Experiment: Added a rectilinear monotonic infill without perimeter

connection lines for top / bottom infill patterns.
Co-authored-by: lane.wei <lane.wei@bambulab.com>

src/libslic3r/Fill/Fill.cpp

@@ -109,6 +109,11 @@ struct SurfaceFill {
 	SurfaceFillParams	params;
 };
 
+static inline bool fill_type_monotonic(InfillPattern pattern)
+{
+	return pattern == ipMonotonic || pattern == ipMonotonicLines;
+}
+
 std::vector<SurfaceFill> group_fills(const Layer &layer)
 {
 	std::vector<SurfaceFill> surface_fills;
@@ -137,7 +142,7 @@ std::vector<SurfaceFill> group_fills(const Layer &layer)
 					//FIXME for non-thick bridges, shall we allow a bottom surface pattern?
 		            params.pattern = (surface.is_external() && ! is_bridge) ? 
 						(surface.is_top() ? region_config.top_fill_pattern.value : region_config.bottom_fill_pattern.value) :
-		                region_config.top_fill_pattern == ipMonotonic ? ipMonotonic : ipRectilinear;
+		                fill_type_monotonic(region_config.top_fill_pattern) ? ipMonotonic : ipRectilinear;
 		        } else if (params.density <= 0)
 		            continue;
 
@@ -278,7 +283,7 @@ std::vector<SurfaceFill> group_fills(const Layer &layer)
 	        if (internal_solid_fill == nullptr) {
 	        	// Produce another solid fill.
 		        params.extruder 	 = layerm.region().extruder(frSolidInfill);
-	            params.pattern 		 = layerm.region().config().top_fill_pattern == ipMonotonic ? ipMonotonic : ipRectilinear;
+	            params.pattern 		 = fill_type_monotonic(layerm.region().config().top_fill_pattern) ? ipMonotonic : ipRectilinear;
 	            params.density 		 = 100.f;
 		        params.extrusion_role = erInternalInfill;
 		        params.angle 		= float(Geometry::deg2rad(layerm.region().config().fill_angle.value));

src/libslic3r/Fill/FillBase.cpp

@@ -35,6 +35,7 @@ Fill* Fill::new_from_type(const InfillPattern type)
     case ipRectilinear:         return new FillRectilinear();
     case ipAlignedRectilinear:  return new FillAlignedRectilinear();
     case ipMonotonic:           return new FillMonotonic();
+    case ipMonotonicLines:      return new FillMonotonicLines();
     case ipLine:                return new FillLine();
     case ipGrid:                return new FillGrid();
     case ipTriangles:           return new FillTriangles();

src/libslic3r/Fill/FillRectilinear.cpp

@@ -2970,7 +2970,18 @@ Polylines FillMonotonic::fill_surface(const Surface *surface, const FillParams &
     params2.monotonic = true;
     Polylines polylines_out;
     if (! fill_surface_by_lines(surface, params2, 0.f, 0.f, polylines_out))
-        BOOST_LOG_TRIVIAL(error) << "FillMonotonous::fill_surface() failed to fill a region.";
+        BOOST_LOG_TRIVIAL(error) << "FillMonotonic::fill_surface() failed to fill a region.";
+    return polylines_out;
+}
+
+Polylines FillMonotonicLines::fill_surface(const Surface *surface, const FillParams &params)
+{
+    FillParams params2 = params;
+    params2.monotonic = true;
+    params2.anchor_length_max = 0.0f;
+    Polylines polylines_out;
+    if (! fill_surface_by_lines(surface, params2, 0.f, 0.f, polylines_out))
+        BOOST_LOG_TRIVIAL(error) << "FillMonotonicLines::fill_surface() failed to fill a region.";
     return polylines_out;
 }
 

src/libslic3r/Fill/FillRectilinear.hpp

@@ -49,6 +49,15 @@ public:
 	bool no_sort() const override { return true; }
 };
 
+class FillMonotonicLines : public FillRectilinear
+{
+public:
+    Fill* clone() const override { return new FillMonotonicLines(*this); }
+    ~FillMonotonicLines() override = default;
+    Polylines fill_surface(const Surface *surface, const FillParams &params) override;
+    bool no_sort() const override { return true; }
+};
+
 class FillGrid : public FillRectilinear
 {
 public:

src/libslic3r/PrintConfig.cpp

@@ -93,6 +93,7 @@ CONFIG_OPTION_ENUM_DEFINE_STATIC_MAPS(FuzzySkinType)
 static const t_config_enum_values s_keys_map_InfillPattern {
     { "rectilinear",        ipRectilinear },
     { "monotonic",          ipMonotonic },
+    { "monotoniclines",     ipMonotonicLines },
     { "alignedrectilinear", ipAlignedRectilinear },
     { "grid",               ipGrid },
     { "triangles",          ipTriangles },
@@ -716,20 +717,17 @@ void PrintConfigDef::init_fff_params()
     def->tooltip = L("Fill pattern for top infill. This only affects the top visible layer, and not its adjacent solid shells.");
     def->cli = "top-fill-pattern|external-fill-pattern|solid-fill-pattern";
     def->enum_keys_map = &ConfigOptionEnum<InfillPattern>::get_enum_values();
-    def->enum_values.push_back("rectilinear");
-    def->enum_values.push_back("monotonic");
-    def->enum_values.push_back("alignedrectilinear");
-    def->enum_values.push_back("concentric");
-    def->enum_values.push_back("hilbertcurve");
-    def->enum_values.push_back("archimedeanchords");
-    def->enum_values.push_back("octagramspiral");
-    def->enum_labels.push_back(L("Rectilinear"));
-    def->enum_labels.push_back(L("Monotonic"));
-    def->enum_labels.push_back(L("Aligned Rectilinear"));
-    def->enum_labels.push_back(L("Concentric"));
-    def->enum_labels.push_back(L("Hilbert Curve"));
-    def->enum_labels.push_back(L("Archimedean Chords"));
-    def->enum_labels.push_back(L("Octagram Spiral"));
+    def->set_enum_values({
+        { "rectilinear",        L("Rectilinear") },
+        { "monotonic",          L("Monotonic") },
+        { "monotoniclines",     L("Monotonic Lines") },
+        { "alignedrectilinear", L("Aligned Rectilinear") },
+        { "concentric",         L("Concentric") },
+        { "hilbertcurve",       L("Hilbert Curve") },
+        { "archimedeanchords",  L("Archimedean Chords") },
+        { "octagramspiral",     L("Octagram Spiral") }
+    });
+
     // solid_fill_pattern is an obsolete equivalent to top_fill_pattern/bottom_fill_pattern.
     def->aliases = { "solid_fill_pattern", "external_fill_pattern" };
     def->set_default_value(new ConfigOptionEnum<InfillPattern>(ipMonotonic));

src/libslic3r/PrintConfig.hpp

@@ -56,7 +56,7 @@ enum class FuzzySkinType {
 };
 
 enum InfillPattern : int {
-    ipRectilinear, ipMonotonic, ipAlignedRectilinear, ipGrid, ipTriangles, ipStars, ipCubic, ipLine, ipConcentric, ipHoneycomb, ip3DHoneycomb,
+    ipRectilinear, ipMonotonic, ipMonotonicLines, ipAlignedRectilinear, ipGrid, ipTriangles, ipStars, ipCubic, ipLine, ipConcentric, ipHoneycomb, ip3DHoneycomb,
     ipGyroid, ipHilbertCurve, ipArchimedeanChords, ipOctagramSpiral, ipAdaptiveCubic, ipSupportCubic, ipSupportBase,
     ipLightning,
 ipCount,