SuperSlicer/src/libslic3r/PerimeterGenerator.hpp

#ifndef slic3r_PerimeterGenerator_hpp_
#define slic3r_PerimeterGenerator_hpp_

#include "libslic3r.h"
#include <vector>
#include "ExPolygonCollection.hpp"
#include "Flow.hpp"
#include "Layer.hpp"
#include "Polygon.hpp"
#include "PrintConfig.hpp"
#include "SurfaceCollection.hpp"
#include "ExtrusionEntityCollection.hpp"

namespace Slic3r {

struct PerimeterIntersectionPoint {
    size_t idx_children;
    Point child_best;
    Point outter_best;
    size_t idx_polyline_outter;
    coord_t distance;
};

// Hierarchy of perimeters.
class PerimeterGeneratorLoop {
public:
    // Polygon of this contour.
    Polygon polygon;
    // Is it a contour or a hole?
    // Contours are CCW oriented, holes are CW oriented.
    bool is_contour;
    //overhang may need to be reversed
    bool is_steep_overhang;
    // Depth in the hierarchy. External perimeter has depth = 0. An external perimeter could be both a contour and a hole.
    unsigned short depth;
    // Children contour, may be both CCW and CW oriented (outer contours or holes).
    std::vector<PerimeterGeneratorLoop> children;


    PerimeterGeneratorLoop(Polygon polygon, unsigned short depth, bool is_contour) :
        polygon(polygon), is_contour(is_contour), depth(depth), is_steep_overhang(false) {}
    PerimeterGeneratorLoop(Polygon polygon, unsigned short depth, bool is_contour, bool is_steep_overhang) :
        polygon(polygon), is_contour(is_contour), depth(depth), is_steep_overhang(is_steep_overhang) {}
    // External perimeter. It may be CCW or CW oriented (outer contour or hole contour).
    bool is_external() const { return this->depth == 0; }
    // it's the last loop of the contour (not hol), so the first to be printed (if all goes well)
    bool is_internal_contour() const;
};

typedef std::vector<PerimeterGeneratorLoop> PerimeterGeneratorLoops;

class PerimeterGenerator {
public:
    // Inputs:
    const SurfaceCollection     *slices;
    const ExPolygons            *upper_slices;
    const ExPolygons            *lower_slices;
    Layer                       *layer;
    Flow                         perimeter_flow;
    Flow                         ext_perimeter_flow;
    Flow                         overhang_flow;
    Flow                         solid_infill_flow;
    const PrintRegionConfig     *config;
    const PrintObjectConfig     *object_config;
    const PrintConfig           *print_config;
    // Outputs:
    ExtrusionEntityCollection   *loops;
    ExtrusionEntityCollection   *gap_fill;
    SurfaceCollection           *fill_surfaces;
    ExPolygons fill_no_overlap;
    
    PerimeterGenerator(
        // Input:
        const SurfaceCollection*    slices,
        Flow                        flow,
        const PrintRegionConfig*    config,
        const PrintObjectConfig*    object_config,
        const PrintConfig*          print_config,
        const bool                  spiral_vase,
        // Output:
        // Loops with the external thin walls
        ExtrusionEntityCollection*  loops,
        // Gaps without the thin walls
        ExtrusionEntityCollection*  gap_fill,
        // Infills without the gap fills
        SurfaceCollection*          fill_surfaces)
        : slices(slices), lower_slices(nullptr), upper_slices(nullptr), layer(nullptr),
            perimeter_flow(flow), ext_perimeter_flow(flow),
            overhang_flow(flow), solid_infill_flow(flow),
            config(config), object_config(object_config), print_config(print_config),
            m_spiral_vase(spiral_vase),
            loops(loops), gap_fill(gap_fill), fill_surfaces(fill_surfaces),
            _ext_mm3_per_mm(-1), _mm3_per_mm(-1), _mm3_per_mm_overhang(-1)
        {};
    void process();

private:
    bool        m_spiral_vase;
    double      _ext_mm3_per_mm;
    double      _mm3_per_mm;
    double      _mm3_per_mm_overhang;
    Polygons    _lower_slices_bridge_flow_small;
    Polygons    _lower_slices_bridge_flow_big;
    Polygons    _lower_slices_bridge_speed_small;
    Polygons    _lower_slices_bridge_speed_big;

    ExtrusionPaths create_overhangs(const Polyline& loop_polygons, ExtrusionRole role, bool is_external) const;

    // transform loops into ExtrusionEntityCollection, adding also thin walls into it.
    ExtrusionEntityCollection _traverse_loops(const PerimeterGeneratorLoops &loops, ThickPolylines &thin_walls) const;
    // try to merge thin walls to a current periemter exrusion or just add it to the end of the list.
    void _merge_thin_walls(ExtrusionEntityCollection &extrusions, ThickPolylines &thin_walls) const;
    // like _traverse_loops but with merging all periemter into one continuous loop
    ExtrusionLoop _traverse_and_join_loops(const PerimeterGeneratorLoop &loop, const PerimeterGeneratorLoops &childs, const Point entryPoint) const;
    // sub-function of _traverse_and_join_loops, transform a single loop as a cut extrusion to be merged with an other one.
    ExtrusionLoop _extrude_and_cut_loop(const PerimeterGeneratorLoop& loop, const Point entryPoint, const Line& direction = Line(Point(0, 0), Point(0, 0)), bool enforce_loop = false) const;
    // sub-function of _traverse_and_join_loops, find the good splot to cut a loop to be able to join it with an other one
    PerimeterIntersectionPoint _get_nearest_point(const PerimeterGeneratorLoops &children, ExtrusionLoop &myPolylines, const coord_t dist_cut, const coord_t max_dist) const;
};

}

#endif