WIP: Moved sources int src/, separated most of the source code from Perl.

The XS was left only for the unit / integration tests, and it links
libslic3r only. No wxWidgets are allowed to be used from Perl starting
from now.

xs/src/libslic3r/Fill/FillConcentric.cpp

@@ -1,64 +0,0 @@
-#include "../ClipperUtils.hpp"
-#include "../ExPolygon.hpp"
-#include "../Surface.hpp"
-
-#include "FillConcentric.hpp"
-
-namespace Slic3r {
-
-void FillConcentric::_fill_surface_single(
-    const FillParams                &params, 
-    unsigned int                     thickness_layers,
-    const std::pair<float, Point>   &direction, 
-    ExPolygon                       &expolygon, 
-    Polylines                       &polylines_out)
-{
-    // no rotation is supported for this infill pattern
-    BoundingBox bounding_box = expolygon.contour.bounding_box();
-    
-    coord_t min_spacing = scale_(this->spacing);
-    coord_t distance = coord_t(min_spacing / params.density);
-    
-    if (params.density > 0.9999f && !params.dont_adjust) {
-        distance = this->_adjust_solid_spacing(bounding_box.size()(0), distance);
-        this->spacing = unscale<double>(distance);
-    }
-
-    Polygons loops = (Polygons)expolygon;
-    Polygons last  = loops;
-    while (! last.empty()) {
-        last = offset2(last, -(distance + min_spacing/2), +min_spacing/2);
-        loops.insert(loops.end(), last.begin(), last.end());
-    }
-
-    // generate paths from the outermost to the innermost, to avoid
-    // adhesion problems of the first central tiny loops
-    loops = union_pt_chained(loops, false);
-    
-    // split paths using a nearest neighbor search
-    size_t iPathFirst = polylines_out.size();
-    Point last_pos(0, 0);
-    for (const Polygon &loop : loops) {
-        polylines_out.push_back(loop.split_at_index(last_pos.nearest_point_index(loop)));
-        last_pos = polylines_out.back().last_point();
-    }
-
-    // clip the paths to prevent the extruder from getting exactly on the first point of the loop
-    // Keep valid paths only.
-    size_t j = iPathFirst;
-    for (size_t i = iPathFirst; i < polylines_out.size(); ++ i) {
-        polylines_out[i].clip_end(this->loop_clipping);
-        if (polylines_out[i].is_valid()) {
-            if (j < i)
-                polylines_out[j] = std::move(polylines_out[i]);
-            ++ j;
-        }
-    }
-    if (j < polylines_out.size())
-        polylines_out.erase(polylines_out.begin() + j, polylines_out.end());
-    //TODO: return ExtrusionLoop objects to get better chained paths,
-    // otherwise the outermost loop starts at the closest point to (0, 0).
-    // We want the loops to be split inside the G-code generator to get optimum path planning.
-}
-
-} // namespace Slic3r