Reworked pad creation algorithm with new parameters:

* brim size
* force pad around object everywhere

sandboxes/slabasebed/slabasebed.cpp

@@ -16,9 +16,9 @@ const std::string USAGE_STR = {
 
 namespace Slic3r { namespace sla {
 
-Contour3D create_base_pool(const Polygons &ground_layer,
+Contour3D create_pad(const Polygons &ground_layer,
                            const ExPolygons &holes = {},
-                           const PoolConfig& cfg = PoolConfig());
+                           const PadConfig& cfg = PadConfig());
 
 Contour3D walls(const Polygon& floor_plate, const Polygon& ceiling,
                 double floor_z_mm, double ceiling_z_mm,
@@ -45,7 +45,7 @@ int main(const int argc, const char *argv[]) {
     model.align_to_origin();
 
     ExPolygons ground_slice;
-    sla::base_plate(model, ground_slice, 0.1f);
+    sla::pad_plate(model, ground_slice, 0.1f);
     if(ground_slice.empty()) return EXIT_FAILURE;
 
     ground_slice = offset_ex(ground_slice, 0.5);
@@ -56,10 +56,10 @@ int main(const int argc, const char *argv[]) {
 
     bench.start();
 
-    sla::PoolConfig cfg;
+    sla::PadConfig cfg;
     cfg.min_wall_height_mm = 0;
     cfg.edge_radius_mm = 0;
-    mesh = sla::create_base_pool(to_polygons(ground_slice), {}, cfg);
+    mesh = sla::create_pad(to_polygons(ground_slice), {}, cfg);
 
     bench.stop();
 

src/libslic3r/CMakeLists.txt

@@ -176,8 +176,8 @@ add_library(libslic3r STATIC
     miniz_extension.cpp
     SLA/SLACommon.hpp
     SLA/SLABoilerPlate.hpp
-    SLA/SLABasePool.hpp
+    SLA/SLAPad.hpp
-    SLA/SLABasePool.cpp
+    SLA/SLAPad.cpp
     SLA/SLASupportTree.hpp
     SLA/SLASupportTree.cpp
     SLA/SLASupportTreeIGL.cpp
@@ -215,6 +215,7 @@ target_link_libraries(libslic3r
     qhull
     semver
     tbb
+    ${CMAKE_DL_LIBS}
     )
 
 if(WIN32)

src/libslic3r/MTUtils.hpp

@@ -252,22 +252,15 @@ template<class T> struct remove_cvref
 
 template<class T> using remove_cvref_t = typename remove_cvref<T>::type;
 
-template<template<class> class C, class T>
-class Container : public C<remove_cvref_t<T>>
-{
-public:
-    explicit Container(size_t count, T &&initval)
-        : C<remove_cvref_t<T>>(count, initval)
-    {}
-};
-
 template<class T> using DefaultContainer = std::vector<T>;
 
 /// Exactly like Matlab https://www.mathworks.com/help/matlab/ref/linspace.html
-template<class T, class I, template<class> class C = DefaultContainer>
+template<class T, class I, template<class> class Container = DefaultContainer>
-inline C<remove_cvref_t<T>> linspace(const T &start, const T &stop, const I &n)
+inline Container<remove_cvref_t<T>> linspace(const T &start,
+                                             const T &stop,
+                                             const I &n)
 {
-    Container<C, T> vals(n, T());
+    Container<remove_cvref_t<T>> vals(n, T());
 
     T      stride = (stop - start) / n;
     size_t i      = 0;
@@ -282,10 +275,13 @@ inline C<remove_cvref_t<T>> linspace(const T &start, const T &stop, const I &n)
 /// in the closest multiple of 'stride' less than or equal to 'end' and
 /// leaving 'stride' space between each value. 
 /// Very similar to Matlab [start:stride:end] notation.
-template<class T, template<class> class C = DefaultContainer>
+template<class T, template<class> class Container = DefaultContainer>
-inline C<remove_cvref_t<T>> grid(const T &start, const T &stop, const T &stride)
+inline Container<remove_cvref_t<T>> grid(const T &start,
+                                         const T &stop,
+                                         const T &stride)
 {
-    Container<C, T> vals(size_t(std::ceil((stop - start) / stride)), T());
+    Container<remove_cvref_t<T>>
+        vals(size_t(std::ceil((stop - start) / stride)), T());
     
     int i = 0;
     std::generate(vals.begin(), vals.end(), [&i, start, stride] {
@@ -387,10 +383,12 @@ unscaled(const Eigen::Matrix<Tin, N, EigenArgs...> &v) noexcept
     return v.template cast<Tout>() * SCALING_FACTOR;
 }
 
-template<class T> inline std::vector<T> reserve_vector(size_t capacity)
+template<class T, class I, class... Args> // Arbitrary allocator can be used
+inline IntegerOnly<I, std::vector<T, Args...>> reserve_vector(I capacity)
 {
-    std::vector<T> ret;
+    std::vector<T, Args...> ret;
-    ret.reserve(capacity);
+    if (capacity > I(0)) ret.reserve(size_t(capacity));
+    
     return ret;
 }
 

src/libslic3r/PrintConfig.cpp

@@ -2695,6 +2695,17 @@ void PrintConfigDef::init_sla_params()
     def->mode = comExpert;
     def->set_default_value(new ConfigOptionFloat(0.));
     
+    def = this->add("pad_brim_size", coFloat);
+    def->label = L("Pad brim size");
+    def->tooltip = L("How far should the pad extend around the contained geometry");
+    def->category = L("Pad");
+    //     def->tooltip = L("");
+    def->sidetext = L("mm");
+    def->min = 0;
+    def->max = 30;
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionFloat(1.6));
+
     def = this->add("pad_max_merge_distance", coFloat);
     def->label = L("Max merge distance");
     def->category = L("Pad");
@@ -2735,6 +2746,13 @@ void PrintConfigDef::init_sla_params()
     def->mode = comSimple;
     def->set_default_value(new ConfigOptionBool(false));
     
+    def = this->add("pad_around_object_everywhere", coBool);
+    def->label = L("Pad around object everywhere");
+    def->category = L("Pad");
+    def->tooltip = L("Force pad around object everywhere");
+    def->mode = comSimple;
+    def->set_default_value(new ConfigOptionBool(false));
+
     def = this->add("pad_object_gap", coFloat);
     def->label = L("Pad object gap");
     def->category = L("Pad");

src/libslic3r/PrintConfig.hpp

@@ -1023,6 +1023,9 @@ public:
     // The height of the pad from the bottom to the top not considering the pit
     ConfigOptionFloat pad_wall_height /*= 5*/;
     
+    // How far should the pad extend around the contained geometry
+    ConfigOptionFloat pad_brim_size;
+
     // The greatest distance where two individual pads are merged into one. The
     // distance is measured roughly from the centroids of the pads.
     ConfigOptionFloat pad_max_merge_distance /*= 50*/;
@@ -1042,7 +1045,9 @@ public:
     // /////////////////////////////////////////////////////////////////////////
 
     // Disable the elevation (ignore its value) and use the zero elevation mode
-    ConfigOptionBool  pad_around_object;
+    ConfigOptionBool pad_around_object;
+    
+    ConfigOptionBool pad_around_object_everywhere;
 
     // This is the gap between the object bottom and the generated pad
     ConfigOptionFloat pad_object_gap;
@@ -1082,10 +1087,12 @@ protected:
         OPT_PTR(pad_enable);
         OPT_PTR(pad_wall_thickness);
         OPT_PTR(pad_wall_height);
+        OPT_PTR(pad_brim_size);
         OPT_PTR(pad_max_merge_distance);
         // OPT_PTR(pad_edge_radius);
         OPT_PTR(pad_wall_slope);
         OPT_PTR(pad_around_object);
+        OPT_PTR(pad_around_object_everywhere);
         OPT_PTR(pad_object_gap);
         OPT_PTR(pad_object_connector_stride);
         OPT_PTR(pad_object_connector_width);

src/libslic3r/SLA/SLAAutoSupports.cpp

@@ -16,6 +16,7 @@
 #include <random>
 
 namespace Slic3r {
+namespace sla {
 
 /*float SLAAutoSupports::approximate_geodesic_distance(const Vec3d& p1, const Vec3d& p2, Vec3d& n1, Vec3d& n2)
 {
@@ -48,9 +49,16 @@ float SLAAutoSupports::distance_limit(float angle) const
     return 1./(2.4*get_required_density(angle));
 }*/
 
-SLAAutoSupports::SLAAutoSupports(const TriangleMesh& mesh, const sla::EigenMesh3D& emesh, const std::vector<ExPolygons>& slices, const std::vector<float>& heights,
+SLAAutoSupports::SLAAutoSupports(const sla::EigenMesh3D &       emesh,
-                                   const Config& config, std::function<void(void)> throw_on_cancel, std::function<void(int)> statusfn)
+                                 const std::vector<ExPolygons> &slices,
-: m_config(config), m_emesh(emesh), m_throw_on_cancel(throw_on_cancel), m_statusfn(statusfn)
+                                 const std::vector<float> &     heights,
+                                 const Config &                 config,
+                                 std::function<void(void)> throw_on_cancel,
+                                 std::function<void(int)>  statusfn)
+    : m_config(config)
+    , m_emesh(emesh)
+    , m_throw_on_cancel(throw_on_cancel)
+    , m_statusfn(statusfn)
 {
     process(slices, heights);
     project_onto_mesh(m_output);
@@ -505,6 +513,21 @@ void SLAAutoSupports::uniformly_cover(const ExPolygons& islands, Structure& stru
     }
 }
 
+void remove_bottom_points(std::vector<SupportPoint> &pts, double gnd_lvl, double tolerance)
+{
+    // get iterator to the reorganized vector end
+    auto endit =
+        std::remove_if(pts.begin(), pts.end(),
+                       [tolerance, gnd_lvl](const sla::SupportPoint &sp) {
+        double diff = std::abs(gnd_lvl -
+                               double(sp.pos(Z)));
+        return diff <= tolerance;
+    });
+
+    // erase all elements after the new end
+    pts.erase(endit, pts.end());
+}
+
 #ifdef SLA_AUTOSUPPORTS_DEBUG
 void SLAAutoSupports::output_structures(const std::vector<Structure>& structures)
 {
@@ -533,4 +556,5 @@ void SLAAutoSupports::output_expolygons(const ExPolygons& expolys, const std::st
 }
 #endif
 
+} // namespace sla
 } // namespace Slic3r

src/libslic3r/SLA/SLAAutoSupports.hpp

@@ -11,20 +11,22 @@
 // #define SLA_AUTOSUPPORTS_DEBUG
 
 namespace Slic3r {
+namespace sla {
 
 class SLAAutoSupports {
 public:
     struct Config {
-            float density_relative;
+            float density_relative {1.f};
-            float minimal_distance;
+            float minimal_distance {1.f};
-            float head_diameter;
+            float head_diameter {0.4f};
             ///////////////
             inline float support_force() const { return 7.7f / density_relative; } // a force one point can support       (arbitrary force unit)
             inline float tear_pressure() const { return 1.f; }  // pressure that the display exerts    (the force unit per mm2)
         };
 
-    SLAAutoSupports(const TriangleMesh& mesh, const sla::EigenMesh3D& emesh, const std::vector<ExPolygons>& slices,
+    SLAAutoSupports(const sla::EigenMesh3D& emesh, const std::vector<ExPolygons>& slices,
                      const std::vector<float>& heights, const Config& config, std::function<void(void)> throw_on_cancel, std::function<void(int)> statusfn);
+    
     const std::vector<sla::SupportPoint>& output() { return m_output; }
 
 	struct MyLayer;
@@ -199,7 +201,9 @@ private:
     std::function<void(int)>  m_statusfn;
 };
 
+void remove_bottom_points(std::vector<SupportPoint> &pts, double gnd_lvl, double tolerance);
 
+} // namespace sla
 } // namespace Slic3r
 
 

src/libslic3r/SLA/SLABasePool.cpp

@@ -1,922 +0,0 @@
-#include "SLABasePool.hpp"
-#include "SLABoilerPlate.hpp"
-
-#include "boost/log/trivial.hpp"
-#include "SLABoostAdapter.hpp"
-#include "ClipperUtils.hpp"
-#include "Tesselate.hpp"
-#include "MTUtils.hpp"
-
-// For debugging:
-// #include <fstream>
-// #include <libnest2d/tools/benchmark.h>
-// #include "SVG.hpp"
-
-namespace Slic3r { namespace sla {
-
-/// This function will return a triangulation of a sheet connecting an upper
-/// and a lower plate given as input polygons. It will not triangulate the
-/// plates themselves only the sheet. The caller has to specify the lower and
-/// upper z levels in world coordinates as well as the offset difference
-/// between the sheets. If the lower_z_mm is higher than upper_z_mm or the
-/// offset difference is negative, the resulting triangle orientation will be
-/// reversed.
-///
-/// IMPORTANT: This is not a universal triangulation algorithm. It assumes
-/// that the lower and upper polygons are offsetted versions of the same
-/// original polygon. In general, it assumes that one of the polygons is
-/// completely inside the other. The offset difference is the reference
-/// distance from the inner polygon's perimeter to the outer polygon's
-/// perimeter. The real distance will be variable as the clipper offset has
-/// different strategies (rounding, etc...). This algorithm should have
-/// O(2n + 3m) complexity where n is the number of upper vertices and m is the
-/// number of lower vertices.
-Contour3D walls(const Polygon& lower, const Polygon& upper,
-                double lower_z_mm, double upper_z_mm,
-                double offset_difference_mm, ThrowOnCancel thr)
-{
-    Contour3D ret;
-
-    if(upper.points.size() < 3 || lower.size() < 3) return ret;
-
-    // The concept of the algorithm is relatively simple. It will try to find
-    // the closest vertices from the upper and the lower polygon and use those
-    // as starting points. Then it will create the triangles sequentially using
-    // an edge from the upper polygon and a vertex from the lower or vice versa,
-    // depending on the resulting triangle's quality.
-    // The quality is measured by a scalar value. So far it looks like it is
-    // enough to derive it from the slope of the triangle's two edges connecting
-    // the upper and the lower part. A reference slope is calculated from the
-    // height and the offset difference.
-
-    // Offset in the index array for the ceiling
-    const auto offs = upper.points.size();
-
-    // Shorthand for the vertex arrays
-    auto& upoints = upper.points, &lpoints = lower.points;
-    auto& rpts = ret.points; auto& ind = ret.indices;
-
-    // If the Z levels are flipped, or the offset difference is negative, we
-    // will interpret that as the triangles normals should be inverted.
-    bool inverted = upper_z_mm < lower_z_mm || offset_difference_mm < 0;
-
-    // Copy the points into the mesh, convert them from 2D to 3D
-    rpts.reserve(upoints.size() + lpoints.size());
-    ind.reserve(2 * upoints.size() + 2 * lpoints.size());
-    for (auto &p : upoints)
-        rpts.emplace_back(unscaled(p.x()), unscaled(p.y()), upper_z_mm);
-    for (auto &p : lpoints)
-        rpts.emplace_back(unscaled(p.x()), unscaled(p.y()), lower_z_mm);
-
-    // Create pointing indices into vertex arrays. u-upper, l-lower
-    size_t uidx = 0, lidx = offs, unextidx = 1, lnextidx = offs + 1;
-
-    // Simple squared distance calculation.
-    auto distfn = [](const Vec3d& p1, const Vec3d& p2) {
-        auto p = p1 - p2; return p.transpose() * p;
-    };
-
-    // We need to find the closest point on lower polygon to the first point on
-    // the upper polygon. These will be our starting points.
-    double distmin = std::numeric_limits<double>::max();
-    for(size_t l = lidx; l < rpts.size(); ++l) {
-        thr();
-        double d = distfn(rpts[l], rpts[uidx]);
-        if(d < distmin) { lidx = l; distmin = d; }
-    }
-
-    // Set up lnextidx to be ahead of lidx in cyclic mode
-    lnextidx = lidx + 1;
-    if(lnextidx == rpts.size()) lnextidx = offs;
-
-    // This will be the flip switch to toggle between upper and lower triangle
-    // creation mode
-    enum class Proceed {
-        UPPER, // A segment from the upper polygon and one vertex from the lower
-        LOWER  // A segment from the lower polygon and one vertex from the upper
-    } proceed = Proceed::UPPER;
-
-    // Flags to help evaluating loop termination.
-    bool ustarted = false, lstarted = false;
-
-    // The variables for the fitness values, one for the actual and one for the
-    // previous.
-    double current_fit = 0, prev_fit = 0;
-
-    // Every triangle of the wall has two edges connecting the upper plate with
-    // the lower plate. From the length of these two edges and the zdiff we
-    // can calculate the momentary squared offset distance at a particular
-    // position on the wall. The average of the differences from the reference
-    // (squared) offset distance will give us the driving fitness value.
-    const double offsdiff2 = std::pow(offset_difference_mm, 2);
-    const double zdiff2 = std::pow(upper_z_mm - lower_z_mm, 2);
-
-    // Mark the current vertex iterator positions. If the iterators return to
-    // the same position, the loop can be terminated.
-    size_t uendidx = uidx, lendidx = lidx;
-
-    do { thr();  // check throw if canceled
-
-        prev_fit = current_fit;
-
-        switch(proceed) {   // proceed depending on the current state
-        case Proceed::UPPER:
-            if(!ustarted || uidx != uendidx) { // there are vertices remaining
-                // Get the 3D vertices in order
-                const Vec3d& p_up1 = rpts[uidx];
-                const Vec3d& p_low = rpts[lidx];
-                const Vec3d& p_up2 = rpts[unextidx];
-
-                // Calculate fitness: the average of the two connecting edges
-                double a = offsdiff2 - (distfn(p_up1, p_low) - zdiff2);
-                double b = offsdiff2 - (distfn(p_up2, p_low) - zdiff2);
-                current_fit = (std::abs(a) + std::abs(b)) / 2;
-
-                if(current_fit > prev_fit) { // fit is worse than previously
-                    proceed = Proceed::LOWER;
-                } else {    // good to go, create the triangle
-                    inverted
-                        ? ind.emplace_back(int(unextidx), int(lidx), int(uidx))
-                        : ind.emplace_back(int(uidx), int(lidx), int(unextidx));
-
-                    // Increment the iterators, rotate if necessary
-                    ++uidx; ++unextidx;
-                    if(unextidx == offs) unextidx = 0;
-                    if(uidx == offs) uidx = 0;
-
-                    ustarted = true;    // mark the movement of the iterators
-                    // so that the comparison to uendidx can be made correctly
-                }
-            } else proceed = Proceed::LOWER;
-
-            break;
-        case Proceed::LOWER:
-            // Mode with lower segment, upper vertex. Same structure:
-            if(!lstarted || lidx != lendidx) {
-                const Vec3d& p_low1 = rpts[lidx];
-                const Vec3d& p_low2 = rpts[lnextidx];
-                const Vec3d& p_up   = rpts[uidx];
-
-                double a = offsdiff2 - (distfn(p_up, p_low1) - zdiff2);
-                double b = offsdiff2 - (distfn(p_up, p_low2) - zdiff2);
-                current_fit = (std::abs(a) + std::abs(b)) / 2;
-
-                if(current_fit > prev_fit) {
-                    proceed = Proceed::UPPER;
-                } else {
-                    inverted
-                        ? ind.emplace_back(int(uidx), int(lnextidx), int(lidx))
-                        : ind.emplace_back(int(lidx), int(lnextidx), int(uidx));
-
-                    ++lidx; ++lnextidx;
-                    if(lnextidx == rpts.size()) lnextidx = offs;
-                    if(lidx == rpts.size()) lidx = offs;
-
-                    lstarted = true;
-                }
-            } else proceed = Proceed::UPPER;
-
-            break;
-        } // end of switch
-    } while(!ustarted || !lstarted || uidx != uendidx || lidx != lendidx);
-
-    return ret;
-}
-
-/// Offsetting with clipper and smoothing the edges into a curvature.
-void offset(ExPolygon& sh, coord_t distance, bool edgerounding = true) {
-    using ClipperLib::ClipperOffset;
-    using ClipperLib::jtRound;
-    using ClipperLib::jtMiter;
-    using ClipperLib::etClosedPolygon;
-    using ClipperLib::Paths;
-    using ClipperLib::Path;
-
-    auto&& ctour = Slic3rMultiPoint_to_ClipperPath(sh.contour);
-    auto&& holes = Slic3rMultiPoints_to_ClipperPaths(sh.holes);
-
-    // If the input is not at least a triangle, we can not do this algorithm
-    if(ctour.size() < 3 ||
-       std::any_of(holes.begin(), holes.end(),
-                   [](const Path& p) { return p.size() < 3; })
-            ) {
-        BOOST_LOG_TRIVIAL(error) << "Invalid geometry for offsetting!";
-        return;
-    }
-
-    auto jointype = edgerounding? jtRound : jtMiter;
-    
-    ClipperOffset offs;
-    offs.ArcTolerance = scaled<double>(0.01);
-    Paths result;
-    offs.AddPath(ctour, jointype, etClosedPolygon);
-    offs.AddPaths(holes, jointype, etClosedPolygon);
-    offs.Execute(result, static_cast<double>(distance));
-
-    // Offsetting reverts the orientation and also removes the last vertex
-    // so boost will not have a closed polygon.
-
-    bool found_the_contour = false;
-    sh.holes.clear();
-    for(auto& r : result) {
-        if(ClipperLib::Orientation(r)) {
-            // We don't like if the offsetting generates more than one contour
-            // but throwing would be an overkill. Instead, we should warn the
-            // caller about the inability to create correct geometries
-            if(!found_the_contour) {
-                auto rr = ClipperPath_to_Slic3rPolygon(r);
-                sh.contour.points.swap(rr.points);
-                found_the_contour = true;
-            } else {
-                BOOST_LOG_TRIVIAL(warning)
-                        << "Warning: offsetting result is invalid!";
-            }
-        } else {
-            // TODO If there are multiple contours we can't be sure which hole
-            // belongs to the first contour. (But in this case the situation is
-            // bad enough to let it go...)
-            sh.holes.emplace_back(ClipperPath_to_Slic3rPolygon(r));
-        }
-    }
-}
-
-void offset(Polygon &sh, coord_t distance, bool edgerounding = true)
-{
-    using ClipperLib::ClipperOffset;
-    using ClipperLib::jtRound;
-    using ClipperLib::jtMiter;
-    using ClipperLib::etClosedPolygon;
-    using ClipperLib::Paths;
-    using ClipperLib::Path;
-
-    auto &&ctour = Slic3rMultiPoint_to_ClipperPath(sh);
-
-    // If the input is not at least a triangle, we can not do this algorithm
-    if (ctour.size() < 3) {
-        BOOST_LOG_TRIVIAL(error) << "Invalid geometry for offsetting!";
-        return;
-    }
-
-    ClipperOffset offs;
-    offs.ArcTolerance = 0.01 * scaled(1.);
-    Paths result;
-    offs.AddPath(ctour, edgerounding ? jtRound : jtMiter, etClosedPolygon);
-    offs.Execute(result, static_cast<double>(distance));
-
-    // Offsetting reverts the orientation and also removes the last vertex
-    // so boost will not have a closed polygon.
-
-    bool found_the_contour = false;
-    for (auto &r : result) {
-        if (ClipperLib::Orientation(r)) {
-            // We don't like if the offsetting generates more than one contour
-            // but throwing would be an overkill. Instead, we should warn the
-            // caller about the inability to create correct geometries
-            if (!found_the_contour) {
-                auto rr = ClipperPath_to_Slic3rPolygon(r);
-                sh.points.swap(rr.points);
-                found_the_contour = true;
-            } else {
-                BOOST_LOG_TRIVIAL(warning)
-                    << "Warning: offsetting result is invalid!";
-            }
-        }
-    }
-}
-
-/// Unification of polygons (with clipper) preserving holes as well.
-ExPolygons unify(const ExPolygons& shapes) {
-    using ClipperLib::ptSubject;
-
-    ExPolygons retv;
-
-    bool closed = true;
-    bool valid = true;
-
-    ClipperLib::Clipper clipper;
-
-    for(auto& path : shapes) {
-        auto clipperpath = Slic3rMultiPoint_to_ClipperPath(path.contour);
-
-        if(!clipperpath.empty())
-            valid &= clipper.AddPath(clipperpath, ptSubject, closed);
-
-        auto clipperholes = Slic3rMultiPoints_to_ClipperPaths(path.holes);
-
-        for(auto& hole : clipperholes) {
-            if(!hole.empty())
-                valid &= clipper.AddPath(hole, ptSubject, closed);
-        }
-    }
-
-    if(!valid) BOOST_LOG_TRIVIAL(warning) << "Unification of invalid shapes!";
-
-    ClipperLib::PolyTree result;
-    clipper.Execute(ClipperLib::ctUnion, result, ClipperLib::pftNonZero);
-
-    retv.reserve(static_cast<size_t>(result.Total()));
-
-    // Now we will recursively traverse the polygon tree and serialize it
-    // into an ExPolygon with holes. The polygon tree has the clipper-ish
-    // PolyTree structure which alternates its nodes as contours and holes
-
-    // A "declaration" of function for traversing leafs which are holes
-    std::function<void(ClipperLib::PolyNode*, ExPolygon&)> processHole;
-
-    // Process polygon which calls processHoles which than calls processPoly
-    // again until no leafs are left.
-    auto processPoly = [&retv, &processHole](ClipperLib::PolyNode *pptr) {
-        ExPolygon poly;
-        poly.contour.points = ClipperPath_to_Slic3rPolygon(pptr->Contour);
-        for(auto h : pptr->Childs) { processHole(h, poly); }
-        retv.push_back(poly);
-    };
-
-    // Body of the processHole function
-    processHole = [&processPoly](ClipperLib::PolyNode *pptr, ExPolygon& poly)
-    {
-        poly.holes.emplace_back();
-        poly.holes.back().points = ClipperPath_to_Slic3rPolygon(pptr->Contour);
-        for(auto c : pptr->Childs) processPoly(c);
-    };
-
-    // Wrapper for traversing.
-    auto traverse = [&processPoly] (ClipperLib::PolyNode *node)
-    {
-        for(auto ch : node->Childs) {
-            processPoly(ch);
-        }
-    };
-
-    // Here is the actual traverse
-    traverse(&result);
-
-    return retv;
-}
-
-Polygons unify(const Polygons& shapes) {
-    using ClipperLib::ptSubject;
-    
-    bool closed = true;
-    bool valid = true;
-
-    ClipperLib::Clipper clipper;
-
-    for(auto& path : shapes) {
-        auto clipperpath = Slic3rMultiPoint_to_ClipperPath(path);
-
-        if(!clipperpath.empty())
-            valid &= clipper.AddPath(clipperpath, ptSubject, closed);
-    }
-
-    if(!valid) BOOST_LOG_TRIVIAL(warning) << "Unification of invalid shapes!";
-
-    ClipperLib::Paths result;
-    clipper.Execute(ClipperLib::ctUnion, result, ClipperLib::pftNonZero);
-
-    Polygons ret;
-    for (ClipperLib::Path &p : result) {
-        Polygon pp = ClipperPath_to_Slic3rPolygon(p);
-        if (!pp.is_clockwise()) ret.emplace_back(std::move(pp));
-    }
-    
-    return ret;
-}
-
-// Function to cut tiny connector cavities for a given polygon. The input poly
-// will be offsetted by "padding" and small rectangle shaped cavities will be
-// inserted along the perimeter in every "stride" distance. The stick rectangles
-// will have a with about "stick_width". The input dimensions are in world 
-// measure, not the scaled clipper units.
-void breakstick_holes(ExPolygon& poly,
-                      double padding,
-                      double stride,
-                      double stick_width,
-                      double penetration)
-{   
-    // SVG svg("bridgestick_plate.svg");
-    // svg.draw(poly);
-
-    auto transf = [stick_width, penetration, padding, stride](Points &pts) {
-        // The connector stick will be a small rectangle with dimensions
-        // stick_width x (penetration + padding) to have some penetration
-        // into the input polygon.
-
-        Points out;
-        out.reserve(2 * pts.size()); // output polygon points
-
-        // stick bottom and right edge dimensions
-        double sbottom = scaled(stick_width);
-        double sright  = scaled(penetration + padding);
-
-        // scaled stride distance
-        double sstride = scaled(stride);
-        double t       = 0;
-
-        // process pairs of vertices as an edge, start with the last and
-        // first point
-        for (size_t i = pts.size() - 1, j = 0; j < pts.size(); i = j, ++j) {
-            // Get vertices and the direction vectors
-            const Point &a = pts[i], &b = pts[j];
-            Vec2d        dir = b.cast<double>() - a.cast<double>();
-            double       nrm = dir.norm();
-            dir /= nrm;
-            Vec2d dirp(-dir(Y), dir(X));
-
-            // Insert start point
-            out.emplace_back(a);
-
-            // dodge the start point, do not make sticks on the joins
-            while (t < sbottom) t += sbottom;
-            double tend = nrm - sbottom;
-
-            while (t < tend) { // insert the stick on the polygon perimeter
-
-                // calculate the stick rectangle vertices and insert them
-                // into the output.
-                Point p1 = a + (t * dir).cast<coord_t>();
-                Point p2 = p1 + (sright * dirp).cast<coord_t>();
-                Point p3 = p2 + (sbottom * dir).cast<coord_t>();
-                Point p4 = p3 + (sright * -dirp).cast<coord_t>();
-                out.insert(out.end(), {p1, p2, p3, p4});
-
-                // continue along the perimeter
-                t += sstride;
-            }
-
-            t = t - nrm;
-
-            // Insert edge endpoint
-            out.emplace_back(b);
-        }
-        
-        // move the new points
-        out.shrink_to_fit();
-        pts.swap(out);
-    };
-    
-    if(stride > 0.0 && stick_width > 0.0 && padding > 0.0) {
-        transf(poly.contour.points);
-        for (auto &h : poly.holes) transf(h.points);
-    }
-    
-    // svg.draw(poly);
-    // svg.Close();
-}
-
-/// This method will create a rounded edge around a flat polygon in 3d space.
-/// 'base_plate' parameter is the target plate.
-/// 'radius' is the radius of the edges.
-/// 'degrees' is tells how much of a circle should be created as the rounding.
-///     It should be in degrees, not radians.
-/// 'ceilheight_mm' is the Z coordinate of the flat polygon in 3D space.
-/// 'dir' Is the direction of the round edges: inward or outward
-/// 'thr' Throws if a cancel signal was received
-/// 'last_offset' An auxiliary output variable to save the last offsetted
-///     version of 'base_plate'
-/// 'last_height' An auxiliary output to save the last z coordinate of the
-/// offsetted base_plate. In other words, where the rounded edges end.
-Contour3D round_edges(const ExPolygon& base_plate,
-                      double radius_mm,
-                      double degrees,
-                      double ceilheight_mm,
-                      bool dir,
-                      ThrowOnCancel thr,
-                      ExPolygon& last_offset, double& last_height)
-{
-    auto ob = base_plate;
-    auto ob_prev = ob;
-    double wh = ceilheight_mm, wh_prev = wh;
-    Contour3D curvedwalls;
-
-    int steps = 30;
-    double stepx = radius_mm / steps;
-    coord_t s = dir? 1 : -1;
-    degrees = std::fmod(degrees, 180);
-
-    // we use sin for x distance because we interpret the angle starting from
-    // PI/2
-    int tos = degrees < 90?
-            int(radius_mm*std::cos(degrees * PI / 180 - PI/2) / stepx) : steps;
-
-    for(int i = 1; i <= tos; ++i) {
-        thr();
-
-        ob = base_plate;
-
-        double r2 = radius_mm * radius_mm;
-        double xx = i*stepx;
-        double x2 = xx*xx;
-        double stepy = std::sqrt(r2 - x2);
-
-        offset(ob, s * scaled(xx));
-        wh = ceilheight_mm - radius_mm + stepy;
-
-        Contour3D pwalls;
-        double prev_x = xx - (i - 1) * stepx;
-        pwalls = walls(ob.contour, ob_prev.contour, wh, wh_prev, s*prev_x, thr);
-
-        curvedwalls.merge(pwalls);
-        ob_prev = ob;
-        wh_prev = wh;
-    }
-
-    if(degrees > 90) {
-        double tox = radius_mm - radius_mm*std::cos(degrees * PI / 180 - PI/2);
-        int tos = int(tox / stepx);
-
-        for(int i = 1; i <= tos; ++i) {
-            thr();
-            ob = base_plate;
-
-            double r2 = radius_mm * radius_mm;
-            double xx = radius_mm - i*stepx;
-            double x2 = xx*xx;
-            double stepy = std::sqrt(r2 - x2);
-            offset(ob, s * scaled(xx));
-            wh = ceilheight_mm - radius_mm - stepy;
-
-            Contour3D pwalls;
-            double prev_x = xx - radius_mm + (i - 1)*stepx;
-            pwalls =
-                walls(ob_prev.contour, ob.contour, wh_prev, wh, s*prev_x, thr);
-
-            curvedwalls.merge(pwalls);
-            ob_prev = ob;
-            wh_prev = wh;
-        }
-    }
-
-    last_offset = std::move(ob);
-    last_height = wh;
-
-    return curvedwalls;
-}
-
-inline Point centroid(Points& pp) {
-    Point c;
-    switch(pp.size()) {
-    case 0: break;
-    case 1: c = pp.front(); break;
-    case 2: c = (pp[0] + pp[1]) / 2; break;
-    default: {
-        auto MAX = std::numeric_limits<Point::coord_type>::max();
-        auto MIN = std::numeric_limits<Point::coord_type>::min();
-        Point min = {MAX, MAX}, max = {MIN, MIN};
-
-        for(auto& p : pp) {
-            if(p(0) < min(0)) min(0) = p(0);
-            if(p(1) < min(1)) min(1) = p(1);
-            if(p(0) > max(0)) max(0) = p(0);
-            if(p(1) > max(1)) max(1) = p(1);
-        }
-        c(0) = min(0) + (max(0) - min(0)) / 2;
-        c(1) = min(1) + (max(1) - min(1)) / 2;
-
-        // TODO: fails for non convex cluster
-//        c = std::accumulate(pp.begin(), pp.end(), Point{0, 0});
-//        x(c) /= coord_t(pp.size()); y(c) /= coord_t(pp.size());
-        break;
-    }
-    }
-
-    return c;
-}
-
-inline Point centroid(const Polygon& poly) {
-    return poly.centroid();
-}
-
-/// A fake concave hull that is constructed by connecting separate shapes
-/// with explicit bridges. Bridges are generated from each shape's centroid
-/// to the center of the "scene" which is the centroid calculated from the shape
-/// centroids (a star is created...)
-Polygons concave_hull(const Polygons& polys, double maxd_mm, ThrowOnCancel thr)
-{
-    namespace bgi = boost::geometry::index;
-    using SpatElement = std::pair<Point, unsigned>;
-    using SpatIndex = bgi::rtree< SpatElement, bgi::rstar<16, 4> >;
-
-    if(polys.empty()) return Polygons();
-    
-    const double max_dist = scaled(maxd_mm);
-
-    Polygons punion = unify(polys);   // could be redundant
-
-    if(punion.size() == 1) return punion;
-
-    // We get the centroids of all the islands in the 2D slice
-    Points centroids; centroids.reserve(punion.size());
-    std::transform(punion.begin(), punion.end(), std::back_inserter(centroids),
-                   [](const Polygon& poly) { return centroid(poly); });
-
-    SpatIndex ctrindex;
-    unsigned  idx = 0;
-    for(const Point &ct : centroids) ctrindex.insert(std::make_pair(ct, idx++));
-    
-    // Centroid of the centroids of islands. This is where the additional
-    // connector sticks are routed.
-    Point cc = centroid(centroids);
-
-    punion.reserve(punion.size() + centroids.size());
-
-    idx = 0;
-    std::transform(centroids.begin(), centroids.end(),
-                   std::back_inserter(punion),
-                   [&centroids, &ctrindex, cc, max_dist, &idx, thr]
-                   (const Point& c)
-    {
-        thr();
-        double dx = x(c) - x(cc), dy = y(c) - y(cc);
-        double l = std::sqrt(dx * dx + dy * dy);
-        double nx = dx / l, ny = dy / l;
-        
-        Point& ct = centroids[idx];
-        
-        std::vector<SpatElement> result;
-        ctrindex.query(bgi::nearest(ct, 2), std::back_inserter(result));
-
-        double dist = max_dist;
-        for (const SpatElement &el : result)
-            if (el.second != idx) {
-                dist = Line(el.first, ct).length();
-                break;
-            }
-        
-        idx++;
-        
-        if (dist >= max_dist) return Polygon();
-        
-        Polygon r;
-        auto& ctour = r.points;
-
-        ctour.reserve(3);
-        ctour.emplace_back(cc);
-
-        Point d(scaled(nx), scaled(ny));
-        ctour.emplace_back(c + Point( -y(d),  x(d) ));
-        ctour.emplace_back(c + Point(  y(d), -x(d) ));
-        offset(r, scaled(1.));
-
-        return r;
-    });
-
-    // This is unavoidable...
-    punion = unify(punion);
-
-    return punion;
-}
-
-void base_plate(const TriangleMesh &      mesh,
-                ExPolygons &              output,
-                const std::vector<float> &heights,
-                ThrowOnCancel             thrfn)
-{
-    if (mesh.empty()) return;
-    //    m.require_shared_vertices(); // TriangleMeshSlicer needs this    
-    TriangleMeshSlicer slicer(&mesh);
-    
-    std::vector<ExPolygons> out; out.reserve(heights.size());
-    slicer.slice(heights, 0.f, &out, thrfn);
-    
-    size_t count = 0; for(auto& o : out) count += o.size();
-    
-    // Now we have to unify all slice layers which can be an expensive operation
-    // so we will try to simplify the polygons
-    ExPolygons tmp; tmp.reserve(count);
-    for(ExPolygons& o : out)
-        for(ExPolygon& e : o) {
-            auto&& exss = e.simplify(scaled<double>(0.1));
-            for(ExPolygon& ep : exss) tmp.emplace_back(std::move(ep));
-        }
-    
-    ExPolygons utmp = unify(tmp);
-    
-    for(auto& o : utmp) {
-        auto&& smp = o.simplify(scaled<double>(0.1));
-        output.insert(output.end(), smp.begin(), smp.end());
-    }
-}
-
-void base_plate(const TriangleMesh &mesh,
-                ExPolygons &        output,
-                float               h,
-                float               layerh,
-                ThrowOnCancel       thrfn)
-{
-    auto bb = mesh.bounding_box();
-    float gnd = float(bb.min(Z));
-    std::vector<float> heights = {float(bb.min(Z))};
-    
-    for(float hi = gnd + layerh; hi <= gnd + h; hi += layerh)
-        heights.emplace_back(hi);
-    
-    base_plate(mesh, output, heights, thrfn);
-}
-
-Contour3D create_base_pool(const Polygons &ground_layer, 
-                           const ExPolygons &obj_self_pad = {},
-                           const PoolConfig& cfg = PoolConfig()) 
-{
-    // for debugging:
-    // Benchmark bench;
-    // bench.start();
-
-    double mergedist = 2*(1.8*cfg.min_wall_thickness_mm + 4*cfg.edge_radius_mm)+
-                       cfg.max_merge_distance_mm;
-
-    // Here we get the base polygon from which the pad has to be generated.
-    // We create an artificial concave hull from this polygon and that will
-    // serve as the bottom plate of the pad. We will offset this concave hull
-    // and then offset back the result with clipper with rounding edges ON. This
-    // trick will create a nice rounded pad shape.
-    Polygons concavehs = concave_hull(ground_layer, mergedist, cfg.throw_on_cancel);
-
-    const double thickness      = cfg.min_wall_thickness_mm;
-    const double wingheight     = cfg.min_wall_height_mm;
-    const double fullheight     = wingheight + thickness;
-    const double slope          = cfg.wall_slope;
-    const double wingdist       = wingheight / std::tan(slope);
-    const double bottom_offs    = (thickness + wingheight) / std::tan(slope);
-
-    // scaled values
-    const coord_t s_thickness   = scaled(thickness);
-    const coord_t s_eradius     = scaled(cfg.edge_radius_mm);
-    const coord_t s_safety_dist = 2*s_eradius + coord_t(0.8*s_thickness);
-    const coord_t s_wingdist    = scaled(wingdist);
-    const coord_t s_bottom_offs = scaled(bottom_offs);
-
-    auto& thrcl = cfg.throw_on_cancel;
-
-    Contour3D pool;
-
-    for(Polygon& concaveh : concavehs) {
-        if(concaveh.points.empty()) return pool;
-
-        // Here lies the trick that does the smoothing only with clipper offset
-        // calls. The offset is configured to round edges. Inner edges will
-        // be rounded because we offset twice: ones to get the outer (top) plate
-        // and again to get the inner (bottom) plate
-        auto outer_base = concaveh;
-        offset(outer_base, s_safety_dist + s_wingdist + s_thickness);
-
-        ExPolygon bottom_poly; bottom_poly.contour = outer_base;
-        offset(bottom_poly, -s_bottom_offs);
-
-        // Punching a hole in the top plate for the cavity
-        ExPolygon top_poly;
-        ExPolygon middle_base;
-        ExPolygon inner_base;
-        top_poly.contour = outer_base;
-
-        if(wingheight > 0) {
-            inner_base.contour = outer_base;
-            offset(inner_base, -(s_thickness + s_wingdist + s_eradius));
-
-            middle_base.contour = outer_base;
-            offset(middle_base, -s_thickness);
-            top_poly.holes.emplace_back(middle_base.contour);
-            auto& tph = top_poly.holes.back().points;
-            std::reverse(tph.begin(), tph.end());
-        }
-
-        ExPolygon ob; ob.contour = outer_base; double wh = 0;
-
-        // now we will calculate the angle or portion of the circle from
-        // pi/2 that will connect perfectly with the bottom plate.
-        // this is a tangent point calculation problem and the equation can
-        // be found for example here:
-        // http://www.ambrsoft.com/TrigoCalc/Circles2/CirclePoint/CirclePointDistance.htm
-        // the y coordinate would be:
-        // y = cy + (r^2*py - r*px*sqrt(px^2 + py^2 - r^2) / (px^2 + py^2)
-        // where px and py are the coordinates of the point outside the circle
-        // cx and cy are the circle center, r is the radius
-        // We place the circle center to (0, 0) in the calculation the make
-        // things easier.
-        // to get the angle we use arcsin function and subtract 90 degrees then
-        // flip the sign to get the right input to the round_edge function.
-        double r = cfg.edge_radius_mm;
-        double cy = 0;
-        double cx = 0;
-        double px = thickness + wingdist;
-        double py = r - fullheight;
-
-        double pxcx = px - cx;
-        double pycy = py - cy;
-        double b_2 = pxcx*pxcx + pycy*pycy;
-        double r_2 = r*r;
-        double D = std::sqrt(b_2 - r_2);
-        double vy = (r_2*pycy - r*pxcx*D) / b_2;
-        double phi = -(std::asin(vy/r) * 180 / PI - 90);
-
-
-        // Generate the smoothed edge geometry
-        if(s_eradius > 0) pool.merge(round_edges(ob,
-                               r,
-                               phi,
-                               0,    // z position of the input plane
-                               true,
-                               thrcl,
-                               ob, wh));
-
-        // Now that we have the rounded edge connecting the top plate with
-        // the outer side walls, we can generate and merge the sidewall geometry
-        pool.merge(walls(ob.contour, bottom_poly.contour, wh, -fullheight,
-                         bottom_offs, thrcl));
-
-        if(wingheight > 0) {
-            // Generate the smoothed edge geometry
-            wh = 0;
-            ob = middle_base;
-            if(s_eradius) pool.merge(round_edges(middle_base,
-                                   r,
-                                   phi - 90, // from tangent lines
-                                   0,  // z position of the input plane
-                                   false,
-                                   thrcl,
-                                   ob, wh));
-
-            // Next is the cavity walls connecting to the top plate's
-            // artificially created hole.
-            pool.merge(walls(inner_base.contour, ob.contour, -wingheight,
-                             wh, -wingdist, thrcl));
-        }
-
-        if (cfg.embed_object) {
-            ExPolygons bttms = diff_ex(to_polygons(bottom_poly),
-                                       to_polygons(obj_self_pad));
-            
-            assert(!bttms.empty());
-            
-            std::sort(bttms.begin(), bttms.end(),
-                      [](const ExPolygon& e1, const ExPolygon& e2) {
-                          return e1.contour.area() > e2.contour.area();
-                      });
-            
-            if(wingheight > 0) inner_base.holes = bttms.front().holes;
-            else top_poly.holes = bttms.front().holes;
-
-            auto straight_walls =
-                [&pool](const Polygon &cntr, coord_t z_low, coord_t z_high) {
-                    
-                auto lines = cntr.lines();
-                
-                for (auto &l : lines) {
-                    auto s = coord_t(pool.points.size());
-                    auto& pts = pool.points;
-                    pts.emplace_back(unscale(l.a.x(), l.a.y(), z_low));
-                    pts.emplace_back(unscale(l.b.x(), l.b.y(), z_low));
-                    pts.emplace_back(unscale(l.a.x(), l.a.y(), z_high));
-                    pts.emplace_back(unscale(l.b.x(), l.b.y(), z_high));
-                    
-                    pool.indices.emplace_back(s, s + 1, s + 3);
-                    pool.indices.emplace_back(s, s + 3, s + 2);
-                }
-            };
-            
-            coord_t z_lo = -scaled(fullheight), z_hi = -scaled(wingheight);
-            for (ExPolygon &ep : bttms) {
-                pool.merge(triangulate_expolygon_3d(ep, -fullheight, true));
-                for (auto &h : ep.holes) straight_walls(h, z_lo, z_hi);
-            }
-            
-            // Skip the outer contour, triangulate the holes
-            for (auto it = std::next(bttms.begin()); it != bttms.end(); ++it) {
-                pool.merge(triangulate_expolygon_3d(*it, -wingheight));
-                straight_walls(it->contour, z_lo, z_hi);
-            }
-            
-        } else {
-            // Now we need to triangulate the top and bottom plates as well as
-            // the cavity bottom plate which is the same as the bottom plate
-            // but it is elevated by the thickness.
-            
-            pool.merge(triangulate_expolygon_3d(bottom_poly, -fullheight, true));
-        }
-        
-        pool.merge(triangulate_expolygon_3d(top_poly));
-
-        if(wingheight > 0)
-            pool.merge(triangulate_expolygon_3d(inner_base, -wingheight));
-
-    }
-    
-    return pool;
-}
-
-void create_base_pool(const Polygons &ground_layer, TriangleMesh& out,
-                      const ExPolygons &holes, const PoolConfig& cfg)
-{
-    
-
-    // For debugging:
-    // bench.stop();
-    // std::cout << "Pad creation time: " << bench.getElapsedSec() << std::endl;
-    // std::fstream fout("pad_debug.obj", std::fstream::out);
-    // if(fout.good()) pool.to_obj(fout);
-
-    out.merge(mesh(create_base_pool(ground_layer, holes, cfg)));
-}
-
-}
-}

src/libslic3r/SLA/SLABasePool.hpp

@@ -1,92 +0,0 @@
-#ifndef SLABASEPOOL_HPP
-#define SLABASEPOOL_HPP
-
-#include <vector>
-#include <functional>
-#include <cmath>
-
-namespace Slic3r {
-
-class ExPolygon;
-class Polygon;
-using ExPolygons = std::vector<ExPolygon>;
-using Polygons = std::vector<Polygon>;
-
-class TriangleMesh;
-
-namespace sla {
-
-using ThrowOnCancel = std::function<void(void)>;
-
-/// Calculate the polygon representing the silhouette from the specified height
-void base_plate(const TriangleMesh& mesh,       // input mesh
-                ExPolygons& output,             // Output will be merged with
-                float samplingheight = 0.1f,    // The height range to sample
-                float layerheight = 0.05f,      // The sampling height
-                ThrowOnCancel thrfn = [](){});  // Will be called frequently
-
-void base_plate(const TriangleMesh& mesh,       // input mesh
-                ExPolygons& output,             // Output will be merged with
-                const std::vector<float>&,      // Exact Z levels to sample
-                ThrowOnCancel thrfn = [](){});  // Will be called frequently
-
-// Function to cut tiny connector cavities for a given polygon. The input poly
-// will be offsetted by "padding" and small rectangle shaped cavities will be
-// inserted along the perimeter in every "stride" distance. The stick rectangles
-// will have a with about "stick_width". The input dimensions are in world 
-// measure, not the scaled clipper units.
-void breakstick_holes(ExPolygon &poly,
-                      double     padding,
-                      double     stride,
-                      double     stick_width,
-                      double     penetration = 0.0);
-
-Polygons concave_hull(const Polygons& polys, double max_dist_mm = 50,
-                      ThrowOnCancel throw_on_cancel = [](){});
-
-struct PoolConfig {
-    double min_wall_thickness_mm = 2;
-    double min_wall_height_mm = 5;
-    double max_merge_distance_mm = 50;
-    double edge_radius_mm = 1;
-    double wall_slope = std::atan(1.0);          // Universal constant for Pi/4
-    struct EmbedObject {
-        double object_gap_mm = 0.5;
-        double stick_stride_mm = 10;
-        double stick_width_mm = 0.3;
-        double stick_penetration_mm = 0.1;
-        bool enabled = false;
-        operator bool() const { return enabled; }
-    } embed_object;
-
-    ThrowOnCancel throw_on_cancel = [](){};
-
-    inline PoolConfig() {}
-    inline PoolConfig(double wt, double wh, double md, double er, double slope):
-        min_wall_thickness_mm(wt),
-        min_wall_height_mm(wh),
-        max_merge_distance_mm(md),
-        edge_radius_mm(er),
-        wall_slope(slope) {}
-};
-
-/// Calculate the pool for the mesh for SLA printing
-void create_base_pool(const Polygons& base_plate,
-                      TriangleMesh& output_mesh,
-                      const ExPolygons& holes,
-                      const PoolConfig& = PoolConfig());
-
-/// Returns the elevation needed for compensating the pad.
-inline double get_pad_elevation(const PoolConfig& cfg) {
-    return cfg.min_wall_thickness_mm;
-}
-
-inline double get_pad_fullheight(const PoolConfig& cfg) {
-    return cfg.min_wall_height_mm + cfg.min_wall_thickness_mm;
-}
-
-}
-
-}
-
-#endif // SLABASEPOOL_HPP

src/libslic3r/SLA/SLABoilerPlate.hpp

@@ -8,35 +8,19 @@
 #include <libslic3r/ExPolygon.hpp>
 #include <libslic3r/TriangleMesh.hpp>
 
+#include "SLACommon.hpp"
+#include "SLASpatIndex.hpp"
+
 namespace Slic3r {
 namespace sla {
 
-/// Get x and y coordinates (because we are eigenizing...)
-inline coord_t x(const Point& p) { return p(0); }
-inline coord_t y(const Point& p) { return p(1); }
-inline coord_t& x(Point& p) { return p(0); }
-inline coord_t& y(Point& p) { return p(1); }
-
-inline coordf_t x(const Vec3d& p) { return p(0); }
-inline coordf_t y(const Vec3d& p) { return p(1); }
-inline coordf_t z(const Vec3d& p) { return p(2); }
-inline coordf_t& x(Vec3d& p) { return p(0); }
-inline coordf_t& y(Vec3d& p) { return p(1); }
-inline coordf_t& z(Vec3d& p) { return p(2); }
-
-inline coord_t& x(Vec3crd& p) { return p(0); }
-inline coord_t& y(Vec3crd& p) { return p(1); }
-inline coord_t& z(Vec3crd& p) { return p(2); }
-inline coord_t x(const Vec3crd& p) { return p(0); }
-inline coord_t y(const Vec3crd& p) { return p(1); }
-inline coord_t z(const Vec3crd& p) { return p(2); }
-
 /// Intermediate struct for a 3D mesh
 struct Contour3D {
     Pointf3s points;
     std::vector<Vec3i> indices;
 
-    void merge(const Contour3D& ctr) {
+    Contour3D& merge(const Contour3D& ctr)
+    {
         auto s3 = coord_t(points.size());
         auto s = indices.size();
 
@@ -44,21 +28,27 @@ struct Contour3D {
         indices.insert(indices.end(), ctr.indices.begin(), ctr.indices.end());
 
         for(size_t n = s; n < indices.size(); n++) {
-            auto& idx = indices[n]; x(idx) += s3; y(idx) += s3; z(idx) += s3;
+            auto& idx = indices[n]; idx.x() += s3; idx.y() += s3; idx.z() += s3;
         }
+        
+        return *this;
     }
 
-    void merge(const Pointf3s& triangles) {
+    Contour3D& merge(const Pointf3s& triangles)
+    {
         const size_t offs = points.size();
         points.insert(points.end(), triangles.begin(), triangles.end());
         indices.reserve(indices.size() + points.size() / 3);
         
-        for(int i = (int)offs; i < (int)points.size(); i += 3)
+        for(int i = int(offs); i < int(points.size()); i += 3)
             indices.emplace_back(i, i + 1, i + 2);
+        
+        return *this;
     }
 
     // Write the index triangle structure to OBJ file for debugging purposes.
-    void to_obj(std::ostream& stream) {
+    void to_obj(std::ostream& stream)
+    {
         for(auto& p : points) {
             stream << "v " << p.transpose() << "\n";
         }
@@ -72,6 +62,31 @@ struct Contour3D {
 using ClusterEl = std::vector<unsigned>;
 using ClusteredPoints = std::vector<ClusterEl>;
 
+// Clustering a set of points by the given distance.
+ClusteredPoints cluster(const std::vector<unsigned>& indices,
+                        std::function<Vec3d(unsigned)> pointfn,
+                        double dist,
+                        unsigned max_points);
+
+ClusteredPoints cluster(const PointSet& points,
+                        double dist,
+                        unsigned max_points);
+
+ClusteredPoints cluster(
+    const std::vector<unsigned>& indices,
+    std::function<Vec3d(unsigned)> pointfn,
+    std::function<bool(const PointIndexEl&, const PointIndexEl&)> predicate,
+    unsigned max_points);
+
+
+// Calculate the normals for the selected points (from 'points' set) on the
+// mesh. This will call squared distance for each point.
+PointSet normals(const PointSet& points,
+                 const EigenMesh3D& mesh,
+                 double eps = 0.05,  // min distance from edges
+                 std::function<void()> throw_on_cancel = [](){},
+                 const std::vector<unsigned>& selected_points = {});
+
 /// Mesh from an existing contour.
 inline TriangleMesh mesh(const Contour3D& ctour) {
     return {ctour.points, ctour.indices};

src/libslic3r/SLA/SLACommon.hpp

@@ -175,6 +175,8 @@ public:
     }
 };
 
+using PointSet = Eigen::MatrixXd;
+
 } // namespace sla
 } // namespace Slic3r
 

src/libslic3r/SLA/SLAPad.cpp

@@ -0,0 +1,865 @@
+#include "SLAPad.hpp"
+#include "SLABoilerPlate.hpp"
+#include "SLASpatIndex.hpp"
+
+#include "boost/log/trivial.hpp"
+#include "SLABoostAdapter.hpp"
+#include "ClipperUtils.hpp"
+#include "Tesselate.hpp"
+#include "MTUtils.hpp"
+
+// For debugging:
+// #include <fstream>
+// #include <libnest2d/tools/benchmark.h>
+#include "SVG.hpp"
+
+#include "I18N.hpp"
+#include <boost/log/trivial.hpp>
+
+//! macro used to mark string used at localization,
+//! return same string
+#define L(s) Slic3r::I18N::translate(s)
+
+namespace Slic3r { namespace sla {
+
+namespace {
+
+/// This function will return a triangulation of a sheet connecting an upper
+/// and a lower plate given as input polygons. It will not triangulate the
+/// plates themselves only the sheet. The caller has to specify the lower and
+/// upper z levels in world coordinates as well as the offset difference
+/// between the sheets. If the lower_z_mm is higher than upper_z_mm or the
+/// offset difference is negative, the resulting triangle orientation will be
+/// reversed.
+///
+/// IMPORTANT: This is not a universal triangulation algorithm. It assumes
+/// that the lower and upper polygons are offsetted versions of the same
+/// original polygon. In general, it assumes that one of the polygons is
+/// completely inside the other. The offset difference is the reference
+/// distance from the inner polygon's perimeter to the outer polygon's
+/// perimeter. The real distance will be variable as the clipper offset has
+/// different strategies (rounding, etc...). This algorithm should have
+/// O(2n + 3m) complexity where n is the number of upper vertices and m is the
+/// number of lower vertices.
+Contour3D walls(
+    const Polygon &lower,
+    const Polygon &upper,
+    double         lower_z_mm,
+    double         upper_z_mm,
+    double         offset_difference_mm,
+    ThrowOnCancel  thr = [] {})
+{
+    Contour3D ret;
+
+    if(upper.points.size() < 3 || lower.size() < 3) return ret;
+
+    // The concept of the algorithm is relatively simple. It will try to find
+    // the closest vertices from the upper and the lower polygon and use those
+    // as starting points. Then it will create the triangles sequentially using
+    // an edge from the upper polygon and a vertex from the lower or vice versa,
+    // depending on the resulting triangle's quality.
+    // The quality is measured by a scalar value. So far it looks like it is
+    // enough to derive it from the slope of the triangle's two edges connecting
+    // the upper and the lower part. A reference slope is calculated from the
+    // height and the offset difference.
+
+    // Offset in the index array for the ceiling
+    const auto offs = upper.points.size();
+
+    // Shorthand for the vertex arrays
+    auto& upts = upper.points, &lpts = lower.points;
+    auto& rpts = ret.points; auto& ind = ret.indices;
+
+    // If the Z levels are flipped, or the offset difference is negative, we
+    // will interpret that as the triangles normals should be inverted.
+    bool inverted = upper_z_mm < lower_z_mm || offset_difference_mm < 0;
+
+    // Copy the points into the mesh, convert them from 2D to 3D
+    rpts.reserve(upts.size() + lpts.size());
+    ind.reserve(2 * upts.size() + 2 * lpts.size());
+    for (auto &p : upts)
+        rpts.emplace_back(unscaled(p.x()), unscaled(p.y()), upper_z_mm);
+    for (auto &p : lpts)
+        rpts.emplace_back(unscaled(p.x()), unscaled(p.y()), lower_z_mm);
+
+    // Create pointing indices into vertex arrays. u-upper, l-lower
+    size_t uidx = 0, lidx = offs, unextidx = 1, lnextidx = offs + 1;
+
+    // Simple squared distance calculation.
+    auto distfn = [](const Vec3d& p1, const Vec3d& p2) {
+        auto p = p1 - p2; return p.transpose() * p;
+    };
+
+    // We need to find the closest point on lower polygon to the first point on
+    // the upper polygon. These will be our starting points.
+    double distmin = std::numeric_limits<double>::max();
+    for(size_t l = lidx; l < rpts.size(); ++l) {
+        thr();
+        double d = distfn(rpts[l], rpts[uidx]);
+        if(d < distmin) { lidx = l; distmin = d; }
+    }
+
+    // Set up lnextidx to be ahead of lidx in cyclic mode
+    lnextidx = lidx + 1;
+    if(lnextidx == rpts.size()) lnextidx = offs;
+
+    // This will be the flip switch to toggle between upper and lower triangle
+    // creation mode
+    enum class Proceed {
+        UPPER, // A segment from the upper polygon and one vertex from the lower
+        LOWER  // A segment from the lower polygon and one vertex from the upper
+    } proceed = Proceed::UPPER;
+
+    // Flags to help evaluating loop termination.
+    bool ustarted = false, lstarted = false;
+
+    // The variables for the fitness values, one for the actual and one for the
+    // previous.
+    double current_fit = 0, prev_fit = 0;
+
+    // Every triangle of the wall has two edges connecting the upper plate with
+    // the lower plate. From the length of these two edges and the zdiff we
+    // can calculate the momentary squared offset distance at a particular
+    // position on the wall. The average of the differences from the reference
+    // (squared) offset distance will give us the driving fitness value.
+    const double offsdiff2 = std::pow(offset_difference_mm, 2);
+    const double zdiff2 = std::pow(upper_z_mm - lower_z_mm, 2);
+
+    // Mark the current vertex iterator positions. If the iterators return to
+    // the same position, the loop can be terminated.
+    size_t uendidx = uidx, lendidx = lidx;
+
+    do { thr();  // check throw if canceled
+
+        prev_fit = current_fit;
+
+        switch(proceed) {   // proceed depending on the current state
+        case Proceed::UPPER:
+            if(!ustarted || uidx != uendidx) { // there are vertices remaining
+                // Get the 3D vertices in order
+                const Vec3d& p_up1 = rpts[uidx];
+                const Vec3d& p_low = rpts[lidx];
+                const Vec3d& p_up2 = rpts[unextidx];
+
+                // Calculate fitness: the average of the two connecting edges
+                double a = offsdiff2 - (distfn(p_up1, p_low) - zdiff2);
+                double b = offsdiff2 - (distfn(p_up2, p_low) - zdiff2);
+                current_fit = (std::abs(a) + std::abs(b)) / 2;
+
+                if(current_fit > prev_fit) { // fit is worse than previously
+                    proceed = Proceed::LOWER;
+                } else {    // good to go, create the triangle
+                    inverted
+                        ? ind.emplace_back(int(unextidx), int(lidx), int(uidx))
+                        : ind.emplace_back(int(uidx), int(lidx), int(unextidx));
+
+                    // Increment the iterators, rotate if necessary
+                    ++uidx; ++unextidx;
+                    if(unextidx == offs) unextidx = 0;
+                    if(uidx == offs) uidx = 0;
+
+                    ustarted = true;    // mark the movement of the iterators
+                    // so that the comparison to uendidx can be made correctly
+                }
+            } else proceed = Proceed::LOWER;
+
+            break;
+        case Proceed::LOWER:
+            // Mode with lower segment, upper vertex. Same structure:
+            if(!lstarted || lidx != lendidx) {
+                const Vec3d& p_low1 = rpts[lidx];
+                const Vec3d& p_low2 = rpts[lnextidx];
+                const Vec3d& p_up   = rpts[uidx];
+
+                double a = offsdiff2 - (distfn(p_up, p_low1) - zdiff2);
+                double b = offsdiff2 - (distfn(p_up, p_low2) - zdiff2);
+                current_fit = (std::abs(a) + std::abs(b)) / 2;
+
+                if(current_fit > prev_fit) {
+                    proceed = Proceed::UPPER;
+                } else {
+                    inverted
+                        ? ind.emplace_back(int(uidx), int(lnextidx), int(lidx))
+                        : ind.emplace_back(int(lidx), int(lnextidx), int(uidx));
+
+                    ++lidx; ++lnextidx;
+                    if(lnextidx == rpts.size()) lnextidx = offs;
+                    if(lidx == rpts.size()) lidx = offs;
+
+                    lstarted = true;
+                }
+            } else proceed = Proceed::UPPER;
+
+            break;
+        } // end of switch
+    } while(!ustarted || !lstarted || uidx != uendidx || lidx != lendidx);
+
+    return ret;
+}
+
+// Same as walls() but with identical higher and lower polygons.
+Contour3D inline straight_walls(const Polygon &plate,
+                                double         lo_z,
+                                double         hi_z,
+                                ThrowOnCancel  thr)
+{
+    return walls(plate, plate, lo_z, hi_z, .0 /*offset_diff*/, thr);
+}
+
+// As it shows, the current offset_ex in ClipperUtils hangs if used in jtRound
+// mode
+ClipperLib::Paths fast_offset(const ClipperLib::Paths &paths,
+                              coord_t                  delta,
+                              ClipperLib::JoinType     jointype)
+{
+    using ClipperLib::ClipperOffset;
+    using ClipperLib::etClosedPolygon;
+    using ClipperLib::Paths;
+    using ClipperLib::Path;
+    
+    ClipperOffset offs;
+    offs.ArcTolerance = scaled<double>(0.01);
+    
+    for (auto &p : paths)
+        // If the input is not at least a triangle, we can not do this algorithm
+        if(p.size() < 3) {
+            BOOST_LOG_TRIVIAL(error) << "Invalid geometry for offsetting!";
+            return {};
+        }
+    
+    offs.AddPaths(paths, jointype, etClosedPolygon);
+    
+    Paths result; 
+    offs.Execute(result, static_cast<double>(delta));
+    
+    return result;
+}
+
+
+// Function to cut tiny connector cavities for a given polygon. The input poly
+// will be offsetted by "padding" and small rectangle shaped cavities will be
+// inserted along the perimeter in every "stride" distance. The stick rectangles
+// will have a with about "stick_width". The input dimensions are in world
+// measure, not the scaled clipper units.
+void breakstick_holes(Points& pts,
+                      double padding,
+                      double stride,
+                      double stick_width,
+                      double penetration)
+{
+    if(stride <= EPSILON || stick_width <= EPSILON || padding <= EPSILON)
+        return;
+    
+    // SVG svg("bridgestick_plate.svg");
+    // svg.draw(poly);
+    
+    // The connector stick will be a small rectangle with dimensions
+    // stick_width x (penetration + padding) to have some penetration
+    // into the input polygon.
+    
+    Points out;
+    out.reserve(2 * pts.size()); // output polygon points
+    
+    // stick bottom and right edge dimensions
+    double sbottom = scaled(stick_width);
+    double sright  = scaled(penetration + padding);
+    
+    // scaled stride distance
+    double sstride = scaled(stride);
+    double t       = 0;
+    
+    // process pairs of vertices as an edge, start with the last and
+    // first point
+    for (size_t i = pts.size() - 1, j = 0; j < pts.size(); i = j, ++j) {
+        // Get vertices and the direction vectors
+        const Point &a = pts[i], &b = pts[j];
+        Vec2d        dir = b.cast<double>() - a.cast<double>();
+        double       nrm = dir.norm();
+        dir /= nrm;
+        Vec2d dirp(-dir(Y), dir(X));
+        
+        // Insert start point
+        out.emplace_back(a);
+        
+        // dodge the start point, do not make sticks on the joins
+        while (t < sbottom) t += sbottom;
+        double tend = nrm - sbottom;
+        
+        while (t < tend) { // insert the stick on the polygon perimeter
+            
+            // calculate the stick rectangle vertices and insert them
+            // into the output.
+            Point p1 = a + (t * dir).cast<coord_t>();
+            Point p2 = p1 + (sright * dirp).cast<coord_t>();
+            Point p3 = p2 + (sbottom * dir).cast<coord_t>();
+            Point p4 = p3 + (sright * -dirp).cast<coord_t>();
+            out.insert(out.end(), {p1, p2, p3, p4});
+            
+            // continue along the perimeter
+            t += sstride;
+        }
+        
+        t = t - nrm;
+        
+        // Insert edge endpoint
+        out.emplace_back(b);
+    }
+    
+    // move the new points
+    out.shrink_to_fit();
+    pts.swap(out);
+}
+
+void breakstick_holes(Points &pts, const PadConfig::EmbedObject &c)
+{
+    breakstick_holes(pts, c.object_gap_mm, c.stick_stride_mm,
+                     c.stick_width_mm, c.stick_penetration_mm);
+}
+
+ExPolygons breakstick_holes(const ExPolygons &input,
+                      const PadConfig::EmbedObject &cfg)
+{
+    ExPolygons ret = offset_ex(input, scaled(cfg.object_gap_mm), ClipperLib::jtMiter, 1);
+    
+    for (ExPolygon &p : ret) {
+        breakstick_holes(p.contour.points, cfg);
+        for (auto &h : p.holes) breakstick_holes(h.points, cfg);
+    }
+    
+    return ret;
+}
+
+/// A fake concave hull that is constructed by connecting separate shapes
+/// with explicit bridges. Bridges are generated from each shape's centroid
+/// to the center of the "scene" which is the centroid calculated from the shape
+/// centroids (a star is created...)
+class ConcaveHull {
+    Polygons m_polys;
+    
+    Point centroid(const Points& pp) const
+    {
+        Point c;
+        switch(pp.size()) {
+        case 0: break;
+        case 1: c = pp.front(); break;
+        case 2: c = (pp[0] + pp[1]) / 2; break;
+        default: {
+            auto MAX = std::numeric_limits<Point::coord_type>::max();
+            auto MIN = std::numeric_limits<Point::coord_type>::min();
+            Point min = {MAX, MAX}, max = {MIN, MIN};
+            
+            for(auto& p : pp) {
+                if(p(0) < min(0)) min(0) = p(0);
+                if(p(1) < min(1)) min(1) = p(1);
+                if(p(0) > max(0)) max(0) = p(0);
+                if(p(1) > max(1)) max(1) = p(1);
+            }
+            c(0) = min(0) + (max(0) - min(0)) / 2;
+            c(1) = min(1) + (max(1) - min(1)) / 2;
+            break;
+        }
+        }
+        
+        return c;
+    }
+
+    inline Point centroid(const Polygon &poly) const { return poly.centroid(); }
+
+    Points calculate_centroids() const
+    {
+        // We get the centroids of all the islands in the 2D slice
+        Points centroids = reserve_vector<Point>(m_polys.size());
+        std::transform(m_polys.begin(), m_polys.end(),
+                       std::back_inserter(centroids),
+                       [this](const Polygon &poly) { return centroid(poly); });
+        
+        return centroids;
+    }
+    
+    void merge_polygons() { m_polys = union_(m_polys); }
+
+    void add_connector_rectangles(const Points &centroids,
+                                  coord_t       max_dist,
+                                  ThrowOnCancel thr)
+    {
+        namespace bgi = boost::geometry::index;
+        using PointIndexElement = std::pair<Point, unsigned>;
+        using PointIndex = bgi::rtree<PointIndexElement, bgi::rstar<16, 4>>;
+        
+        // Centroid of the centroids of islands. This is where the additional
+        // connector sticks are routed.
+        Point cc = centroid(centroids);
+        
+        PointIndex ctrindex;
+        unsigned  idx = 0;
+        for(const Point &ct : centroids)
+            ctrindex.insert(std::make_pair(ct, idx++));
+        
+        m_polys.reserve(m_polys.size() + centroids.size());
+        
+        idx = 0;
+        for (const Point &c : centroids) {
+            thr();
+            
+            double dx = c.x() - cc.x(), dy = c.y() - cc.y();
+            double l  = std::sqrt(dx * dx + dy * dy);
+            double nx = dx / l, ny = dy / l;
+            
+            const Point &ct = centroids[idx];
+            
+            std::vector<PointIndexElement> result;
+            ctrindex.query(bgi::nearest(ct, 2), std::back_inserter(result));
+            
+            double dist = max_dist;
+            for (const PointIndexElement &el : result)
+                if (el.second != idx) {
+                    dist = Line(el.first, ct).length();
+                    break;
+                }
+            
+            idx++;
+            
+            if (dist >= max_dist) return;
+            
+            Polygon r;
+            r.points.reserve(3);
+            r.points.emplace_back(cc);
+            
+            Point d(scaled(nx), scaled(ny));
+            r.points.emplace_back(c + Point(-d.y(), d.x()));
+            r.points.emplace_back(c + Point(d.y(), -d.x()));
+            offset(r, scaled(1.));
+            
+            m_polys.emplace_back(r);
+        }
+    }
+
+public:
+    
+    ConcaveHull(const ExPolygons& polys, double merge_dist, ThrowOnCancel thr)
+        : ConcaveHull{to_polygons(polys), merge_dist, thr} {}
+        
+    ConcaveHull(const Polygons& polys, double mergedist, ThrowOnCancel thr)
+    {        
+        if(polys.empty()) return;
+        
+        m_polys = polys;
+        merge_polygons();
+        
+        if(m_polys.size() == 1) return;
+        
+        Points centroids = calculate_centroids();        
+        
+        add_connector_rectangles(centroids, scaled(mergedist), thr);
+        
+        merge_polygons();
+    }
+
+    // const Polygons & polygons() const { return m_polys; }
+    
+    ExPolygons to_expolygons() const
+    {
+        auto ret = reserve_vector<ExPolygon>(m_polys.size());
+        for (const Polygon &p : m_polys) ret.emplace_back(ExPolygon(p));
+        return ret;
+    }
+
+    void offset_waffle_style(coord_t delta) {
+        ClipperLib::Paths paths = Slic3rMultiPoints_to_ClipperPaths(m_polys);
+        paths = fast_offset(paths, 2 * delta, ClipperLib::jtRound);
+        paths = fast_offset(paths, -delta, ClipperLib::jtRound);
+        m_polys = ClipperPaths_to_Slic3rPolygons(paths);
+    }
+    
+    static inline coord_t get_waffle_offset(const PadConfig &c)
+    {
+        return scaled(c.brim_size_mm + c.wing_distance() + c.wall_thickness_mm);  
+    }
+    
+    static inline double get_merge_distance(const PadConfig &c)
+    {
+        return 2. * (1.8 * c.wall_thickness_mm) + c.max_merge_dist_mm;
+    }
+};
+
+// Part of the pad configuration that is used for 3D geometry generation
+struct PadConfig3D {
+    double thickness, height, wing_height, slope;
+
+    explicit PadConfig3D(const PadConfig &cfg2d)
+        : thickness{cfg2d.wall_thickness_mm}
+        , height{cfg2d.full_height()}
+        , wing_height{cfg2d.wall_height_mm}
+        , slope{cfg2d.wall_slope}
+    {}
+
+    inline double bottom_offset() const
+    {
+        return (thickness + wing_height) / std::tan(slope);
+    }
+};
+
+// Outer part of the skeleton is used to generate the waffled edges of the pad.
+// Inner parts will not be waffled or offsetted. Inner parts are only used if
+// pad is generated around the object and correspond to holes and inner polygons
+// in the model blueprint.
+struct PadSkeleton { ExPolygons inner, outer; };
+
+PadSkeleton divide_blueprint(const ExPolygons &bp)
+{
+    ClipperLib::PolyTree ptree = union_pt(bp);
+    
+    PadSkeleton ret;
+    ret.inner.reserve(size_t(ptree.Total()));
+    ret.outer.reserve(size_t(ptree.Total()));
+    
+    for (ClipperLib::PolyTree::PolyNode *node : ptree.Childs) {
+        ExPolygon poly(ClipperPath_to_Slic3rPolygon(node->Contour));
+        for (ClipperLib::PolyTree::PolyNode *child : node->Childs) {
+            if (child->IsHole()) {
+                poly.holes.emplace_back(
+                    ClipperPath_to_Slic3rPolygon(child->Contour));
+                
+                traverse_pt_unordered(child->Childs, &ret.inner);
+            }
+            else traverse_pt_unordered(child, &ret.inner);
+        }
+        
+        ret.outer.emplace_back(poly);
+    }
+    
+    return ret;
+}
+
+// A helper class for storing polygons and maintaining a spatial index of their
+// bounding boxes.
+class Intersector {
+    BoxIndex       m_index;
+    ExPolygons     m_polys;
+    
+public:
+    
+    // Add a new polygon to the index
+    void add(const ExPolygon &ep)
+    {
+        m_polys.emplace_back(ep);
+        m_index.insert(BoundingBox{ep}, unsigned(m_index.size()));
+    }
+    
+    // Check an arbitrary polygon for intersection with the indexed polygons
+    bool intersects(const ExPolygon &poly)
+    {
+        // Create a suitable query bounding box.
+        auto bb = poly.contour.bounding_box();
+        
+        std::vector<BoxIndexEl> qres = m_index.query(bb, BoxIndex::qtIntersects);
+        
+        // Now check intersections on the actual polygons (not just the boxes)
+        bool is_overlap = false;
+        auto qit        = qres.begin();
+        while (!is_overlap && qit != qres.end())
+            is_overlap = is_overlap || poly.overlaps(m_polys[(qit++)->second]);
+        
+        return is_overlap;
+    }  
+};
+
+// This dummy intersector to implement the "force pad everywhere" feature
+struct DummyIntersector
+{
+    inline void add(const ExPolygon &) {}
+    inline bool intersects(const ExPolygon &) { return true; }
+};
+
+template<class _Intersector>
+class _AroundPadSkeleton : public PadSkeleton
+{
+    // A spatial index used to be able to efficiently find intersections of
+    // support polygons with the model polygons.
+    _Intersector m_intersector;
+    
+public:
+    _AroundPadSkeleton(const ExPolygons &support_blueprint,
+                       const ExPolygons &model_blueprint,
+                       const PadConfig & cfg,
+                       ThrowOnCancel     thr)
+    {
+        // We need to merge the support and the model contours in a special
+        // way in which the model contours have to be substracted from the
+        // support contours. The pad has to have a hole in which the model can
+        // fit perfectly (thus the substraction -- diff_ex). Also, the pad has
+        // to be eliminated from areas where there is no need for a pad, due
+        // to missing supports.  
+
+        add_supports_to_index(support_blueprint);
+        
+        ConcaveHull fullcvh =
+            wafflized_concave_hull(support_blueprint, model_blueprint, cfg, thr);
+        
+        auto model_bp_sticks =
+            breakstick_holes(model_blueprint, cfg.embed_object);
+        
+        ExPolygons fullpad = diff_ex(fullcvh.to_expolygons(), model_bp_sticks);
+        
+        remove_redundant_parts(fullpad);
+        
+        PadSkeleton divided = divide_blueprint(fullpad);
+        outer = std::move(divided.outer);
+        inner = std::move(divided.inner);
+    }
+    
+private:
+    
+    // Add the support blueprint to the search index to be queried later
+    void add_supports_to_index(const ExPolygons &supp_bp)
+    {
+        for (auto &ep : supp_bp) m_intersector.add(ep);
+    }
+    
+    // Create the wafflized pad around all object in the scene. This pad doesnt
+    // have any holes yet.
+    ConcaveHull wafflized_concave_hull(const ExPolygons &supp_bp,
+                                       const ExPolygons &model_bp,
+                                       const PadConfig  &cfg,
+                                       ThrowOnCancel     thr)
+    {
+        auto allin = reserve_vector<ExPolygon>(supp_bp.size() + model_bp.size());
+        
+        for (auto &ep : supp_bp) allin.emplace_back(ep.contour);
+        for (auto &ep : model_bp) allin.emplace_back(ep.contour);
+        
+        ConcaveHull ret{allin, ConcaveHull::get_merge_distance(cfg), thr};
+        ret.offset_waffle_style(ConcaveHull::get_waffle_offset(cfg));
+        
+        return ret;
+    }
+    
+    // To remove parts of the pad skeleton which do not host any supports
+    void remove_redundant_parts(ExPolygons &parts)
+    {
+        auto endit = std::remove_if(parts.begin(), parts.end(),
+                                    [this](const ExPolygon &p) {
+                                        return !m_intersector.intersects(p);
+                                    });
+        
+        parts.erase(endit, parts.end());
+    }
+};
+
+using AroundPadSkeleton = _AroundPadSkeleton<Intersector>;
+using BrimPadSkeleton   = _AroundPadSkeleton<DummyIntersector>;
+
+class BelowPadSkeleton : public PadSkeleton
+{
+public:
+    BelowPadSkeleton(const ExPolygons &support_blueprint,
+                     const ExPolygons &model_blueprint,
+                     const PadConfig & cfg,
+                     ThrowOnCancel     thr)
+    {
+        outer.reserve(support_blueprint.size() + model_blueprint.size());
+
+        for (auto &ep : support_blueprint) outer.emplace_back(ep.contour);
+        for (auto &ep : model_blueprint) outer.emplace_back(ep.contour);
+        
+        ConcaveHull ochull{outer, ConcaveHull::get_merge_distance(cfg), thr};
+        
+        ochull.offset_waffle_style(ConcaveHull::get_waffle_offset(cfg));
+        outer = ochull.to_expolygons();
+    }
+};
+
+// Offset the contour only, leave the holes untouched
+template<class...Args>
+ExPolygon offset_contour_only(const ExPolygon &poly, coord_t delta, Args...args)
+{
+    ExPolygons tmp = offset_ex(poly.contour, delta, args...);
+    
+    if (tmp.empty()) return {};
+    
+    Polygons holes = poly.holes;
+    for (auto &h : holes) h.reverse();
+    
+    tmp = diff_ex(to_polygons(tmp), holes);
+    
+    if (tmp.empty()) return {};
+    
+    return tmp.front();
+}
+
+bool add_cavity(Contour3D &pad, ExPolygon &top_poly, const PadConfig3D &cfg,
+                ThrowOnCancel thr)
+{
+    auto logerr = []{BOOST_LOG_TRIVIAL(error)<<"Could not create pad cavity";};
+    
+    double    wing_distance = cfg.wing_height / std::tan(cfg.slope);
+    coord_t   delta_inner   = -scaled(cfg.thickness + wing_distance);
+    coord_t   delta_middle  = -scaled(cfg.thickness);
+    ExPolygon inner_base    = offset_contour_only(top_poly, delta_inner);
+    ExPolygon middle_base   = offset_contour_only(top_poly, delta_middle);
+    
+    if (inner_base.empty() || middle_base.empty()) { logerr(); return false; }
+    
+    ExPolygons pdiff = diff_ex(top_poly, middle_base.contour);
+    
+    if (pdiff.size() != 1) { logerr(); return false; }
+
+    top_poly = pdiff.front();
+
+    double z_min = -cfg.wing_height, z_max = 0;
+    double offset_difference = -wing_distance;
+    pad.merge(walls(inner_base.contour, middle_base.contour, z_min, z_max,
+                    offset_difference, thr));
+
+    pad.merge(triangulate_expolygon_3d(inner_base, z_min, NORMALS_UP));
+
+    return true;
+}
+
+Contour3D create_outer_pad_geometry(const ExPolygons & skeleton,
+                                    const PadConfig3D &cfg,
+                                    ThrowOnCancel      thr)
+{
+    Contour3D ret;
+    
+    for (const ExPolygon &pad_part : skeleton) {
+        ExPolygon top_poly{pad_part};
+        ExPolygon bottom_poly =
+            offset_contour_only(pad_part, -scaled(cfg.bottom_offset()));
+        
+        if (bottom_poly.empty()) continue;
+        
+        double z_min = -cfg.height, z_max = 0;
+        ret.merge(walls(top_poly.contour, bottom_poly.contour, z_max, z_min,
+                        cfg.bottom_offset(), thr));
+        
+        if (cfg.wing_height > 0. && add_cavity(ret, top_poly, cfg, thr))     
+            z_max = -cfg.wing_height;
+        
+        for (auto &h : bottom_poly.holes)
+            ret.merge(straight_walls(h, z_max, z_min, thr));
+        
+        ret.merge(triangulate_expolygon_3d(bottom_poly, z_min, NORMALS_DOWN));
+        ret.merge(triangulate_expolygon_3d(top_poly, NORMALS_UP));  
+    }
+    
+    return ret;
+}
+
+Contour3D create_inner_pad_geometry(const ExPolygons & skeleton,
+                                    const PadConfig3D &cfg,
+                                    ThrowOnCancel      thr)
+{
+    Contour3D ret;
+    
+    double z_max = 0., z_min = -cfg.height;
+    for (const ExPolygon &pad_part : skeleton) {
+        ret.merge(straight_walls(pad_part.contour, z_max, z_min,thr));
+        
+        for (auto &h : pad_part.holes)
+            ret.merge(straight_walls(h, z_max, z_min, thr));
+        
+        ret.merge(triangulate_expolygon_3d(pad_part, z_min, NORMALS_DOWN));
+        ret.merge(triangulate_expolygon_3d(pad_part, z_max, NORMALS_UP));
+    }
+    
+    return ret;
+}
+
+Contour3D create_pad_geometry(const PadSkeleton &skelet,
+                              const PadConfig &  cfg,
+                              ThrowOnCancel      thr)
+{
+#ifndef NDEBUG
+    SVG svg("pad_skeleton.svg");
+    svg.draw(skelet.outer, "green");
+    svg.draw(skelet.inner, "blue");
+    svg.Close();
+#endif
+    
+    PadConfig3D cfg3d(cfg);
+    return create_outer_pad_geometry(skelet.outer, cfg3d, thr)
+        .merge(create_inner_pad_geometry(skelet.inner, cfg3d, thr));
+}
+
+Contour3D create_pad_geometry(const ExPolygons &supp_bp,
+                              const ExPolygons &model_bp,
+                              const PadConfig & cfg,
+                              ThrowOnCancel thr)
+{
+    PadSkeleton skelet;
+
+    if (cfg.embed_object.enabled) {
+        if (cfg.embed_object.everywhere)
+            skelet = BrimPadSkeleton(supp_bp, model_bp, cfg, thr);
+        else
+            skelet = AroundPadSkeleton(supp_bp, model_bp, cfg, thr);
+    } else
+        skelet = BelowPadSkeleton(supp_bp, model_bp, cfg, thr);
+
+    return create_pad_geometry(skelet, cfg, thr);
+}
+
+} // namespace
+
+void pad_blueprint(const TriangleMesh &      mesh,
+                   ExPolygons &              output,
+                   const std::vector<float> &heights,
+                   ThrowOnCancel             thrfn)
+{
+    if (mesh.empty()) return;
+    TriangleMeshSlicer slicer(&mesh);
+    
+    auto out = reserve_vector<ExPolygons>(heights.size());
+    slicer.slice(heights, 0.f, &out, thrfn);
+    
+    size_t count = 0;
+    for(auto& o : out) count += o.size();
+    
+    // Unification is expensive, a simplify also speeds up the pad generation
+    auto tmp = reserve_vector<ExPolygon>(count);
+    for(ExPolygons& o : out)
+        for(ExPolygon& e : o) {
+            auto&& exss = e.simplify(scaled<double>(0.1));
+            for(ExPolygon& ep : exss) tmp.emplace_back(std::move(ep));
+        }
+    
+    ExPolygons utmp = union_ex(tmp);
+    
+    for(auto& o : utmp) {
+        auto&& smp = o.simplify(scaled<double>(0.1));
+        output.insert(output.end(), smp.begin(), smp.end());
+    }
+}
+
+void pad_blueprint(const TriangleMesh &mesh,
+                   ExPolygons &        output,
+                   float               h,
+                   float               layerh,
+                   ThrowOnCancel       thrfn)
+{
+    float gnd = float(mesh.bounding_box().min(Z));
+    
+    std::vector<float> slicegrid = grid(gnd, gnd + h, layerh);
+    pad_blueprint(mesh, output, slicegrid, thrfn);
+}
+
+void create_pad(const ExPolygons &sup_blueprint,
+                const ExPolygons &model_blueprint,
+                TriangleMesh &    out,
+                const PadConfig & cfg,
+                ThrowOnCancel thr)
+{
+    Contour3D t = create_pad_geometry(sup_blueprint, model_blueprint, cfg, thr);
+    out.merge(mesh(std::move(t)));
+}
+
+std::string PadConfig::validate() const
+{   
+    if (bottom_offset() > brim_size_mm + wing_distance())
+        return L("Pad brim size is too low for the current slope.");
+    
+    return "";
+}
+
+}} // namespace Slic3r::sla

src/libslic3r/SLA/SLAPad.hpp

@@ -0,0 +1,93 @@
+#ifndef SLABASEPOOL_HPP
+#define SLABASEPOOL_HPP
+
+#include <vector>
+#include <functional>
+#include <cmath>
+
+namespace Slic3r {
+
+class ExPolygon;
+class Polygon;
+using ExPolygons = std::vector<ExPolygon>;
+using Polygons = std::vector<Polygon>;
+
+class TriangleMesh;
+
+namespace sla {
+
+using ThrowOnCancel = std::function<void(void)>;
+
+/// Calculate the polygon representing the silhouette.
+void pad_blueprint(
+    const TriangleMesh &mesh,       // input mesh
+    ExPolygons &        output,     // Output will be merged with
+    const std::vector<float> &,     // Exact Z levels to sample
+    ThrowOnCancel thrfn = [] {}); // Function that throws if cancel was requested
+
+void pad_blueprint(
+    const TriangleMesh &mesh,                   
+    ExPolygons &        output,                 
+    float               samplingheight = 0.1f,  // The height range to sample
+    float               layerheight    = 0.05f, // The sampling height
+    ThrowOnCancel       thrfn = [] {});
+
+struct PadConfig {
+    double wall_thickness_mm = 1.;
+    double wall_height_mm = 1.;
+    double max_merge_dist_mm = 50;
+    double wall_slope = std::atan(1.0);          // Universal constant for Pi/4
+    double brim_size_mm = 1.6;
+    
+    struct EmbedObject {
+        double object_gap_mm = 1.;
+        double stick_stride_mm = 10.;
+        double stick_width_mm = 0.5;
+        double stick_penetration_mm = 0.1;
+        bool enabled = false;
+        bool everywhere = false;
+        operator bool() const { return enabled; }
+    } embed_object;
+    
+    inline PadConfig() = default;
+    inline PadConfig(double thickness,
+                     double height,
+                     double mergedist,
+                     double slope)
+        : wall_thickness_mm(thickness)
+        , wall_height_mm(height)
+        , max_merge_dist_mm(mergedist)
+        , wall_slope(slope)
+    {}
+
+    inline double bottom_offset() const
+    {
+        return (wall_thickness_mm + wall_height_mm) / std::tan(wall_slope);
+    }
+
+    inline double wing_distance() const
+    {
+        return wall_height_mm / std::tan(wall_slope);
+    }
+
+    inline double full_height() const
+    {
+        return wall_height_mm + wall_thickness_mm;
+    }
+    
+    /// Returns the elevation needed for compensating the pad.    
+    inline double required_elevation() const { return wall_thickness_mm; }
+    
+    std::string validate() const;
+};
+
+void create_pad(const ExPolygons &support_contours,
+                const ExPolygons &model_contours,
+                TriangleMesh &    output_mesh,
+                const PadConfig & = PadConfig(),
+                ThrowOnCancel throw_on_cancel = []{});
+
+} // namespace sla
+} // namespace Slic3r
+
+#endif // SLABASEPOOL_HPP

src/libslic3r/SLA/SLASpatIndex.hpp

@@ -39,14 +39,19 @@ public:
         insert(std::make_pair(v, unsigned(idx)));
     }
 
-    std::vector<PointIndexEl> query(std::function<bool(const PointIndexEl&)>);
+    std::vector<PointIndexEl> query(std::function<bool(const PointIndexEl&)>) const;
-    std::vector<PointIndexEl> nearest(const Vec3d&, unsigned k);
+    std::vector<PointIndexEl> nearest(const Vec3d&, unsigned k) const;
+    std::vector<PointIndexEl> query(const Vec3d &v, unsigned k) const // wrapper
+    {
+        return nearest(v, k);
+    }
 
     // For testing
     size_t size() const;
     bool empty() const { return size() == 0; }
 
     void foreach(std::function<void(const PointIndexEl& el)> fn);
+    void foreach(std::function<void(const PointIndexEl& el)> fn) const;
 };
 
 using BoxIndexEl = std::pair<Slic3r::BoundingBox, unsigned>;

src/libslic3r/SLA/SLASupportTree.cpp

@@ -7,7 +7,7 @@
 #include "SLASupportTree.hpp"
 #include "SLABoilerPlate.hpp"
 #include "SLASpatIndex.hpp"
-#include "SLABasePool.hpp"
+#include "SLAPad.hpp"
 
 #include <libslic3r/MTUtils.hpp>
 #include <libslic3r/ClipperUtils.hpp>
@@ -17,6 +17,8 @@
 #include <libnest2d/optimizers/nlopt/subplex.hpp>
 #include <boost/log/trivial.hpp>
 #include <tbb/parallel_for.h>
+#include <tbb/mutex.h>
+#include <tbb/spin_mutex.h>
 #include <libslic3r/I18N.hpp>
 
 //! macro used to mark string used at localization,
@@ -91,27 +93,34 @@ template<bool> struct _ccr {};
 
 template<> struct _ccr<true>
 {
-    using Mutex = SpinMutex;
+    using SpinningMutex = tbb::spin_mutex;
+    using LockingMutex  = tbb::mutex;
 
     template<class It, class Fn>
     static inline void enumerate(It from, It to, Fn fn)
     {
-        using TN = size_t;
+        auto   iN = to - from;
-        auto iN  = to - from;
+        size_t N  = iN < 0 ? 0 : size_t(iN);
-        TN   N   = iN < 0 ? 0 : TN(iN);
 
-        tbb::parallel_for(TN(0), N, [from, fn](TN n) { fn(*(from + n), n); });
+        tbb::parallel_for(size_t(0), N, [from, fn](size_t n) {
+            fn(*(from + decltype(iN)(n)), n);
+        });
     }
 };
 
 template<> struct _ccr<false>
 {
-    struct Mutex { inline void lock() {} inline void unlock() {} };
+private:
+    struct _Mtx { inline void lock() {} inline void unlock() {} };
+    
+public:
+    using SpinningMutex = _Mtx;
+    using LockingMutex = _Mtx;
 
     template<class It, class Fn>
     static inline void enumerate(It from, It to, Fn fn)
     {
-        for (auto it = from; it != to; ++it) fn(*it, it - from);
+        for (auto it = from; it != to; ++it) fn(*it, size_t(it - from));
     }
 };
 
@@ -132,6 +141,8 @@ template<class Vec> double distance(const Vec& pp1, const Vec& pp2) {
     return distance(p);
 }
 
+namespace {
+
 Contour3D sphere(double rho, Portion portion = make_portion(0.0, 2.0*PI),
                  double fa=(2*PI/360)) {
 
@@ -175,10 +186,11 @@ Contour3D sphere(double rho, Portion portion = make_portion(0.0, 2.0*PI),
         Vec2d b = Eigen::Rotation2Dd(ring[i]) * Eigen::Vector2d(0, r);
         vertices.emplace_back(Vec3d(b(0), b(1), z));
 
-        if(sbegin == 0)
+        if (sbegin == 0)
-        facets.emplace_back((i == 0) ? Vec3crd(coord_t(ring.size()), 0, 1) :
+            facets.emplace_back((i == 0) ?
-                                       Vec3crd(id - 1, 0, id));
+                                    Vec3crd(coord_t(ring.size()), 0, 1) :
-        ++ id;
+                                    Vec3crd(id - 1, 0, id));
+        ++id;
     }
 
     // General case: insert and form facets for each step,
@@ -229,7 +241,7 @@ Contour3D sphere(double rho, Portion portion = make_portion(0.0, 2.0*PI),
 // h: Height
 // ssteps: how many edges will create the base circle
 // sp: starting point
-Contour3D cylinder(double r, double h, size_t ssteps, const Vec3d sp = {0,0,0})
+Contour3D cylinder(double r, double h, size_t ssteps, const Vec3d &sp = {0,0,0})
 {
     Contour3D ret;
 
@@ -289,6 +301,8 @@ Contour3D cylinder(double r, double h, size_t ssteps, const Vec3d sp = {0,0,0})
     return ret;
 }
 
+const constexpr long ID_UNSET = -1;
+
 struct Head {
     Contour3D mesh;
 
@@ -303,22 +317,22 @@ struct Head {
     
     // For identification purposes. This will be used as the index into the
     // container holding the head structures. See SLASupportTree::Impl
-    long id = -1;
+    long id = ID_UNSET;
 
     // If there is a pillar connecting to this head, then the id will be set.
-    long pillar_id = -1;
+    long pillar_id = ID_UNSET;
 
-    inline void invalidate() { id = -1; }
+    inline void invalidate() { id = ID_UNSET; }
     inline bool is_valid() const { return id >= 0; }
 
     Head(double r_big_mm,
          double r_small_mm,
          double length_mm,
          double penetration,
-         Vec3d direction = {0, 0, -1},    // direction (normal to the dull end )
+         const Vec3d &direction = {0, 0, -1},  // direction (normal to the dull end)
-         Vec3d offset = {0, 0, 0},        // displacement
+         const Vec3d &offset = {0, 0, 0},      // displacement
          const size_t circlesteps = 45):
-            steps(circlesteps), dir(direction), tr(offset),
+        steps(circlesteps), dir(direction), tr(offset),
             r_back_mm(r_big_mm), r_pin_mm(r_small_mm), width_mm(length_mm),
             penetration_mm(penetration)
     {
@@ -347,7 +361,7 @@ struct Head {
         auto&& s1 = sphere(r_big_mm, make_portion(0, PI/2 + phi), detail);
         auto&& s2 = sphere(r_small_mm, make_portion(PI/2 + phi, PI), detail);
 
-        for(auto& p : s2.points) z(p) += h;
+        for(auto& p : s2.points) p.z() += h;
 
         mesh.merge(s1);
         mesh.merge(s2);
@@ -373,7 +387,7 @@ struct Head {
 
         // To simplify further processing, we translate the mesh so that the
         // last vertex of the pointing sphere (the pinpoint) will be at (0,0,0)
-        for(auto& p : mesh.points) z(p) -= (h + r_small_mm - penetration_mm);
+        for(auto& p : mesh.points) p.z() -= (h + r_small_mm - penetration_mm);
     }
 
     void transform()
@@ -393,11 +407,6 @@ struct Head {
         return 2 * r_pin_mm + width_mm + 2*r_back_mm - penetration_mm;
     }
 
-    static double fullwidth(const SupportConfig& cfg) {
-        return 2 * cfg.head_front_radius_mm + cfg.head_width_mm +
-               2 * cfg.head_back_radius_mm - cfg.head_penetration_mm;
-    }
-
     Vec3d junction_point() const {
         return tr + ( 2 * r_pin_mm + width_mm + r_back_mm - penetration_mm)*dir;
     }
@@ -414,7 +423,7 @@ struct Junction {
     size_t steps = 45;
     Vec3d pos;
 
-    long id = -1;
+    long id = ID_UNSET;
 
     Junction(const Vec3d& tr, double r_mm, size_t stepnum = 45):
         r(r_mm), steps(stepnum), pos(tr)
@@ -432,11 +441,11 @@ struct Pillar {
     Vec3d endpt;
     double height = 0;
 
-    long id = -1;
+    long id = ID_UNSET;
 
     // If the pillar connects to a head, this is the id of that head
     bool starts_from_head = true; // Could start from a junction as well
-    long start_junction_id = -1;
+    long start_junction_id = ID_UNSET;
 
     // How many bridges are connected to this pillar
     unsigned bridges = 0;
@@ -461,22 +470,24 @@ struct Pillar {
         }
     }
 
-    Pillar(const Junction& junc, const Vec3d& endp):
+    Pillar(const Junction &junc, const Vec3d &endp)
-        Pillar(junc.pos, endp, junc.r, junc.steps){}
+        : Pillar(junc.pos, endp, junc.r, junc.steps)
+    {}
 
-    Pillar(const Head& head, const Vec3d& endp, double radius = 1):
+    Pillar(const Head &head, const Vec3d &endp, double radius = 1)
-        Pillar(head.junction_point(), endp, head.request_pillar_radius(radius),
+        : Pillar(head.junction_point(), endp,
-               head.steps)
+                 head.request_pillar_radius(radius), head.steps)
+    {}
+
+    inline Vec3d startpoint() const
     {
-    }
-
-    inline Vec3d startpoint() const {
         return {endpt(X), endpt(Y), endpt(Z) + height};
     }
 
     inline const Vec3d& endpoint() const { return endpt; }
 
-    Pillar& add_base(double baseheight = 3, double radius = 2) {
+    Pillar& add_base(double baseheight = 3, double radius = 2)
+    {
         if(baseheight <= 0) return *this;
         if(baseheight > height) baseheight = height;
 
@@ -523,8 +534,6 @@ struct Pillar {
         indices.emplace_back(offs, offs + last, lcenter);
         return *this;
     }
-
-    bool has_base() const { return !base.points.empty(); }
 };
 
 // A Bridge between two pillars (with junction endpoints)
@@ -532,9 +541,9 @@ struct Bridge {
     Contour3D mesh;
     double r = 0.8;
 
-    long id = -1;
+    long id = ID_UNSET;
-    long start_jid = -1;
+    long start_jid = ID_UNSET;
-    long end_jid = -1;
+    long end_jid = ID_UNSET;
 
     // We should reduce the radius a tiny bit to help the convex hull algorithm
     Bridge(const Vec3d& j1, const Vec3d& j2,
@@ -550,17 +559,13 @@ struct Bridge {
         auto quater = Quaternion::FromTwoVectors(Vec3d{0,0,1}, dir);
         for(auto& p : mesh.points) p = quater * p + j1;
     }
-
-    Bridge(const Junction& j1, const Junction& j2, double r_mm = 0.8):
-        Bridge(j1.pos, j2.pos, r_mm, j1.steps) {}
-
 };
 
 // A bridge that spans from model surface to model surface with small connecting
 // edges on the endpoints. Used for headless support points.
 struct CompactBridge {
     Contour3D mesh;
-    long id = -1;
+    long id = ID_UNSET;
 
     CompactBridge(const Vec3d& sp,
                   const Vec3d& ep,
@@ -594,123 +599,28 @@ struct CompactBridge {
 // A wrapper struct around the base pool (pad)
 struct Pad {
     TriangleMesh tmesh;
-    PoolConfig cfg;
+    PadConfig cfg;
     double zlevel = 0;
 
     Pad() = default;
 
-    Pad(const TriangleMesh& support_mesh,
+    Pad(const TriangleMesh &support_mesh,
-        const ExPolygons& modelbase,
+        const ExPolygons &  model_contours,
-        double ground_level,
+        double              ground_level,
-        const PoolConfig& pcfg) :
+        const PadConfig &   pcfg,
-        cfg(pcfg),
+        ThrowOnCancel       thr)
-        zlevel(ground_level +
+        : cfg(pcfg)
-               sla::get_pad_fullheight(pcfg) -
+        , zlevel(ground_level + pcfg.full_height() - pcfg.required_elevation())
-               sla::get_pad_elevation(pcfg))
     {
-        Polygons basep;
-        auto &thr = cfg.throw_on_cancel;
-
         thr();
 
-        // Get a sample for the pad from the support mesh
+        ExPolygons sup_contours;
-        {
-            ExPolygons platetmp;
 
-            float zstart = float(zlevel);
+        float zstart = float(zlevel);
-            float zend   = zstart + float(get_pad_fullheight(pcfg) + EPSILON);
+        float zend   = zstart + float(pcfg.full_height() + EPSILON);
 
-            base_plate(support_mesh, platetmp, grid(zstart, zend, 0.1f), thr);
+        pad_blueprint(support_mesh, sup_contours, grid(zstart, zend, 0.1f), thr);
-
+        create_pad(sup_contours, model_contours, tmesh, pcfg);
-            // We don't need no... holes control...
-            for (const ExPolygon &bp : platetmp)
-                basep.emplace_back(std::move(bp.contour));
-        }
-
-        if(pcfg.embed_object) {
-
-            // If the zero elevation mode is ON, we need to process the model
-            // base silhouette. Create the offsetted version and punch the
-            // breaksticks across its perimeter.
-
-            ExPolygons modelbase_offs = modelbase;
-
-            if (pcfg.embed_object.object_gap_mm > 0.0)
-                modelbase_offs
-                    = offset_ex(modelbase_offs,
-                                float(scaled(pcfg.embed_object.object_gap_mm)));
-
-            // Create a spatial index of the support silhouette polygons.
-            // This will be used to check for intersections with the model
-            // silhouette polygons. If there is no intersection, then a certain
-            // part of the pad is redundant as it does not host any supports.
-            BoxIndex bindex;
-            {
-                unsigned idx = 0;
-                for(auto &bp : basep) {
-                    auto bb = bp.bounding_box();
-                    bb.offset(float(scaled(pcfg.min_wall_thickness_mm)));
-                    bindex.insert(bb, idx++);
-                }
-            }
-
-            ExPolygons concaveh = offset_ex(
-                concave_hull(basep, pcfg.max_merge_distance_mm, thr),
-                scaled<float>(pcfg.min_wall_thickness_mm));
-
-            // Punching the breaksticks across the offsetted polygon perimeters
-            auto pad_stickholes = reserve_vector<ExPolygon>(modelbase.size());
-            for(auto& poly : modelbase_offs) {
-
-                bool overlap = false;
-                for (const ExPolygon &p : concaveh)
-                    overlap = overlap || poly.overlaps(p);
-
-                auto bb = poly.contour.bounding_box();
-                bb.offset(scaled<float>(pcfg.min_wall_thickness_mm));
-
-                std::vector<BoxIndexEl> qres =
-                    bindex.query(bb, BoxIndex::qtIntersects);
-
-                if (!qres.empty() || overlap) {
-
-                    // The model silhouette polygon 'poly' HAS an intersection
-                    // with the support silhouettes. Include this polygon
-                    // in the pad holes with the breaksticks and merge the
-                    // original (offsetted) version with the rest of the pad
-                    // base plate.
-
-                    basep.emplace_back(poly.contour);
-
-                    // The holes of 'poly' will become positive parts of the
-                    // pad, so they has to be checked for intersections as well
-                    // and erased if there is no intersection with the supports
-                    auto it = poly.holes.begin();
-                    while(it != poly.holes.end()) {
-                        if (bindex.query(it->bounding_box(),
-                                         BoxIndex::qtIntersects).empty())
-                            it = poly.holes.erase(it);
-                        else
-                            ++it;
-                    }
-
-                    // Punch the breaksticks
-                    sla::breakstick_holes(
-                        poly,
-                        pcfg.embed_object.object_gap_mm,   // padding
-                        pcfg.embed_object.stick_stride_mm,
-                        pcfg.embed_object.stick_width_mm,
-                        pcfg.embed_object.stick_penetration_mm);
-
-                    pad_stickholes.emplace_back(poly);
-                }
-            }
-
-            create_base_pool(basep, tmesh, pad_stickholes, cfg);
-        } else {
-            for (const ExPolygon &bp : modelbase) basep.emplace_back(bp.contour);
-            create_base_pool(basep, tmesh, {}, cfg);
-        }
 
         tmesh.translate(0, 0, float(zlevel));
         if (!tmesh.empty()) tmesh.require_shared_vertices();
@@ -720,43 +630,18 @@ struct Pad {
 };
 
 // The minimum distance for two support points to remain valid.
-static const double /*constexpr*/ D_SP   = 0.1;
+const double /*constexpr*/ D_SP = 0.1;
+
+} // namespace
 
 enum { // For indexing Eigen vectors as v(X), v(Y), v(Z) instead of numbers
   X, Y, Z
 };
 
-// Calculate the normals for the selected points (from 'points' set) on the
-// mesh. This will call squared distance for each point.
-PointSet normals(const PointSet& points,
-                 const EigenMesh3D& mesh,
-                 double eps = 0.05,  // min distance from edges
-                 std::function<void()> throw_on_cancel = [](){},
-                 const std::vector<unsigned>& selected_points = {});
-
 inline Vec2d to_vec2(const Vec3d& v3) {
     return {v3(X), v3(Y)};
 }
 
-bool operator==(const PointIndexEl& e1, const PointIndexEl& e2) {
-    return e1.second == e2.second;
-}
-
-// Clustering a set of points by the given distance.
-ClusteredPoints cluster(const std::vector<unsigned>& indices,
-                        std::function<Vec3d(unsigned)> pointfn,
-                        double dist,
-                        unsigned max_points);
-
-ClusteredPoints cluster(const PointSet& points,
-                        double dist,
-                        unsigned max_points);
-
-ClusteredPoints cluster(
-        const std::vector<unsigned>& indices,
-        std::function<Vec3d(unsigned)> pointfn,
-        std::function<bool(const PointIndexEl&, const PointIndexEl&)> predicate,
-        unsigned max_points);
 
 // This class will hold the support tree meshes with some additional bookkeeping
 // as well. Various parts of the support geometry are stored separately and are
@@ -775,20 +660,20 @@ class SLASupportTree::Impl {
     // For heads it is beneficial to use the same IDs as for the support points.
     std::vector<Head> m_heads;
     std::vector<size_t> m_head_indices;
-
     std::vector<Pillar> m_pillars;
     std::vector<Junction> m_junctions;
     std::vector<Bridge> m_bridges;
     std::vector<CompactBridge> m_compact_bridges;    
-    Controller m_ctl;
-
     Pad m_pad;
     
-    using Mutex = ccr::Mutex;
+    Controller m_ctl;
 
+    using Mutex = ccr::SpinningMutex;
+
+    mutable TriangleMesh m_meshcache;
     mutable Mutex m_mutex;
-    mutable TriangleMesh meshcache; mutable bool meshcache_valid = false;
+    mutable bool m_meshcache_valid = false;
-    mutable double model_height = 0; // the full height of the model
+    mutable double m_model_height = 0; // the full height of the model
 
 public:
     double ground_level = 0;
@@ -807,7 +692,7 @@ public:
         if (id >= m_head_indices.size()) m_head_indices.resize(id + 1);
         m_head_indices[id] = m_heads.size() - 1;
 
-        meshcache_valid = false;
+        m_meshcache_valid = false;
         return m_heads.back();
     }
 
@@ -825,7 +710,7 @@ public:
         pillar.start_junction_id = head.id;
         pillar.starts_from_head = true;
 
-        meshcache_valid = false;
+        m_meshcache_valid = false;
         return m_pillars.back();
     }
 
@@ -854,22 +739,10 @@ public:
         Pillar& pillar = m_pillars.back();
         pillar.id = long(m_pillars.size() - 1);
         pillar.starts_from_head = false;
-        meshcache_valid = false;
+        m_meshcache_valid = false;
         return m_pillars.back();
     }
 
-    const Head& pillar_head(long pillar_id) const
-    {
-        std::lock_guard<Mutex> lk(m_mutex);
-        assert(pillar_id >= 0 && pillar_id < long(m_pillars.size()));
-
-        const Pillar& p = m_pillars[size_t(pillar_id)];
-        assert(p.starts_from_head && p.start_junction_id >= 0);
-        assert(size_t(p.start_junction_id) < m_head_indices.size());
-
-        return m_heads[m_head_indices[p.start_junction_id]];
-    }
-
     const Pillar& head_pillar(unsigned headid) const
     {
         std::lock_guard<Mutex> lk(m_mutex);
@@ -886,7 +759,7 @@ public:
         std::lock_guard<Mutex> lk(m_mutex);
         m_junctions.emplace_back(std::forward<Args>(args)...);
         m_junctions.back().id = long(m_junctions.size() - 1);
-        meshcache_valid = false;
+        m_meshcache_valid = false;
         return m_junctions.back();
     }
 
@@ -895,7 +768,7 @@ public:
         std::lock_guard<Mutex> lk(m_mutex);
         m_bridges.emplace_back(std::forward<Args>(args)...);
         m_bridges.back().id = long(m_bridges.size() - 1);
-        meshcache_valid = false;
+        m_meshcache_valid = false;
         return m_bridges.back();
     }
 
@@ -904,7 +777,7 @@ public:
         std::lock_guard<Mutex> lk(m_mutex);
         m_compact_bridges.emplace_back(std::forward<Args>(args)...);
         m_compact_bridges.back().id = long(m_compact_bridges.size() - 1);
-        meshcache_valid = false;
+        m_meshcache_valid = false;
         return m_compact_bridges.back();
     }
 
@@ -913,7 +786,7 @@ public:
         std::lock_guard<Mutex> lk(m_mutex);
         assert(id < m_head_indices.size());
 
-        meshcache_valid = false;
+        m_meshcache_valid = false;
         return m_heads[m_head_indices[id]];
     }
 
@@ -933,9 +806,10 @@ public:
 
     const Pad &create_pad(const TriangleMesh &object_supports,
                           const ExPolygons &  modelbase,
-                          const PoolConfig &  cfg)
+                          const PadConfig &   cfg)
     {
-        m_pad = Pad(object_supports, modelbase, ground_level, cfg);
+        m_pad = Pad{object_supports, modelbase, ground_level, cfg, m_ctl.cancelfn};
+
         return m_pad;
     }
 
@@ -946,7 +820,7 @@ public:
     // WITHOUT THE PAD!!!
     const TriangleMesh &merged_mesh() const
     {
-        if (meshcache_valid) return meshcache;
+        if (m_meshcache_valid) return m_meshcache;
 
         Contour3D merged;
 
@@ -978,39 +852,39 @@ public:
 
         if (m_ctl.stopcondition()) {
             // In case of failure we have to return an empty mesh
-            meshcache = TriangleMesh();
+            m_meshcache = TriangleMesh();
-            return meshcache;
+            return m_meshcache;
         }
 
-        meshcache = mesh(merged);
+        m_meshcache = mesh(merged);
 
         // The mesh will be passed by const-pointer to TriangleMeshSlicer,
         // which will need this.
-        if (!meshcache.empty()) meshcache.require_shared_vertices();
+        if (!m_meshcache.empty()) m_meshcache.require_shared_vertices();
 
-        BoundingBoxf3 &&bb = meshcache.bounding_box();
+        BoundingBoxf3 &&bb = m_meshcache.bounding_box();
-        model_height       = bb.max(Z) - bb.min(Z);
+        m_model_height       = bb.max(Z) - bb.min(Z);
 
-        meshcache_valid = true;
+        m_meshcache_valid = true;
-        return meshcache;
+        return m_meshcache;
     }
 
     // WITH THE PAD
     double full_height() const
     {
         if (merged_mesh().empty() && !pad().empty())
-            return get_pad_fullheight(pad().cfg);
+            return pad().cfg.full_height();
 
         double h = mesh_height();
-        if (!pad().empty()) h += sla::get_pad_elevation(pad().cfg);
+        if (!pad().empty()) h += pad().cfg.required_elevation();
         return h;
     }
 
     // WITHOUT THE PAD!!!
     double mesh_height() const
     {
-        if (!meshcache_valid) merged_mesh();
+        if (!m_meshcache_valid) merged_mesh();
-        return model_height;
+        return m_model_height;
     }
 
     // Intended to be called after the generation is fully complete
@@ -1032,11 +906,11 @@ public:
 // vector of point indices.
 template<class DistFn>
 long cluster_centroid(const ClusterEl& clust,
-                      std::function<Vec3d(size_t)> pointfn,
+                      const std::function<Vec3d(size_t)> &pointfn,
                       DistFn df)
 {
     switch(clust.size()) {
-    case 0: /* empty cluster */ return -1;
+    case 0: /* empty cluster */ return ID_UNSET;
     case 1: /* only one element */ return 0;
     case 2: /* if two elements, there is no center */ return 0;
     default: ;
@@ -1116,7 +990,52 @@ class SLASupportTree::Algorithm {
     ThrowOnCancel m_thr;
 
     // A spatial index to easily find strong pillars to connect to.
-    PointIndex m_pillar_index;
+    
+    class PillarIndex {
+        PointIndex m_index;
+        mutable ccr::LockingMutex m_mutex;
+        
+    public:
+        
+        template<class...Args> inline void guarded_insert(Args&&...args)
+        {
+            std::lock_guard<ccr::LockingMutex> lck(m_mutex);
+            m_index.insert(std::forward<Args>(args)...);
+        }
+        
+        template<class...Args>
+        inline std::vector<PointIndexEl> guarded_query(Args&&...args) const
+        {
+            std::lock_guard<ccr::LockingMutex> lck(m_mutex);
+            return m_index.query(std::forward<Args>(args)...);
+        }
+        
+        template<class...Args> inline void insert(Args&&...args)
+        {
+            m_index.insert(std::forward<Args>(args)...);
+        }
+        
+        template<class...Args>
+        inline std::vector<PointIndexEl> query(Args&&...args) const
+        {
+            return m_index.query(std::forward<Args>(args)...);
+        }
+        
+        template<class Fn> inline void foreach(Fn fn) { m_index.foreach(fn); }
+        template<class Fn> inline void guarded_foreach(Fn fn)
+        {
+            std::lock_guard<ccr::LockingMutex> lck(m_mutex);
+            m_index.foreach(fn);
+        }
+        
+        PointIndex guarded_clone()
+        {
+            std::lock_guard<ccr::LockingMutex> lck(m_mutex);
+            return m_index;
+        }
+        
+    } m_pillar_index;
+    
     
     inline double ray_mesh_intersect(const Vec3d& s,
                                      const Vec3d& dir)
@@ -1382,7 +1301,7 @@ class SLASupportTree::Algorithm {
             // Align to center
             double available_dist = (startz - endz);
             double rounds = std::floor(available_dist / std::abs(zstep));
-            startz -= 0.5 * (available_dist - rounds * std::abs(zstep));;
+            startz -= 0.5 * (available_dist - rounds * std::abs(zstep));
         }
 
         auto pcm = m_cfg.pillar_connection_mode;
@@ -1507,9 +1426,9 @@ class SLASupportTree::Algorithm {
     }
 
     bool search_pillar_and_connect(const Head& head) {
-        PointIndex spindex = m_pillar_index;
+        PointIndex spindex = m_pillar_index.guarded_clone();
 
-        long nearest_id = -1;
+        long nearest_id = ID_UNSET;
 
         Vec3d querypoint = head.junction_point();
 
@@ -1530,8 +1449,8 @@ class SLASupportTree::Algorithm {
                 auto nearpillarID = unsigned(nearest_id);
                 if(nearpillarID < m_result.pillarcount()) {
                     if(!connect_to_nearpillar(head, nearpillarID)) {
-                        nearest_id = -1;    // continue searching
+                        nearest_id = ID_UNSET;    // continue searching
-                        spindex.remove(ne); // without the current pillar
+                        spindex.remove(ne);       // without the current pillar
                     }
                 }
             }
@@ -1545,7 +1464,7 @@ class SLASupportTree::Algorithm {
     void create_ground_pillar(const Vec3d &jp,
                               const Vec3d &sourcedir,
                               double       radius,
-                              int          head_id = -1)
+                              long         head_id = ID_UNSET)
     {
         // People were killed for this number (seriously)
         static const double SQR2 = std::sqrt(2.0);
@@ -1554,7 +1473,7 @@ class SLASupportTree::Algorithm {
         double gndlvl       = m_result.ground_level;
         Vec3d  endp         = {jp(X), jp(Y), gndlvl};
         double sd           = m_cfg.pillar_base_safety_distance_mm;
-        int    pillar_id    = -1;
+        long   pillar_id    = ID_UNSET;
         double min_dist     = sd + m_cfg.base_radius_mm + EPSILON;
         double dist         = 0;
         bool   can_add_base = true;
@@ -1567,7 +1486,7 @@ class SLASupportTree::Algorithm {
             // the ground level only.
 
             normal_mode     = false;
-            double mv       = min_dist - dist;
+            double mind       = min_dist - dist;
             double azimuth  = std::atan2(sourcedir(Y), sourcedir(X));
             double sinpolar = std::sin(PI - m_cfg.bridge_slope);
             double cospolar = std::cos(PI - m_cfg.bridge_slope);
@@ -1584,14 +1503,14 @@ class SLASupportTree::Algorithm {
 
             auto result = solver.optimize_max(
                 [this, dir, jp, gndlvl](double mv) {
-                    Vec3d endp = jp + SQR2 * mv * dir;
+                    Vec3d endpt = jp + SQR2 * mv * dir;
-                    endp(Z)    = gndlvl;
+                    endpt(Z)    = gndlvl;
-                    return std::sqrt(m_mesh.squared_distance(endp));
+                    return std::sqrt(m_mesh.squared_distance(endpt));
                 },
-                initvals(mv), bound(0.0, 2 * min_dist));
+                initvals(mind), bound(0.0, 2 * min_dist));
 
-            mv           = std::get<0>(result.optimum);
+            mind           = std::get<0>(result.optimum);
-            endp         = jp + SQR2 * mv * dir;
+            endp         = jp + SQR2 * mind * dir;
             Vec3d pgnd   = {endp(X), endp(Y), gndlvl};
             can_add_base = result.score > min_dist;
 
@@ -1651,7 +1570,7 @@ class SLASupportTree::Algorithm {
         }
 
         if(pillar_id >= 0) // Save the pillar endpoint in the spatial index
-            m_pillar_index.insert(endp, pillar_id);
+            m_pillar_index.guarded_insert(endp, unsigned(pillar_id));
     }
 
 public:
@@ -1717,9 +1636,9 @@ public:
         using libnest2d::opt::GeneticOptimizer;
         using libnest2d::opt::StopCriteria;
 
-        ccr::Mutex mutex;
+        ccr::SpinningMutex mutex;
         auto addfn = [&mutex](PtIndices &container, unsigned val) {
-            std::lock_guard<ccr::Mutex> lk(mutex);
+            std::lock_guard<ccr::SpinningMutex> lk(mutex);
             container.emplace_back(val);
         };
 
@@ -1728,7 +1647,7 @@ public:
         {
             m_thr();
             
-            auto n = nmls.row(i);
+            auto n = nmls.row(Eigen::Index(i));
 
             // for all normals we generate the spherical coordinates and
             // saturate the polar angle to 45 degrees from the bottom then
@@ -1786,19 +1705,20 @@ public:
                     auto oresult = solver.optimize_max(
                         [this, pin_r, w, hp](double plr, double azm)
                         {
-                            auto n = Vec3d(std::cos(azm) * std::sin(plr),
+                            auto dir = Vec3d(std::cos(azm) * std::sin(plr),
-                                           std::sin(azm) * std::sin(plr),
+                                             std::sin(azm) * std::sin(plr),
-                                           std::cos(plr)).normalized();
+                                             std::cos(plr)).normalized();
 
                             double score = pinhead_mesh_intersect(
-                                hp, n, pin_r, m_cfg.head_back_radius_mm, w);
+                                hp, dir, pin_r, m_cfg.head_back_radius_mm, w);
 
                             return score;
                         },
                         initvals(polar, azimuth), // start with what we have
-                        bound(3*PI/4, PI),  // Must not exceed the tilt limit
+                        bound(3 * PI / 4,
-                        bound(-PI, PI)      // azimuth can be a full search
+                              PI),     // Must not exceed the tilt limit
-                        );
+                        bound(-PI, PI) // azimuth can be a full search
+                    );
 
                     if(oresult.score > w) {
                         polar = std::get<0>(oresult.optimum);
@@ -1921,7 +1841,9 @@ public:
         ClusterEl cl_centroids;
         cl_centroids.reserve(m_pillar_clusters.size());
 
-        for(auto& cl : m_pillar_clusters) { m_thr();
+        for(auto& cl : m_pillar_clusters) {
+            m_thr();
+            
             // place all the centroid head positions into the index. We
             // will query for alternative pillar positions. If a sidehead
             // cannot connect to the cluster centroid, we have to search
@@ -1957,7 +1879,8 @@ public:
         // sidepoints with the cluster centroid (which is a ground pillar)
         // or a nearby pillar if the centroid is unreachable.
         size_t ci = 0;
-        for(auto cl : m_pillar_clusters) { m_thr();
+        for(auto cl : m_pillar_clusters) {
+            m_thr();
 
             auto cidx = cl_centroids[ci++];
 
@@ -2015,7 +1938,7 @@ public:
         };
 
         std::vector<unsigned> modelpillars;
-        ccr::Mutex mutex;
+        ccr::SpinningMutex mutex;
 
         // TODO: connect these to the ground pillars if possible
         ccr::enumerate(m_iheads_onmodel.begin(), m_iheads_onmodel.end(),
@@ -2161,7 +2084,7 @@ public:
                 pill.base = tailhead.mesh;
 
                 // Experimental: add the pillar to the index for cascading
-                std::lock_guard<ccr::Mutex> lk(mutex);
+                std::lock_guard<ccr::SpinningMutex> lk(mutex);
                 modelpillars.emplace_back(unsigned(pill.id));
                 return;
             }
@@ -2184,13 +2107,10 @@ public:
     // in O(log) or even constant time with a set or an unordered set of hash
     // values uniquely representing a pair of integers. The order of numbers
     // within the pair should not matter, it has the same unique hash.
-    template<class I> static I pairhash(I a, I b)
+    template<class I> static IntegerOnly<I> pairhash(I a, I b)
     {
         using std::ceil; using std::log2; using std::max; using std::min;
 
-        static_assert(std::is_integral<I>::value,
-                      "This function works only for integral types.");
-
         I g = min(a, b), l = max(a, b);
 
         auto bits_g = g ? int(ceil(log2(g))) : 0;
@@ -2414,7 +2334,8 @@ public:
 
         // We will sink the pins into the model surface for a distance of 1/3 of
         // the pin radius
-        for(unsigned i : m_iheadless) { m_thr();
+        for(unsigned i : m_iheadless) {
+            m_thr();
 
             const auto R = double(m_support_pts[i].head_front_radius);
             const double HWIDTH_MM = R/3;
@@ -2618,7 +2539,8 @@ std::vector<ExPolygons> SLASupportTree::slice(
         auto bb = pad_mesh.bounding_box();
         auto maxzit = std::upper_bound(grid.begin(), grid.end(), bb.max.z());
         
-        auto padgrid = reserve_vector<float>(grid.end() - maxzit);
+        long cap = grid.end() - maxzit;
+        auto padgrid = reserve_vector<float>(size_t(cap > 0 ? cap : 0));
         std::copy(grid.begin(), maxzit, std::back_inserter(padgrid));
 
         TriangleMeshSlicer pad_slicer(&pad_mesh);
@@ -2645,7 +2567,7 @@ std::vector<ExPolygons> SLASupportTree::slice(
 }
 
 const TriangleMesh &SLASupportTree::add_pad(const ExPolygons& modelbase,
-                                            const PoolConfig& pcfg) const
+                                            const PadConfig& pcfg) const
 {
     return m_impl->create_pad(merged_mesh(), modelbase, pcfg).tmesh;
 }
@@ -2670,6 +2592,9 @@ SLASupportTree::SLASupportTree(const std::vector<SupportPoint> &points,
     generate(points, emesh, cfg, ctl);
 }
 
+SLASupportTree::SLASupportTree(SLASupportTree &&o) = default;
+SLASupportTree &SLASupportTree::operator=(SLASupportTree &&o) = default;
+
 SLASupportTree::~SLASupportTree() {}
 
 }

src/libslic3r/SLA/SLASupportTree.hpp

@@ -9,7 +9,6 @@
 
 #include "SLACommon.hpp"
 
-
 namespace Slic3r {
 
 // Needed types from Point.hpp
@@ -86,6 +85,11 @@ struct SupportConfig {
     // body. This is only useful when elevation is set to zero.
     double pillar_base_safety_distance_mm = 0.5;
     
+    double head_fullwidth() const {
+        return 2 * head_front_radius_mm + head_width_mm +
+               2 * head_back_radius_mm - head_penetration_mm;
+    }
+
     // /////////////////////////////////////////////////////////////////////////
     // Compile time configuration values (candidates for runtime)
     // /////////////////////////////////////////////////////////////////////////
@@ -104,7 +108,7 @@ struct SupportConfig {
     static const unsigned max_bridges_on_pillar;
 };
 
-struct PoolConfig;
+struct PadConfig;
 
 /// A Control structure for the support calculation. Consists of the status
 /// indicator callback and the stop condition predicate.
@@ -124,17 +128,6 @@ struct Controller {
     std::function<void(void)> cancelfn = [](){};
 };
 
-using PointSet = Eigen::MatrixXd;
-
-//EigenMesh3D to_eigenmesh(const TriangleMesh& m);
-
-// needed for find best rotation
-//EigenMesh3D to_eigenmesh(const ModelObject& model);
-
-// Simple conversion of 'vector of points' to an Eigen matrix
-//PointSet    to_point_set(const std::vector<sla::SupportPoint>&);
-
-
 /* ************************************************************************** */
 
 /// The class containing mesh data for the generated supports.
@@ -175,6 +168,9 @@ public:
     SLASupportTree(const SLASupportTree&) = delete;
     SLASupportTree& operator=(const SLASupportTree&) = delete;
     
+    SLASupportTree(SLASupportTree &&o);
+    SLASupportTree &operator=(SLASupportTree &&o);
+
     ~SLASupportTree();
 
     /// Get the whole mesh united into the output TriangleMesh
@@ -192,7 +188,7 @@ public:
     /// Otherwise, the modelbase will be unified with the base plate calculated
     /// from the supports.
     const TriangleMesh& add_pad(const ExPolygons& modelbase,
-                                const PoolConfig& pcfg) const;
+                                const PadConfig& pcfg) const;
 
     /// Get the pad geometry
     const TriangleMesh& get_pad() const;

src/libslic3r/SLA/SLASupportTreeIGL.cpp

@@ -77,7 +77,7 @@ bool PointIndex::remove(const PointIndexEl& el)
 }
 
 std::vector<PointIndexEl>
-PointIndex::query(std::function<bool(const PointIndexEl &)> fn)
+PointIndex::query(std::function<bool(const PointIndexEl &)> fn) const
 {
     namespace bgi = boost::geometry::index;
 
@@ -86,7 +86,7 @@ PointIndex::query(std::function<bool(const PointIndexEl &)> fn)
     return ret;
 }
 
-std::vector<PointIndexEl> PointIndex::nearest(const Vec3d &el, unsigned k = 1)
+std::vector<PointIndexEl> PointIndex::nearest(const Vec3d &el, unsigned k = 1) const
 {
     namespace bgi = boost::geometry::index;
     std::vector<PointIndexEl> ret; ret.reserve(k);
@@ -104,6 +104,11 @@ void PointIndex::foreach(std::function<void (const PointIndexEl &)> fn)
     for(auto& el : m_impl->m_store) fn(el);
 }
 
+void PointIndex::foreach(std::function<void (const PointIndexEl &)> fn) const
+{
+    for(const auto &el : m_impl->m_store) fn(el);
+}
+
 /* **************************************************************************
  * BoxIndex implementation
  * ************************************************************************** */
@@ -274,6 +279,8 @@ double EigenMesh3D::squared_distance(const Vec3d &p, int& i, Vec3d& c) const {
  * Misc functions
  * ****************************************************************************/
 
+namespace  {
+
 bool point_on_edge(const Vec3d& p, const Vec3d& e1, const Vec3d& e2,
                    double eps = 0.05)
 {
@@ -289,11 +296,13 @@ template<class Vec> double distance(const Vec& pp1, const Vec& pp2) {
     return std::sqrt(p.transpose() * p);
 }
 
+}
+
 PointSet normals(const PointSet& points,
                  const EigenMesh3D& mesh,
                  double eps,
                  std::function<void()> thr, // throw on cancel
-                 const std::vector<unsigned>& pt_indices = {})
+                 const std::vector<unsigned>& pt_indices)
 {
     if(points.rows() == 0 || mesh.V().rows() == 0 || mesh.F().rows() == 0)
         return {};
@@ -419,9 +428,17 @@ PointSet normals(const PointSet& points,
 
     return ret;
 }
+
 namespace bgi = boost::geometry::index;
 using Index3D = bgi::rtree< PointIndexEl, bgi::rstar<16, 4> /* ? */ >;
 
+namespace {
+
+bool cmp_ptidx_elements(const PointIndexEl& e1, const PointIndexEl& e2)
+{
+    return e1.second < e2.second;
+};
+
 ClusteredPoints cluster(Index3D &sindex,
                         unsigned max_points,
                         std::function<std::vector<PointIndexEl>(
@@ -436,22 +453,19 @@ ClusteredPoints cluster(Index3D &sindex,
     {        
         for(auto& p : pts) {
             std::vector<PointIndexEl> tmp = qfn(sindex, p);
-            auto cmp = [](const PointIndexEl& e1, const PointIndexEl& e2){
-                return e1.second < e2.second;
-            };
            
-            std::sort(tmp.begin(), tmp.end(), cmp);
+            std::sort(tmp.begin(), tmp.end(), cmp_ptidx_elements);
 
             Elems newpts;
             std::set_difference(tmp.begin(), tmp.end(),
                                 cluster.begin(), cluster.end(),
-                                std::back_inserter(newpts), cmp);
+                                std::back_inserter(newpts), cmp_ptidx_elements);
 
             int c = max_points && newpts.size() + cluster.size() > max_points?
                         int(max_points - cluster.size()) : int(newpts.size());
 
             cluster.insert(cluster.end(), newpts.begin(), newpts.begin() + c);
-            std::sort(cluster.begin(), cluster.end(), cmp);
+            std::sort(cluster.begin(), cluster.end(), cmp_ptidx_elements);
 
             if(!newpts.empty() && (!max_points || cluster.size() < max_points))
                 group(newpts, cluster);
@@ -479,7 +493,6 @@ ClusteredPoints cluster(Index3D &sindex,
     return result;
 }
 
-namespace {
 std::vector<PointIndexEl> distance_queryfn(const Index3D& sindex,
                                           const PointIndexEl& p,
                                           double dist,
@@ -496,7 +509,8 @@ std::vector<PointIndexEl> distance_queryfn(const Index3D& sindex,
 
     return tmp;
 }
-}
+
+} // namespace
 
 // Clustering a set of points by the given criteria
 ClusteredPoints cluster(
@@ -558,5 +572,5 @@ ClusteredPoints cluster(const PointSet& pts, double dist, unsigned max_points)
     });
 }
 
-}
+} // namespace sla
-}
+} // namespace Slic3r

src/libslic3r/SLAPrint.cpp

@@ -1,6 +1,6 @@
 #include "SLAPrint.hpp"
 #include "SLA/SLASupportTree.hpp"
-#include "SLA/SLABasePool.hpp"
+#include "SLA/SLAPad.hpp"
 #include "SLA/SLAAutoSupports.hpp"
 #include "ClipperUtils.hpp"
 #include "Geometry.hpp"
@@ -53,7 +53,7 @@ const std::array<unsigned, slaposCount>     OBJ_STEP_LEVELS =
     30,     // slaposObjectSlice,
     20,     // slaposSupportPoints,
     10,     // slaposSupportTree,
-    10,     // slaposBasePool,
+    10,     // slaposPad,
     30,     // slaposSliceSupports,
 };
 
@@ -64,7 +64,7 @@ std::string OBJ_STEP_LABELS(size_t idx)
     case slaposObjectSlice:     return L("Slicing model");
     case slaposSupportPoints:   return L("Generating support points");
     case slaposSupportTree:     return L("Generating support tree");
-    case slaposBasePool:        return L("Generating pad");
+    case slaposPad:             return L("Generating pad");
     case slaposSliceSupports:   return L("Slicing supports");
     default:;
     }
@@ -612,12 +612,13 @@ sla::SupportConfig make_support_cfg(const SLAPrintObjectConfig& c) {
     return scfg;
 }
 
-sla::PoolConfig::EmbedObject builtin_pad_cfg(const SLAPrintObjectConfig& c) {
+sla::PadConfig::EmbedObject builtin_pad_cfg(const SLAPrintObjectConfig& c) {
-    sla::PoolConfig::EmbedObject ret;
+    sla::PadConfig::EmbedObject ret;
 
     ret.enabled = is_zero_elevation(c);
 
     if(ret.enabled) {
+        ret.everywhere           = c.pad_around_object_everywhere.getBool();
         ret.object_gap_mm        = c.pad_object_gap.getFloat();
         ret.stick_width_mm       = c.pad_object_connector_width.getFloat();
         ret.stick_stride_mm      = c.pad_object_connector_stride.getFloat();
@@ -628,17 +629,15 @@ sla::PoolConfig::EmbedObject builtin_pad_cfg(const SLAPrintObjectConfig& c) {
     return ret;
 }
 
-sla::PoolConfig make_pool_config(const SLAPrintObjectConfig& c) {
+sla::PadConfig make_pad_cfg(const SLAPrintObjectConfig& c) {
-    sla::PoolConfig pcfg;
+    sla::PadConfig pcfg;
 
-    pcfg.min_wall_thickness_mm = c.pad_wall_thickness.getFloat();
+    pcfg.wall_thickness_mm = c.pad_wall_thickness.getFloat();
     pcfg.wall_slope = c.pad_wall_slope.getFloat() * PI / 180.0;
 
-    // We do not support radius for now
+    pcfg.max_merge_dist_mm = c.pad_max_merge_distance.getFloat();
-    pcfg.edge_radius_mm = 0.0; //c.pad_edge_radius.getFloat();
+    pcfg.wall_height_mm = c.pad_wall_height.getFloat();
-
+    pcfg.brim_size_mm = c.pad_brim_size.getFloat();
-    pcfg.max_merge_distance_mm = c.pad_max_merge_distance.getFloat();
-    pcfg.min_wall_height_mm = c.pad_wall_height.getFloat();
 
     // set builtin pad implicitly ON
     pcfg.embed_object = builtin_pad_cfg(c);
@@ -646,6 +645,13 @@ sla::PoolConfig make_pool_config(const SLAPrintObjectConfig& c) {
     return pcfg;
 }
 
+bool validate_pad(const TriangleMesh &pad, const sla::PadConfig &pcfg) 
+{
+    // An empty pad can only be created if embed_object mode is enabled
+    // and the pad is not forced everywhere
+    return !pad.empty() || (pcfg.embed_object.enabled && !pcfg.embed_object.everywhere);
+}
+
 }
 
 std::string SLAPrint::validate() const
@@ -663,17 +669,12 @@ std::string SLAPrint::validate() const
 
         sla::SupportConfig cfg = make_support_cfg(po->config());
 
-        double pinhead_width =
-                2 * cfg.head_front_radius_mm +
-                cfg.head_width_mm +
-                2 * cfg.head_back_radius_mm -
-                cfg.head_penetration_mm;
-
         double elv = cfg.object_elevation_mm;
         
-        sla::PoolConfig::EmbedObject builtinpad = builtin_pad_cfg(po->config());
+        sla::PadConfig padcfg = make_pad_cfg(po->config());
+        sla::PadConfig::EmbedObject &builtinpad = padcfg.embed_object;
         
-        if(supports_en && !builtinpad.enabled && elv < pinhead_width )
+        if(supports_en && !builtinpad.enabled && elv < cfg.head_fullwidth())
             return L(
                 "Elevation is too low for object. Use the \"Pad around "
                 "object\" feature to print the object without elevation.");
@@ -686,6 +687,9 @@ std::string SLAPrint::validate() const
                 "distance' has to be greater than the 'Pad object gap' "
                 "parameter to avoid this.");
         }
+        
+        std::string pval = padcfg.validate();
+        if (!pval.empty()) return pval;
     }
 
     double expt_max = m_printer_config.max_exposure_time.getFloat();
@@ -876,8 +880,7 @@ void SLAPrint::process()
 
             // Construction of this object does the calculation.
             this->throw_if_canceled();
-            SLAAutoSupports auto_supports(po.transformed_mesh(),
+            SLAAutoSupports auto_supports(po.m_supportdata->emesh,
-                                          po.m_supportdata->emesh,
                                           po.get_model_slices(),
                                           heights,
                                           config,
@@ -908,23 +911,13 @@ void SLAPrint::process()
         // If the zero elevation mode is engaged, we have to filter out all the
         // points that are on the bottom of the object
         if (is_zero_elevation(po.config())) {
-            double gnd       = po.m_supportdata->emesh.ground_level();
-            auto & pts       = po.m_supportdata->support_points;
             double tolerance = po.config().pad_enable.getBool()
                                    ? po.m_config.pad_wall_thickness.getFloat()
                                    : po.m_config.support_base_height.getFloat();
 
-            // get iterator to the reorganized vector end
+            remove_bottom_points(po.m_supportdata->support_points,
-            auto endit = std::remove_if(
+                                 po.m_supportdata->emesh.ground_level(),
-                pts.begin(),
+                                 tolerance);
-                pts.end(),
-                [tolerance, gnd](const sla::SupportPoint &sp) {
-                    double diff = std::abs(gnd - double(sp.pos(Z)));
-                    return diff <= tolerance;
-                });
-
-            // erase all elements after the new end
-            pts.erase(endit, pts.end());
         }
     };
 
@@ -933,11 +926,11 @@ void SLAPrint::process()
     {
         if(!po.m_supportdata) return;
 
-        sla::PoolConfig pcfg = make_pool_config(po.m_config);
+        sla::PadConfig pcfg = make_pad_cfg(po.m_config);
 
         if (pcfg.embed_object)
             po.m_supportdata->emesh.ground_level_offset(
-                pcfg.min_wall_thickness_mm);
+                pcfg.wall_thickness_mm);
 
         if(!po.m_config.supports_enable.getBool()) {
 
@@ -993,7 +986,7 @@ void SLAPrint::process()
     };
 
     // This step generates the sla base pad
-    auto base_pool = [this](SLAPrintObject& po) {
+    auto generate_pad = [this](SLAPrintObject& po) {
         // this step can only go after the support tree has been created
         // and before the supports had been sliced. (or the slicing has to be
         // repeated)
@@ -1001,10 +994,10 @@ void SLAPrint::process()
         if(po.m_config.pad_enable.getBool())
         {
             // Get the distilled pad configuration from the config
-            sla::PoolConfig pcfg = make_pool_config(po.m_config);
+            sla::PadConfig pcfg = make_pad_cfg(po.m_config);
 
             ExPolygons bp; // This will store the base plate of the pad.
-            double   pad_h             = sla::get_pad_fullheight(pcfg);
+            double   pad_h             = pcfg.full_height();
             const TriangleMesh &trmesh = po.transformed_mesh();
 
             // This call can get pretty time consuming
@@ -1015,15 +1008,19 @@ void SLAPrint::process()
                 // we sometimes call it "builtin pad" is enabled so we will
                 // get a sample from the bottom of the mesh and use it for pad
                 // creation.
-                sla::base_plate(trmesh,
+                sla::pad_blueprint(trmesh, bp, float(pad_h),
-                                bp,
+                               float(po.m_config.layer_height.getFloat()),
-                                float(pad_h),
+                               thrfn);
-                                float(po.m_config.layer_height.getFloat()),
-                                thrfn);
             }
 
-            pcfg.throw_on_cancel = thrfn;
             po.m_supportdata->support_tree_ptr->add_pad(bp, pcfg);
+            auto &pad_mesh = po.m_supportdata->support_tree_ptr->get_pad();
+            
+            if (!validate_pad(pad_mesh, pcfg))
+                throw std::runtime_error(
+                    L("No pad can be generated for this model with the "
+                      "current configuration"));
+
         } else if(po.m_supportdata && po.m_supportdata->support_tree_ptr) {
             po.m_supportdata->support_tree_ptr->remove_pad();
         }
@@ -1478,12 +1475,12 @@ void SLAPrint::process()
 
     slaposFn pobj_program[] =
     {
-        slice_model, support_points, support_tree, base_pool, slice_supports
+        slice_model, support_points, support_tree, generate_pad, slice_supports
     };
 
     // We want to first process all objects...
     std::vector<SLAPrintObjectStep> level1_obj_steps = {
-        slaposObjectSlice, slaposSupportPoints, slaposSupportTree, slaposBasePool
+        slaposObjectSlice, slaposSupportPoints, slaposSupportTree, slaposPad
     };
 
     // and then slice all supports to allow preview to be displayed ASAP
@@ -1730,6 +1727,7 @@ bool SLAPrintObject::invalidate_state_by_config_options(const std::vector<t_conf
             || opt_key == "supports_enable"
             || opt_key == "support_object_elevation"
             || opt_key == "pad_around_object"
+            || opt_key == "pad_around_object_everywhere"
             || opt_key == "slice_closing_radius") {
             steps.emplace_back(slaposObjectSlice);
         } else if (
@@ -1754,6 +1752,7 @@ bool SLAPrintObject::invalidate_state_by_config_options(const std::vector<t_conf
             steps.emplace_back(slaposSupportTree);
         } else if (
                opt_key == "pad_wall_height"
+            || opt_key == "pad_brim_size"
             || opt_key == "pad_max_merge_distance"
             || opt_key == "pad_wall_slope"
             || opt_key == "pad_edge_radius"
@@ -1762,7 +1761,7 @@ bool SLAPrintObject::invalidate_state_by_config_options(const std::vector<t_conf
             || opt_key == "pad_object_connector_width"
             || opt_key == "pad_object_connector_penetration"
             ) {
-            steps.emplace_back(slaposBasePool);
+            steps.emplace_back(slaposPad);
         } else {
             // All keys should be covered.
             assert(false);
@@ -1782,12 +1781,12 @@ bool SLAPrintObject::invalidate_step(SLAPrintObjectStep step)
     if (step == slaposObjectSlice) {
         invalidated |= this->invalidate_all_steps();
     } else if (step == slaposSupportPoints) {
-        invalidated |= this->invalidate_steps({ slaposSupportTree, slaposBasePool, slaposSliceSupports });
+        invalidated |= this->invalidate_steps({ slaposSupportTree, slaposPad, slaposSliceSupports });
         invalidated |= m_print->invalidate_step(slapsMergeSlicesAndEval);
     } else if (step == slaposSupportTree) {
-        invalidated |= this->invalidate_steps({ slaposBasePool, slaposSliceSupports });
+        invalidated |= this->invalidate_steps({ slaposPad, slaposSliceSupports });
         invalidated |= m_print->invalidate_step(slapsMergeSlicesAndEval);
-    } else if (step == slaposBasePool) {
+    } else if (step == slaposPad) {
         invalidated |= this->invalidate_steps({slaposSliceSupports});
         invalidated |= m_print->invalidate_step(slapsMergeSlicesAndEval);
     } else if (step == slaposSliceSupports) {
@@ -1813,8 +1812,8 @@ double SLAPrintObject::get_elevation() const {
         // its walls but currently it is half of its thickness. Whatever it
         // will be in the future, we provide the config to the get_pad_elevation
         // method and we will have the correct value
-        sla::PoolConfig pcfg = make_pool_config(m_config);
+        sla::PadConfig pcfg = make_pad_cfg(m_config);
-        if(!pcfg.embed_object) ret += sla::get_pad_elevation(pcfg);
+        if(!pcfg.embed_object) ret += pcfg.required_elevation();
     }
 
     return ret;
@@ -1825,7 +1824,7 @@ double SLAPrintObject::get_current_elevation() const
     if (is_zero_elevation(m_config)) return 0.;
 
     bool has_supports = is_step_done(slaposSupportTree);
-    bool has_pad      = is_step_done(slaposBasePool);
+    bool has_pad      = is_step_done(slaposPad);
 
     if(!has_supports && !has_pad)
         return 0;
@@ -1896,7 +1895,7 @@ bool SLAPrintObject::has_mesh(SLAPrintObjectStep step) const
     switch (step) {
     case slaposSupportTree:
         return ! this->support_mesh().empty();
-    case slaposBasePool:
+    case slaposPad:
         return ! this->pad_mesh().empty();
     default:
         return false;
@@ -1908,7 +1907,7 @@ TriangleMesh SLAPrintObject::get_mesh(SLAPrintObjectStep step) const
     switch (step) {
     case slaposSupportTree:
         return this->support_mesh();
-    case slaposBasePool:
+    case slaposPad:
         return this->pad_mesh();
     default:
         return TriangleMesh();

src/libslic3r/SLAPrint.hpp

@@ -21,7 +21,7 @@ enum SLAPrintObjectStep : unsigned int {
 	slaposObjectSlice,
 	slaposSupportPoints,
 	slaposSupportTree,
-	slaposBasePool,
+	slaposPad,
     slaposSliceSupports,
 	slaposCount
 };
@@ -54,7 +54,7 @@ public:
     bool                        is_left_handed() const { return m_left_handed; }
 
     struct Instance {
-        Instance(ObjectID instance_id, const Point &shift, float rotation) : instance_id(instance_id), shift(shift), rotation(rotation) {}
+        Instance(ObjectID inst_id, const Point &shft, float rot) : instance_id(inst_id), shift(shft), rotation(rot) {}
         bool operator==(const Instance &rhs) const { return this->instance_id == rhs.instance_id && this->shift == rhs.shift && this->rotation == rhs.rotation; }
         // ID of the corresponding ModelInstance.
         ObjectID instance_id;

src/libslic3r/Tesselate.hpp

@@ -10,12 +10,15 @@ namespace Slic3r {
 class ExPolygon;
 typedef std::vector<ExPolygon> ExPolygons;
 
-extern std::vector<Vec3d> triangulate_expolygon_3d (const ExPolygon  &poly,  coordf_t z = 0, bool flip = false);
+const bool constexpr NORMALS_UP = false;
-extern std::vector<Vec3d> triangulate_expolygons_3d(const ExPolygons &polys, coordf_t z = 0, bool flip = false);
+const bool constexpr NORMALS_DOWN = true;
-extern std::vector<Vec2d> triangulate_expolygon_2d (const ExPolygon  &poly,  bool flip = false);
+
-extern std::vector<Vec2d> triangulate_expolygons_2d(const ExPolygons &polys, bool flip = false);
+extern std::vector<Vec3d> triangulate_expolygon_3d (const ExPolygon  &poly,  coordf_t z = 0, bool flip = NORMALS_UP);
-extern std::vector<Vec2f> triangulate_expolygon_2f (const ExPolygon  &poly,  bool flip = false);
+extern std::vector<Vec3d> triangulate_expolygons_3d(const ExPolygons &polys, coordf_t z = 0, bool flip = NORMALS_UP);
-extern std::vector<Vec2f> triangulate_expolygons_2f(const ExPolygons &polys, bool flip = false);
+extern std::vector<Vec2d> triangulate_expolygon_2d (const ExPolygon  &poly,  bool flip = NORMALS_UP);
+extern std::vector<Vec2d> triangulate_expolygons_2d(const ExPolygons &polys, bool flip = NORMALS_UP);
+extern std::vector<Vec2f> triangulate_expolygon_2f (const ExPolygon  &poly,  bool flip = NORMALS_UP);
+extern std::vector<Vec2f> triangulate_expolygons_2f(const ExPolygons &polys, bool flip = NORMALS_UP);
 
 } // namespace Slic3r
 

src/slic3r/GUI/3DScene.cpp

@@ -417,7 +417,7 @@ void GLVolume::render(int color_id, int detection_id, int worldmatrix_id) const
 }
 
 bool GLVolume::is_sla_support() const { return this->composite_id.volume_id == -int(slaposSupportTree); }
-bool GLVolume::is_sla_pad() const { return this->composite_id.volume_id == -int(slaposBasePool); }
+bool GLVolume::is_sla_pad() const { return this->composite_id.volume_id == -int(slaposPad); }
 
 std::vector<int> GLVolumeCollection::load_object(
     const ModelObject       *model_object,
@@ -501,7 +501,7 @@ void GLVolumeCollection::load_object_auxiliary(
     TriangleMesh convex_hull = mesh.convex_hull_3d();
     for (const std::pair<size_t, size_t>& instance_idx : instances) {
         const ModelInstance& model_instance = *print_object->model_object()->instances[instance_idx.first];
-        this->volumes.emplace_back(new GLVolume((milestone == slaposBasePool) ? GLVolume::SLA_PAD_COLOR : GLVolume::SLA_SUPPORT_COLOR));
+        this->volumes.emplace_back(new GLVolume((milestone == slaposPad) ? GLVolume::SLA_PAD_COLOR : GLVolume::SLA_SUPPORT_COLOR));
         GLVolume& v = *this->volumes.back();
         v.indexed_vertex_array.load_mesh(mesh);
 	    v.indexed_vertex_array.finalize_geometry(opengl_initialized);

src/slic3r/GUI/ConfigManipulation.cpp

@@ -349,15 +349,18 @@ void ConfigManipulation::toggle_print_sla_options(DynamicPrintConfig* config)
 
     toggle_field("pad_wall_thickness", pad_en);
     toggle_field("pad_wall_height", pad_en);
+    toggle_field("pad_brim_size", pad_en);
     toggle_field("pad_max_merge_distance", pad_en);
  // toggle_field("pad_edge_radius", supports_en);
     toggle_field("pad_wall_slope", pad_en);
     toggle_field("pad_around_object", pad_en);
+    toggle_field("pad_around_object_everywhere", pad_en);
 
     bool zero_elev = config->opt_bool("pad_around_object") && pad_en;
 
     toggle_field("support_object_elevation", supports_en && !zero_elev);
     toggle_field("pad_object_gap", zero_elev);
+    toggle_field("pad_around_object_everywhere", zero_elev);
     toggle_field("pad_object_connector_stride", zero_elev);
     toggle_field("pad_object_connector_width", zero_elev);
     toggle_field("pad_object_connector_penetration", zero_elev);

src/slic3r/GUI/GLCanvas3D.cpp

@@ -1767,7 +1767,7 @@ void GLCanvas3D::reload_scene(bool refresh_immediately, bool force_full_scene_re
 
     // SLA steps to pull the preview meshes for.
 	typedef std::array<SLAPrintObjectStep, 2> SLASteps;
-	SLASteps sla_steps = { slaposSupportTree, slaposBasePool };
+	SLASteps sla_steps = { slaposSupportTree, slaposPad };
     struct SLASupportState {
 		std::array<PrintStateBase::StateWithTimeStamp, std::tuple_size<SLASteps>::value> step;
     };
@@ -5340,8 +5340,8 @@ void GLCanvas3D::_load_sla_shells()
                 m_volumes.volumes.back()->extruder_id = obj->model_object()->volumes.front()->extruder_id();
                 if (obj->is_step_done(slaposSupportTree) && obj->has_mesh(slaposSupportTree))
                     add_volume(*obj, -int(slaposSupportTree), instance, obj->support_mesh(), GLVolume::SLA_SUPPORT_COLOR, true);
-                if (obj->is_step_done(slaposBasePool) && obj->has_mesh(slaposBasePool))
+                if (obj->is_step_done(slaposPad) && obj->has_mesh(slaposPad))
-                    add_volume(*obj, -int(slaposBasePool), instance, obj->pad_mesh(), GLVolume::SLA_PAD_COLOR, false);
+                    add_volume(*obj, -int(slaposPad), instance, obj->pad_mesh(), GLVolume::SLA_PAD_COLOR, false);
             }
             double shift_z = obj->get_current_elevation();
             for (unsigned int i = initial_volumes_count; i < m_volumes.volumes.size(); ++ i) {

src/slic3r/GUI/MainFrame.cpp

@@ -261,7 +261,7 @@ bool MainFrame::can_export_supports() const
     const PrintObjects& objects = m_plater->sla_print().objects();
     for (const SLAPrintObject* object : objects)
     {
-        if (object->has_mesh(slaposBasePool) || object->has_mesh(slaposSupportTree))
+        if (object->has_mesh(slaposPad) || object->has_mesh(slaposSupportTree))
         {
             can_export = true;
             break;

src/slic3r/GUI/Plater.cpp

@@ -4467,10 +4467,10 @@ void Plater::export_stl(bool extended, bool selection_only)
                 bool is_left_handed = object->is_left_handed();
 
                 TriangleMesh pad_mesh;
-                bool has_pad_mesh = object->has_mesh(slaposBasePool);
+                bool has_pad_mesh = object->has_mesh(slaposPad);
                 if (has_pad_mesh)
                 {
-                    pad_mesh = object->get_mesh(slaposBasePool);
+                    pad_mesh = object->get_mesh(slaposPad);
                     pad_mesh.transform(mesh_trafo_inv);
                 }
 
@@ -4646,7 +4646,7 @@ void Plater::reslice_SLA_supports(const ModelObject &object, bool postpone_error
     // Otherwise calculate everything, but start with the provided object.
     if (!this->p->background_processing_enabled()) {
         task.single_model_instance_only = true;
-        task.to_object_step = slaposBasePool;
+        task.to_object_step = slaposPad;
     }
     this->p->background_process.set_task(task);
     // and let the background processing start.

src/slic3r/GUI/Preset.cpp

@@ -476,11 +476,13 @@ const std::vector<std::string>& Preset::sla_print_options()
             "pad_enable",
             "pad_wall_thickness",
             "pad_wall_height",
+            "pad_brim_size",
             "pad_max_merge_distance",
             // "pad_edge_radius",
             "pad_wall_slope",
             "pad_object_gap",
             "pad_around_object",
+            "pad_around_object_everywhere",
             "pad_object_connector_stride",
             "pad_object_connector_width",
             "pad_object_connector_penetration",

src/slic3r/GUI/Tab.cpp

@@ -3539,12 +3539,14 @@ void TabSLAPrint::build()
     optgroup->append_single_option_line("pad_enable");
     optgroup->append_single_option_line("pad_wall_thickness");
     optgroup->append_single_option_line("pad_wall_height");
+    optgroup->append_single_option_line("pad_brim_size");
     optgroup->append_single_option_line("pad_max_merge_distance");
     // TODO: Disabling this parameter for the beta release
 //    optgroup->append_single_option_line("pad_edge_radius");
     optgroup->append_single_option_line("pad_wall_slope");
 
     optgroup->append_single_option_line("pad_around_object");
+    optgroup->append_single_option_line("pad_around_object_everywhere");
     optgroup->append_single_option_line("pad_object_gap");
     optgroup->append_single_option_line("pad_object_connector_stride");
     optgroup->append_single_option_line("pad_object_connector_width");