Fix line-clipping and add WKT-multiline.

CuraEngineInfillGenerate/tiles/cont_honeycomb.wkt

@@ -1,3 +1,2 @@
-POLYGON ((866 2000, 1732 1500, 1732 500, 866 0, 0 500, 0 1500))
-LINESTRING (866 0, 166 404, 166 1595, 866 2000)
-LINESTRING (1830 404, 1834 404, 1834 1595)
+POLYGON ((866 2000, 1732 1500, 1732 500, 866 0, 0 500, 0 1500, 866 2000))
+MULTILINESTRING ((1334 404, 1334 1595), (866 0, 166 404, 166 1595, 866 2000))

include/infill/content_reader.h

@@ -36,6 +36,12 @@ std::tuple<std::vector<geometry::polyline<>>, std::vector<geometry::polygon_oute
  boost::geometry::read_wkt(line, linestring);
  linestrings.push_back(linestring);
  }
+ if (line.starts_with("MULTILINESTRING"))
+ {
+ boost::geometry::model::multi_linestring<geometry::polyline<>> multilinestring;
+ boost::geometry::read_wkt(line, multilinestring);
+ linestrings.insert(linestrings.end(), multilinestring.begin(), multilinestring.end());
+ }
  if (line.starts_with("POLYGON"))
  {
  geometry::polygon_outer<> polygon;

include/infill/geometry.h

@@ -42,26 +42,35 @@ static ClipperLib::IntPoint computeCoG(const auto& contour)
  return cog;
 }
 
-static ClipperLib::Paths clip(const auto& polys, const std::vector<geometry::polygon_outer<>>& outer_contours)
+static ClipperLib::Paths clip(const auto& polys, const bool& is_poly_closed, const std::vector<geometry::polygon_outer<>>& outer_contours)
 {
  ClipperLib::Clipper clipper;
  ClipperLib::Paths outline_poly;
  for (const auto& poly : outer_contours)
  {
  outline_poly.push_back(poly);
  }
- clipper.AddPaths(outline_poly, ClipperLib::PolyType::ptSubject, true);
+ clipper.AddPaths(outline_poly, ClipperLib::PolyType::ptClip, true);
 
  ClipperLib::Paths grid_poly;
  for (auto& poly : polys)
  {
  grid_poly.push_back(poly);
  }
- clipper.AddPaths(grid_poly, ClipperLib::PolyType::ptClip, true);
+ clipper.AddPaths(grid_poly, ClipperLib::PolyType::ptSubject, is_poly_closed);
 
- ClipperLib::Paths result;
- clipper.Execute(ClipperLib::ClipType::ctIntersection, result);
- return result;
+ ClipperLib::Paths ret;
+ if (! is_poly_closed)
+ {
+ ClipperLib::PolyTree result;
+ clipper.Execute(ClipperLib::ClipType::ctIntersection, result);
+ ClipperLib::OpenPathsFromPolyTree(result, ret);
+ }
+ else
+ {
+ clipper.Execute(ClipperLib::ClipType::ctIntersection, ret);
+ }
+ return ret;
 }
 
 } // namespace infill::geometry

include/infill/infill_generator.h

@@ -79,7 +79,7 @@ class InfillGenerator
 
  // Cut the grid with the outer contour using Clipper
  auto [lines, polys] = gridToPolygon(grid);
- return { geometry::clip(lines, outer_contours), geometry::clip(polys, outer_contours) };
+ return { geometry::clip(lines, false, outer_contours), geometry::clip(polys, true, outer_contours) };
  }
 };