3DPrinting/PrusaSlicer-NonPlainar
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Slicing of meshes, chaining of open polylines:

Browse Source 
The open polylines are sorted by decreasing length, so the new chains
are seeded with the longer chains.
This commit is contained in:
bubnikv 2018-10-05 11:23:24 +02:00
parent 517b96eef8
commit b8c2566c44
1 changed files with 345 additions and 303 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

648
xs/src/libslic3r/TriangleMesh.cpp
View File

@ -1,6 +1,7 @@
#include "TriangleMesh.hpp"
#include "ClipperUtils.hpp"
#include "Geometry.hpp"
#include "MultiPoint.hpp"
#include "qhull/src/libqhullcpp/Qhull.h"
#include "qhull/src/libqhullcpp/QhullFacetList.h"
#include "qhull/src/libqhullcpp/QhullVertexSet.h"
@ -1232,6 +1233,344 @@ static inline void remove_tangent_edges(std::vector<IntersectionLine> &lines)
}
}
struct OpenPolyline {
OpenPolyline() {};
OpenPolyline(const IntersectionReference &start, const IntersectionReference &end, Points &&points) :
start(start), end(end), points(std::move(points)), consumed(false) { this->length = Slic3r::length(this->points); }
void reverse() {
std::swap(start, end);
std::reverse(points.begin(), points.end());
}
IntersectionReference start;
IntersectionReference end;
Points points;
double length;
bool consumed;
};
// called by TriangleMeshSlicer::make_loops() to connect sliced triangles into closed loops and open polylines by the triangle connectivity.
// Only connects segments crossing triangles of the same orientation.
static void chain_lines_by_triangle_connectivity(std::vector<IntersectionLine> &lines, Polygons &loops, std::vector<OpenPolyline> &open_polylines)
{
// Build a map of lines by edge_a_id and a_id.
std::vector<IntersectionLine*> by_edge_a_id;
std::vector<IntersectionLine*> by_a_id;
by_edge_a_id.reserve(lines.size());
by_a_id.reserve(lines.size());
for (IntersectionLine &line : lines) {
if (! line.skip()) {
if (line.edge_a_id != -1)
by_edge_a_id.emplace_back(&line);
if (line.a_id != -1)
by_a_id.emplace_back(&line);
}
}
auto by_edge_lower = [](const IntersectionLine* il1, const IntersectionLine *il2) { return il1->edge_a_id < il2->edge_a_id; };
auto by_vertex_lower = [](const IntersectionLine* il1, const IntersectionLine *il2) { return il1->a_id < il2->a_id; };
std::sort(by_edge_a_id.begin(), by_edge_a_id.end(), by_edge_lower);
std::sort(by_a_id.begin(), by_a_id.end(), by_vertex_lower);
// Chain the segments with a greedy algorithm, collect the loops and unclosed polylines.
IntersectionLines::iterator it_line_seed = lines.begin();
for (;;) {
// take first spare line and start a new loop
IntersectionLine *first_line = nullptr;
for (; it_line_seed != lines.end(); ++ it_line_seed)
if (it_line_seed->is_seed_candidate()) {
//if (! it_line_seed->skip()) {
first_line = &(*it_line_seed ++);
break;
}
if (first_line == nullptr)
break;
first_line->set_skip();
Points loop_pts;
loop_pts.emplace_back(first_line->a);
IntersectionLine *last_line = first_line;
/*
printf("first_line edge_a_id = %d, edge_b_id = %d, a_id = %d, b_id = %d, a = %d,%d, b = %d,%d\n",
first_line->edge_a_id, first_line->edge_b_id, first_line->a_id, first_line->b_id,
first_line->a.x, first_line->a.y, first_line->b.x, first_line->b.y);
*/
IntersectionLine key;
for (;;) {
// find a line starting where last one finishes
IntersectionLine* next_line = nullptr;
if (last_line->edge_b_id != -1) {
key.edge_a_id = last_line->edge_b_id;
auto it_begin = std::lower_bound(by_edge_a_id.begin(), by_edge_a_id.end(), &key, by_edge_lower);
if (it_begin != by_edge_a_id.end()) {
auto it_end = std::upper_bound(it_begin, by_edge_a_id.end(), &key, by_edge_lower);
for (auto it_line = it_begin; it_line != it_end; ++ it_line)
if (! (*it_line)->skip()) {
next_line = *it_line;
break;
}
}
}
if (next_line == nullptr && last_line->b_id != -1) {
key.a_id = last_line->b_id;
auto it_begin = std::lower_bound(by_a_id.begin(), by_a_id.end(), &key, by_vertex_lower);
if (it_begin != by_a_id.end()) {
auto it_end = std::upper_bound(it_begin, by_a_id.end(), &key, by_vertex_lower);
for (auto it_line = it_begin; it_line != it_end; ++ it_line)
if (! (*it_line)->skip()) {
next_line = *it_line;
break;
}
}
}
if (next_line == nullptr) {
// Check whether we closed this loop.
if ((first_line->edge_a_id != -1 && first_line->edge_a_id == last_line->edge_b_id) ||
(first_line->a_id != -1 && first_line->a_id == last_line->b_id)) {
// The current loop is complete. Add it to the output.
loops.emplace_back(std::move(loop_pts));
#ifdef SLIC3R_TRIANGLEMESH_DEBUG
printf(" Discovered %s polygon of %d points\n", (p.is_counter_clockwise() ? "ccw" : "cw"), (int)p.points.size());
#endif
} else {
// This is an open polyline. Add it to the list of open polylines. These open polylines will processed later.
loop_pts.emplace_back(last_line->b);
open_polylines.emplace_back(OpenPolyline(
IntersectionReference(first_line->a_id, first_line->edge_a_id),
IntersectionReference(last_line->b_id, last_line->edge_b_id), std::move(loop_pts)));
}
break;
}
/*
printf("next_line edge_a_id = %d, edge_b_id = %d, a_id = %d, b_id = %d, a = %d,%d, b = %d,%d\n",
next_line->edge_a_id, next_line->edge_b_id, next_line->a_id, next_line->b_id,
next_line->a.x, next_line->a.y, next_line->b.x, next_line->b.y);
*/
loop_pts.emplace_back(next_line->a);
last_line = next_line;
next_line->set_skip();
}
}
}
std::vector<OpenPolyline*> open_polylines_sorted(std::vector<OpenPolyline> &open_polylines, bool update_lengths)
{
std::vector<OpenPolyline*> out;
out.reserve(open_polylines.size());
for (OpenPolyline &opl : open_polylines)
if (! opl.consumed) {
if (update_lengths)
opl.length = Slic3r::length(opl.points);
out.emplace_back(&opl);
}
std::sort(out.begin(), out.end(), [](const OpenPolyline *lhs, const OpenPolyline *rhs){ return lhs->length > rhs->length; });
return out;
}
// called by TriangleMeshSlicer::make_loops() to connect remaining open polylines across shared triangle edges and vertices.
// Depending on "try_connect_reversed", it may or may not connect segments crossing triangles of opposite orientation.
static void chain_open_polylines_exact(std::vector<OpenPolyline> &open_polylines, Polygons &loops, bool try_connect_reversed)
{
// Store the end points of open_polylines into vectors sorted
struct OpenPolylineEnd {
OpenPolylineEnd(OpenPolyline *polyline, bool start) : polyline(polyline), start(start) {}
OpenPolyline *polyline;
// Is it the start or end point?
bool start;
const IntersectionReference& ipref() const { return start ? polyline->start : polyline->end; }
// Return a unique ID for the intersection point.
// Return a positive id for a point, or a negative id for an edge.
int id() const { const IntersectionReference &r = ipref(); return (r.point_id >= 0) ? r.point_id : - r.edge_id; }
bool operator==(const OpenPolylineEnd &rhs) const { return this->polyline == rhs.polyline && this->start == rhs.start; }
};
auto by_id_lower = [](const OpenPolylineEnd &ope1, const OpenPolylineEnd &ope2) { return ope1.id() < ope2.id(); };
std::vector<OpenPolylineEnd> by_id;
by_id.reserve(2 * open_polylines.size());
for (OpenPolyline &opl : open_polylines) {
if (opl.start.point_id != -1 || opl.start.edge_id != -1)
by_id.emplace_back(OpenPolylineEnd(&opl, true));
if (try_connect_reversed && (opl.end.point_id != -1 || opl.end.edge_id != -1))
by_id.emplace_back(OpenPolylineEnd(&opl, false));
}
std::sort(by_id.begin(), by_id.end(), by_id_lower);
// Find an iterator to by_id_lower for the particular end of OpenPolyline (by comparing the OpenPolyline pointer and the start attribute).
auto find_polyline_end = [&by_id, by_id_lower](const OpenPolylineEnd &end) -> std::vector<OpenPolylineEnd>::iterator {
for (auto it = std::lower_bound(by_id.begin(), by_id.end(), end, by_id_lower);
it != by_id.end() && it->id() == end.id(); ++ it)
if (*it == end)
return it;
return by_id.end();
};
// Try to connect the loops.
std::vector<OpenPolyline*> sorted_by_length = open_polylines_sorted(open_polylines, false);
for (OpenPolyline *opl : sorted_by_length) {
if (opl->consumed)
continue;
opl->consumed = true;
OpenPolylineEnd end(opl, false);
for (;;) {
// find a line starting where last one finishes
auto it_next_start = std::lower_bound(by_id.begin(), by_id.end(), end, by_id_lower);
for (; it_next_start != by_id.end() && it_next_start->id() == end.id(); ++ it_next_start)
if (! it_next_start->polyline->consumed)
goto found;
// The current loop could not be closed. Unmark the segment.
opl->consumed = false;
break;
found:
// Attach this polyline to the end of the initial polyline.
if (it_next_start->start) {
auto it = it_next_start->polyline->points.begin();
std::copy(++ it, it_next_start->polyline->points.end(), back_inserter(opl->points));
} else {
auto it = it_next_start->polyline->points.rbegin();
std::copy(++ it, it_next_start->polyline->points.rend(), back_inserter(opl->points));
}
opl->length += it_next_start->polyline->length;
// Mark the next polyline as consumed.
it_next_start->polyline->points.clear();
it_next_start->polyline->length = 0.;
it_next_start->polyline->consumed = true;
if (try_connect_reversed) {
// Running in a mode, where the polylines may be connected by mixing their orientations.
// Update the end point lookup structure after the end point of the current polyline was extended.
auto it_end = find_polyline_end(end);
auto it_next_end = find_polyline_end(OpenPolylineEnd(it_next_start->polyline, !it_next_start->start));
// Swap the end points of the current and next polyline, but keep the polyline ptr and the start flag.
std::swap(opl->end, it_next_end->start ? it_next_end->polyline->start : it_next_end->polyline->end);
// Swap the positions of OpenPolylineEnd structures in the sorted array to match their respective end point positions.
std::swap(*it_end, *it_next_end);
}
// Check whether we closed this loop.
if ((opl->start.edge_id != -1 && opl->start.edge_id == opl->end.edge_id) ||
(opl->start.point_id != -1 && opl->start.point_id == opl->end.point_id)) {
// The current loop is complete. Add it to the output.
//assert(opl->points.front().point_id == opl->points.back().point_id);
//assert(opl->points.front().edge_id == opl->points.back().edge_id);
// Remove the duplicate last point.
opl->points.pop_back();
if (opl->points.size() >= 3) {
if (try_connect_reversed && area(opl->points) < 0)
// The closed polygon is patched from pieces with messed up orientation, therefore
// the orientation of the patched up polygon is not known.
// Orient the patched up polygons CCW. This heuristic may close some holes and cavities.
std::reverse(opl->points.begin(), opl->points.end());
loops.emplace_back(std::move(opl->points));
}
opl->points.clear();
break;
}
// Continue with the current loop.
}
}
}
// called by TriangleMeshSlicer::make_loops() to connect remaining open polylines across shared triangle edges and vertices,
// possibly closing small gaps.
// Depending on "try_connect_reversed", it may or may not connect segments crossing triangles of opposite orientation.
static void chain_open_polylines_close_gaps(std::vector<OpenPolyline> &open_polylines, Polygons &loops, double max_gap, bool try_connect_reversed)
{
const coord_t max_gap_scaled = (coord_t)scale_(max_gap);
// Sort the open polylines by their length, so the new loops will be seeded from longer chains.
// Update the polyline lengths, return only not yet consumed polylines.
std::vector<OpenPolyline*> sorted_by_length = open_polylines_sorted(open_polylines, true);
// Store the end points of open_polylines into ClosestPointInRadiusLookup<OpenPolylineEnd>.
struct OpenPolylineEnd {
OpenPolylineEnd(OpenPolyline *polyline, bool start) : polyline(polyline), start(start) {}
OpenPolyline *polyline;
// Is it the start or end point?
bool start;
const Point& point() const { return start ? polyline->points.front() : polyline->points.back(); }
bool operator==(const OpenPolylineEnd &rhs) const { return this->polyline == rhs.polyline && this->start == rhs.start; }
};
struct OpenPolylineEndAccessor {
const Point* operator()(const OpenPolylineEnd &pt) const { return pt.polyline->consumed ? nullptr : &pt.point(); }
};
typedef ClosestPointInRadiusLookup<OpenPolylineEnd, OpenPolylineEndAccessor> ClosestPointLookupType;
ClosestPointLookupType closest_end_point_lookup(max_gap_scaled);
for (OpenPolyline *opl : sorted_by_length) {
closest_end_point_lookup.insert(OpenPolylineEnd(opl, true));
if (try_connect_reversed)
closest_end_point_lookup.insert(OpenPolylineEnd(opl, false));
}
// Try to connect the loops.
for (OpenPolyline *opl : sorted_by_length) {
if (opl->consumed)
continue;
OpenPolylineEnd end(opl, false);
if (try_connect_reversed)
// The end point of this polyline will be modified, thus the following entry will become invalid. Remove it.
closest_end_point_lookup.erase(end);
opl->consumed = true;
size_t n_segments_joined = 1;
for (;;) {
// Find a line starting where last one finishes, only return non-consumed open polylines (OpenPolylineEndAccessor returns null for consumed).
std::pair<const OpenPolylineEnd*, double> next_start_and_dist = closest_end_point_lookup.find(end.point());
const OpenPolylineEnd *next_start = next_start_and_dist.first;
// Check whether we closed this loop.
double current_loop_closing_distance2 = opl->points.front().distance_to_sq(opl->points.back());
bool loop_closed = current_loop_closing_distance2 < coordf_t(max_gap_scaled) * coordf_t(max_gap_scaled);
if (next_start != nullptr && loop_closed && current_loop_closing_distance2 < next_start_and_dist.second) {
// Heuristics to decide, whether to close the loop, or connect another polyline.
// One should avoid closing loops shorter than max_gap_scaled.
loop_closed = sqrt(current_loop_closing_distance2) < 0.3 * length(opl->points);
}
if (loop_closed) {
// Remove the start point of the current polyline from the lookup.
// Mark the current segment as not consumed, otherwise the closest_end_point_lookup.erase() would fail.
opl->consumed = false;
closest_end_point_lookup.erase(OpenPolylineEnd(opl, true));
if (current_loop_closing_distance2 == 0.) {
// Remove the duplicate last point.
opl->points.pop_back();
} else {
// The end points are different, keep both of them.
}
if (opl->points.size() >= 3) {
if (try_connect_reversed && n_segments_joined > 1 && area(opl->points) < 0)
// The closed polygon is patched from pieces with messed up orientation, therefore
// the orientation of the patched up polygon is not known.
// Orient the patched up polygons CCW. This heuristic may close some holes and cavities.
std::reverse(opl->points.begin(), opl->points.end());
loops.emplace_back(std::move(opl->points));
}
opl->points.clear();
opl->consumed = true;
break;
}
if (next_start == nullptr) {
// The current loop could not be closed. Unmark the segment.
opl->consumed = false;
if (try_connect_reversed)
// Re-insert the end point.
closest_end_point_lookup.insert(OpenPolylineEnd(opl, false));
break;
}
// Attach this polyline to the end of the initial polyline.
if (next_start->start) {
auto it = next_start->polyline->points.begin();
if (*it == opl->points.back())
++ it;
std::copy(it, next_start->polyline->points.end(), back_inserter(opl->points));
} else {
auto it = next_start->polyline->points.rbegin();
if (*it == opl->points.back())
++ it;
std::copy(it, next_start->polyline->points.rend(), back_inserter(opl->points));
}
++ n_segments_joined;
// Remove the end points of the consumed polyline segment from the lookup.
OpenPolyline *opl2 = next_start->polyline;
closest_end_point_lookup.erase(OpenPolylineEnd(opl2, true));
if (try_connect_reversed)
closest_end_point_lookup.erase(OpenPolylineEnd(opl2, false));
opl2->points.clear();
opl2->consumed = true;
// Continue with the current loop.
}
}
}
void TriangleMeshSlicer::make_loops(std::vector<IntersectionLine> &lines, Polygons* loops) const
{
#if 0
@ -1260,119 +1599,8 @@ void TriangleMeshSlicer::make_loops(std::vector<IntersectionLine> &lines, Polygo
}
#endif /* SLIC3R_DEBUG_SLICE_PROCESSING */
struct OpenPolyline {
OpenPolyline() {};
OpenPolyline(const IntersectionReference &start, const IntersectionReference &end, Points &&points) :
start(start), end(end), points(std::move(points)), consumed(false) {}
void reverse() {
std::swap(start, end);
std::reverse(points.begin(), points.end());
}
IntersectionReference start;
IntersectionReference end;
Points points;
bool consumed;
};
std::vector<OpenPolyline> open_polylines;
{
// Build a map of lines by edge_a_id and a_id.
std::vector<IntersectionLine*> by_edge_a_id;
std::vector<IntersectionLine*> by_a_id;
by_edge_a_id.reserve(lines.size());
by_a_id.reserve(lines.size());
for (IntersectionLine &line : lines) {
if (! line.skip()) {
if (line.edge_a_id != -1)
by_edge_a_id.emplace_back(&line);
if (line.a_id != -1)
by_a_id.emplace_back(&line);
}
}
auto by_edge_lower = [](const IntersectionLine* il1, const IntersectionLine *il2) { return il1->edge_a_id < il2->edge_a_id; };
auto by_vertex_lower = [](const IntersectionLine* il1, const IntersectionLine *il2) { return il1->a_id < il2->a_id; };
std::sort(by_edge_a_id.begin(), by_edge_a_id.end(), by_edge_lower);
std::sort(by_a_id.begin(), by_a_id.end(), by_vertex_lower);
// Chain the segments with a greedy algorithm, collect the loops and unclosed polylines.
IntersectionLines::iterator it_line_seed = lines.begin();
for (;;) {
// take first spare line and start a new loop
IntersectionLine *first_line = nullptr;
for (; it_line_seed != lines.end(); ++ it_line_seed)
if (it_line_seed->is_seed_candidate()) {
//if (! it_line_seed->skip()) {
first_line = &(*it_line_seed ++);
break;
}
if (first_line == nullptr)
break;
first_line->set_skip();
Points loop_pts;
loop_pts.emplace_back(first_line->a);
IntersectionLine *last_line = first_line;
/*
printf("first_line edge_a_id = %d, edge_b_id = %d, a_id = %d, b_id = %d, a = %d,%d, b = %d,%d\n",
first_line->edge_a_id, first_line->edge_b_id, first_line->a_id, first_line->b_id,
first_line->a.x, first_line->a.y, first_line->b.x, first_line->b.y);
*/
IntersectionLine key;
for (;;) {
// find a line starting where last one finishes
IntersectionLine* next_line = nullptr;
if (last_line->edge_b_id != -1) {
key.edge_a_id = last_line->edge_b_id;
auto it_begin = std::lower_bound(by_edge_a_id.begin(), by_edge_a_id.end(), &key, by_edge_lower);
if (it_begin != by_edge_a_id.end()) {
auto it_end = std::upper_bound(it_begin, by_edge_a_id.end(), &key, by_edge_lower);
for (auto it_line = it_begin; it_line != it_end; ++ it_line)
if (! (*it_line)->skip()) {
next_line = *it_line;
break;
}
}
}
if (next_line == nullptr && last_line->b_id != -1) {
key.a_id = last_line->b_id;
auto it_begin = std::lower_bound(by_a_id.begin(), by_a_id.end(), &key, by_vertex_lower);
if (it_begin != by_a_id.end()) {
auto it_end = std::upper_bound(it_begin, by_a_id.end(), &key, by_vertex_lower);
for (auto it_line = it_begin; it_line != it_end; ++ it_line)
if (! (*it_line)->skip()) {
next_line = *it_line;
break;
}
}
}
if (next_line == nullptr) {
// Check whether we closed this loop.
if ((first_line->edge_a_id != -1 && first_line->edge_a_id == last_line->edge_b_id) ||
(first_line->a_id != -1 && first_line->a_id == last_line->b_id)) {
// The current loop is complete. Add it to the output.
loops->emplace_back(std::move(loop_pts));
#ifdef SLIC3R_TRIANGLEMESH_DEBUG
printf(" Discovered %s polygon of %d points\n", (p.is_counter_clockwise() ? "ccw" : "cw"), (int)p.points.size());
#endif
} else {
// This is an open polyline. Add it to the list of open polylines. These open polylines will processed later.
loop_pts.emplace_back(last_line->b);
open_polylines.emplace_back(OpenPolyline(
IntersectionReference(first_line->a_id, first_line->edge_a_id),
IntersectionReference(last_line->b_id, last_line->edge_b_id), std::move(loop_pts)));
}
break;
}
/*
printf("next_line edge_a_id = %d, edge_b_id = %d, a_id = %d, b_id = %d, a = %d,%d, b = %d,%d\n",
next_line->edge_a_id, next_line->edge_b_id, next_line->a_id, next_line->b_id,
next_line->a.x, next_line->a.y, next_line->b.x, next_line->b.y);
*/
loop_pts.emplace_back(next_line->a);
last_line = next_line;
next_line->set_skip();
}
}
}
chain_lines_by_triangle_connectivity(lines, *loops, open_polylines);
#ifdef SLIC3R_DEBUG_SLICE_PROCESSING
{
@ -1388,98 +1616,8 @@ void TriangleMeshSlicer::make_loops(std::vector<IntersectionLine> &lines, Polygo
// Now process the open polylines.
// Do it in two rounds, first try to connect in the same direction only,
// then try to connect the open polylines in reversed order as well.
for (size_t round = 0; round < 2 && ! open_polylines.empty(); ++ round) {
bool try_connect_reversed = round == 1;
// Store the end points of open_polylines into vectors sorted
struct OpenPolylineEnd {
OpenPolylineEnd(OpenPolyline *polyline, bool start) : polyline(polyline), start(start) {}
OpenPolyline *polyline;
// Is it the start or end point?
bool start;
const IntersectionReference& ipref() const { return start ? polyline->start : polyline->end; }
// Return a unique ID for the intersection point.
// Return a positive id for a point, or a negative id for an edge.
int id() const { const IntersectionReference &r = ipref(); return (r.point_id >= 0) ? r.point_id : - r.edge_id; }
bool operator==(const OpenPolylineEnd &rhs) const { return this->polyline == rhs.polyline && this->start == rhs.start; }
};
auto by_id_lower = [](const OpenPolylineEnd &ope1, const OpenPolylineEnd &ope2) { return ope1.id() < ope2.id(); };
std::vector<OpenPolylineEnd> by_id;
by_id.reserve(2 * open_polylines.size());
for (OpenPolyline &opl : open_polylines) {
if (opl.start.point_id != -1 || opl.start.edge_id != -1)
by_id.emplace_back(OpenPolylineEnd(&opl, true));
if (try_connect_reversed && (opl.end.point_id != -1 || opl.end.edge_id != -1))
by_id.emplace_back(OpenPolylineEnd(&opl, false));
}
std::sort(by_id.begin(), by_id.end(), by_id_lower);
// Find an iterator to by_id_lower for the particular end of OpenPolyline (by comparing the OpenPolyline pointer and the start attribute).
auto find_polyline_end = [&by_id, by_id_lower](const OpenPolylineEnd &end) -> std::vector<OpenPolylineEnd>::iterator {
for (auto it = std::lower_bound(by_id.begin(), by_id.end(), end, by_id_lower);
it != by_id.end() && it->id() == end.id(); ++ it)
if (*it == end)
return it;
return by_id.end();
};
// Try to connect the loops.
for (OpenPolyline &opl : open_polylines) {
if (opl.consumed)
continue;
opl.consumed = true;
OpenPolylineEnd end(&opl, false);
for (;;) {
// find a line starting where last one finishes
auto it_next_start = std::lower_bound(by_id.begin(), by_id.end(), end, by_id_lower);
for (; it_next_start != by_id.end() && it_next_start->id() == end.id(); ++ it_next_start)
if (! it_next_start->polyline->consumed)
goto found;
// The current loop could not be closed. Unmark the segment.
opl.consumed = false;
break;
found:
// Attach this polyline to the end of the initial polyline.
if (it_next_start->start) {
auto it = it_next_start->polyline->points.begin();
std::copy(++ it, it_next_start->polyline->points.end(), back_inserter(opl.points));
} else {
auto it = it_next_start->polyline->points.rbegin();
std::copy(++ it, it_next_start->polyline->points.rend(), back_inserter(opl.points));
}
// Mark the next polyline as consumed.
it_next_start->polyline->points.clear();
it_next_start->polyline->consumed = true;
if (try_connect_reversed) {
// Running in a mode, where the polylines may be connected by mixing their orientations.
// Update the end point lookup structure after the end point of the current polyline was extended.
auto it_end = find_polyline_end(end);
auto it_next_end = find_polyline_end(OpenPolylineEnd(it_next_start->polyline, !it_next_start->start));
// Swap the end points of the current and next polyline, but keep the polyline ptr and the start flag.
std::swap(opl.end, it_next_end->start ? it_next_end->polyline->start : it_next_end->polyline->end);
// Swap the positions of OpenPolylineEnd structures in the sorted array to match their respective end point positions.
std::swap(*it_end, *it_next_end);
}
// Check whether we closed this loop.
if ((opl.start.edge_id != -1 && opl.start.edge_id == opl.end.edge_id) ||
(opl.start.point_id != -1 && opl.start.point_id == opl.end.point_id)) {
// The current loop is complete. Add it to the output.
//assert(opl.points.front().point_id == opl.points.back().point_id);
//assert(opl.points.front().edge_id == opl.points.back().edge_id);
// Remove the duplicate last point.
opl.points.pop_back();
if (opl.points.size() >= 3) {
if (try_connect_reversed && area(opl.points) < 0)
// The closed polygon is patched from pieces with messed up orientation, therefore
// the orientation of the patched up polygon is not known.
// Orient the patched up polygons CCW. This heuristic may close some holes and cavities.
std::reverse(opl.points.begin(), opl.points.end());
loops->emplace_back(std::move(opl.points));
}
opl.points.clear();
break;
}
// Continue with the current loop.
}
}
}
chain_open_polylines_exact(open_polylines, *loops, false);
chain_open_polylines_exact(open_polylines, *loops, true);
#ifdef SLIC3R_DEBUG_SLICE_PROCESSING
{
@ -1500,105 +1638,9 @@ void TriangleMeshSlicer::make_loops(std::vector<IntersectionLine> &lines, Polygo
// Try to close gaps.
// Do it in two rounds, first try to connect in the same direction only,
// then try to connect the open polylines in reversed order as well.
const coord_t max_gap_scaled = (coord_t)scale_(2.); // 2mm
for (size_t round = 0; round < 2 && ! open_polylines.empty(); ++ round) {
bool try_connect_reversed = round == 1;
// Store the end points of open_polylines into ClosestPointInRadiusLookup<OpenPolylineEnd>.
struct OpenPolylineEnd {
OpenPolylineEnd(OpenPolyline *polyline, bool start) : polyline(polyline), start(start) {}
OpenPolyline *polyline;
// Is it the start or end point?
bool start;
const Point& point() const { return start ? polyline->points.front() : polyline->points.back(); }
bool operator==(const OpenPolylineEnd &rhs) const { return this->polyline == rhs.polyline && this->start == rhs.start; }
};
struct OpenPolylineEndAccessor {
const Point* operator()(const OpenPolylineEnd &pt) const { return pt.polyline->consumed ? nullptr : &pt.point(); }
};
typedef ClosestPointInRadiusLookup<OpenPolylineEnd, OpenPolylineEndAccessor> ClosestPointLookupType;
ClosestPointLookupType closest_end_point_lookup(max_gap_scaled);
for (OpenPolyline &opl : open_polylines) {
closest_end_point_lookup.insert(OpenPolylineEnd(&opl, true));
if (try_connect_reversed)
closest_end_point_lookup.insert(OpenPolylineEnd(&opl, false));
}
// Try to connect the loops.
for (OpenPolyline &opl : open_polylines) {
if (opl.consumed)
continue;
OpenPolylineEnd end(&opl, false);
if (try_connect_reversed)
// The end point of this polyline will be modified, thus the following entry will become invalid. Remove it.
closest_end_point_lookup.erase(end);
opl.consumed = true;
size_t n_segments_joined = 1;
for (;;) {
// Find a line starting where last one finishes, only return non-consumed open polylines (OpenPolylineEndAccessor returns null for consumed).
std::pair<const OpenPolylineEnd*, double> next_start_and_dist = closest_end_point_lookup.find(end.point());
const OpenPolylineEnd *next_start = next_start_and_dist.first;
// Check whether we closed this loop.
double current_loop_closing_distance2 = opl.points.front().distance_to_sq(opl.points.back());
bool loop_closed = current_loop_closing_distance2 < coordf_t(max_gap_scaled) * coordf_t(max_gap_scaled);
if (next_start != nullptr && loop_closed && current_loop_closing_distance2 < next_start_and_dist.second) {
// Heuristics to decide, whether to close the loop, or connect another polyline.
// One should avoid closing loops shorter than max_gap_scaled.
loop_closed = sqrt(current_loop_closing_distance2) < 0.3 * length(opl.points);
}
if (loop_closed) {
// Remove the start point of the current polyline from the lookup.
// Mark the current segment as not consumed, otherwise the closest_end_point_lookup.erase() would fail.
opl.consumed = false;
closest_end_point_lookup.erase(OpenPolylineEnd(&opl, true));
if (current_loop_closing_distance2 == 0.) {
// Remove the duplicate last point.
opl.points.pop_back();
} else {
// The end points are different, keep both of them.
}
if (opl.points.size() >= 3) {
if (try_connect_reversed && n_segments_joined > 1 && area(opl.points) < 0)
// The closed polygon is patched from pieces with messed up orientation, therefore
// the orientation of the patched up polygon is not known.
// Orient the patched up polygons CCW. This heuristic may close some holes and cavities.
std::reverse(opl.points.begin(), opl.points.end());
loops->emplace_back(std::move(opl.points));
}
opl.points.clear();
opl.consumed = true;
break;
}
if (next_start == nullptr) {
// The current loop could not be closed. Unmark the segment.
opl.consumed = false;
if (try_connect_reversed)
// Re-insert the end point.
closest_end_point_lookup.insert(OpenPolylineEnd(&opl, false));
break;
}
// Attach this polyline to the end of the initial polyline.
if (next_start->start) {
auto it = next_start->polyline->points.begin();
if (*it == opl.points.back())
++ it;
std::copy(it, next_start->polyline->points.end(), back_inserter(opl.points));
} else {
auto it = next_start->polyline->points.rbegin();
if (*it == opl.points.back())
++ it;
std::copy(it, next_start->polyline->points.rend(), back_inserter(opl.points));
}
++ n_segments_joined;
// Remove the end points of the consumed polyline segment from the lookup.
OpenPolyline *opl2 = next_start->polyline;
closest_end_point_lookup.erase(OpenPolylineEnd(opl2, true));
if (try_connect_reversed)
closest_end_point_lookup.erase(OpenPolylineEnd(opl2, false));
opl2->points.clear();
opl2->consumed = true;
// Continue with the current loop.
}
}
}
const double max_gap = 2.; //mm
chain_open_polylines_close_gaps(open_polylines, *loops, max_gap, false);
chain_open_polylines_close_gaps(open_polylines, *loops, max_gap, true);
#ifdef SLIC3R_DEBUG_SLICE_PROCESSING
{