Use closure instead of function-struct (+ code style).

Also make formula more clear. (And slightly better -- if we ever had a ridiculus amount of extruders, it would become incorrect.)

part of CURA-9066

2 files changed, 25 insertions, 15 deletions

diff --git a/include/SkirtBrim.h b/include/SkirtBrim.h
index 743dc3f28..a9f362517 100644
--- a/include/SkirtBrim.h
+++ b/include/SkirtBrim.h
@@ -22,15 +22,25 @@ private:
      */
     struct Offset
     {
-        Offset(const Polygons* reference_outline, const size_t reference_idx, bool external_only, const coord_t offset_value, const coord_t total_offset, size_t inset_idx, const int extruder_nr, bool is_last)
-        : reference_outline(reference_outline)
-        , reference_idx(reference_idx)
-        , external_only(external_only)
-        , offset_value(offset_value)
-        , total_offset(total_offset)
-        , inset_idx(inset_idx)
-        , extruder_nr(extruder_nr)
-        , is_last(is_last)
+        Offset
+        (
+            const Polygons* reference_outline,
+            const size_t reference_idx,
+            bool external_only,
+            const coord_t offset_value,
+            const coord_t total_offset,
+            size_t inset_idx,
+            const int extruder_nr,
+            bool is_last
+        ) :
+            reference_outline(reference_outline),
+            reference_idx(reference_idx),
+            external_only(external_only),
+            offset_value(offset_value),
+            total_offset(total_offset),
+            inset_idx(inset_idx),
+            extruder_nr(extruder_nr),
+            is_last(is_last)
         {}
         const Polygons* reference_outline; //!< Optional reference polygons from which to offset
         int reference_idx; //!< Optional reference index into storage.skirt_brim from which to offset
@@ -45,12 +55,12 @@ private:
     /*!
      * Defines an order on offsets (potentially from different extruders) based on how far the offset is from the original outline.
      */
-    struct OffsetSorter
+    static inline const auto OffsetSorter
     {
-        bool operator()(const Offset& a, const Offset& b)
+        [](const Offset& a, const Offset& b)
         {
-            return a.total_offset + a.extruder_nr
-            < b.total_offset + b.extruder_nr; // add extruder_nr so that it's more stable when both extruders have the same offset settings
+            // Use extruder_nr in case both extruders have the same offset settings.
+            return a.total_offset != b.total_offset ? a.total_offset < b.total_offset : a.extruder_nr < b.extruder_nr;
         }
     };
 
diff --git a/src/SkirtBrim.cpp b/src/SkirtBrim.cpp
index 34b141ab5..8f27db436 100644
--- a/src/SkirtBrim.cpp
+++ b/src/SkirtBrim.cpp
@@ -123,7 +123,7 @@ std::vector<SkirtBrim::Offset> SkirtBrim::generateBrimOffsetPlan(std::vector<Pol
         }
     }
 
-    std::sort(all_brim_offsets.begin(), all_brim_offsets.end(), OffsetSorter{});
+    std::sort(all_brim_offsets.begin(), all_brim_offsets.end(), OffsetSorter);
 
     return all_brim_offsets;
 }
@@ -217,7 +217,7 @@ std::vector<coord_t> SkirtBrim::generatePrimaryBrim(std::vector<Offset>& all_bri
             constexpr bool is_last = true;
             constexpr Polygons* reference_outline = nullptr; // not used
             all_brim_offsets.emplace_back(reference_outline, offset.inset_idx, external_polys_only[offset.extruder_nr], line_widths[offset.extruder_nr], offset.total_offset + line_widths[offset.extruder_nr], offset.inset_idx + 1, offset.extruder_nr, is_last);
-            std::sort(all_brim_offsets.begin() + offset_idx + 1, all_brim_offsets.end(), OffsetSorter{}); // reorder remaining offsets
+            std::sort(all_brim_offsets.begin() + offset_idx + 1, all_brim_offsets.end(), OffsetSorter); // reorder remaining offsets
         }
     }
     return total_length;