(top_level_objects_with_brim.size());
for (const PrintObject *object : top_level_objects_with_brim)
top_level_objects_idx.insert(object->id().id);
ExPolygons brim_area;
ExPolygons no_brim_area;
Polygons holes;
for (const PrintObject *object : print.objects()) {
const BrimType brim_type = object->config().brim_type.value;
const float brim_offset = scale_(object->config().brim_offset.value);
const float brim_width = scale_(object->config().brim_width.value);
const bool top_outer_brim = top_level_objects_idx.find(object->id().id) != top_level_objects_idx.end();
ExPolygons brim_area_object;
ExPolygons no_brim_area_object;
Polygons holes_object;
for (const ExPolygon &ex_poly : object->layers().front()->lslices) {
if (brim_type == BrimType::btOuterOnly || brim_type == BrimType::btOuterAndInner) {
if (top_outer_brim)
no_brim_area_object.emplace_back(ex_poly);
else
append(brim_area_object, diff_ex(offset(ex_poly.contour, brim_width + brim_offset), offset(ex_poly.contour, brim_offset)));
}
if (brim_type == BrimType::btInnerOnly || brim_type == BrimType::btOuterAndInner)
append(brim_area_object, diff_ex(offset_ex(ex_poly.holes, -brim_offset), offset_ex(ex_poly.holes, -brim_width - brim_offset)));
if (brim_type == BrimType::btInnerOnly || brim_type == BrimType::btNoBrim)
append(no_brim_area_object, to_expolygons(offset(ex_poly.contour, no_brim_offset)));
if (brim_type == BrimType::btOuterOnly || brim_type == BrimType::btNoBrim)
append(no_brim_area_object, offset_ex(ex_poly.holes, -no_brim_offset));
append(holes_object, ex_poly.holes);
}
append(no_brim_area_object, offset_ex(object->layers().front()->lslices, brim_offset));
for (const PrintInstance &instance : object->instances()) {
append_and_translate(brim_area, brim_area_object, instance);
append_and_translate(no_brim_area, no_brim_area_object, instance);
append_and_translate(holes, holes_object, instance);
}
}
return diff_ex(intersection_ex(to_polygons(std::move(brim_area)), holes), no_brim_area);
}
// Flip orientation of open polylines to minimize travel distance.
static void optimize_polylines_by_reversing(Polylines *polylines)
{
for (size_t poly_idx = 1; poly_idx < polylines->size(); ++poly_idx) {
const Polyline &prev = (*polylines)[poly_idx - 1];
Polyline & next = (*polylines)[poly_idx];
if (!next.is_closed()) {
double dist_to_start = (next.first_point() - prev.last_point()).cast<double>().norm();
double dist_to_end = (next.last_point() - prev.last_point()).cast<double>().norm();
if (dist_to_end < dist_to_start)
next.reverse();
}
}
}
static Polylines connect_brim_lines(Polylines &&polylines, const Polygons &brim_area, float max_connection_length)
{
if (polylines.empty())
return Polylines();
BoundingBox bbox = get_extents(polylines);
bbox.merge(get_extents(brim_area));
EdgeGrid::Grid grid(bbox.inflated(SCALED_EPSILON));
grid.create(brim_area, polylines, coord_t(scale_(10.)));
struct Visitor
{
explicit Visitor(const EdgeGrid::Grid &grid) : grid(grid) {}
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);
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, brim_line.a, brim_line.b)) {
this->intersect = true;
return false;
}
}
// Continue traversing the grid along the edge.
return true;
}
const EdgeGrid::Grid &grid;
Line brim_line;
bool intersect;
} visitor(grid);
// Connect successive polylines if they are open, their ends are closer than max_connection_length.
// Remove empty polylines.
{
// Skip initial empty lines.
size_t poly_idx = 0;
for (; poly_idx < polylines.size() && polylines[poly_idx].empty(); ++ poly_idx) ;
size_t end = ++ poly_idx;
double max_connection_length2 = Slic3r::sqr(max_connection_length);
for (; poly_idx < polylines.size(); ++poly_idx) {
Polyline &next = polylines[poly_idx];
if (! next.empty()) {
Polyline &prev = polylines[end - 1];
bool connect = false;
if (! prev.is_closed() && ! next.is_closed()) {
double dist2 = (prev.last_point() - next.first_point()).cast<double>().squaredNorm();
if (dist2 <= max_connection_length2) {
visitor.brim_line.a = prev.last_point();
visitor.brim_line.b = next.first_point();
// Shrink the connection line to avoid collisions with the brim centerlines.
visitor.brim_line.extend(-SCALED_EPSILON);
grid.visit_cells_intersecting_line(visitor.brim_line.a, visitor.brim_line.b, visitor);
connect = ! visitor.intersect;
}
}
if (connect) {
append(prev.points, std::move(next.points));
} else {
if (end < poly_idx)
polylines[end] = std::move(next);
++ end;
}
}
}
if (end < polylines.size())
polylines.erase(polylines.begin() + end, polylines.end());
}
return std::move(polylines);
}
static void make_inner_brim(const Print &print, const ConstPrintObjectPtrs &top_level_objects_with_brim, ExtrusionEntityCollection &brim)
{
Flow flow = print.brim_flow();
ExPolygons islands_ex = inner_brim_area(print, top_level_objects_with_brim, flow.scaled_spacing());
Polygons loops;
islands_ex = offset_ex(islands_ex, -0.5f * float(flow.scaled_spacing()), jtSquare);
for (size_t i = 0; !islands_ex.empty(); ++i) {
for (ExPolygon &poly_ex : islands_ex)
poly_ex.douglas_peucker(SCALED_RESOLUTION);
polygons_append(loops, to_polygons(islands_ex));
islands_ex = offset_ex(islands_ex, -float(flow.scaled_spacing()), jtSquare);
}
loops = union_pt_chained_outside_in(loops);
std::reverse(loops.begin(), loops.end());
extrusion_entities_append_loops(brim.entities, std::move(loops), erSkirt, float(flow.mm3_per_mm()),
float(flow.width()), float(print.skirt_first_layer_height()));
}
// Produce brim lines around those objects, that have the brim enabled.
// Collect islands_area to be merged into the final 1st layer convex hull.
ExtrusionEntityCollection make_brim(const Print &print, PrintTryCancel try_cancel, Polygons &islands_area)
{
Flow flow = print.brim_flow();
ConstPrintObjectPtrs top_level_objects_with_brim = get_top_level_objects_with_brim(print);
Polygons islands = top_level_outer_brim_islands(top_level_objects_with_brim);
ExPolygons islands_area_ex = top_level_outer_brim_area(print, top_level_objects_with_brim, flow.scaled_spacing());
islands_area = to_polygons(islands_area_ex);
Polygons loops;
size_t num_loops = size_t(floor(max_brim_width(print.objects()) / flow.spacing()));
for (size_t i = 0; i < num_loops; ++i) {
try_cancel();
islands = offset(islands, float(flow.scaled_spacing()), jtSquare);
for (Polygon &poly : islands)
poly.douglas_peucker(SCALED_RESOLUTION);
polygons_append(loops, offset(islands, -0.5f * float(flow.scaled_spacing())));
}
loops = union_pt_chained_outside_in(loops);
std::vector<Polylines> loops_pl_by_levels;
{
Polylines loops_pl = to_polylines(loops);
loops_pl_by_levels.assign(loops_pl.size(), Polylines());
tbb::parallel_for(tbb::blocked_range<size_t>(0, loops_pl.size()),
[&loops_pl_by_levels, &loops_pl, &islands_area](const tbb::blocked_range<size_t> &range) {
for (size_t i = range.begin(); i < range.end(); ++i) {
loops_pl_by_levels[i] = chain_polylines(intersection_pl({ std::move(loops_pl[i]) }, islands_area));
}
});
}
// output
ExtrusionEntityCollection brim;
// Reduce down to the ordered list of polylines.
Polylines all_loops;
for (Polylines &polylines : loops_pl_by_levels)
append(all_loops, std::move(polylines));
loops_pl_by_levels.clear();
// Flip orientation of open polylines to minimize travel distance.
optimize_polylines_by_reversing(&all_loops);
#ifdef BRIM_DEBUG_TO_SVG
static int irun = 0;
++ irun;
{
SVG svg(debug_out_path("brim-%d.svg", irun).c_str(), get_extents(all_loops));
svg.draw(union_ex(islands), "blue");
svg.draw(islands_area_ex, "green");
svg.draw(all_loops, "black", coord_t(scale_(0.1)));
}
#endif // BRIM_DEBUG_TO_SVG
all_loops = connect_brim_lines(std::move(all_loops), offset(islands_area_ex, float(SCALED_EPSILON)), flow.scaled_spacing() * 2.f);
#ifdef BRIM_DEBUG_TO_SVG
{
SVG svg(debug_out_path("brim-connected-%d.svg", irun).c_str(), get_extents(all_loops));
svg.draw(union_ex(islands), "blue");
svg.draw(islands_area_ex, "green");
svg.draw(all_loops, "black", coord_t(scale_(0.1)));
}
#endif // BRIM_DEBUG_TO_SVG
const bool could_brim_intersects_skirt = std::any_of(print.objects().begin(), print.objects().end(), [&print](PrintObject *object) {
const BrimType &bt = object->config().brim_type;
return (bt == btOuterOnly || bt == btOuterAndInner) && print.config().skirt_distance.value < object->config().brim_width;
});
// If there is a possibility that brim intersects skirt, go through loops and split those extrusions
// The result is either the original Polygon or a list of Polylines
if (! print.skirt().empty() && could_brim_intersects_skirt)
{
// Find the bounding polygons of the skirt
const Polygons skirt_inners = offset(dynamic_cast<ExtrusionLoop*>(print.skirt().entities.back())->polygon(),
-float(scale_(print.skirt_flow().spacing()))/2.f,
ClipperLib::jtRound,
float(scale_(0.1)));
const Polygons skirt_outers = offset(dynamic_cast<ExtrusionLoop*>(print.skirt().entities.front())->polygon(),
float(scale_(print.skirt_flow().spacing()))/2.f,
ClipperLib::jtRound,
float(scale_(0.1)));
// First calculate the trimming region.
ClipperLib_Z::Paths trimming;
{
ClipperLib_Z::Paths input_subject;
ClipperLib_Z::Paths input_clip;
for (const Polygon &poly : skirt_outers) {
input_subject.emplace_back();
ClipperLib_Z::Path &out = input_subject.back();
out.reserve(poly.points.size());
for (const Point &pt : poly.points)
out.emplace_back(pt.x(), pt.y(), 0);
}
for (const Polygon &poly : skirt_inners) {
input_clip.emplace_back();
ClipperLib_Z::Path &out = input_clip.back();
out.reserve(poly.points.size());
for (const Point &pt : poly.points)
out.emplace_back(pt.x(), pt.y(), 0);
}
// init Clipper
ClipperLib_Z::Clipper clipper;
// add polygons
clipper.AddPaths(input_subject, ClipperLib_Z::ptSubject, true);
clipper.AddPaths(input_clip, ClipperLib_Z::ptClip, true);
// perform operation
clipper.Execute(ClipperLib_Z::ctDifference, trimming, ClipperLib_Z::pftEvenOdd, ClipperLib_Z::pftEvenOdd);
}
// Second, trim the extrusion loops with the trimming regions.
ClipperLib_Z::Paths loops_trimmed;
{
// Produce ClipperLib_Z::Paths from polylines (not necessarily closed).
ClipperLib_Z::Paths input_clip;
for (const Polyline &loop_pl : all_loops) {
input_clip.emplace_back();
ClipperLib_Z::Path& out = input_clip.back();
out.reserve(loop_pl.points.size());
int64_t loop_idx = &loop_pl - &all_loops.front();
for (const Point& pt : loop_pl.points)
// The Z coordinate carries index of the source loop.
out.emplace_back(pt.x(), pt.y(), loop_idx + 1);
}
// init Clipper
ClipperLib_Z::Clipper clipper;
clipper.ZFillFunction([](const ClipperLib_Z::IntPoint& e1bot, const ClipperLib_Z::IntPoint& e1top, const ClipperLib_Z::IntPoint& e2bot, const ClipperLib_Z::IntPoint& e2top, ClipperLib_Z::IntPoint& pt) {
// Assign a valid input loop identifier. Such an identifier is strictly positive, the next line is safe even in case one side of a segment
// hat the Z coordinate not set to the contour coordinate.
pt.z() = std::max(std::max(e1bot.z(), e1top.z()), std::max(e2bot.z(), e2top.z()));
});
// add polygons
clipper.AddPaths(input_clip, ClipperLib_Z::ptSubject, false);
clipper.AddPaths(trimming, ClipperLib_Z::ptClip, true);
// perform operation
ClipperLib_Z::PolyTree loops_trimmed_tree;
clipper.Execute(ClipperLib_Z::ctDifference, loops_trimmed_tree, ClipperLib_Z::pftEvenOdd, ClipperLib_Z::pftEvenOdd);
ClipperLib_Z::PolyTreeToPaths(loops_trimmed_tree, loops_trimmed);
}
// Third, produce the extrusions, sorted by the source loop indices.
{
std::vector<std::pair<const ClipperLib_Z::Path*, size_t>> loops_trimmed_order;
loops_trimmed_order.reserve(loops_trimmed.size());
for (const ClipperLib_Z::Path &path : loops_trimmed) {
size_t input_idx = 0;
for (const ClipperLib_Z::IntPoint &pt : path)
if (pt.z() > 0) {
input_idx = (size_t)pt.z();
break;
}
assert(input_idx != 0);
loops_trimmed_order.emplace_back(&path, input_idx);
}
std::stable_sort(loops_trimmed_order.begin(), loops_trimmed_order.end(),
[](const std::pair<const ClipperLib_Z::Path*, size_t> &l, const std::pair<const ClipperLib_Z::Path*, size_t> &r) {
return l.second < r.second;
});
Point last_pt(0, 0);
for (size_t i = 0; i < loops_trimmed_order.size();) {
// Find all pieces that the initial loop was split into.
size_t j = i + 1;
for (; j < loops_trimmed_order.size() && loops_trimmed_order[i].second == loops_trimmed_order[j].second; ++ j) ;
const ClipperLib_Z::Path &first_path = *loops_trimmed_order[i].first;
if (i + 1 == j && first_path.size() > 3 && first_path.front().x() == first_path.back().x() && first_path.front().y() == first_path.back().y()) {
auto *loop = new ExtrusionLoop();
brim.entities.emplace_back(loop);
loop->paths.emplace_back(erSkirt, float(flow.mm3_per_mm()), float(flow.width()), float(print.skirt_first_layer_height()));
Points &points = loop->paths.front().polyline.points;
points.reserve(first_path.size());
for (const ClipperLib_Z::IntPoint &pt : first_path)
points.emplace_back(coord_t(pt.x()), coord_t(pt.y()));
i = j;
} else {
//FIXME The path chaining here may not be optimal.
ExtrusionEntityCollection this_loop_trimmed;
this_loop_trimmed.entities.reserve(j - i);
for (; i < j; ++ i) {
this_loop_trimmed.entities.emplace_back(new ExtrusionPath(erSkirt, float(flow.mm3_per_mm()), float(flow.width()), float(print.skirt_first_layer_height())));
const ClipperLib_Z::Path &path = *loops_trimmed_order[i].first;
Points &points = static_cast<ExtrusionPath*>(this_loop_trimmed.entities.back())->polyline.points;
points.reserve(path.size());
for (const ClipperLib_Z::IntPoint &pt : path)
points.emplace_back(coord_t(pt.x()), coord_t(pt.y()));
}
chain_and_reorder_extrusion_entities(this_loop_trimmed.entities, &last_pt);
brim.entities.reserve(brim.entities.size() + this_loop_trimmed.entities.size());
append(brim.entities, std::move(this_loop_trimmed.entities));
this_loop_trimmed.entities.clear();
}
last_pt = brim.last_point();
}
}
} else {
extrusion_entities_append_loops_and_paths(brim.entities, std::move(all_loops), erSkirt, float(flow.mm3_per_mm()), float(flow.width()), float(print.skirt_first_layer_height()));
}
make_inner_brim(print, top_level_objects_with_brim, brim);
return brim;
}
} // namespace Slic3r