ENH: Arrange - experimental packer (sparrow) uses up to 50% fewer plates

.gitignore

@@ -41,4 +41,5 @@ compile_commands.json
 # Legacy device_page bundle copies (runtime lives in resources/web/device_page/dist/)
 resources/web/device_page/assets/
 resources/web/device_page/index.html
+src/sparrow_arrange/target/
 

CMakeLists.txt

@@ -49,6 +49,7 @@ option(SLIC3R_MSVC_COMPILE_PARALLEL "Compile on Visual Studio in parallel" 1)
 option(SLIC3R_MSVC_PDB          "Generate PDB files on MSVC in Release mode" 1)
 option(SLIC3R_PERL_XS           "Compile XS Perl module and enable Perl unit and integration tests" 0)
 option(SLIC3R_ASAN              "Enable ASan on Clang and GCC" 0)
+option(SLIC3R_SPARROW_ARRANGE   "Build and use the sparrow (Rust) 2D packing backend for Arrange" ON)
 # If SLIC3R_FHS is 1 -> SLIC3R_DESKTOP_INTEGRATION is always 0, othrewise variable.
 CMAKE_DEPENDENT_OPTION(SLIC3R_DESKTOP_INTEGRATION "Allow performing desktop integration during runtime" 1 "NOT SLIC3R_FHS" 0)
 

src/BambuStudio.cpp

@@ -4911,6 +4911,23 @@ int CLI::run(int argc, char **argv)
     bool user_center_specified = false;
     Points beds = get_bed_shape(m_print_config);
     ArrangeParams arrange_cfg;
+    //BBS: BBS_ARRANGE_SPARROW=1 selects the sparrow packer for the CLI. Set before
+    //     any ArrangePolygon is collected so get_arrange_polygon() emits true outlines.
+    const char *sparrow_env = std::getenv("BBS_ARRANGE_SPARROW");
+    const bool  use_sparrow = sparrow_env && std::string(sparrow_env) == "1";
+    arrangement::use_true_outline.store(use_sparrow, std::memory_order_relaxed);
+    if (use_sparrow)
+        BOOST_LOG_TRIVIAL(info) << "BBS_ARRANGE_SPARROW=1: using the sparrow packer";
+    //BBS: BBS_ARRANGE_SPARROW_TIME=<seconds> overrides the per-plate search budget.
+    float sparrow_time_limit_s = 8.f;
+    if (const char *t = std::getenv("BBS_ARRANGE_SPARROW_TIME")) {
+        try {
+            sparrow_time_limit_s = std::stof(t);
+            BOOST_LOG_TRIVIAL(info) << "BBS_ARRANGE_SPARROW_TIME=" << sparrow_time_limit_s << "s per plate";
+        } catch (const std::exception &) {
+            BOOST_LOG_TRIVIAL(warning) << "ignoring invalid BBS_ARRANGE_SPARROW_TIME=" << t;
+        }
+    }
 
     BOOST_LOG_TRIVIAL(info) << "will start transforms, commands count " << m_transforms.size() << "\n";
 #if defined(__linux__) || defined(__LINUX__)
@@ -5427,6 +5444,8 @@ int CLI::run(int argc, char **argv)
 
                 //Step-2:prepare the arrange params
                 arrange_cfg.allow_rotations = allow_rotations;
+                arrange_cfg.use_sparrow     = use_sparrow;
+                arrange_cfg.sparrow_time_limit_s = sparrow_time_limit_s;
                 arrange_cfg.allow_multi_materials_on_same_plate = allow_multicolor_oneplate;
                 arrange_cfg.avoid_extrusion_cali_region = avoid_extrusion_cali_region;
                 arrange_cfg.clearance_height_to_rod = height_to_rod;
@@ -5879,6 +5898,8 @@ int CLI::run(int argc, char **argv)
 
                 //Step-2:prepare the arrange params
                 arrange_cfg.allow_rotations  = allow_rotations;
+                arrange_cfg.use_sparrow      = use_sparrow;
+                arrange_cfg.sparrow_time_limit_s = sparrow_time_limit_s;
                 arrange_cfg.allow_multi_materials_on_same_plate = allow_multicolor_oneplate;
                 arrange_cfg.avoid_extrusion_cali_region         = avoid_extrusion_cali_region;
                 arrange_cfg.clearance_height_to_rod             = height_to_rod;

src/libslic3r/Arrange.cpp

@@ -2,6 +2,10 @@
 #include "Print.hpp"
 #include "BoundingBox.hpp"
 
+#ifdef SLIC3R_SPARROW_ARRANGE
+#include "ArrangeSparrow.hpp"
+#endif
+
 #include <libnest2d/backends/libslic3r/geometries.hpp>
 #include <libnest2d/optimizers/nlopt/subplex.hpp>
 #include <libnest2d/placers/nfpplacer.hpp>
@@ -77,6 +81,8 @@ using SpatElement = std::pair<Box, unsigned>;
 using SpatIndex = bgi::rtree< SpatElement, bgi::rstar<16, 4> >;
 using ItemGroup = std::vector<std::reference_wrapper<Item>>;
 
+std::atomic<bool> use_true_outline{false};
+
 // A coefficient used in separating bigger items and smaller items.
 const double BIG_ITEM_TRESHOLD = 0.02;
 #define VITRIFY_TEMP_DIFF_THRSH 15  // bed temp can be higher than vitrify temp, but not higher than this thresh
@@ -1191,6 +1197,22 @@ void arrange(ArrangePolygons &      arrangables,
 {
     namespace clppr = Slic3r::ClipperLib;
 
+#ifdef SLIC3R_SPARROW_ARRANGE
+    // BBS: sparrow handles rectangular beds only (every Bambu printer); other bed
+    // types and a failed sparrow run fall through to libnest2d. It has no notion of
+    // print order, height or per-plate filament grouping, so sequential print and
+    // "one material per plate" also stay on libnest2d.
+    if (params.use_sparrow && !params.is_seq_print && params.allow_multi_materials_on_same_plate) {
+        if constexpr (std::is_same_v<BedT, BoundingBox>) {
+            if (arrange_sparrow(arrangables, excludes, bed, params))
+                return;
+            BOOST_LOG_TRIVIAL(warning) << "sparrow arrange unavailable, using libnest2d";
+        } else {
+            BOOST_LOG_TRIVIAL(warning) << "sparrow arrange needs a rectangular bed, using libnest2d";
+        }
+    }
+#endif
+
     std::vector<Item> items, fixeditems;
     items.reserve(arrangables.size());
 

src/libslic3r/Arrange.hpp

@@ -4,6 +4,8 @@
 #include "ExPolygon.hpp"
 #include "PrintConfig.hpp"
 
+#include <atomic>
+
 #define BED_SHRINK_SEQ_PRINT 0
 
 namespace Slic3r {
@@ -31,6 +33,11 @@ struct InfiniteBed {
     explicit InfiniteBed(const Point &p = {0, 0}): center{p} {}
 };
 
+/// Set by the arrange caller (ArrangeJob, the CLI) before ArrangePolygons are
+/// collected; read by ModelInstance::get_arrange_polygon() to choose between the
+/// convex hull and the true outline. A global because that function has no ArrangeParams.
+extern std::atomic<bool> use_true_outline;
+
 /// A logical bed representing an object not being arranged. Either the arrange
 /// has not yet successfully run on this ArrangePolygon or it could not fit the
 /// object due to overly large size or invalid geometry.
@@ -127,6 +134,11 @@ struct ArrangeParams {
 
     bool allow_rotations = false;
 
+    //BBS: use the sparrow (Rust) packer instead of the libnest2d NFP placer
+    bool  use_sparrow = false;
+    /// Sparrow search budget in seconds, per plate (not for the whole run).
+    float sparrow_time_limit_s = 8.f;
+
     bool do_final_align = true;
 
     //BBS: add specific arrange params
@@ -170,6 +182,8 @@ struct ArrangeParams {
         ret += "\"accuracy\":" + std::to_string(accuracy) + ",";
         ret += "\"parallel\":" + std::to_string(parallel) + ",";
         ret += "\"allow_rotations\":" + std::to_string(allow_rotations) + ",";
+        ret += "\"use_sparrow\":" + std::to_string(use_sparrow) + ",";
+        ret += "\"sparrow_time_limit_s\":" + std::to_string(sparrow_time_limit_s) + ",";
         ret += "\"do_final_align\":" + std::to_string(do_final_align) + ",";
         ret += "\"allow_multi_materials_on_same_plate\":" + std::to_string(allow_multi_materials_on_same_plate) + ",";
         ret += "\"avoid_extrusion_cali_region\":" + std::to_string(avoid_extrusion_cali_region) + ",";