Support island points are generated as unique ptr for option to move with them

+ add fix for cell 2 polygon transformation

src/libslic3r/Geometry.hpp

@@ -314,11 +314,11 @@ bool liang_barsky_line_clipping(
 template<typename T>
 int ray_circle_intersections_r2_lv2_c(T r2, T a, T b, T lv2, T c, std::pair<Eigen::Matrix<T, 2, 1, Eigen::DontAlign>, Eigen::Matrix<T, 2, 1, Eigen::DontAlign>> &out)
 {
-    T x0 = - a * c / lv2;
-    T y0 = - b * c / lv2;
     T d = r2 - c * c / lv2;
     if (d < T(0))
         return 0;
+    T x0 = - a * c / lv2;
+    T y0 = - b * c / lv2;
     T mult = sqrt(d / lv2);
     out.first.x() = x0 + b * mult;
     out.first.y() = y0 - a * mult;

src/libslic3r/SLA/SupportIslands/LineUtils.cpp

@@ -59,7 +59,7 @@ std::optional<Slic3r::Linef> LineUtils::crop_ray(const Linef &ray,
     Vec2d center_d = center.cast<double>();
     if (is_parallel_y(ray)) {
         double x        = ray.a.x();
-        double diff     = x - center.x();
+        double diff     = x - center_d.x();
         double abs_diff = fabs(diff);
         if (abs_diff > radius) return {};
         // create cross points
@@ -247,6 +247,13 @@ void LineUtils::draw(SVG &       svg,
     }
 }
 
+double LineUtils::perp_distance(const Linef &line, Vec2d p)
+{
+    Vec2d v  = line.b - line.a; // direction
+    Vec2d va = p - line.a;
+    return std::abs(cross2(v, va)) / v.norm();
+}
+
 void LineUtils::draw(SVG &        svg,
                      const Lines &lines,
                      const char * color,

src/libslic3r/SLA/SupportIslands/LineUtils.hpp

@@ -84,6 +84,14 @@ public:
     static std::tuple<double, double, double> get_param(const Line &line);
     static std::tuple<double, double, double> get_param(const Linef &line);
 
+    /// <summary>
+    /// Calculate distance between point and ray
+    /// </summary>
+    /// <param name="line">a and b are only for direction, not limit</param>
+    /// <param name="p">Point in space</param>
+    /// <returns>Euclid perpedicular distance</returns>
+    static double perp_distance(const Linef &line, Vec2d p);
+
     static void draw(SVG &       svg,
                      const Line &line,
                      const char *color        = "gray",

src/libslic3r/SLA/SupportIslands/SampleIslandUtils.cpp

@@ -19,18 +19,17 @@
 
 using namespace Slic3r::sla;
 
-
-SupportIslandPoint SampleIslandUtils::create_point(
+std::unique_ptr<SupportIslandPoint> SampleIslandUtils::create_point(
     const VoronoiGraph::Node::Neighbor *neighbor,
     double                              ratio,
     SupportIslandPoint::Type            type)
 {
     VoronoiGraph::Position position(neighbor, ratio);
     Slic3r::Point p = VoronoiGraphUtils::create_edge_point(position);
-    return SupportIslandPoint(p, type, position);
+    return std::make_unique<SupportCenterIslandPoint>(p, position, type);
 }
 
-SupportIslandPoint SampleIslandUtils::create_point_on_path(
+std::unique_ptr<SupportIslandPoint> SampleIslandUtils::create_point_on_path(
     const VoronoiGraph::Nodes &path,
     double                     distance,
     SupportIslandPoint::Type   type)
@@ -57,12 +56,10 @@ SupportIslandPoint SampleIslandUtils::create_point_on_path(
     // distance must be inside path
     // this means bad input params
     assert(false);
-    return SupportIslandPoint(Point(0, 0),
-                              SupportIslandPoint::Type::undefined,
-                              VoronoiGraph::Position(nullptr,0.));
+    return nullptr; // unreachable
 }
 
-SupportIslandPoint SampleIslandUtils::create_middle_path_point(
+SupportIslandPointPtr SampleIslandUtils::create_middle_path_point(
     const VoronoiGraph::Path &path, SupportIslandPoint::Type  type)
 {
     return create_point_on_path(path.nodes, path.length / 2, type);
@@ -73,10 +70,11 @@ SupportIslandPoints SampleIslandUtils::create_side_points(
 {
     VoronoiGraph::Nodes reverse_path = path; // copy
     std::reverse(reverse_path.begin(), reverse_path.end());
-    return {
-        create_point_on_path(path, side_distance, SupportIslandPoint::Type::two_points),
-        create_point_on_path(reverse_path, side_distance, SupportIslandPoint::Type::two_points)
-    };
+    SupportIslandPoints result;
+    result.reserve(2);
+    result.push_back(create_point_on_path(path, side_distance, SupportIslandPoint::Type::two_points));
+    result.push_back(create_point_on_path(reverse_path, side_distance, SupportIslandPoint::Type::two_points));
+    return std::move(result);
 }
 
 SupportIslandPoints SampleIslandUtils::sample_side_branch(
@@ -92,7 +90,11 @@ SupportIslandPoints SampleIslandUtils::sample_side_branch(
         VoronoiGraph::Nodes reverse_path = side_path.nodes;
         std::reverse(reverse_path.begin(), reverse_path.end());
         reverse_path.push_back(first_node);
-        return {create_point_on_path(reverse_path, cfg.side_distance, SupportIslandPoint::Type::center_line_end)};
+        SupportIslandPoints result;
+        result.push_back(
+            create_point_on_path(reverse_path, cfg.side_distance,
+                                 SupportIslandPoint::Type::center_line_end));
+        return std::move(result);
     }
     // count of segment between points on main path
     size_t segment_count = static_cast<size_t>(
@@ -113,13 +115,13 @@ SupportIslandPoints SampleIslandUtils::sample_side_branch(
             if (side_item->second.top().length > cfg.min_length) {
                 auto side_samples = sample_side_branches(side_item,
                                                          start_offset, cfg);
-                result.insert(result.end(), side_samples.begin(),
-                              side_samples.end());
+                result.insert(result.end(), std::move_iterator(side_samples.begin()),
+                              std::move_iterator(side_samples.end()));
             }
         }
         while (distance < neighbor->edge_length) {
             double edge_ratio = distance / neighbor->edge_length;
-            result.emplace_back(
+            result.push_back(
                 create_point(neighbor, edge_ratio, SupportIslandPoint::Type::center_line)
             );
             distance += sample_distance;
@@ -128,8 +130,8 @@ SupportIslandPoints SampleIslandUtils::sample_side_branch(
         prev_node = node;
     }
     assert(fabs(distance - (sample_distance - cfg.side_distance)) < 1e-5);
-    result.back().type = SupportIslandPoint::Type::center_line_end;
-    return result;
+    result.back()->type = SupportIslandPoint::Type::center_line_end;
+    return std::move(result);
 }
 
 SupportIslandPoints SampleIslandUtils::sample_side_branches(
@@ -150,10 +152,12 @@ SupportIslandPoints SampleIslandUtils::sample_side_branches(
     while (side_branches_cpy.top().length > cfg.min_length) {
         auto samples = sample_side_branch(first_node, side_branches_cpy.top(),
                                           start_offset, cfg);
-        result.insert(result.end(), samples.begin(), samples.end());
+        result.insert(result.end(), 
+            std::move_iterator(samples.begin()), 
+            std::move_iterator(samples.end()));
         side_branches_cpy.pop();
     }
-    return result;
+    return std::move(result);
 }
 
 std::vector<std::set<const VoronoiGraph::Node *>> create_circles_sets(
@@ -187,14 +191,16 @@ std::vector<std::set<const VoronoiGraph::Node *>> create_circles_sets(
 
 Slic3r::Points SampleIslandUtils::to_points(const SupportIslandPoints &support_points)
 { 
-    std::function<Point(const SupportIslandPoint &)> transform_func = &SupportIslandPoint::point;
+    std::function<Point(const std::unique_ptr<SupportIslandPoint> &)> transform_func = &SupportIslandPoint::point;
     return VectorUtils::transform(support_points, transform_func);
 }
 
 std::vector<Slic3r::Vec2f> SampleIslandUtils::to_points_f(const SupportIslandPoints &support_points)
 {
-    std::function<Vec2f(const SupportIslandPoint &p)> transform_func =
-        [](const SupportIslandPoint &p) { return p.point.cast<float>(); };
+    std::function<Vec2f(const std::unique_ptr<SupportIslandPoint> &)> transform_func =
+        [](const std::unique_ptr<SupportIslandPoint> &p) {
+            return p->point.cast<float>();
+        };
     return VectorUtils::transform(support_points, transform_func);
 }
 
@@ -246,13 +252,13 @@ coord_t SampleIslandUtils::align_once(SupportIslandPoints &samples,
     construct_voronoi(points.begin(), points.end(), &vd);
     coord_t max_move = 0;
     for (const VD::cell_type &cell : vd.cells()) {
-        SupportIslandPoint &sample = samples[cell.source_index()];
-        if (!sample.can_move()) continue;
+        SupportIslandPointPtr &sample = samples[cell.source_index()];
+        if (!sample->can_move()) continue;
         Polygon polygon = VoronoiGraphUtils::to_polygon(cell, points, config.max_distance);
         Polygons intersections = Slic3r::intersection(island, ExPolygon(polygon));
         const Polygon *island_cell   = nullptr;
         for (const Polygon &intersection : intersections) {
-            if (intersection.contains(sample.point)) {
+            if (intersection.contains(sample->point)) {
                 island_cell = &intersection;
                 break;
             }
@@ -265,27 +271,13 @@ coord_t SampleIslandUtils::align_once(SupportIslandPoints &samples,
         svg.draw(*island_cell, "gray");
         svg.draw(sample.point, "black", config.head_radius);
         svg.draw(Line(sample.point, center), "blue", config.head_radius / 5);
-#endif // VISUALIZE_SAMPLE_ISLAND_UTILS_ALIGN_ONCE        
-        coord_t act_move = align_support(sample, center, config.max_align_distance);
+#endif // VISUALIZE_SAMPLE_ISLAND_UTILS_ALIGN_ONCE 
+        coord_t act_move = sample->move(center);
         if (max_move < act_move) max_move = act_move;
     }
     return max_move;
 }
 
-coord_t SampleIslandUtils::align_support(SupportIslandPoint &support,
-                                         const Point &       wanted,
-                                         double              max_distance)
-{
-    //move only along VD
-    VoronoiGraph::Position position =
-        VoronoiGraphUtils::align(support.position, wanted, max_distance);
-    Point new_point = VoronoiGraphUtils::create_edge_point(position);
-    Point move      = new_point - support.point;
-    support.position= position;
-    support.point   = new_point;
-    return abs(move.x()) + abs(move.y());
-}
-
 SupportIslandPoints SampleIslandUtils::sample_center_line(
     const VoronoiGraph::ExPath &path, const CenterLineConfiguration &cfg)
 {
@@ -300,7 +292,7 @@ SupportIslandPoints SampleIslandUtils::sample_center_line(
     if (path.circles.empty()) return result;
     sample_center_circles(path, cfg, result);
     
-    return result;
+    return std::move(result);
 }
 
 void SampleIslandUtils::sample_center_circle_end(
@@ -325,7 +317,7 @@ void SampleIslandUtils::sample_center_circle_end(
     double distance_between = distance / (count_supports + 1);
     if (distance_between < neighbor_distance) {
         // point is calculated to be in done path, SP will be on edge point
-        result.emplace_back(create_point(&neighbor, 1., SupportIslandPoint::Type::center_circle_end));
+        result.push_back(create_point(&neighbor, 1., SupportIslandPoint::Type::center_circle_end));
         neighbor_distance = 0.;
         count_supports -= 1;
         if (count_supports == 0) {
@@ -340,7 +332,7 @@ void SampleIslandUtils::sample_center_circle_end(
     nodes.insert(nodes.begin(), neighbor.node);
     for (int i = 1; i <= count_supports; ++i) {
         double distance_from_neighbor = i * (distance_between) - neighbor_distance;
-        result.emplace_back(
+        result.push_back(
             create_point_on_path(nodes, distance_from_neighbor, SupportIslandPoint::Type::center_circle_end2));
         double distance_support_to_node = fabs(neighbor.edge_length -
                                                distance_from_neighbor);
@@ -435,11 +427,13 @@ SupportDistanceMap create_path_distances(
     return path_distances;
 }
 
+// do not use
 SupportDistanceMap create_support_distance_map(const SupportIslandPoints &support_points)
 {
     SupportDistanceMap support_distance_map;
-    for (const SupportIslandPoint &support_point : support_points) {
-        const VoronoiGraph::Position &position = support_point.position;
+    for (const SupportIslandPointPtr &support_point : support_points) {
+        auto ptr = dynamic_cast<SupportCenterIslandPoint*>(support_point.get()); // bad use
+        const VoronoiGraph::Position &position = ptr->position;
         const VoronoiGraph::Node *node = position.neighbor->node; 
         const VoronoiGraph::Node *twin_node = VoronoiGraphUtils::get_twin_node(position.neighbor);
         double distance = (1 - position.ratio) * position.neighbor->edge_length;
@@ -516,7 +510,9 @@ void SampleIslandUtils::sample_center_circles(
     for (const auto &circle_set : circles_sets) {
         SupportDistanceMap  path_distances = create_path_distances(circle_set, path_set, support_distance_map, cfg.max_sample_distance/2);
         SupportIslandPoints circle_result = sample_center_circle(circle_set, path_distances, cfg);
-        result.insert(result.end(), circle_result.begin(), circle_result.end());
+        result.insert(result.end(), 
+            std::make_move_iterator(circle_result.begin()),
+            std::make_move_iterator(circle_result.end()));
     }
 }
 
@@ -589,7 +585,7 @@ SupportIslandPoints SampleIslandUtils::sample_center_circle(
                                                 .distance_from_support_point -
                                             nd.distance_from_support_point;
                 double ratio = distance_from_node / neighbor.edge_length;
-                result.emplace_back(
+                result.push_back(
                     create_point(&neighbor, ratio, SupportIslandPoint::Type::center_circle));
                 next_nd.distance_from_support_point -= cfg.max_sample_distance;
             }
@@ -605,9 +601,10 @@ SupportIslandPoints SampleIslandUtils::sample_expath(
     // 1) One support point
     if (path.length < config.max_length_for_one_support_point) {
         // create only one point in center
-        return {
-            create_middle_path_point(path, SupportIslandPoint::Type::one_center_point)
-        };        
+        SupportIslandPoints result;
+        result.push_back(create_middle_path_point(
+            path, SupportIslandPoint::Type::one_center_point));
+        return std::move(result);
     }
 
     double max_width = VoronoiGraphUtils::get_max_width(path);
@@ -624,8 +621,8 @@ SupportIslandPoints SampleIslandUtils::sample_expath(
                                     config.max_distance,
                                     config.minimal_distance_from_outline);
         SupportIslandPoints samples = sample_center_line(path, centerLineConfiguration);
-        samples.front().type = SupportIslandPoint::Type::center_line_end2;
-        return samples;
+        samples.front()->type = SupportIslandPoint::Type::center_line_end2;
+        return std::move(samples);
     }
 
     // line of zig zag points
@@ -641,7 +638,7 @@ SupportIslandPoints SampleIslandUtils::sample_expath(
     SupportIslandPoints points;
     points.emplace_back(create_point_on_path(path.nodes, config.minimal_distance_from_outline));
 
-    return points;
+    return std::move(points);
 }
 
 SupportIslandPoints SampleIslandUtils::sample_voronoi_graph(
@@ -665,10 +662,10 @@ void SampleIslandUtils::draw(SVG &                      svg,
                              bool                       write_type)
 {
     for (const auto &p : supportIslandPoints) {
-        svg.draw(p.point, color, size);
-        if (write_type && p.type != SupportIslandPoint::Type::undefined) {
-            auto type_name = magic_enum::enum_name(p.type);
-            Point start     = p.point + Point(size, 0.);
+        svg.draw(p->point, color, size);
+        if (write_type && p->type != SupportIslandPoint::Type::undefined) {
+            auto type_name = magic_enum::enum_name(p->type);
+            Point start     = p->point + Point(size, 0.);
             svg.draw_text(start, std::string(type_name).c_str(), color);
         }
     }

src/libslic3r/SLA/SupportIslands/SampleIslandUtils.hpp

@@ -28,7 +28,7 @@ public:
     /// <param name="ratio">Source distance ratio for position on edge</param>
     /// <param name="type">Type of point</param>
     /// <returns>created support island point</returns>
-    static SupportIslandPoint create_point(
+    static SupportIslandPointPtr create_point(
         const VoronoiGraph::Node::Neighbor *neighbor,
         double                              ratio,
         SupportIslandPoint::Type type = SupportIslandPoint::Type::undefined);
@@ -39,7 +39,7 @@ public:
     /// <param name="path">Neighbor connected Nodes</param>
     /// <param name="distance">Distance to final point</param>
     /// <returns>Points with distance to first node</returns>
-    static SupportIslandPoint create_point_on_path(
+    static SupportIslandPointPtr create_point_on_path(
         const VoronoiGraph::Nodes &path,
         double                     distance,
         SupportIslandPoint::Type type = SupportIslandPoint::Type::undefined);
@@ -52,7 +52,7 @@ public:
     /// <param name="path">Queue of neighbor nodes.(must be neighbor)</param>
     /// <param name="path_length">length of path</param>
     /// <returns>Point laying on voronoi diagram</returns>
-    static SupportIslandPoint create_middle_path_point(
+    static SupportIslandPointPtr create_middle_path_point(
         const VoronoiGraph::Path &path,
         SupportIslandPoint::Type  type = SupportIslandPoint::Type::undefined);    
 

src/libslic3r/SLA/SupportIslands/SupportIslandPoint.hpp

@@ -2,6 +2,7 @@
 #define slic3r_SLA_SuppotstIslands_SupportIslandPoint_hpp_
 
 #include <set>
+#include <memory>
 #include <libslic3r/Point.hpp>
 #include "VoronoiGraph.hpp"
 
@@ -12,59 +13,106 @@ namespace Slic3r::sla {
 /// </summary>
 struct SupportIslandPoint
 {
-    enum class Type : unsigned char {
+    enum class Type: unsigned char {
         one_center_point,
         two_points,
         center_line,
-        center_line_end, // end of branch
+        center_line_end,  // end of branch
         center_line_end2, // start of main path(only one per VD)
         center_circle,
-        center_circle_end, // circle finish by one point (one end per circle - need allign)
-        center_circle_end2, // circle finish by multi points (one end per circle - need allign)
+        center_circle_end, // circle finish by one point (one end per circle -
+                           // need allign)
+        center_circle_end2, // circle finish by multi points (one end per
+                            // circle - need allign)
+
+        outline, // keep position align with island outline 
         undefined
     };
 
-    Slic3r::Point point; // 2 point in layer coordinate
+    Type type;
+    Slic3r::Point point; // 2 coordinate point in a layer (in one slice)
 
+    //SupportIslandPoint() : point(0, 0), type(Type::undefined) {}
+    SupportIslandPoint(Slic3r::Point point, Type type = Type::undefined);
+    virtual ~SupportIslandPoint() = default;
+
+    static bool can_move(const Type &type)
+    {
+        // use shorter list
+        /*
+        static const std::set<Type> can_move({
+            Type::center_line,
+            Type::center_circle,
+            Type::center_circle_end,
+            Type::center_circle_end2});
+        return can_move.find(type) != can_move.end();
+        /*/     // switch comment center
+        static const std::set<Type> cant_move({
+            Type::one_center_point,
+            Type::two_points,
+            Type::center_line_end,
+            Type::center_line_end2});
+        return cant_move.find(type) == cant_move.end();
+        //*/
+    }
+
+    virtual bool can_move() const { return can_move(type); }
+
+    /// <summary>
+    /// Move position of support point close to destination
+    /// with support point restrictions
+    /// </summary>
+    /// <param name="destination">Wanted position</param>
+    /// <returns>Move distance</returns>
+    virtual coord_t move(const Point &destination);
+};
+
+using SupportIslandPointPtr = std::unique_ptr<SupportIslandPoint>;
+using SupportIslandPoints = std::vector<SupportIslandPointPtr>;
+
+struct SupportCenterIslandPoint : public SupportIslandPoint
+{
     // Define position on voronoi graph
     // Lose data when voronoi graph does NOT exist
     VoronoiGraph::Position position;
+    // IMPROVE: not need ratio, only neighbor
+    // const VoronoiGraph::Node::Neighbor* neighbor;
 
-    Type type;
+    // TODO: should earn when created
+    const double max_distance = 1e6; // [in nm] --> 1 mm
 
-    SupportIslandPoint(Slic3r::Point          point,
-                       Type                   type,
-                       VoronoiGraph::Position position)
-        : point(std::move(point)), type(type), position(position)
+    SupportCenterIslandPoint(Slic3r::Point          point,
+                             VoronoiGraph::Position position,
+                             Type                   type = Type::center_line)
+        : SupportIslandPoint(point, type), position(position)
     {}
 
-    bool can_move() const{ 
-        // use shorter list
-        /*
-        
-        static const std::set<Type> can_move({
-            Type::center_line, 
-            Type::center_circle, 
-            Type::center_circle_end,
-            Type::center_circle_end2
-        });
-        return can_move.find(type) != can_move.end();
-        
-        /*/
-        
-        static const std::set<Type> cant_move({
-            Type::one_center_point, 
-            Type::two_points, 
-            Type::center_line_end,
-            Type::center_line_end2
-            });
-        return cant_move.find(type) == cant_move.end();
-        
-        //*/
+    bool can_move() const override{ return true; }
+    coord_t move(const Point &destination) override;
+};
+
+struct SupportOutlineIslandPoint : public SupportIslandPoint
+{
+    // index of line form island outline 
+    size_t index;
+    SupportOutlineIslandPoint(Slic3r::Point point,
+                              size_t        index,
+                              Type          type = Type::outline)
+        : SupportIslandPoint(point, type), index(index)
+    {}
+
+    bool can_move() const override { return true; }
+
+    coord_t move(const Point &destination) override
+    { 
+        // TODO: For decide of move need information about
+        // + island outlines        \    May be 
+        // + distance from outline  /    offseted outlines
+        // + search distance for allowed move over outlines(count, distance)
+        assert(false); // Not implemented
+        return 0;
     }
 };
 
-using SupportIslandPoints = std::vector<SupportIslandPoint>;
-
 } // namespace Slic3r::sla
 #endif // slic3r_SLA_SuppotstIslands_SupportIslandPoint_hpp_

src/libslic3r/SLA/SupportIslands/VectorUtils.hpp

@@ -26,6 +26,7 @@ public:
     template<typename T1, typename T2>
     static void sort_by(std::vector<T1> &data, std::function<T2(const T1 &)> &calc)
     {
+        assert(!data.empty());
         // initialize original index locations
         std::vector<size_t> idx(data.size());
         iota(idx.begin(), idx.end(), 0);

src/libslic3r/SLA/SupportIslands/VoronoiGraphUtils.cpp

@@ -13,10 +13,10 @@
 #include <libslic3r/VoronoiVisualUtils.hpp>
 
 // comment definition of NDEBUG to enable assert()
-// #define NDEBUG
+//#define NDEBUG
 #include <cassert>
 
-//#define SLA_CELL_2_POLYGON_DEBUG
+//#define SLA_SVG_VISUALIZATION_CELL_2_POLYGON
 
 using namespace Slic3r::sla;
 
@@ -38,7 +38,7 @@ Slic3r::Point VoronoiGraphUtils::to_point(const VD::vertex_type *vertex)
 
 Slic3r::Vec2d VoronoiGraphUtils::to_point_d(const VD::vertex_type *vertex)
 {
-    return Vec2d(to_coord(vertex->x()), to_coord(vertex->y()));
+    return Vec2d(vertex->x(), vertex->y());
 }
 
 bool VoronoiGraphUtils::is_coord_in_limits(const VD::coordinate_type &coord,
@@ -78,13 +78,6 @@ Slic3r::Line VoronoiGraphUtils::create_line_between_source_points(
     return Line(middle - side_dir, middle + side_dir);
 }
 
-bool is_oposit_direction(const Slic3r::Point &p1, const Slic3r::Point &p2) {
-    if (abs(p1.x()) > abs(p1.y())) { 
-        return (p1.x() > 0) != (p2.x() > 0);
-    }
-    return (p1.y() > 0) != (p2.y() > 0);
-}
-
 std::optional<Slic3r::Line> VoronoiGraphUtils::to_line(
     const VD::edge_type &edge, const Points &points, double maximal_distance)
 {
@@ -137,12 +130,22 @@ std::optional<Slic3r::Line> VoronoiGraphUtils::to_line(
     }
     std::optional<Linef> segment;
     if (use_both) { 
-        Linef edge_segment(Vec2d(v0->x(), v0->y()), Vec2d(v1->x(), v1->y()));
+        Linef edge_segment(to_point_d(v0), to_point_d(v1));
         segment = LineUtils::crop_line(edge_segment, p1, maximal_distance);
     } else {
-        Vec2d ray_point(edge_vertex->x(), edge_vertex->y());
-        Linef ray(ray_point, ray_point + direction.cast<double>());
-        segment = LineUtils::crop_half_ray(ray, p1, maximal_distance);
+        // Vertex can't be used as start point because data type limitation
+        // Explanation for shortening line is in Test::bad_vertex
+        Vec2d middle    = (p1.cast<double>() + p2.cast<double>()) / 2.;
+        Vec2d vertex = to_point_d(edge_vertex);
+        Vec2d vertex_direction = (vertex - middle);
+        Vec2d vertex_dir_abs(fabs(vertex_direction.x()), fabs(vertex_direction.y()));
+        double divider = (vertex_dir_abs.x() > vertex_dir_abs.y()) ?
+                                      vertex_dir_abs.x() / maximal_distance :
+                                      vertex_dir_abs.y() / maximal_distance;
+        Vec2d  vertex_dir_short = vertex_direction / divider;
+        Vec2d  start_point      = middle + vertex_dir_short;
+        Linef  line_short(start_point, start_point + direction.cast<double>());
+        segment = LineUtils::crop_half_ray(line_short, p1, maximal_distance);
     }
     if (!segment.has_value()) return {};
     return Line(segment->a.cast<coord_t>(), segment->b.cast<coord_t>());
@@ -218,32 +221,24 @@ Slic3r::Polygon VoronoiGraphUtils::to_polygon(const VD::cell_type & cell,
     const VD::edge_type *edge = cell.incident_edge();
     do {
         assert(edge->is_linear());
-        if (!edge->is_primary()) {
-            edge = edge->next();
-            continue;
-        }
+        if (!edge->is_primary()) continue;
         std::optional<Line> line = to_line(*edge, points, maximal_distance);
-        if (!line.has_value()) {
-            edge = edge->next();
-            continue;            
-        }
+        if (!line.has_value()) continue;
         Geometry::Orientation orientation = Geometry::orient(center, line->a, line->b);
-        if (orientation == Geometry::Orientation::ORIENTATION_COLINEAR) 
-        { // on circle over source point edge
-            edge = edge->next();
+        // Can be rich on circle over source point edge
+        if (orientation == Geometry::Orientation::ORIENTATION_COLINEAR)
             continue;
-        }
         if (orientation == Geometry::Orientation::ORIENTATION_CW)
             std::swap(line->a, line->b);
         lines.push_back(line.value());
-        edge = edge->next();
-    } while (edge != cell.incident_edge());
+    } while ((edge = edge->next()) && edge != cell.incident_edge());
+    assert(!lines.empty());
     LineUtils::sort_CCW(lines, center);
     // preccission to decide when not connect neighbor points
     double          min_distance = maximal_distance / 1000.; 
     size_t          count_point  = 6; // count added points
     Slic3r::Polygon polygon = to_polygon(lines, center, maximal_distance, min_distance, count_point);
-#ifdef SLA_CELL_2_POLYGON_DEBUG
+#ifdef SLA_SVG_VISUALIZATION_CELL_2_POLYGON
     {
         std::cout << "cell " << cell.source_index() << " has " << lines.size()  << "edges" << std::endl;
         BoundingBox bbox(center - Point(maximal_distance, maximal_distance),
@@ -261,7 +256,7 @@ Slic3r::Polygon VoronoiGraphUtils::to_polygon(const VD::cell_type & cell,
         }
         svg.draw(center, "red", maximal_distance / 100);
     }
-#endif /* SLA_CELL_2_POLYGON_DEBUG */
+#endif /* SLA_SVG_VISUALIZATION_CELL_2_POLYGON */
     return polygon;
 }
 

tests/libslic3r/test_voronoi.cpp

@@ -2284,3 +2284,79 @@ TEST_CASE("Voronoi cell doesn't contain a source point - SPE-2298", "[VoronoiCel
     REQUIRE(vd.is_valid());
 }
 // */
+
+//#include <libslic3r/SLA/SupportIslands/LineUtils.hpp>
+TEST_CASE("bad vertex cause overflow of data type precisin when use VD result", "[VoronoiDiagram]")
+{
+    // Points are almost in line
+    Points points = {
+        {-106641371, 61644934},
+        {-56376476, 32588892},
+        {0, 0}
+    };
+
+    //auto perp_distance = sla::LineUtils::perp_distance;
+    auto perp_distance = [](const Linef &line, Vec2d p) {
+        Vec2d v  = line.b - line.a; // direction
+        Vec2d va = p - line.a;
+        return std::abs(cross2(v, va)) / v.norm();
+    };
+
+    using VD      = Slic3r::Geometry::VoronoiDiagram;
+    VD vd;
+    construct_voronoi(points.begin(), points.end(), &vd);
+
+    // edge between source index 0 and 1 has bad vertex
+    size_t bad_index0 = 0;
+    size_t bad_index1 = 1;
+    for (auto &edge : vd.edges()) {
+        size_t i1 = edge.cell()->source_index();
+        size_t i2 = edge.twin()->cell()->source_index();
+        if (i1 == bad_index0 && i2 == bad_index1 ||
+            i1 == bad_index1 && i2 == bad_index0) {
+            Vec2d p1     = points[bad_index0].cast<double>();
+            Vec2d p2     = points[bad_index1].cast<double>();
+            Vec2d middle = (p1 + p2) / 2;
+            // direction for edge is perpendicular point connection
+            Vec2d direction(p2.y() - p1.y(), p1.x() - p2.x());
+            const VD::vertex_type *vrtx = (edge.vertex0() == nullptr) ?
+                                                edge.vertex1() :
+                                                edge.vertex0();
+            if (vrtx == nullptr) continue;
+            Vec2d vertex(vrtx->x(), vrtx->y());
+
+            double point_distance = (p1 - p2).norm();
+            double half_point_distance = point_distance/2;
+
+            Linef line_from_middle(middle, middle + direction); // line between source points
+            double distance_vertex = perp_distance(line_from_middle, vertex);
+            double distance_p1 = perp_distance(line_from_middle, p1);
+            double distance_p2 = perp_distance(line_from_middle, p2);
+
+            Linef line_from_vertex(vertex, vertex + direction);
+            double distance_middle = perp_distance(line_from_vertex, middle);
+            double distance_p1_ = perp_distance(line_from_vertex, p1);
+            double distance_p2_ = perp_distance(line_from_vertex, p2);
+
+            double maximal_distance = 9e6;
+            Vec2d  vertex_direction = (vertex - middle);
+            Vec2d  vertex_dir_abs(fabs(vertex_direction.x()),
+                                 fabs(vertex_direction.y()));
+            double divider = (vertex_dir_abs.x() > vertex_dir_abs.y()) ?
+                                 vertex_dir_abs.x() / maximal_distance :
+                                 vertex_dir_abs.y() / maximal_distance;
+            Vec2d  vertex_dir_short = vertex_direction / divider;
+            Vec2d start_point      = middle + vertex_dir_short;
+            Linef  line_short(start_point, start_point + direction);
+            double distance_short_vertex  = perp_distance(line_short, vertex);
+            double distance_short_middle = perp_distance(line_short, middle);
+            double distance_p1_short    = perp_distance(line_short, p1);
+            double distance_p2_short   = perp_distance(line_short, p2);
+
+            CHECK(distance_vertex < 10);
+            //CHECK(distance_middle < 10); // This is bad
+            CHECK(distance_short_vertex < 10);
+            CHECK(distance_short_middle < 10);
+        }
+    }
+}

tests/sla_print/sla_supptgen_tests.cpp

@@ -331,8 +331,8 @@ SupportIslandPoints test_island_sampling(const ExPolygon &   island,
         const Point &chck_point  = chck_points[index];
         double &min_distance = point_distances[index];
         bool         exist_close_support_point = false;
-        for (auto &island_point : points) {
-            Point& p = island_point.point;
+        for (const auto &island_point : points) {
+            const Point& p = island_point->point;
             Point abs_diff(fabs(p.x() - chck_point.x()),
                            fabs(p.y() - chck_point.y()));
             if (abs_diff.x() < min_distance && abs_diff.y() < min_distance) {
@@ -354,7 +354,7 @@ SupportIslandPoints test_island_sampling(const ExPolygon &   island,
         SVG svg("Error" + std::to_string(++counter) + ".svg", bb);
         svg.draw(island, "blue", 0.5f);
         for (auto& p : points)
-            svg.draw(p.point, "lightgreen", config.head_radius);
+            svg.draw(p->point, "lightgreen", config.head_radius);
         for (size_t index = 0; index < chck_points.size(); ++index) {
             const Point &chck_point = chck_points[index];
             double       distance   = point_distances[index];
@@ -367,7 +367,7 @@ SupportIslandPoints test_island_sampling(const ExPolygon &   island,
     //CHECK(is_ok);
 
     // all points must be inside of island
-    for (const auto &point : points) { CHECK(island.contains(point.point)); }
+    for (const auto &point : points) { CHECK(island.contains(point->point)); }
     return points;
 }
 
@@ -428,10 +428,10 @@ TEST_CASE("Speed align", "[VoronoiSkeleton]")
     Slic3r::Voronoi::annotate_inside_outside(vd, lines);
     VoronoiGraph::ExPath longest_path;
     VoronoiGraph skeleton = VoronoiGraphUtils::create_skeleton(vd, lines);
-    auto samples = SampleIslandUtils::sample_voronoi_graph(skeleton, cfg, longest_path);
 
-    for (int i = 0; i < 100; ++i) { auto sample_copy = samples; // copy
-        SampleIslandUtils::align_samples(sample_copy, island, cfg);
+    for (int i = 0; i < 100; ++i) {
+        auto samples = SampleIslandUtils::sample_voronoi_graph(skeleton, cfg, longest_path);
+        SampleIslandUtils::align_samples(samples, island, cfg);
     }
 }
 

tests/sla_print/sla_voronoi_graph_tests.cpp

@@ -47,7 +47,7 @@ void check(Slic3r::Points points, double max_distance) {
 
 TEST_CASE("Polygon from cell", "[Voronoi]")
 {
-    // for debug #define SLA_CELL_2_POLYGON_DEBUG in VoronoiGraphUtils
+    // for debug #define SLA_SVG_VISUALIZATION_CELL_2_POLYGON in VoronoiGraphUtils
     double  max_distance = 1e7;
     coord_t size         = (int) (4e6);
     coord_t half_size         = size/2;