Align outline points

src/libslic3r/SLA/SupportIslands/LineUtils.cpp

@@ -279,7 +279,18 @@ std::optional<Slic3r::Vec2d> LineUtils::intersection(const Line &ray1, const Lin
     return (ray1.a.cast<double>() + t * v1);
 }
 
-LineUtils::LineConnection LineUtils::create_line_connection(const Slic3r::Lines &lines)
+double LineUtils::foot(const Line &line, const Point &point)
+{
+    Vec2d  a   = line.a.cast<double>();
+    Vec2d  vec = point.cast<double>() - a;
+    Vec2d  b   = line.b.cast<double>();
+    Vec2d  dir = b - a;
+    double l2  = dir.squaredNorm();
+    return vec.dot(dir) / l2;
+}
+
+LineUtils::LineConnection LineUtils::create_line_connection(
+    const Slic3r::Lines &lines)
 {
     LineConnection line_connection;
     static const size_t bad_index = -1;

src/libslic3r/SLA/SupportIslands/LineUtils.hpp

@@ -119,6 +119,15 @@ public:
     /// <returns>line direction</returns>
     static Point direction(const Line &line) { return line.b - line.a; }
 
+    /// <summary>
+    /// Calculate foot point in maner of Geometry::foot_pt
+    /// - without unnecessary conversion
+    /// </summary>
+    /// <param name="line">input line</param>
+    /// <param name="point">point to search foot on line</param>
+    /// <returns>ration betwen point line.a and line.b (in range from 0. to 1.)</returns>
+    static double foot(const Line &line, const Point& point);
+
     //                          line index, <a connection, b connection>
     using LineConnection = std::map<size_t, std::pair<size_t, size_t>>;
     /// <summary>

src/libslic3r/SLA/SupportIslands/SampleIslandUtils.cpp

@@ -1209,69 +1209,204 @@ SampleIslandUtils::Field SampleIslandUtils::create_field(
     return field;
 }
 
+std::pair<Slic3r::ExPolygon, std::map<size_t, size_t>>
+SampleIslandUtils::outline_offset(const Slic3r::ExPolygon &island,
+                                  coord_t                  offset_distance)
+{
+    Polygons polygons = offset(island, -offset_distance, ClipperLib::jtSquare);
+    if (polygons.empty()) return {}; // no place for support point
+    assert(polygons.front().is_counter_clockwise());
+    ExPolygon offseted(polygons.front());
+    for (size_t i = 1; i < polygons.size(); ++i) {
+        Polygon &hole = polygons[i];
+        assert(hole.is_clockwise());
+        offseted.holes.push_back(hole);
+    }
+
+    // TODO: Connect indexes for convert during creation of offset
+    // !! this implementation was fast for develop BUT NOT for running !!
+    Lines island_lines = to_lines(island);
+    Lines offset_lines = to_lines(offseted);
+    // Convert index map from island index to offseted index
+    std::map<size_t, size_t> converter;
+    for (size_t island_line_index = 0; island_line_index < island_lines.size(); ++island_line_index) {
+        const Line &island_line = island_lines[island_line_index];
+        Vec2f dir1 = LineUtils::direction(island_line).cast<float>();
+        for (size_t offset_line_index = 0; offset_line_index < offset_lines.size(); ++offset_line_index) {
+            const Line &offset_line = offset_lines[offset_line_index];
+            Vec2f dir2 = LineUtils::direction(offset_line).cast<float>();
+            if (fabs(dir1.dot(dir2)) < 1e-4) { // in similar direction
+                Point  middle   = offset_line.a / 2 + offset_line.b / 2;
+                double distance = island_line.perp_distance_to(middle);
+                if (fabs(distance - offset_distance) < 20) { 
+                    // found offseted line
+                    converter[island_line_index] = offset_line_index;
+                    break;
+                }
+            }
+        }
+    }
+
+    return {offseted, converter};
+}
+
 SupportIslandPoints SampleIslandUtils::sample_outline(
     const Field &field, const SampleConfig &config)
 {
-    // TODO: fix it by neighbor line angles
-    // Do not create inner expoly and test all points to lay inside
-    Polygons polygons = offset(field.border,-config.minimal_distance_from_outline + 5, ClipperLib::jtSquare);
-    if (polygons.empty()) return {}; // no place for support point
-    ExPolygon inner(polygons.front());
-    for (size_t i = 1; i < polygons.size(); ++i) {
-        Polygon &hole = polygons[i];
-        inner.holes.push_back(hole);
-    }
-
+    const ExPolygon &border        = field.border;
+    const Polygon &contour = border.contour;
+    assert(field.source_indexes.size() >= contour.size());
+    // convert map from field index to inner(line index)
+    std::map<size_t, size_t> field_2_inner;
+    ExPolygon                inner;
+    std::tie(inner, field_2_inner) = outline_offset(border, config.minimal_distance_from_outline);
+    coord_t max_align_distance = config.max_align_distance;
     coord_t sample_distance = config.outline_sample_distance;
-    coord_t outline_distance = config.minimal_distance_from_outline;
     SupportIslandPoints result;
-    auto add_sample = [&](const Line &line, size_t source_index, coord_t& last_support) {
-        double  line_length_double = line.length();
-        coord_t line_length        = static_cast<coord_t>(line_length_double);
+
+    using RestrictionPtr = std::shared_ptr<SupportOutlineIslandPoint::Restriction>;
+    auto add_sample = [&](size_t index, const RestrictionPtr& restriction, coord_t &last_support) {
+        using Position = SupportOutlineIslandPoint::Position;
+        const Line &  line = restriction->lines[index];
+        const double &line_length_double = restriction->lengths[index];
+        coord_t line_length = static_cast<coord_t>(std::round(line_length_double));
         if (last_support + line_length > sample_distance) {
-            Point  dir               = LineUtils::direction(line);
-            Point  perp              = PointUtils::perp(dir);
-            double size              = perp.cast<double>().norm();
-            Point  move_from_outline = perp * (outline_distance / size);
+            Point direction = LineUtils::direction(line);
             do {
                 double ratio = (sample_distance - last_support) / line_length_double;
-                Point point = line.a + dir * ratio + move_from_outline;
-
-                // TODO: improve prevent sampling out of field near sharp corner
-                // use range for possible ratio
-                if (inner.contains(point))
-                    result.emplace_back(std::make_unique<SupportOutlineIslandPoint>(
-                        point, source_index, SupportIslandPoint::Type::outline));
-
+                result.emplace_back(
+                    std::make_unique<SupportOutlineIslandPoint>(
+                        Position(index, ratio), restriction,
+                        SupportIslandPoint::Type::outline)
+                );
                 last_support -= sample_distance;
             } while (last_support + line_length > sample_distance);
         }
         last_support += line_length;
     };
-    Lines contour_lines = to_lines(field.border.contour);
-    coord_t last_support = sample_distance / 2;
-    for (const Line &line : contour_lines) {
-        size_t index = &line - &contour_lines.front();
-        assert(field.source_indexes.size() > index);
-        size_t source_index = field.source_indexes[index];
-        if (source_index == field.source_indexe_for_change) { 
-            last_support = sample_distance / 2;
-            continue;
+    auto add_circle_sample = [&](const Polygon& polygon) {
+        // IMPROVE: find interesting points to start sampling
+        Lines lines = to_lines(polygon);
+        std::vector<double> lengths;
+        lengths.reserve(lines.size());
+        double sum_lengths = 0;
+        for (const Line &line : lines) {
+            double length = line.length();
+            sum_lengths += length;
+            lengths.push_back(length);
         }
-        add_sample(line, source_index, last_support);
-    }
-    size_t index_offset = contour_lines.size();
-    for (const Polygon &hole : field.border.holes) {
-        Lines hole_lines = to_lines(hole);
-        coord_t last_support = sample_distance / 2;
-        for (const Line &line : hole_lines) {
-            size_t hole_line_index = (&line - &hole_lines.front());
-            size_t index           = index_offset + hole_line_index;
-            assert(field.source_indexes.size() > index);
+        // no samples on this polygon
+
+        using Restriction = SupportOutlineIslandPoint::RestrictionCircleSequence;
+        auto restriction  = std::make_shared<Restriction>(lines, lengths, max_align_distance);
+        coord_t last_support = std::min(static_cast<coord_t>(sum_lengths), sample_distance) / 2;
+        for (size_t index = 0; index < lines.size(); ++index) {
+            add_sample(index, restriction, last_support);
+        }
+    };
+
+    // sample line sequence
+    auto add_lines_samples = [&](const Lines &inner_lines,
+                                 size_t       first_index,
+                                 size_t       last_index) {        
+        Lines lines;
+        // is over start ?
+        if (first_index > last_index) {
+            size_t count = first_index + inner_lines.size() - last_index;
+            lines.reserve(count);
+            std::copy(inner_lines.begin() + last_index,
+                        inner_lines.end(),
+                        std::back_inserter(lines));
+            std::copy(inner_lines.begin(),
+                        inner_lines.begin() + first_index,
+                        std::back_inserter(lines));
+        } else {
+            size_t count = last_index - first_index;
+            lines.reserve(count);
+            std::copy(inner_lines.begin() + first_index,
+                        inner_lines.begin() + last_index,
+                        std::back_inserter(lines));
+        }
+
+        // IMPROVE: find interesting points to start sampling
+        std::vector<double> lengths;
+        lengths.reserve(lines.size());
+        double sum_lengths = 0;
+        for (const Line &line : lines) { 
+            double length = line.length();
+            sum_lengths += length;
+            lengths.push_back(length);
+        }
+        
+        using Restriction = SupportOutlineIslandPoint::RestrictionLineSequence;
+        auto restriction = std::make_shared<Restriction>(lines, lengths, max_align_distance);
+        
+        // CHECK: Is correct to has always one support on outline sequence? 
+        // or no sample small sequence at all?
+        coord_t last_support = std::min(static_cast<coord_t>(sum_lengths), sample_distance) / 2;
+        for (size_t index = 0; index < lines.size(); ++index) { 
+            add_sample(index, restriction, last_support);
+        }
+    };
+
+    const size_t& change_index = field.source_indexe_for_change;
+    auto sample_polygon = [&](const Polygon &polygon,
+                              const Polygon &inner_polygon,
+                              size_t         index_offset) {
+        // contain polygon tiny wide change?
+        size_t first_change_index = polygon.size();
+        for (size_t polygon_index = 0; polygon_index < polygon.size(); ++polygon_index) {
+            size_t index = polygon_index + index_offset;
+            assert(index < field.source_indexes.size());
             size_t source_index = field.source_indexes[index];
-            add_sample(line, source_index, last_support);
+            if (source_index == change_index) {
+                // found change from wide to tiny part
+                first_change_index = polygon_index;
+                break;
+            }
         }
-        index_offset += hole_lines.size();
+
+        // is polygon without change
+        if (first_change_index == polygon.size()) {
+            add_circle_sample(inner_polygon);
+        } else { // exist change create line sequences
+            // initialize with non valid values
+            Lines  inner_lines   = to_lines(inner_polygon);
+            size_t inner_invalid = inner_lines.size();
+            // first and last index to inner lines
+            size_t inner_first = inner_invalid;
+            size_t inner_last  = inner_invalid;
+            for (size_t polygon_index = first_change_index + 1;
+                 polygon_index != first_change_index; ++polygon_index) {
+                if (polygon_index == polygon.size()) polygon_index = 0;
+                size_t index = polygon_index + index_offset;
+                assert(index < field.source_indexes.size());
+                size_t source_index = field.source_indexes[index];
+                if (source_index == change_index) {
+                    if (inner_first == inner_invalid) continue;
+                    // create Restriction object
+                    add_lines_samples(inner_lines, inner_first, inner_last);
+                    inner_first = inner_invalid;
+                    inner_last  = inner_invalid;
+                    continue;
+                }
+                auto convert_index_item = field_2_inner.find(polygon_index);
+                // check if exist inner line
+                if (convert_index_item == field_2_inner.end()) continue;
+                inner_last = convert_index_item->second - index_offset;
+                // initialize first index
+                if (inner_first == inner_invalid) inner_first = inner_last;
+            }
+        }
+    };
+
+    size_t index_offset = 0;
+    sample_polygon(contour, inner.contour, index_offset);
+    index_offset = contour.size();    
+    for (size_t hole_index = 0; hole_index < border.holes.size(); ++hole_index) {
+        const Polygon &hole = border.holes[hole_index];
+        sample_polygon(hole, inner.holes[hole_index], index_offset);
+        index_offset += hole.size();
     }
     return result;
 }

src/libslic3r/SLA/SupportIslands/SampleIslandUtils.hpp

@@ -289,8 +289,21 @@ public:
     /// <returns>support for outline</returns>
     static SupportIslandPoints sample_outline(const Field &       field,
                                               const SampleConfig &config);
+private:
+    /// <summary>
+    /// create offsetted field
+    /// </summary>
+    /// <param name="island">source field</param>
+    /// <param name="offset_distance">distance from outline</param>
+    /// <returns>offseted field
+    /// First  - offseted island outline
+    /// Second - map for convert source field index to result border index
+    /// </returns>
+    static std::pair<Slic3r::ExPolygon, std::map<size_t, size_t>>
+    outline_offset(const Slic3r::ExPolygon &island, coord_t offset_distance);
 
     // debug draw functions
+public :
     static void draw(SVG &        svg,
                      const Field &field,
                      bool         draw_border_line_indexes  = false,

src/libslic3r/SLA/SupportIslands/SupportIslandPoint.cpp

@@ -1,5 +1,6 @@
 #include "SupportIslandPoint.hpp"
 #include "VoronoiGraphUtils.hpp"
+#include "LineUtils.hpp"
 
 using namespace Slic3r::sla;
 
@@ -39,9 +40,7 @@ coord_t SupportIslandPoint::move(const Point &destination)
 {
     Point diff = destination - point;
     point      = destination;
-    // TODO: check move out of island !!
-    // + need island ExPolygon
-    return diff.x() + diff.y(); // Manhatn distance
+    return abs(diff.x()) + abs(diff.y()); // Manhatn distance
 }
 
 std::string SupportIslandPoint::to_string(const Type &type)
@@ -86,9 +85,88 @@ coord_t SupportCenterIslandPoint::move(const Point &destination)
         VoronoiGraphUtils::align(position, destination,
                                  configuration->max_align_distance);
     Point new_point  = VoronoiGraphUtils::create_edge_point(position);
-    Point move       = new_point - point;
-    point    = new_point;
-    coord_t manhatn_distance = abs(move.x()) + abs(move.y());
-    return manhatn_distance;
+    return SupportIslandPoint::move(new_point);
 }
 
+///////////////
+// Point on Outline
+///////////////
+
+SupportOutlineIslandPoint::SupportOutlineIslandPoint(
+    Position position, std::shared_ptr<Restriction> restriction, Type type)
+    : SupportIslandPoint(calc_point(position, *restriction), type)
+    , position(position)
+    , restriction(std::move(restriction))
+{}
+
+bool SupportOutlineIslandPoint::can_move() const { return true; }
+
+coord_t SupportOutlineIslandPoint::move(const Point &destination)
+{
+    size_t index   = position.index;
+    MoveResult closest = create_result(index, destination);
+
+    const double &length = restriction->lengths[position.index];
+    double distance = (1.0 - position.ratio) * length;
+    while (distance < restriction->max_align_distance) {
+        auto next_index = restriction->next_index(index);
+        if (!next_index.has_value()) break;
+        index = *next_index;
+        update_result(closest, index, destination);
+        distance += restriction->lengths[index];
+    }
+
+    index    = position.index;
+    distance = static_cast<coord_t>(position.ratio) * length;
+    while (distance < restriction->max_align_distance) {
+        auto prev_index = restriction->prev_index(index);
+        if (!prev_index.has_value()) break;
+        index         = *prev_index;
+        update_result(closest, index, destination);
+        distance += restriction->lengths[index];
+    }
+
+    // apply closest result of move
+    this->point = closest.point;
+    this->position = closest.position;
+    return closest.distance;
+}
+
+Slic3r::Point SupportOutlineIslandPoint::calc_point(const Position &position, const Restriction &restriction)
+{
+    const Line &line = restriction.lines[position.index];
+    Point direction = LineUtils::direction(line);
+    return line.a + direction * position.ratio;
+}
+
+SupportOutlineIslandPoint::MoveResult SupportOutlineIslandPoint::create_result(
+    size_t index, const Point &destination)
+{
+    const Line &line       = restriction->lines[index];
+    double      line_ratio_full = LineUtils::foot(line, destination);
+    double      line_ratio      = std::clamp(line_ratio_full, 0., 1.);
+    Position    new_position(index, line_ratio);
+    Point       new_point = calc_point(new_position, *restriction);
+    double point_distance = (new_point - destination).cast<double>().norm();
+    return MoveResult(new_position, new_point, point_distance);
+}
+
+void SupportOutlineIslandPoint::update_result(MoveResult & result,
+                                              size_t       index,
+                                              const Point &destination)
+{
+    const Line &line       = restriction->lines[index];
+    double      line_ratio_full = LineUtils::foot(line, destination);
+    double      line_ratio = std::clamp(line_ratio_full, 0., 1.);
+    Position    new_position(index, line_ratio);
+    Point       new_point = calc_point(new_position, *restriction);
+    Point       diff      = new_point - destination;
+    if (abs(diff.x()) > result.distance) return;
+    if (abs(diff.y()) > result.distance) return;
+    double point_distance = diff.cast<double>().norm();
+    if (result.distance > point_distance) {
+        result.distance = point_distance;
+        result.position = new_position;
+        result.point    = new_point;
+    }
+}

src/libslic3r/SLA/SupportIslands/SupportIslandPoint.hpp

@@ -107,33 +107,157 @@ public:
 };
 
 /// <summary>
-/// DTO Support point laying on Outline of island
+/// Support point laying on Outline of island
 /// Restriction to move only on outline
 /// </summary>
 class SupportOutlineIslandPoint : public SupportIslandPoint
 {
 public:
-    // index of line form island outline 
-    size_t index;
+    // definition of restriction
+    class Restriction;
+
+    struct Position
+    {
+        // index of line form island outline - index into Restriction
+        // adress line inside inner polygon --> SupportOutline
+        size_t index;
+
+        // define position on line by ratio 
+        // from 0 (line point a) 
+        // to   1 (line point b)
+        float ratio;
+
+        Position(size_t index, float ratio) : index(index), ratio(ratio) {}
+    };    
+    Position position;
+
+
+    // store lines for allowed move - with distance from island source lines
+    std::shared_ptr<Restriction> restriction;
 
 public:
-    SupportOutlineIslandPoint(Slic3r::Point point,
-                              size_t        index,
-                              Type          type = Type::outline)
-        : SupportIslandPoint(point, type), index(index)
-    {}
+    SupportOutlineIslandPoint(Position                     position,
+                              std::shared_ptr<Restriction> restriction,
+                              Type type = Type::outline);
+    // return true
+    bool can_move() const override;
 
-    bool can_move() const override { return true; }
+    /// <summary>
+    /// Move nearest to destination point
+    /// only along restriction lines
+    /// + change current position
+    /// </summary>
+    /// <param name="destination">Wanted support position</param>
+    /// <returns>move distance manhatn</returns>
+    coord_t move(const Point &destination) override;
 
-    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;
-    }
+    /// <summary>
+    /// Calculate 2d point belong to line position
+    /// </summary>
+    /// <param name="position">Define position on line from restriction</param>
+    /// <param name="restriction">Hold lines</param>
+    /// <returns>Position in 2d</returns>
+    static Point calc_point(const Position &   position,
+                            const Restriction &restriction);
+
+    /// <summary>
+    /// Keep data for align support point on bordred of island
+    /// Define possible move of point along outline
+    /// IMPROVE: Should contain list of Points on outline.
+    /// (to keep maximal distance of neighbor points on outline)
+    /// </summary>
+    class Restriction
+    {
+    public:
+        // line restriction
+        // must be connected line.a == prev_line.b && line.b == next_line.a
+        Lines lines;
+
+        // keep stored line lengths
+        // same size as lines
+        std::vector<double> lengths;
+
+        // maximal distance for search nearest line to destination point during aligning
+        coord_t max_align_distance;
+
+        Restriction(Lines               lines,
+                    std::vector<double> lengths,
+                    coord_t             max_align_distance)
+            : lines(lines)
+            , lengths(lengths)
+            , max_align_distance(max_align_distance)
+        {
+            assert(lines.size() == lengths.size());
+        }
+
+        virtual std::optional<size_t> next_index(size_t index) const = 0;
+        virtual std::optional<size_t> prev_index(size_t index) const = 0;
+    };
+    
+    class RestrictionLineSequence: public Restriction
+    {
+    public:
+        // inherit constructors
+        using Restriction::Restriction;
+        
+        virtual std::optional<size_t> next_index(size_t index) const override
+        {
+            assert(index < lines.size());
+            ++index;
+            if (index >= lines.size()) return {}; // index out of range
+            return index;
+        }
+
+        virtual std::optional<size_t> prev_index(size_t index) const override
+        {
+            assert(index < lines.size());
+            if (index >= lines.size()) return {}; // index out of range
+            if (index == 0) return {}; // no prev line
+            return index - 1;
+        }
+    };
+
+    class RestrictionCircleSequence : public Restriction
+    {
+    public:
+        // inherit constructors
+        using Restriction::Restriction;
+
+        virtual std::optional<size_t> next_index(size_t index) const override
+        {
+            assert(index < lines.size());
+            if (index >= lines.size()) return {}; // index out of range
+            ++index;
+            if (index == lines.size()) return 0;
+            return index;
+        }
+
+        virtual std::optional<size_t> prev_index(size_t index) const override
+        {
+            assert(index < lines.size());
+            if (index >= lines.size()) return {}; // index out of range
+            if (index == 0) return lines.size() - 1;
+            return index - 1;
+        }
+    };
+
+private:
+    // DTO for result of move
+    struct MoveResult
+    {
+        // define position on restriction line
+        Position position;
+        // point laying on restricted line
+        Point point;
+        // distance point on restricted line from destination point
+        double distance;
+
+        MoveResult(Position position, Point point, double distance)
+            : position(position), point(point), distance(distance)
+        {}
+    };
+    MoveResult create_result(size_t index, const Point &destination);
+    void update_result(MoveResult& result, size_t index, const Point &destination);
 };
 
 } // namespace Slic3r::sla