Merge branch 'lm_seam_fixes2'

src/libslic3r/ExtrusionEntity.cpp

@@ -193,12 +193,8 @@ bool ExtrusionLoop::split_at_vertex(const Point &point)
     return false;
 }
 
-// Splitting an extrusion loop, possibly made of multiple segments, some of the segments may be bridging.
+std::pair<size_t, Point> ExtrusionLoop::get_closest_path_and_point(const Point& point, bool prefer_non_overhang) const
-void ExtrusionLoop::split_at(const Point &point, bool prefer_non_overhang)
 {
-    if (this->paths.empty())
-        return;
-    
     // Find the closest path and closest point belonging to that path. Avoid overhangs, if asked for.
     size_t path_idx = 0;
     Point  p;
@@ -227,6 +223,16 @@ void ExtrusionLoop::split_at(const Point &point, bool prefer_non_overhang)
             p = p_non_overhang;
         }
     }
+    return std::make_pair(path_idx, p);
+}
+
+// Splitting an extrusion loop, possibly made of multiple segments, some of the segments may be bridging.
+void ExtrusionLoop::split_at(const Point &point, bool prefer_non_overhang)
+{
+    if (this->paths.empty())
+        return;
+    
+    auto [path_idx, p] = get_closest_path_and_point(point, prefer_non_overhang);
     
     // now split path_idx in two parts
     const ExtrusionPath &path = this->paths[path_idx];

src/libslic3r/ExtrusionEntity.hpp

@@ -258,6 +258,7 @@ public:
     double length() const override;
     bool split_at_vertex(const Point &point);
     void split_at(const Point &point, bool prefer_non_overhang);
+    std::pair<size_t, Point> get_closest_path_and_point(const Point& point, bool prefer_non_overhang) const;
     void clip_end(double distance, ExtrusionPaths* paths) const;
     // Test, whether the point is extruded by a bridging flow.
     // This used to be used to avoid placing seams on overhangs, but now the EdgeGrid is used instead.

src/libslic3r/GCode.cpp

@@ -2479,18 +2479,14 @@ std::string GCode::change_layer(coordf_t print_z)
 
 
 
-std::string GCode::extrude_loop(ExtrusionLoop loop, std::string description, double speed, std::unique_ptr<EdgeGrid::Grid> *lower_layer_edge_grid)
+static std::unique_ptr<EdgeGrid::Grid> calculate_layer_edge_grid(const Layer& layer)
 {
-    // get a copy; don't modify the orientation of the original loop object otherwise
+    auto out = make_unique<EdgeGrid::Grid>();
-    // next copies (if any) would not detect the correct orientation
 
-    if (m_layer->lower_layer != nullptr && lower_layer_edge_grid != nullptr) {
-        if (! *lower_layer_edge_grid) {
     // Create the distance field for a layer below.
     const coord_t distance_field_resolution = coord_t(scale_(1.) + 0.5);
-            *lower_layer_edge_grid = make_unique<EdgeGrid::Grid>();
+    out->create(layer.lslices, distance_field_resolution);
-            (*lower_layer_edge_grid)->create(m_layer->lower_layer->lslices, distance_field_resolution);
+    out->calculate_sdf();
-            (*lower_layer_edge_grid)->calculate_sdf();
 #if 0
         {
             static int iRun = 0;
@@ -2502,34 +2498,30 @@ std::string GCode::extrude_loop(ExtrusionLoop loop, std::string description, dou
             EdgeGrid::save_png(*(*lower_layer_edge_grid), bbox, scale_(0.1f), debug_out_path("GCode_extrude_loop_edge_grid-%d.png", iRun++));
         }
 #endif
+    return out;
 }
-    }
+
+
+std::string GCode::extrude_loop(ExtrusionLoop loop, std::string description, double speed, std::unique_ptr<EdgeGrid::Grid> *lower_layer_edge_grid)
+{
+    // get a copy; don't modify the orientation of the original loop object otherwise
+    // next copies (if any) would not detect the correct orientation
+
+    if (m_layer->lower_layer && lower_layer_edge_grid != nullptr && ! *lower_layer_edge_grid)
+        *lower_layer_edge_grid = calculate_layer_edge_grid(*m_layer->lower_layer);
 
     // extrude all loops ccw
     bool was_clockwise = loop.make_counter_clockwise();
 
-    SeamPosition seam_position = m_config.seam_position;
-    if (loop.loop_role() == elrSkirt)
-        seam_position = spNearest;
-
     // find the point of the loop that is closest to the current extruder position
     // or randomize if requested
     Point last_pos = this->last_pos();
     if (m_config.spiral_vase) {
         loop.split_at(last_pos, false);
-    } else {
-        const EdgeGrid::Grid* edge_grid_ptr = (lower_layer_edge_grid && *lower_layer_edge_grid)
-                                                ? lower_layer_edge_grid->get()
-                                                : nullptr;
-        Point seam = m_seam_placer.get_seam(*m_layer, seam_position, loop,
-                         last_pos, EXTRUDER_CONFIG(nozzle_diameter),
-                         (m_layer == NULL ? nullptr : m_layer->object()),
-                         was_clockwise, edge_grid_ptr);
-        // Split the loop at the point with a minium penalty.
-        if (!loop.split_at_vertex(seam))
-            // The point is not in the original loop. Insert it.
-            loop.split_at(seam, true);
     }
+    else
+        m_seam_placer.place_seam(loop, this->last_pos(), m_config.external_perimeters_first,
+                                 EXTRUDER_CONFIG(nozzle_diameter), lower_layer_edge_grid ? lower_layer_edge_grid->get() : nullptr);
 
     // clip the path to avoid the extruder to get exactly on the first point of the loop;
     // if polyline was shorter than the clipping distance we'd get a null polyline, so
@@ -2652,6 +2644,16 @@ std::string GCode::extrude_perimeters(const Print &print, const std::vector<Obje
     for (const ObjectByExtruder::Island::Region &region : by_region)
         if (! region.perimeters.empty()) {
             m_config.apply(print.get_print_region(&region - &by_region.front()).config());
+
+            // plan_perimeters tries to place seams, it needs to have the lower_layer_edge_grid calculated already.
+            if (m_layer->lower_layer && ! lower_layer_edge_grid)
+                lower_layer_edge_grid = calculate_layer_edge_grid(*m_layer->lower_layer);
+
+            m_seam_placer.plan_perimeters(std::vector<const ExtrusionEntity*>(region.perimeters.begin(), region.perimeters.end()),
+                *m_layer, m_config.seam_position, this->last_pos(), EXTRUDER_CONFIG(nozzle_diameter),
+                (m_layer == NULL ? nullptr : m_layer->object()),
+                (lower_layer_edge_grid ? lower_layer_edge_grid.get() : nullptr));
+
             for (const ExtrusionEntity* ee : region.perimeters)
                 gcode += this->extrude_entity(*ee, "perimeter", -1., &lower_layer_edge_grid);
         }

src/libslic3r/GCode/SeamPlacer.cpp

@@ -292,11 +292,165 @@ void SeamPlacer::init(const Print& print)
 
 
 
-Point SeamPlacer::get_seam(const Layer& layer, const SeamPosition seam_position,
+void SeamPlacer::plan_perimeters(const std::vector<const ExtrusionEntity*> perimeters,
-               const ExtrusionLoop& loop, Point last_pos, coordf_t nozzle_dmr,
+                            const Layer& layer, SeamPosition seam_position,
-               const PrintObject* po, bool was_clockwise, const EdgeGrid::Grid* lower_layer_edge_grid)
+                            Point last_pos, coordf_t nozzle_dmr, const PrintObject* po,
+                            const EdgeGrid::Grid* lower_layer_edge_grid)
 {
+    // When printing the perimeters, we want the seams on external and internal perimeters to match.
+    // We have a list of perimeters in the order to be printed. Each internal perimeter must inherit
+    // the seam from the previous external perimeter.
+
+    m_plan.clear();
+    m_plan_idx = 0;
+
+    if (perimeters.empty() || ! po)
+        return;
+
+    m_plan.resize(perimeters.size());
+
+    for (int i = 0; i < int(perimeters.size()); ++i) {
+        if (perimeters[i]->role() == erExternalPerimeter && perimeters[i]->is_loop()) {
+            last_pos = this->calculate_seam(
+                layer, seam_position, *dynamic_cast<const ExtrusionLoop*>(perimeters[i]), nozzle_dmr,
+                po, lower_layer_edge_grid, last_pos);
+            m_plan[i].external = true;
+            m_plan[i].seam_position = seam_position;
+            m_plan[i].layer = &layer;
+            m_plan[i].po = po;
+        }
+        m_plan[i].pt = last_pos;
+    }
+}
+
+
+void SeamPlacer::place_seam(ExtrusionLoop& loop, const Point& last_pos, bool external_first, double nozzle_diameter,
+                            const EdgeGrid::Grid* lower_layer_edge_grid)
+{
+    const double seam_offset = nozzle_diameter;
+
+    Point seam = last_pos;
+    if (! m_plan.empty() && m_plan_idx < m_plan.size()) {
+        if (m_plan[m_plan_idx].external) {
+            seam = m_plan[m_plan_idx].pt;
+            // One more heuristics: if the seam is too far from current nozzle position,
+            // try to place it again. This can happen in cases where the external perimeter
+            // does not belong to the preceding ones and they are ordered so they end up
+            // far from each other.
+            if ((seam.cast<double>() - last_pos.cast<double>()).squaredNorm() > std::pow(scale_(5.*nozzle_diameter), 2.))
+                seam = this->calculate_seam(*m_plan[m_plan_idx].layer, m_plan[m_plan_idx].seam_position, loop, nozzle_diameter,
+                                            m_plan[m_plan_idx].po, lower_layer_edge_grid, last_pos);
+        }
+        else if (! external_first) {
+            // Internal perimeter printed before the external.
+            // First get list of external seams.
+            std::vector<size_t> ext_seams;
+            for (size_t i = 0; i < m_plan.size(); ++i) {
+                if (m_plan[i].external)
+                    ext_seams.emplace_back(i);
+            }
+
+            if (! ext_seams.empty()) {
+                // First find the line segment closest to an external seam:
+                int path_idx = 0;
+                int line_idx = 0;
+                size_t ext_seam_idx = size_t(-1);
+                double min_dist_sqr = std::numeric_limits<double>::max();
+                std::vector<Lines> lines_vect;
+                for (int i = 0; i < int(loop.paths.size()); ++i) {
+                    lines_vect.emplace_back(loop.paths[i].polyline.lines());
+                    const Lines& lines = lines_vect.back();
+                    for (int j = 0; j < int(lines.size()); ++j) {
+                        for (size_t k : ext_seams) {
+                            double d_sqr = lines[j].distance_to_squared(m_plan[k].pt);
+                            if (d_sqr < min_dist_sqr) {
+                                path_idx = i;
+                                line_idx = j;
+                                ext_seam_idx = k;
+                                min_dist_sqr = d_sqr;
+                            }
+                        }
+                    }
+                }
+
+                // Only accept seam that is reasonably close.
+                double limit_dist_sqr = std::pow(double(scale_((ext_seam_idx - m_plan_idx) * nozzle_diameter * 2.)), 2.);
+                if (ext_seam_idx != size_t(-1) && min_dist_sqr < limit_dist_sqr) {
+                    // Now find a projection of the external seam
+                    const Lines& lines = lines_vect[path_idx];
+                    Point closest = m_plan[ext_seam_idx].pt.projection_onto(lines[line_idx]);
+                    double dist = (closest.cast<double>() - lines[line_idx].b.cast<double>()).norm();
+
+                    // And walk along the perimeter until we make enough space for
+                    // seams of all perimeters beforethe external one.
+                    double offset = (ext_seam_idx - m_plan_idx) * scale_(seam_offset);
+                    double last_offset = offset;
+                    offset -= dist;
+                    const Point* a = &closest;
+                    const Point* b = &lines[line_idx].b;
+                    while (++line_idx < int(lines.size()) && offset > 0.) {
+                        last_offset = offset;
+                        offset -= lines[line_idx].length();
+                        a = &lines[line_idx].a;
+                        b = &lines[line_idx].b;
+                    }
+
+                    // We have walked far enough, too far maybe. Interpolate on the
+                    // last segment to find the end precisely.
+                    offset = std::min(0., offset); // In case that offset is still positive (we may have "wrapped around")
+                    double ratio = last_offset / (last_offset - offset);
+                    seam = (a->cast<double>() + ((b->cast<double>() - a->cast<double>()) * ratio)).cast<coord_t>();
+                }
+            }
+        }
+        else {
+            // We should have a candidate ready from before. If not, use last_pos.
+            if (m_plan_idx > 0 && m_plan[m_plan_idx - 1].precalculated)
+                seam = m_plan[m_plan_idx - 1].pt;
+        }
+    }
+
+
+    // Split the loop at the point with a minium penalty.
+    if (!loop.split_at_vertex(seam))
+        // The point is not in the original loop. Insert it.
+        loop.split_at(seam, true);
+
+    if (external_first && m_plan_idx+1<m_plan.size() && ! m_plan[m_plan_idx+1].external) {
+        // Next perimeter should start near this one.
+        const double dist_sqr = std::pow(double(scale_(seam_offset)), 2.);
+        double running_sqr = 0.;
+        double running_sqr_last = 0.;
+        if (!loop.paths.empty() && loop.paths.back().polyline.points.size() > 1) {
+            const ExtrusionPath& last = loop.paths.back();
+            auto it = last.polyline.points.crbegin() + 1;
+            for (; it != last.polyline.points.crend(); ++it) {
+                running_sqr += (it->cast<double>() - (it - 1)->cast<double>()).squaredNorm();
+                if (running_sqr > dist_sqr)
+                    break;
+                running_sqr_last = running_sqr;
+            }
+            if (running_sqr <= dist_sqr)
+                it = last.polyline.points.crend() - 1;
+            // Now interpolate.
+            double ratio = (std::sqrt(dist_sqr) - std::sqrt(running_sqr_last)) / (std::sqrt(running_sqr) - std::sqrt(running_sqr_last));
+            m_plan[m_plan_idx + 1].pt = ((it - 1)->cast<double>() + (it->cast<double>() - (it - 1)->cast<double>()) * std::min(ratio, 1.)).cast<coord_t>();
+            m_plan[m_plan_idx + 1].precalculated = true;
+        }
+    }
+
+    ++m_plan_idx;
+}
+
+
+// Returns a seam for an EXTERNAL perimeter.
+Point SeamPlacer::calculate_seam(const Layer& layer, const SeamPosition seam_position,
+               const ExtrusionLoop& loop, coordf_t nozzle_dmr, const PrintObject* po,
+               const EdgeGrid::Grid* lower_layer_edge_grid, Point last_pos)
+{
+    assert(loop.role() == erExternalPerimeter);
     Polygon polygon = loop.polygon();
+    bool was_clockwise = polygon.make_counter_clockwise();
     BoundingBox polygon_bb = polygon.bounding_box();
     const coord_t  nozzle_r   = coord_t(scale_(0.5 * nozzle_dmr) + 0.5);
 
@@ -438,7 +592,7 @@ Point SeamPlacer::get_seam(const Layer& layer, const SeamPosition seam_position,
             }
         }
 
-        if (seam_position == spAligned && loop.role() == erExternalPerimeter)
+        if (seam_position == spAligned)
             m_seam_history.add_seam(po, polygon.points[idx_min], polygon_bb);
 
 
@@ -466,42 +620,8 @@ Point SeamPlacer::get_seam(const Layer& layer, const SeamPosition seam_position,
         #endif
         return polygon.points[idx_min];
 
-    } else { // spRandom
+    } else
-        if (po->print()->default_region_config().external_perimeters_first) {
+        return this->get_random_seam(layer_idx, polygon, po_idx);
-            if (loop.role() == erExternalPerimeter)
-                last_pos = this->get_random_seam(layer_idx, polygon, po_idx);
-            else {
-                // Internal perimeters will just use last_pos.
-            }
-        } else {
-            if (loop.loop_role() == elrContourInternalPerimeter && loop.role() != erExternalPerimeter) {
-                // This loop does not contain any other loop. Set a random position.
-                // The other loops will get a seam close to the random point chosen
-                // on the innermost contour.
-                last_pos = this->get_random_seam(layer_idx, polygon, po_idx);
-                m_last_loop_was_external = false;
-            }
-            if (loop.role() == erExternalPerimeter) {
-                if (m_last_loop_was_external) {
-                    // There was no internal perimeter before this one.
-                    last_pos = this->get_random_seam(layer_idx, polygon, po_idx);
-                } else {
-                    if (is_custom_seam_on_layer(layer_idx, po_idx)) {
-                        // There is a possibility that the loop will be influenced by custom
-                        // seam enforcer/blocker. In this case do not inherit the seam
-                        // from internal loops (which may conflict with the custom selection
-                        // and generate another random one.
-                        bool saw_custom = false;
-                        Point candidate = this->get_random_seam(layer_idx, polygon, po_idx, &saw_custom);
-                        if (saw_custom)
-                            last_pos = candidate;
-                    }
-                }
-                m_last_loop_was_external = true;
-            }
-        }
-        return last_pos;
-    }
 }
 
 

src/libslic3r/GCode/SeamPlacer.hpp

@@ -2,7 +2,9 @@
 #define libslic3r_SeamPlacer_hpp_
 
 #include <optional>
+#include <vector>
 
+#include "libslic3r/ExtrusionEntity.hpp"
 #include "libslic3r/Polygon.hpp"
 #include "libslic3r/PrintConfig.hpp"
 #include "libslic3r/BoundingBox.hpp"
@@ -41,16 +43,30 @@ class SeamPlacer {
 public:
     void init(const Print& print);
 
-    Point get_seam(const Layer& layer, const SeamPosition seam_position,
+    // When perimeters are printed, first call this function with the respective
-                   const ExtrusionLoop& loop, Point last_pos,
+    // external perimeter. SeamPlacer will find a location for its seam and remember it.
-                   coordf_t nozzle_diameter, const PrintObject* po,
+    // Subsequent calls to get_seam will return this position.
-                   bool was_clockwise, const EdgeGrid::Grid* lower_layer_edge_grid);
+
+
+    void plan_perimeters(const std::vector<const ExtrusionEntity*> perimeters,
+        const Layer& layer, SeamPosition seam_position,
+        Point last_pos, coordf_t nozzle_dmr, const PrintObject* po,
+        const EdgeGrid::Grid* lower_layer_edge_grid);
+
+    void place_seam(ExtrusionLoop& loop, const Point& last_pos, bool external_first, double nozzle_diameter,
+                    const EdgeGrid::Grid* lower_layer_edge_grid);
+    
 
     using TreeType = AABBTreeIndirect::Tree<2, coord_t>;
     using AlignedBoxType = Eigen::AlignedBox<TreeType::CoordType, TreeType::NumDimensions>;
 
 private:
 
+    // When given an external perimeter (!), returns the seam.
+    Point calculate_seam(const Layer& layer, const SeamPosition seam_position,
+        const ExtrusionLoop& loop, coordf_t nozzle_dmr, const PrintObject* po,
+        const EdgeGrid::Grid* lower_layer_edge_grid, Point last_pos);
+
     struct CustomTrianglesPerLayer {
         Polygons polys;
         TreeType tree;
@@ -61,7 +77,16 @@ private:
     coordf_t m_last_print_z = -1.;
     const PrintObject* m_last_po = nullptr;
 
-    bool m_last_loop_was_external = true;
+    struct SeamPoint {
+        Point pt;
+        bool precalculated = false;
+        bool external = false;
+        const Layer* layer = nullptr;
+        SeamPosition seam_position;
+        const PrintObject* po = nullptr;
+    };
+    std::vector<SeamPoint> m_plan;
+    size_t m_plan_idx;
 
     std::vector<std::vector<CustomTrianglesPerLayer>> m_enforcers;
     std::vector<std::vector<CustomTrianglesPerLayer>> m_blockers;

src/libslic3r/MultiPoint.cpp

@@ -47,9 +47,9 @@ void MultiPoint::rotate(double angle, const Point &center)
 
 double MultiPoint::length() const
 {
-    Lines lines = this->lines();
+    const Lines& lines = this->lines();
     double len = 0;
-    for (Lines::iterator it = lines.begin(); it != lines.end(); ++it) {
+    for (auto it = lines.cbegin(); it != lines.cend(); ++it) {
         len += it->length();
     }
     return len;

src/slic3r/GUI/GUI_App.cpp

@@ -673,6 +673,7 @@ void GUI_App::post_init()
     // to popup a modal dialog on start without screwing combo boxes.
     // This is ugly but I honestly found no better way to do it.
     // Neither wxShowEvent nor wxWindowCreateEvent work reliably.
+    assert(this->preset_updater); // FIXME Following condition is probably not neccessary.
     if (this->preset_updater) {
         this->check_updates(false);
         CallAfter([this] {