Merge branch 'main' into feature/texture_displacement

tests/libslic3r/CMakeLists.txt

@@ -8,6 +8,7 @@ add_executable(${_TEST_NAME}_tests
     test_arachne_walls.cpp
     test_arrange.cpp
     test_bambu_networking.cpp
+    test_buildvolume.cpp
     test_calib.cpp
     test_clipper_offset.cpp
     test_clipper_utils.cpp
@@ -18,6 +19,7 @@ add_executable(${_TEST_NAME}_tests
     test_preset_setting_id.cpp
     test_preset_diff.cpp
     test_vendor_cache.cpp
+    test_preset_options.cpp
     test_elephant_foot_compensation.cpp
     test_fill_corner_smoothing.cpp
     test_filament_mixer.cpp
@@ -28,16 +30,21 @@ add_executable(${_TEST_NAME}_tests
     test_polygon.cpp
     test_mutable_polygon.cpp
     test_mutable_priority_queue.cpp
+    test_minimum_spanning_tree.cpp
     test_nozzle_volume_type.cpp
     test_step.cpp
     test_stl.cpp
     test_triangle_selector.cpp
     test_meshboolean.cpp
     test_marchingsquares.cpp
+    test_lay_on_face.cpp
     test_model.cpp
     test_utils.cpp
     test_timeutils.cpp
     test_voronoi.cpp
+    test_wipe_tower_estimate.cpp
+    test_wipe_tower.cpp
+    test_wipe_path.cpp
     test_optimizers.cpp
     test_ordering_strategies.cpp
     # test_png_io.cpp
@@ -46,6 +53,17 @@ add_executable(${_TEST_NAME}_tests
     ../libnest2d/printer_parts.cpp
     )
 
+if (SLIC3R_CAD)
+    target_sources(${_TEST_NAME}_tests PRIVATE
+        test_caddocument.cpp
+        test_sketchconstraints.cpp
+        test_sketchedit.cpp
+        test_sketchprofile.cpp
+        test_sketchimport.cpp
+        test_sketchinference.cpp
+        test_slvs_constraints.cpp)
+endif ()
+
 if (TARGET OpenVDB::openvdb)
     target_sources(${_TEST_NAME}_tests PRIVATE test_hollowing.cpp)
 endif()

tests/libslic3r/test_3mf.cpp

@@ -1,18 +1,24 @@
 
 #include "libslic3r/Model.hpp"
-#include "libslic3r/TriangleSelector.hpp"
 #include "libslic3r/Format/3mf.hpp"
 #include "libslic3r/Format/bbs_3mf.hpp"
 #include "libslic3r/Format/STL.hpp"
+#include "libslic3r/miniz_extension.hpp"
+#include "libslic3r/Zipper.hpp"
 #include "libslic3r/PrintConfig.hpp"
 #include "libslic3r/Semver.hpp"
 #include "libslic3r/Preset.hpp"
 #include "libslic3r/MultiNozzleUtils.hpp"
 #include "libslic3r/ProjectTask.hpp"
+#include "libslic3r/PublishSettings.hpp"
 
 #include "test_utils.hpp"
 
+#include <nlohmann/json.hpp>
+
 #include <boost/filesystem/operations.hpp>
+#include <boost/algorithm/string/predicate.hpp>
+#include <algorithm>
 
 #include <catch2/catch_tostring.hpp>
 #include <Eigen/Core>
@@ -141,6 +147,236 @@ SCENARIO("Export+Import geometry to/from 3mf file cycle", "[3mf]") {
     }
 }
 
+// The recipe is an opaque binary blob (CadDocument::serialize_recipe()), so the 3mf backend has
+// to carry it byte-for-byte — no XML/text mangling, embedded NULs intact.
+static std::string make_cad_recipe()
+{
+    // Built from an explicit length, not append(const char*), which would stop at the first
+    // embedded NUL — the one thing this blob exists to prove survives the archive.
+    static const char blob[] = "\x01" "RECIPE" "\0" "\xff\xfe\x00\x10" "cad-features-blob";
+    return std::string(blob, sizeof(blob) - 1);
+}
+
+static const std::string CAD_RECIPE_ENTRY        = "Metadata/orca_cad.bin";
+static const std::string LEGACY_CAD_RECIPE_ENTRY = "Metadata/SnapOrca_cad.bin";
+
+// Pulls one named entry out of a 3mf archive; false when it is absent.
+static bool read_cad_recipe_entry(const std::string& path, std::string& out,
+                                  const std::string& entry = CAD_RECIPE_ENTRY)
+{
+    mz_zip_archive zip;
+    mz_zip_zero_struct(&zip);
+    REQUIRE(open_zip_reader(&zip, path));
+    bool   found = false;
+    mz_uint n    = mz_zip_reader_get_num_files(&zip);
+    for (mz_uint i = 0; i < n; ++i) {
+        mz_zip_archive_file_stat st;
+        if (!mz_zip_reader_file_stat(&zip, i, &st)) continue;
+        std::string name(st.m_filename);
+        std::replace(name.begin(), name.end(), '\\', '/');
+        if (boost::algorithm::iequals(name, entry)) {
+            out.resize(st.m_uncomp_size);
+            found = mz_zip_reader_extract_to_mem(&zip, i, out.data(), out.size(), 0) != 0;
+            break;
+        }
+    }
+    close_zip_reader(&zip);
+    return found;
+}
+
+// Rewrites the archive at `path` with the recipe entry back under the name it had before the
+// rename, which is what every project saved by an earlier build looks like on disk. Generated
+// rather than checked in because a whole project archive is not frozen evidence the way a bare
+// recipe blob is -- it has to be whatever today's exporter writes, with only the name aged.
+// miniz cannot rename in place and open_zip_writer truncates, so the entries are held across
+// the switch.
+static void rename_cad_recipe_entry_to_legacy(const std::string& path)
+{
+    std::vector<std::pair<std::string, std::string>> entries;
+    bool renamed = false;
+    {
+        mz_zip_archive zip;
+        mz_zip_zero_struct(&zip);
+        REQUIRE(open_zip_reader(&zip, path));
+        mz_uint n = mz_zip_reader_get_num_files(&zip);
+        for (mz_uint i = 0; i < n; ++i) {
+            mz_zip_archive_file_stat st;
+            REQUIRE(mz_zip_reader_file_stat(&zip, i, &st));
+            if (st.m_is_directory) continue;
+            std::string name(st.m_filename);
+            std::replace(name.begin(), name.end(), '\\', '/');
+            std::string data((size_t) st.m_uncomp_size, '\0');
+            if (st.m_uncomp_size > 0)
+                REQUIRE(mz_zip_reader_extract_to_mem(&zip, i, data.data(), data.size(), 0));
+            if (boost::algorithm::iequals(name, CAD_RECIPE_ENTRY)) {
+                name    = LEGACY_CAD_RECIPE_ENTRY;
+                renamed = true;
+            }
+            entries.emplace_back(std::move(name), std::move(data));
+        }
+        close_zip_reader(&zip);
+    }
+    // Without this the scenario would degrade silently into re-testing the new name if the
+    // exporter's constant ever moved again: every load below would still pass.
+    REQUIRE(renamed);
+
+    Zipper out(path);
+    for (const auto& e : entries)
+        out.add_entry(e.first, e.second.data(), e.second.size());
+    out.finalize();
+}
+
+// The recipe lives only in the BBS-native backend, because that is the only one that runs:
+// store_bbs_3mf is the sole exporter the app calls, and 3mf.cpp's load_3mf is reached only for
+// files fingerprinted as PrusaSlicer's, which never carry a recipe. This locks in both halves:
+// the archive entry is at the exact path the importer looks for, and the recipe comes back
+// through the real importer.
+SCENARIO("CAD recipe is embedded in the BBS 3mf archive", "[3mf][CAD]") {
+    GIVEN("a model carrying a binary cad_recipe") {
+        Model model;
+        std::string src = std::string(TEST_DATA_DIR) + "/test_3mf/Prusa.stl";
+        REQUIRE(load_stl(src.c_str(), &model));
+        model.add_default_instances();
+
+        // store_bbs_3mf stages its metadata through the model's backup path; point it at a
+        // writable temp dir, as the sibling BBS scenarios do. The process-global
+        // set_temporary_dir() would leak into every test that ran afterwards.
+        ScopedTemporaryDir backup_dir("orca_cad");
+        model.set_backup_path(backup_dir.string());
+
+        const std::string recipe = make_cad_recipe();
+        model.cad_recipe = recipe;
+
+        WHEN("saved through the BBS backend (the format the GUI uses)") {
+            ScopedTemporaryFile temp(".3mf");
+            const std::string test_file = temp.string();
+
+            DynamicPrintConfig cfg;
+            StoreParams sp;
+            sp.path     = test_file.c_str();
+            sp.model    = &model;
+            sp.config   = &cfg;
+            sp.strategy = SaveStrategy::Zip64 | SaveStrategy::Silence;
+            REQUIRE(store_bbs_3mf(sp));
+
+            THEN("the archive entry is present byte-for-byte") {
+                std::string got;
+                REQUIRE(read_cad_recipe_entry(test_file, got));
+                REQUIRE(got.size() == recipe.size());
+                REQUIRE(got == recipe);
+            }
+
+            THEN("the importer restores it onto the loaded model") {
+                Model dst_model;
+                ScopedTemporaryDir dst_backup_dir("orca_cad_dst");
+                dst_model.set_backup_path(dst_backup_dir.string());
+
+                DynamicPrintConfig dst_config;
+                ConfigSubstitutionContext ctxt{ ForwardCompatibilitySubstitutionRule::Enable };
+                PlateDataPtrs        dst_plates;
+                std::vector<Preset*> project_presets;
+                bool   is_bbl_3mf = false, is_orca_3mf = false;
+                Semver file_version;
+                REQUIRE(load_bbs_3mf(test_file.c_str(), &dst_config, &ctxt, &dst_model, &dst_plates,
+                                     &project_presets, &is_bbl_3mf, &is_orca_3mf, &file_version, nullptr,
+                                     LoadStrategy::LoadModel | LoadStrategy::LoadConfig));
+                REQUIRE(dst_model.cad_recipe.size() == recipe.size());
+                REQUIRE(dst_model.cad_recipe == recipe);
+
+                release_PlateData_list(dst_plates);
+            }
+        }
+
+        WHEN("the same model is saved with no recipe") {
+            model.cad_recipe.clear();
+            ScopedTemporaryFile temp(".3mf");
+            const std::string test_file = temp.string();
+
+            DynamicPrintConfig cfg;
+            StoreParams sp;
+            sp.path     = test_file.c_str();
+            sp.model    = &model;
+            sp.config   = &cfg;
+            sp.strategy = SaveStrategy::Zip64 | SaveStrategy::Silence;
+            REQUIRE(store_bbs_3mf(sp));
+
+            THEN("no entry is written at all") {
+                std::string got;
+                REQUIRE_FALSE(read_cad_recipe_entry(test_file, got));
+            }
+        }
+    }
+}
+
+// The recipe entry was renamed from Metadata/SnapOrca_cad.bin to Metadata/orca_cad.bin. Nothing
+// in the blob marks that move, so a reader that knows only the new name loads a project written
+// before it with an empty cad_recipe and no error at all — a feature tree gone with no symptom
+// but an empty Design tab. The importer must still accept the old name; the exporter may never
+// write it.
+SCENARIO("a project saved under the pre-rename recipe name still loads", "[3mf][CAD]") {
+    GIVEN("a project whose recipe entry carries the old name") {
+        Model model;
+        std::string src = std::string(TEST_DATA_DIR) + "/test_3mf/Prusa.stl";
+        REQUIRE(load_stl(src.c_str(), &model));
+        model.add_default_instances();
+        const std::string recipe = make_cad_recipe();
+        model.cad_recipe = recipe;
+
+        WHEN("it was written by the BBS backend") {
+            ScopedTemporaryDir backup_dir("orca_cad_legacy");
+            model.set_backup_path(backup_dir.string());
+
+            ScopedTemporaryFile temp(".3mf");
+            const std::string test_file = temp.string();
+            DynamicPrintConfig cfg;
+            StoreParams sp;
+            sp.path     = test_file.c_str();
+            sp.model    = &model;
+            sp.config   = &cfg;
+            sp.strategy = SaveStrategy::Zip64 | SaveStrategy::Silence;
+            REQUIRE(store_bbs_3mf(sp));
+            rename_cad_recipe_entry_to_legacy(test_file);
+
+            // Catch2 replays the enclosing sections per THEN, so one load here serves both.
+            Model dst_model;
+            ScopedTemporaryDir dst_backup_dir("orca_cad_legacy_dst");
+            dst_model.set_backup_path(dst_backup_dir.string());
+
+            DynamicPrintConfig dst_config;
+            ConfigSubstitutionContext ctxt{ ForwardCompatibilitySubstitutionRule::Enable };
+            PlateDataPtrs        dst_plates;
+            std::vector<Preset*> project_presets;
+            bool   is_bbl_3mf = false, is_orca_3mf = false;
+            Semver file_version;
+            REQUIRE(load_bbs_3mf(test_file.c_str(), &dst_config, &ctxt, &dst_model, &dst_plates,
+                                 &project_presets, &is_bbl_3mf, &is_orca_3mf, &file_version, nullptr,
+                                 LoadStrategy::LoadModel | LoadStrategy::LoadConfig));
+            release_PlateData_list(dst_plates);
+
+            THEN("the recipe still comes back byte-for-byte") {
+                REQUIRE(dst_model.cad_recipe == recipe);
+            }
+
+            THEN("re-saving migrates it to the new name and leaves the old one behind") {
+                ScopedTemporaryFile again(".3mf");
+                const std::string resaved = again.string();
+                DynamicPrintConfig cfg2;
+                StoreParams sp2;
+                sp2.path     = resaved.c_str();
+                sp2.model    = &dst_model;
+                sp2.config   = &cfg2;
+                sp2.strategy = SaveStrategy::Zip64 | SaveStrategy::Silence;
+                REQUIRE(store_bbs_3mf(sp2));
+
+                std::string got;
+                REQUIRE(read_cad_recipe_entry(resaved, got));
+                REQUIRE(got == recipe);
+                REQUIRE_FALSE(read_cad_recipe_entry(resaved, got, LEGACY_CAD_RECIPE_ENTRY));
+            }
+        }
+    }
+}
+
 // .3mf multi-nozzle round-trip.
 // Locks the load/save handling for the H2C multi-nozzle plate metadata:
 //   * filament_volume_maps  -> plate config "filament_volume_map" (with the >1 -> 0 clamp)
@@ -499,7 +735,6 @@ SCENARIO("Nozzle-group metadata .3mf round-trip", "[3mf][MultiNozzle]") {
     }
 }
 
-
 // A mixed-color filament occupies an ordinary filament slot, and painting with it stores an
 // ordinary extruder state: a project saved by BambuStudio encodes filament 5 of a 5-slot setup
 // as paint state 5, with the mix described by the parallel filament_mixed_* project arrays.
@@ -590,3 +825,639 @@ SCENARIO("Mixed-color filament setup and painting round-trip through a .3mf", "[
         }
     }
 }
+// Locks the serialization contract of the "Publish" metadata: the orca_published flag and the
+// orca_published_keys JSON array in model.model_info->metadata_items must survive a store_bbs_3mf ->
+// load_bbs_3mf round-trip unchanged. (The full preset-preservation behavior is exercised
+// headlessly in test_preset_bundle_loading.cpp.)
+SCENARIO("Published 3MF round-trips the published flag and published_keys metadata", "[3mf]") {
+    GIVEN("a model carrying published metadata") {
+        Model model;
+        std::string src_file = std::string(TEST_DATA_DIR) + "/test_3mf/Prusa.stl";
+        REQUIRE(load_stl(src_file.c_str(), &model));
+        model.add_default_instances();
+
+        model.model_info = std::make_shared<ModelInfo>();
+        model.model_info->metadata_items[ORCA_PUBLISHED_TAG]      = "1";
+        model.model_info->metadata_items[ORCA_PUBLISHED_KEYS_TAG] = R"(["layer_height","wall_thickness"])";
+
+        // store_bbs_3mf stages project_settings.config through the model's backup path; point
+        // it at a writable temp dir (the default lives under a read-only root in CI).
+        ScopedTemporaryDir backup_dir("orca_pub");
+        model.set_backup_path(backup_dir.string());
+
+        WHEN("stored to and reloaded from a .3mf") {
+            ScopedTemporaryFile temp(".3mf");
+            const std::string test_file = temp.string();
+
+            DynamicPrintConfig config = DynamicPrintConfig::full_print_config();
+            StoreParams store_params;
+            store_params.path    = test_file.c_str();
+            store_params.model   = &model;
+            store_params.config  = &config;
+            store_params.strategy = SaveStrategy::Zip64 | SaveStrategy::Silence;
+            REQUIRE(store_bbs_3mf(store_params));
+
+            Model dst_model;
+            DynamicPrintConfig dst_config;
+            ConfigSubstitutionContext ctxt{ ForwardCompatibilitySubstitutionRule::Enable };
+            PlateDataPtrs        dst_plates;
+            std::vector<Preset*> project_presets;
+            bool   is_bbl_3mf = false, is_orca_3mf = false;
+            Semver file_version;
+            bool loaded = load_bbs_3mf(test_file.c_str(), &dst_config, &ctxt, &dst_model, &dst_plates,
+                                       &project_presets, &is_bbl_3mf, &is_orca_3mf, &file_version, nullptr,
+                                       LoadStrategy::LoadModel | LoadStrategy::LoadConfig);
+            THEN("the published metadata round-trips unchanged") {
+                REQUIRE(loaded);
+                REQUIRE(dst_model.model_info != nullptr);
+                REQUIRE(dst_model.model_info->metadata_items[ORCA_PUBLISHED_TAG] == "1");
+                REQUIRE(dst_model.model_info->metadata_items[ORCA_PUBLISHED_KEYS_TAG] == R"(["layer_height","wall_thickness"])");
+
+                // The orca_published_keys value is a JSON array of setting keys; it must parse back to
+                // the same keys that were selected.
+                nlohmann::json keys = nlohmann::json::parse(dst_model.model_info->metadata_items[ORCA_PUBLISHED_KEYS_TAG]);
+                REQUIRE(keys.is_array());
+                REQUIRE(keys.size() == 2);
+                REQUIRE(keys[0] == "layer_height");
+                REQUIRE(keys[1] == "wall_thickness");
+            }
+            release_PlateData_list(dst_plates);
+        }
+    }
+}
+
+// A normal 3MF (no Publish metadata) must load identically: the loader must not fabricate a
+// "orca_published" flag or orca_published_keys for files that never carried them.
+SCENARIO("Legacy 3MF without published metadata loads unchanged", "[3mf]") {
+    GIVEN("a model without any published metadata") {
+        Model model;
+        std::string src_file = std::string(TEST_DATA_DIR) + "/test_3mf/Prusa.stl";
+        REQUIRE(load_stl(src_file.c_str(), &model));
+        model.add_default_instances();
+
+        ScopedTemporaryDir backup_dir("orca_legacy");
+        model.set_backup_path(backup_dir.string());
+
+        WHEN("stored to and reloaded from a .3mf") {
+            ScopedTemporaryFile temp(".3mf");
+            const std::string test_file = temp.string();
+
+            DynamicPrintConfig config = DynamicPrintConfig::full_print_config();
+            StoreParams store_params;
+            store_params.path    = test_file.c_str();
+            store_params.model   = &model;
+            store_params.config  = &config;
+            store_params.strategy = SaveStrategy::Zip64 | SaveStrategy::Silence;
+            REQUIRE(store_bbs_3mf(store_params));
+
+            Model dst_model;
+            DynamicPrintConfig dst_config;
+            ConfigSubstitutionContext ctxt{ ForwardCompatibilitySubstitutionRule::Enable };
+            PlateDataPtrs        dst_plates;
+            std::vector<Preset*> project_presets;
+            bool   is_bbl_3mf = false, is_orca_3mf = false;
+            Semver file_version;
+            bool loaded = load_bbs_3mf(test_file.c_str(), &dst_config, &ctxt, &dst_model, &dst_plates,
+                                       &project_presets, &is_bbl_3mf, &is_orca_3mf, &file_version, nullptr,
+                                       LoadStrategy::LoadModel | LoadStrategy::LoadConfig);
+            THEN("no published key is fabricated") {
+                REQUIRE(loaded);
+                REQUIRE(dst_model.model_info != nullptr);
+                REQUIRE(dst_model.model_info->metadata_items.count(ORCA_PUBLISHED_TAG) == 0);
+                REQUIRE(dst_model.model_info->metadata_items.count(ORCA_PUBLISHED_KEYS_TAG) == 0);
+            }
+            release_PlateData_list(dst_plates);
+        }
+    }
+}
+
+// Locks the serialization contract of the orca_published_material_keys metadata: the per-entry JSON
+// must survive a store_bbs_3mf -> load_bbs_3mf round-trip verbatim, exactly like orca_published_keys.
+SCENARIO("Published 3MF round-trips the published_material_keys metadata", "[3mf]") {
+    GIVEN("a model carrying published material keys metadata") {
+        Model model;
+        std::string src_file = std::string(TEST_DATA_DIR) + "/test_3mf/Prusa.stl";
+        REQUIRE(load_stl(src_file.c_str(), &model));
+        model.add_default_instances();
+
+        const std::string material_keys_json =
+            R"([{"material":{"filament_type":"PLA","filament_vendor":"Generic","filament_id":"GFL99"},"slot":0,"keys":["filament_retraction_length","filament_z_hop"]}])";
+
+        model.model_info = std::make_shared<ModelInfo>();
+        model.model_info->metadata_items[ORCA_PUBLISHED_MATERIAL_TAG] = material_keys_json;
+
+        ScopedTemporaryDir backup_dir("orca_pub_mat");
+        model.set_backup_path(backup_dir.string());
+
+        WHEN("stored to and reloaded from a .3mf") {
+            ScopedTemporaryFile temp(".3mf");
+            const std::string test_file = temp.string();
+
+            DynamicPrintConfig config = DynamicPrintConfig::full_print_config();
+            StoreParams store_params;
+            store_params.path    = test_file.c_str();
+            store_params.model   = &model;
+            store_params.config  = &config;
+            store_params.strategy = SaveStrategy::Zip64 | SaveStrategy::Silence;
+            REQUIRE(store_bbs_3mf(store_params));
+
+            Model dst_model;
+            DynamicPrintConfig dst_config;
+            ConfigSubstitutionContext ctxt{ ForwardCompatibilitySubstitutionRule::Enable };
+            PlateDataPtrs        dst_plates;
+            std::vector<Preset*> project_presets;
+            bool   is_bbl_3mf = false, is_orca_3mf = false;
+            Semver file_version;
+            bool loaded = load_bbs_3mf(test_file.c_str(), &dst_config, &ctxt, &dst_model, &dst_plates,
+                                       &project_presets, &is_bbl_3mf, &is_orca_3mf, &file_version, nullptr,
+                                       LoadStrategy::LoadModel | LoadStrategy::LoadConfig);
+            THEN("the published material keys metadata round-trips unchanged") {
+                REQUIRE(loaded);
+                REQUIRE(dst_model.model_info != nullptr);
+                REQUIRE(dst_model.model_info->metadata_items[ORCA_PUBLISHED_MATERIAL_TAG] == material_keys_json);
+
+                // The value must parse back to one material entry carrying the nested identity
+                // object, the author slot ordinal and the key list.
+                nlohmann::json entries = nlohmann::json::parse(material_keys_json);
+                REQUIRE(entries.is_array());
+                REQUIRE(entries.size() == 1);
+                REQUIRE(entries[0]["material"]["filament_type"] == "PLA");
+                REQUIRE(entries[0]["material"]["filament_vendor"] == "Generic");
+                REQUIRE(entries[0]["material"]["filament_id"] == "GFL99");
+                REQUIRE(entries[0]["slot"] == 0);
+                REQUIRE(entries[0]["keys"].is_array());
+                REQUIRE(entries[0]["keys"].size() == 2);
+                REQUIRE(entries[0]["keys"][0] == "filament_retraction_length");
+            }
+            release_PlateData_list(dst_plates);
+        }
+    }
+}
+
+SCENARIO("Minimal published 3MF omits project config, preset dumps and slicer tags", "[3mf]") {
+    GIVEN("a multi-instance model carrying published metadata and a published_config payload") {
+        Model model;
+        std::string src_file = std::string(TEST_DATA_DIR) + "/test_3mf/Prusa.stl";
+        REQUIRE(load_stl(src_file.c_str(), &model));
+        model.add_default_instances();
+        // A second instance: tag-less third-party files get their multi-instance objects split,
+        // published files must not (the loader recognizes them by their metadata).
+        model.objects.front()->add_instance();
+
+        DynamicPrintConfig full_cfg = DynamicPrintConfig::full_print_config();
+        full_cfg.set_key_value("layer_height", new ConfigOptionFloat(0.24));
+        full_cfg.set_key_value("retraction_length", new ConfigOptionFloats({ 1.2 }));
+
+        const std::vector<std::string> published_keys = { "layer_height", "retraction_length" };
+        const std::vector<PublishedMaterialEntry> material_keys = {
+            { "PLA", "Generic", "GFL99", "", "Generic PLA", 0, { "filament_retraction_length" } }
+        };
+
+        // The payload builder keeps the published and identity keys and drops everything else.
+        DynamicPrintConfig filtered_cfg = filter_published_config(full_cfg, published_keys, material_keys);
+        REQUIRE(filtered_cfg.option("layer_height") != nullptr);
+        REQUIRE(filtered_cfg.option("retraction_length") != nullptr);
+        REQUIRE(filtered_cfg.option("filament_colour") != nullptr);
+        REQUIRE(filtered_cfg.option("filament_type") != nullptr);
+        REQUIRE(filtered_cfg.option("wipe_tower_x") != nullptr);
+        REQUIRE(filtered_cfg.option("sparse_infill_density") == nullptr);
+        REQUIRE(filtered_cfg.option("machine_start_gcode") == nullptr);
+
+        // Serialize the payload exactly like export_published_3mf does.
+        std::string payload;
+        for (const std::string &key : filtered_cfg.keys())
+            payload += key + " = " + filtered_cfg.opt_serialize(key) + "\n";
+
+        model.model_info = std::make_shared<ModelInfo>();
+        model.model_info->metadata_items[ORCA_PUBLISHED_TAG]      = "1";
+        model.model_info->metadata_items[ORCA_PUBLISHED_KEYS_TAG] = R"(["layer_height","retraction_length"])";
+        model.model_info->metadata_items[ORCA_PUBLISHED_CONFIG_TAG] = payload;
+
+        ScopedTemporaryDir backup_dir("orca_min_pub");
+        model.set_backup_path(backup_dir.string());
+
+        WHEN("stored using SaveStrategy::MinimalPublished and reloaded") {
+            ScopedTemporaryFile temp(".3mf");
+            const std::string test_file = temp.string();
+
+            // Create a fake project preset to verify MinimalPublished omits it.
+            Preset preset(Preset::TYPE_PRINT, "TestPrintPreset");
+            preset.config = full_cfg;
+            std::vector<Preset*> project_presets = { &preset };
+
+            StoreParams store_params;
+            store_params.path    = test_file.c_str();
+            store_params.model   = &model;
+            store_params.config  = &filtered_cfg;
+            store_params.project_presets = project_presets;
+            store_params.strategy = SaveStrategy::Zip64 | SaveStrategy::Silence | SaveStrategy::MinimalPublished;
+            REQUIRE(store_bbs_3mf(store_params));
+
+            Model dst_model;
+            ScopedTemporaryDir loaded_backup_dir("orca_min_pub_loaded");
+            dst_model.set_backup_path(loaded_backup_dir.string());
+            DynamicPrintConfig dst_config;
+            ConfigSubstitutionContext ctxt{ ForwardCompatibilitySubstitutionRule::Enable };
+            PlateDataPtrs        dst_plates;
+            std::vector<Preset*> loaded_presets;
+            bool   is_bbl_3mf = false, is_orca_3mf = false;
+            Semver file_version;
+            bool loaded = load_bbs_3mf(test_file.c_str(), &dst_config, &ctxt, &dst_model, &dst_plates,
+                                       &loaded_presets, &is_bbl_3mf, &is_orca_3mf, &file_version, nullptr,
+                                       LoadStrategy::LoadModel | LoadStrategy::LoadConfig);
+            THEN("the 3MF loads without project config or embedded presets") {
+                REQUIRE(loaded);
+                REQUIRE(dst_config.empty());
+                REQUIRE(loaded_presets.empty());
+            }
+            THEN("the file carries no slicer tags and classifies as a generic 3MF") {
+                REQUIRE_FALSE(is_bbl_3mf);
+                REQUIRE_FALSE(is_orca_3mf);
+                // No Application / OrcaSlicer tag: old receivers import the geometry silently
+                // instead of showing a baked-in, wrong "old version" popup.
+                REQUIRE_FALSE(file_version.valid());
+            }
+            THEN("the geometry keeps BBS-grade handling: instances are not split") {
+                REQUIRE(dst_model.objects.size() == 1);
+                REQUIRE(dst_model.objects.front()->instances.size() == 2);
+            }
+            THEN("the published metadata and payload round-trip unchanged") {
+                REQUIRE(dst_model.model_info != nullptr);
+                REQUIRE(dst_model.model_info->metadata_items[ORCA_PUBLISHED_TAG] == "1");
+                REQUIRE(dst_model.model_info->metadata_items[ORCA_PUBLISHED_KEYS_TAG] == R"(["layer_height","retraction_length"])");
+                REQUIRE(dst_model.model_info->metadata_items[ORCA_PUBLISHED_CONFIG_TAG] == payload);
+            }
+            THEN("the payload parses back to the published values") {
+                DynamicPrintConfig parsed_payload;
+                parsed_payload.load_from_ini_string(dst_model.model_info->metadata_items[ORCA_PUBLISHED_CONFIG_TAG], ForwardCompatibilitySubstitutionRule::Enable);
+                REQUIRE(parsed_payload.option("layer_height") != nullptr);
+                REQUIRE_THAT(parsed_payload.opt_float("layer_height"), Catch::Matchers::WithinAbs(0.24, 1e-6));
+                REQUIRE(parsed_payload.option("retraction_length") != nullptr);
+                REQUIRE_THAT(parsed_payload.opt<ConfigOptionFloats>("retraction_length")->get_at(0), Catch::Matchers::WithinAbs(1.2, 1e-6));
+            }
+            release_PlateData_list(dst_plates);
+        }
+    }
+}
+
+// A minimal published 3MF must not leak the slicer tags of the source project. The exporter seeds
+// metadata_item_map from the input file's metadata_items, so re-publishing a project opened from a
+// regular Orca/BBS 3MF (the typical remix flow) must strip the Application / OrcaSlicer tags it
+// came with, otherwise old receivers route onto the baked-in "old version" popup.
+SCENARIO("MinimalPublished strips slicer tags carried by the source project", "[3mf]") {
+    GIVEN("a model loaded from a regular Orca/BBS 3MF whose metadata carries the slicer tags") {
+        Model model;
+        std::string src_file = std::string(TEST_DATA_DIR) + "/test_3mf/Prusa.stl";
+        REQUIRE(load_stl(src_file.c_str(), &model));
+        model.add_default_instances();
+
+        model.model_info = std::make_shared<ModelInfo>();
+        model.model_info->metadata_items[ORCA_PUBLISHED_TAG] = "1";
+        model.model_info->metadata_items["Application"]     = "BambuStudio-2.0.0";
+        model.model_info->metadata_items["OrcaSlicer"]      = "2.1.0";
+
+        ScopedTemporaryDir backup_dir("orca_strip_tags");
+        model.set_backup_path(backup_dir.string());
+
+        WHEN("stored using SaveStrategy::MinimalPublished and reloaded") {
+            ScopedTemporaryFile temp(".3mf");
+            const std::string test_file = temp.string();
+
+            DynamicPrintConfig config = DynamicPrintConfig::full_print_config();
+            StoreParams store_params;
+            store_params.path    = test_file.c_str();
+            store_params.model   = &model;
+            store_params.config  = &config;
+            store_params.strategy = SaveStrategy::Zip64 | SaveStrategy::Silence | SaveStrategy::MinimalPublished;
+            REQUIRE(store_bbs_3mf(store_params));
+
+            Model dst_model;
+            DynamicPrintConfig dst_config;
+            ConfigSubstitutionContext ctxt{ ForwardCompatibilitySubstitutionRule::Enable };
+            PlateDataPtrs        dst_plates;
+            std::vector<Preset*> loaded_presets;
+            bool   is_bbl_3mf = false, is_orca_3mf = false;
+            Semver file_version;
+            bool loaded = load_bbs_3mf(test_file.c_str(), &dst_config, &ctxt, &dst_model, &dst_plates,
+                                       &loaded_presets, &is_bbl_3mf, &is_orca_3mf, &file_version, nullptr,
+                                       LoadStrategy::LoadModel | LoadStrategy::LoadConfig);
+            THEN("the source slicer tags are stripped, not carried through") {
+                REQUIRE(loaded);
+                REQUIRE(dst_model.model_info != nullptr);
+                REQUIRE(dst_model.model_info->metadata_items.count("Application") == 0);
+                REQUIRE(dst_model.model_info->metadata_items.count("OrcaSlicer") == 0);
+                // The published marker itself must survive.
+                REQUIRE(dst_model.model_info->metadata_items[ORCA_PUBLISHED_TAG] == "1");
+            }
+            THEN("the file classifies as a generic 3MF without a version popup") {
+                REQUIRE_FALSE(is_bbl_3mf);
+                REQUIRE_FALSE(is_orca_3mf);
+                REQUIRE_FALSE(file_version.valid());
+            }
+            release_PlateData_list(dst_plates);
+        }
+    }
+}
+
+// An entry masks the non-published slots to their defaults so publishing slot 1 never leaks slot
+// 0's value into the file. Both a full entry (the whole-slot key list) and a partial entry (a
+// per-slot key) go through the same masking path in filter_published_config (keys and full_keys
+// are filtered identically), so the two forms are exercised together.
+SCENARIO("Published entries mask the other slots to their defaults", "[3mf]") {
+    const bool full = GENERATE(true, false);
+    GIVEN("a full print configuration with two filament slots") {
+        DynamicPrintConfig full_cfg = DynamicPrintConfig::full_print_config();
+        full_cfg.opt<ConfigOptionFloats>("filament_diameter")->values = { 1.75, 1.75 };
+        full_cfg.opt<ConfigOptionStrings>("filament_colour")->values = { "#111111", "#222222" };
+        // filament_flow_ratio carries a non-empty option default (1.0) of the same type, so the
+        // mask can restore it on the non-published slot.
+        full_cfg.opt<ConfigOptionFloatsNullable>("filament_flow_ratio", true)->values = { 1.02, 0.98 };
+
+        WHEN("filtering with a published entry for slot 1") {
+            PublishedMaterialEntry entry;
+            entry.slot = 1;
+            if (full) {
+                entry.full      = true;
+                entry.full_keys = { "filament_flow_ratio" };
+            } else {
+                entry.keys = { "filament_flow_ratio" };
+            }
+            DynamicPrintConfig filtered_cfg = filter_published_config(full_cfg, {}, { entry });
+
+            THEN("the selected key is present with the author's slot value") {
+                REQUIRE(filtered_cfg.option("filament_flow_ratio") != nullptr);
+                REQUIRE_THAT(filtered_cfg.opt<ConfigOptionFloatsNullable>("filament_flow_ratio")->values[1], Catch::Matchers::WithinAbs(0.98, 1e-6));
+            }
+            THEN("the non-published slot is masked to its default") {
+                REQUIRE_THAT(filtered_cfg.opt<ConfigOptionFloatsNullable>("filament_flow_ratio")->values[0], Catch::Matchers::WithinAbs(1.0, 1e-6));
+            }
+            THEN("the identity keys stay present") {
+                REQUIRE(filtered_cfg.option("filament_colour") != nullptr);
+            }
+        }
+    }
+}
+
+// A key needing slot masking that cannot be masked (no registered option default of the same
+// type) is dropped from the payload entirely instead of shipping the author's whole vector.
+SCENARIO("Unmaskable keys are dropped from the published payload instead of leaking", "[3mf]") {
+    GIVEN("a config carrying a synthetic def-less vector key and a maskable one") {
+        DynamicPrintConfig full_cfg = DynamicPrintConfig::full_print_config();
+        full_cfg.opt<ConfigOptionFloats>("filament_diameter")->values = { 1.75, 1.75 };
+        full_cfg.opt<ConfigOptionStrings>("filament_colour")->values  = { "#111111", "#222222" };
+        // Not a PrintConfig key: print_config_def has no default to mask with.
+        full_cfg.set_key_value("orca_synthetic_setting", new ConfigOptionFloats({ 9.9, 8.8 }));
+        full_cfg.opt<ConfigOptionFloatsNullable>("filament_flow_ratio", true)->values = { 1.02, 0.98 };
+
+        PublishedMaterialEntry partial_entry;
+        partial_entry.slot = 1;
+        partial_entry.keys = { "orca_synthetic_setting", "filament_flow_ratio" };
+
+        WHEN("filtering with a partial entry for slot 1") {
+            DynamicPrintConfig filtered_cfg = filter_published_config(full_cfg, {}, { partial_entry });
+
+            THEN("the unmaskable synthetic key is not published") {
+                REQUIRE(filtered_cfg.option("orca_synthetic_setting") == nullptr);
+            }
+            THEN("the maskable key is present, author slot kept, other slot masked") {
+                REQUIRE(filtered_cfg.opt<ConfigOptionFloatsNullable>("filament_flow_ratio") != nullptr);
+                REQUIRE_THAT(filtered_cfg.opt<ConfigOptionFloatsNullable>("filament_flow_ratio")->values[1], Catch::Matchers::WithinAbs(0.98, 1e-6));
+                REQUIRE_THAT(filtered_cfg.opt<ConfigOptionFloatsNullable>("filament_flow_ratio")->values[0], Catch::Matchers::WithinAbs(1.0, 1e-6));
+            }
+            THEN("the identity keys stay present") {
+                REQUIRE(filtered_cfg.option("filament_colour") != nullptr);
+            }
+        }
+    }
+}
+
+// A per-extruder printer key carrying a "#N" variant (e.g. retraction_length#1) must not serialize
+// every extruder's value: the base is masked to the author's extruder and the other slots are
+// restored to their option default, matching the material-side slot-masking invariant. A bare
+// printer base key (no variant) keeps whole-vector serialization.
+SCENARIO("Published per-extruder printer keys mask the other extruders to their defaults", "[3mf]") {
+    GIVEN("a full print configuration with three extruders carrying per-extruder retraction values") {
+        DynamicPrintConfig full_cfg = DynamicPrintConfig::full_print_config();
+        // Non-default values on the un-selected slots, so a leak is distinguishable from the mask
+        // restoring the option default (retraction_length defaults to {0.8}).
+        full_cfg.opt<ConfigOptionFloats>("retraction_length")->values = { 3.0, 1.2, 4.0 };
+
+        WHEN("filtering with only extruder 1's retraction_length checked") {
+            DynamicPrintConfig filtered_cfg = filter_published_config(full_cfg, { "retraction_length#1" }, {});
+
+            THEN("the author's extruder value survives") {
+                REQUIRE_THAT(filtered_cfg.opt<ConfigOptionFloats>("retraction_length")->values[1], Catch::Matchers::WithinAbs(1.2, 1e-6));
+            }
+            THEN("the other extruders are masked to their default") {
+                REQUIRE_THAT(filtered_cfg.opt<ConfigOptionFloats>("retraction_length")->values[0], Catch::Matchers::WithinAbs(0.8, 1e-6));
+                REQUIRE_THAT(filtered_cfg.opt<ConfigOptionFloats>("retraction_length")->values[2], Catch::Matchers::WithinAbs(0.8, 1e-6));
+            }
+        }
+        WHEN("filtering the bare base key without a '#N' variant") {
+            DynamicPrintConfig filtered_cfg = filter_published_config(full_cfg, { "retraction_length" }, {});
+
+            THEN("the whole vector is serialized unmasked") {
+                REQUIRE_THAT(filtered_cfg.opt<ConfigOptionFloats>("retraction_length")->values[0], Catch::Matchers::WithinAbs(3.0, 1e-6));
+                REQUIRE_THAT(filtered_cfg.opt<ConfigOptionFloats>("retraction_length")->values[1], Catch::Matchers::WithinAbs(1.2, 1e-6));
+                REQUIRE_THAT(filtered_cfg.opt<ConfigOptionFloats>("retraction_length")->values[2], Catch::Matchers::WithinAbs(4.0, 1e-6));
+            }
+        }
+    }
+}
+
+// The extended per-entry fields (full dump list, published type and colour) travel inside the
+// published_material_keys metadata and round-trip unchanged.
+SCENARIO("Published 3MF round-trips the extended material metadata", "[3mf]") {
+    GIVEN("a model carrying extended published material keys metadata") {
+        Model model;
+        std::string src_file = std::string(TEST_DATA_DIR) + "/test_3mf/Prusa.stl";
+        REQUIRE(load_stl(src_file.c_str(), &model));
+        model.add_default_instances();
+
+        const std::string material_keys_json =
+            R"([{"material":{"filament_type":"PLA","filament_vendor":"Generic","filament_id":"GFL99","setting_id":"RFs9eCKYOMUSmvZf","name":"Generic PLA Matte @System"},"slot":1,"keys":[],"full":true,"full_keys":["filament_retraction_length","filament_colour"],"publish_type":true,"type":"PLA","publish_color":false,"color":""}])";
+
+        model.model_info = std::make_shared<ModelInfo>();
+        model.model_info->metadata_items[ORCA_PUBLISHED_MATERIAL_TAG] = material_keys_json;
+
+        ScopedTemporaryDir backup_dir("orca_pub_mat2");
+        model.set_backup_path(backup_dir.string());
+
+        WHEN("stored to and reloaded from a .3mf") {
+            ScopedTemporaryFile temp(".3mf");
+            const std::string test_file = temp.string();
+
+            DynamicPrintConfig config = DynamicPrintConfig::full_print_config();
+            StoreParams store_params;
+            store_params.path     = test_file.c_str();
+            store_params.model    = &model;
+            store_params.config   = &config;
+            store_params.strategy = SaveStrategy::Zip64 | SaveStrategy::Silence;
+            REQUIRE(store_bbs_3mf(store_params));
+
+            Model dst_model;
+            DynamicPrintConfig dst_config;
+            ConfigSubstitutionContext ctxt{ ForwardCompatibilitySubstitutionRule::Enable };
+            PlateDataPtrs        dst_plates;
+            std::vector<Preset*> project_presets;
+            bool   is_bbl_3mf = false, is_orca_3mf = false;
+            Semver file_version;
+            bool loaded = load_bbs_3mf(test_file.c_str(), &dst_config, &ctxt, &dst_model, &dst_plates,
+                                       &project_presets, &is_bbl_3mf, &is_orca_3mf, &file_version, nullptr,
+                                       LoadStrategy::LoadModel | LoadStrategy::LoadConfig);
+            THEN("the extended material metadata round-trips unchanged") {
+                REQUIRE(loaded);
+                REQUIRE(dst_model.model_info != nullptr);
+                REQUIRE(dst_model.model_info->metadata_items[ORCA_PUBLISHED_MATERIAL_TAG] == material_keys_json);
+
+                // The value must parse back with every extended field intact.
+                nlohmann::json entries = nlohmann::json::parse(material_keys_json);
+                REQUIRE(entries.is_array());
+                REQUIRE(entries.size() == 1);
+                REQUIRE(entries[0]["full"].get<bool>() == true);
+                REQUIRE(entries[0]["full_keys"].is_array());
+                REQUIRE(entries[0]["full_keys"].size() == 2);
+                REQUIRE(entries[0]["publish_type"].get<bool>() == true);
+                REQUIRE(entries[0]["type"] == "PLA");
+                REQUIRE(entries[0]["publish_color"].get<bool>() == false);
+            }
+            release_PlateData_list(dst_plates);
+        }
+    }
+}
+
+// A published mixed filament serializes its whole definition (components, ratios, gradient)
+// masked to the author's slot: the mix slot's values survive, the non-published slots reset to
+// their defaults, so a partial publish never leaks another slot's mix data.
+SCENARIO("Published mixed-filament keys are masked to the author's slot", "[3mf]") {
+    GIVEN("a full print configuration with three slots, one of them mixed") {
+        DynamicPrintConfig full_cfg = DynamicPrintConfig::full_print_config();
+        full_cfg.opt<ConfigOptionFloats>("filament_diameter")->values = { 1.75, 1.75, 1.75 };
+        full_cfg.opt<ConfigOptionStrings>("filament_colour")->values  = { "#111111", "#222222", "#333333" };
+        full_cfg.opt<ConfigOptionBools>("filament_is_mixed")->values  = { 0, 0, 1 };
+        full_cfg.opt<ConfigOptionStrings>("filament_mixed_components")->values       = { "", "", "1,2" };
+        full_cfg.opt<ConfigOptionStrings>("filament_mixed_sublayer_ratios")->values   = { "", "", "0.6,0.4" };
+        full_cfg.opt<ConfigOptionBools>("filament_mixed_gradient")->values            = { 0, 0, 1 };
+        full_cfg.opt<ConfigOptionStrings>("filament_mixed_gradient_range")->values    = { "", "", "0.9,0.1" };
+        full_cfg.opt<ConfigOptionStrings>("filament_mixed_gradient_curve")->values    = { "", "", "0,0.1|1,0.9" };
+        full_cfg.opt<ConfigOptionBools>("filament_mixed_gradient_per_part")->values   = { 0, 0, 1 };
+
+        PublishedMaterialEntry mix_entry;
+        mix_entry.slot = 2;
+        mix_entry.keys = {
+            "filament_is_mixed",          "filament_mixed_components",       "filament_mixed_sublayer_ratios",
+            "filament_mixed_gradient",    "filament_mixed_gradient_range",   "filament_mixed_gradient_curve",
+            "filament_mixed_gradient_per_part"
+        };
+
+        WHEN("filtering with a mixed entry for slot 2") {
+            DynamicPrintConfig filtered_cfg = filter_published_config(full_cfg, {}, { mix_entry });
+
+            THEN("the author's mixed slot keeps its definition") {
+                REQUIRE(filtered_cfg.option("filament_is_mixed") != nullptr);
+                REQUIRE(filtered_cfg.opt<ConfigOptionBools>("filament_is_mixed")->values == std::vector<unsigned char>{ 0, 0, 1 });
+                const auto& components = filtered_cfg.opt<ConfigOptionStrings>("filament_mixed_components")->values;
+                REQUIRE(components.size() == 3);
+                CHECK(components[2] == "1,2");
+                CHECK(filtered_cfg.opt<ConfigOptionStrings>("filament_mixed_sublayer_ratios")->values[2] == "0.6,0.4");
+                CHECK(filtered_cfg.opt<ConfigOptionStrings>("filament_mixed_gradient_curve")->values[2] == "0,0.1|1,0.9");
+                CHECK(filtered_cfg.opt<ConfigOptionBools>("filament_mixed_gradient")->values[2]);
+                CHECK(filtered_cfg.opt<ConfigOptionBools>("filament_mixed_gradient_per_part")->values[2]);
+            }
+            THEN("the non-published slots are masked to their defaults") {
+                CHECK(filtered_cfg.opt<ConfigOptionStrings>("filament_mixed_components")->values[0] == "");
+                CHECK(filtered_cfg.opt<ConfigOptionStrings>("filament_mixed_components")->values[1] == "");
+                CHECK(filtered_cfg.opt<ConfigOptionBools>("filament_is_mixed")->values[0] == 0);
+                CHECK(filtered_cfg.opt<ConfigOptionBools>("filament_is_mixed")->values[1] == 0);
+            }
+            THEN("the identity keys stay present") {
+                REQUIRE(filtered_cfg.option("filament_colour") != nullptr);
+            }
+        }
+    }
+}
+
+// The published flag is gated on the exact string "1": any other serialized value means "not
+// published", so a receiver never treats a file as published on a loose truthiness check.
+TEST_CASE("is_published_3mf_flag accepts only the literal \"1\"", "[3mf]") {
+    CHECK(is_published_3mf_flag("1"));
+    CHECK_FALSE(is_published_3mf_flag("0"));
+    CHECK_FALSE(is_published_3mf_flag("false"));
+    CHECK_FALSE(is_published_3mf_flag("true"));
+    CHECK_FALSE(is_published_3mf_flag(""));
+    CHECK_FALSE(is_published_3mf_flag("YES"));
+}
+
+// bbs_3mf_is_published is the lightweight metadata probe used to decide whether a file was
+// produced by the publish feature (GUI "recently published" tracking). It must return true only
+// for a file whose metadata carries the flag set to "1", and false for legacy files and for a
+// file whose flag is present but not "1" (which loads as a normal, non-published 3MF).
+SCENARIO("bbs_3mf_is_published detects only genuinely published 3MFs", "[3mf]") {
+    auto store_model = [](const std::string &path, const std::string &flag_value, const std::string &keys_value) {
+        Model model;
+        std::string src_file = std::string(TEST_DATA_DIR) + "/test_3mf/Prusa.stl";
+        REQUIRE(load_stl(src_file.c_str(), &model));
+        model.add_default_instances();
+        model.model_info = std::make_shared<ModelInfo>();
+        // An empty flag_value means "don't write the flag at all" (a legacy file).
+        if (!flag_value.empty())
+            model.model_info->metadata_items[ORCA_PUBLISHED_TAG] = flag_value;
+        model.model_info->metadata_items[ORCA_PUBLISHED_KEYS_TAG] = keys_value;
+        ScopedTemporaryDir backup_dir("orca_is_pub");
+        model.set_backup_path(backup_dir.string());
+        DynamicPrintConfig config = DynamicPrintConfig::full_print_config();
+        StoreParams store_params;
+        store_params.path     = path.c_str();
+        store_params.model    = &model;
+        store_params.config   = &config;
+        store_params.strategy = SaveStrategy::Zip64 | SaveStrategy::Silence;
+        REQUIRE(store_bbs_3mf(store_params));
+    };
+
+    GIVEN("a minimal published 3MF whose flag is \"1\"") {
+        ScopedTemporaryFile temp(".3mf");
+        store_model(temp.string(), "1", R"(["layer_height"])");
+        WHEN("probed by bbs_3mf_is_published") {
+            THEN("it is recognized as published") {
+                CHECK(bbs_3mf_is_published(temp.string()));
+            }
+        }
+    }
+    GIVEN("a legacy 3MF without any published flag") {
+        ScopedTemporaryFile temp(".3mf");
+        store_model(temp.string(), "", R"(["layer_height"])");
+        WHEN("probed by bbs_3mf_is_published") {
+            THEN("it is not recognized as published") {
+                CHECK_FALSE(bbs_3mf_is_published(temp.string()));
+            }
+        }
+    }
+    GIVEN("a 3MF carrying the flag set to \"0\"") {
+        ScopedTemporaryFile temp(".3mf");
+        store_model(temp.string(), "0", R"(["layer_height"])");
+        WHEN("probed and loaded") {
+            THEN("it is not recognized as published") {
+                CHECK_FALSE(bbs_3mf_is_published(temp.string()));
+            }
+            THEN("it loads as a normal, non-published 3MF") {
+                Model dst_model;
+                DynamicPrintConfig dst_config;
+                ConfigSubstitutionContext ctxt{ ForwardCompatibilitySubstitutionRule::Enable };
+                PlateDataPtrs        dst_plates;
+                std::vector<Preset*> project_presets;
+                bool   is_bbl_3mf = false, is_orca_3mf = false;
+                Semver file_version;
+                REQUIRE(load_bbs_3mf(temp.string().c_str(), &dst_config, &ctxt, &dst_model, &dst_plates,
+                                     &project_presets, &is_bbl_3mf, &is_orca_3mf, &file_version, nullptr,
+                                     LoadStrategy::LoadModel | LoadStrategy::LoadConfig));
+                REQUIRE(dst_model.model_info != nullptr);
+                // The key is present but not "1", so nothing treats the file as published; the
+                // stored keys still round-trip verbatim.
+                REQUIRE(dst_model.model_info->metadata_items[ORCA_PUBLISHED_TAG] == "0");
+                REQUIRE(dst_model.model_info->metadata_items[ORCA_PUBLISHED_KEYS_TAG] == R"(["layer_height"])");
+                release_PlateData_list(dst_plates);
+            }
+        }
+    }
+}
+

tests/libslic3r/test_arachne_walls.cpp

@@ -22,6 +22,8 @@
 #include "libslic3r/Arachne/utils/ExtrusionLine.hpp"
 #include "libslic3r/Arachne/BeadingStrategy/BeadingStrategyFactory.hpp"
 #include "libslic3r/Arachne/BeadingStrategy/BeadingStrategy.hpp"
+#include "libslic3r/Feature/FuzzySkin/FuzzySkin.hpp"
+#include "libslic3r/Flow.hpp"
 #include "libslic3r/Polygon.hpp"
 #include "libslic3r/ExPolygon.hpp"
 #include "libslic3r/ClipperUtils.hpp"
@@ -309,3 +311,71 @@ TEST_CASE("Beading interpolation tolerates a thicker side with fewer insets", "[
         CHECK(result.bead_widths[i] == expected.bead_widths[i]);
     }
 }
+
+namespace {
+
+// Closed 20 mm square loop at a uniform width.
+Arachne::ExtrusionJunctions square_loop(coord_t width)
+{
+    const coord_t s = scaled<coord_t>(20.);
+    return {{Point(0, 0), width, 0}, {Point(s, 0), width, 0}, {Point(s, s), width, 0}, {Point(0, s), width, 0}, {Point(0, 0), width, 0}};
+}
+
+FuzzySkinConfig thick_fuzzy_config(FuzzySkinMode mode, NoiseType noise_type, double thickness_mm)
+{
+    FuzzySkinConfig cfg{};
+    cfg.type              = FuzzySkinType::All;
+    cfg.thickness         = scaled<coord_t>(thickness_mm);
+    cfg.point_distance    = scaled<coord_t>(0.3);
+    cfg.fuzzy_first_layer = true;
+    cfg.noise_type        = noise_type;
+    cfg.noise_scale       = 1.0;
+    cfg.noise_octaves     = 4;
+    cfg.noise_persistence = 0.5;
+    cfg.mode              = mode;
+    cfg.layer_id          = 5;
+    return cfg;
+}
+
+} // namespace
+
+// Extrusion and Combined mode add noise to each junction's width. A junction narrower than
+// height * (1 - PI/4) makes Flow::rounded_rectangle_extrusion_spacing() throw and fails the slice.
+// The fuzz thickness is 3x the line width so the clamp is hit on every run regardless of RNG seed.
+// Ridged multifractal is covered because its output is not bounded to [-1, 1], so it scales past
+// the configured thickness; the floor has to hold for any noise value, not just an in-range one.
+TEST_CASE("Fuzzy skin extrusion width is floored at the minimum the flow accepts", "[Arachne][FuzzySkin]") {
+    using namespace Slic3r::Feature::FuzzySkin;
+
+    const double layer_height = GENERATE(0.08, 0.2, 0.28);
+    const auto   mode         = GENERATE(FuzzySkinMode::Extrusion, FuzzySkinMode::Combined);
+    const auto   noise_type   = GENERATE(NoiseType::Classic, NoiseType::Perlin, NoiseType::Billow, NoiseType::RidgedMulti, NoiseType::Voronoi);
+    CAPTURE(layer_height, int(mode), int(noise_type));
+
+    const double line_width_mm = 0.42;
+    auto         loop          = square_loop(scaled<coord_t>(line_width_mm));
+    fuzzy_extrusion_line(loop, /*slice_z*/ 1.0, layer_height, thick_fuzzy_config(mode, noise_type, 3 * line_width_mm));
+
+    REQUIRE(loop.size() > 100);
+
+    const auto   narrowest    = std::min_element(loop.begin(), loop.end(), [](const auto& a, const auto& b) { return a.w < b.w; });
+    const double narrowest_mm = unscaled<double>(narrowest->w);
+    const double floor_mm     = layer_height * (1. - 0.25 * PI);
+    CAPTURE(narrowest_mm, floor_mm);
+
+    CHECK(narrowest_mm < line_width_mm); // the clamp was exercised
+    CHECK(narrowest_mm > floor_mm);
+    CHECK_NOTHROW(Flow::rounded_rectangle_extrusion_spacing(float(narrowest_mm), float(layer_height)));
+}
+
+// Displacement mode only moves points; widths must pass through unchanged.
+TEST_CASE("Fuzzy skin displacement mode leaves widths untouched", "[Arachne][FuzzySkin]") {
+    using namespace Slic3r::Feature::FuzzySkin;
+
+    const coord_t width = scaled<coord_t>(0.42);
+    auto          loop  = square_loop(width);
+    fuzzy_extrusion_line(loop, /*slice_z*/ 1.0, /*layer_height*/ 0.2, thick_fuzzy_config(FuzzySkinMode::Displacement, NoiseType::Classic, 1.26));
+
+    REQUIRE(loop.size() > 100);
+    CHECK(std::all_of(loop.begin(), loop.end(), [width](const auto& j) { return j.w == width; }));
+}

tests/libslic3r/test_arrange.cpp

@@ -4,6 +4,8 @@
 #include "libslic3r/BoundingBox.hpp"
 #include "libslic3r/ClipperUtils.hpp"
 #include "libslic3r/ExPolygon.hpp"
+#include "libslic3r/Print.hpp"
+#include "libslic3r/PrintConfig.hpp"
 
 using namespace Slic3r;
 using namespace Slic3r::arrangement;
@@ -24,11 +26,13 @@ ArrangePolygon make_square(coord_t side)
     return ap;
 }
 
-ArrangePolygons squares(int n, double side_mm)
+ArrangePolygons squares(int n, double side_mm, double height_mm = 0.)
 {
     ArrangePolygons items;
-    for (int i = 0; i < n; ++i)
+    for (int i = 0; i < n; ++i) {
         items.emplace_back(make_square(scaled(side_mm)));
+        items.back().height = height_mm;
+    }
     return items;
 }
 
@@ -82,6 +86,38 @@ void require_no_overlap(const ArrangePolygons &items)
     REQUIRE(disjoint(placed_shapes(items)));
 }
 
+// The sequential-print floor is chosen by comparing object height against the nozzle,
+// so the two are defined together and every expectation is derived from them.
+constexpr double NOZZLE_HEIGHT_MM = 2.5;
+constexpr double CLEARANCE_MM     = 30.;
+constexpr double NOZZLE_FLOOR_MM  = MAX_OUTER_NOZZLE_DIAMETER / 2.;
+
+ArrangeParams seq_print_params(coord_t min_dist)
+{
+    ArrangeParams p       = quiet_params(min_dist);
+    p.is_seq_print        = true;
+    p.clearance_radius    = float(CLEARANCE_MM);
+    p.nozzle_height       = float(NOZZLE_HEIGHT_MM);
+    p.object_skirt_offset = 0.f;
+    return p;
+}
+
+// update_selected_items_inflation reads the bed out of the config to cap inflation.
+DynamicPrintConfig bed_config()
+{
+    DynamicPrintConfig c;
+    c.set_key_value("printable_area", new ConfigOptionPoints{{0, 0}, {200, 0}, {200, 200}, {0, 200}});
+    return c;
+}
+
+ArrangePolygons squares_of_heights(const std::vector<double> &heights_mm)
+{
+    ArrangePolygons items;
+    for (double height_mm : heights_mm)
+        items.push_back(squares(1, 20., height_mm).front());
+    return items;
+}
+
 } // namespace
 
 // Prove the overlap check the other tests rely on actually detects overlap.
@@ -222,3 +258,61 @@ TEST_CASE("Arrange aligns the pile to a custom center", "[Arrange]")
         REQUIRE(ap.bed_idx == 0);
     require_no_overlap(items);
 }
+
+TEST_CASE("Sequential print floors the object distance by object height", "[Arrange]")
+{
+    // The only place sequential-print clearance is enforced. The arrange menu offers
+    // no floor of its own, so a stored 0 has to be raised here or not at all.
+    struct Case
+    {
+        std::string         description;
+        std::vector<double> heights;
+        double              skirt_offset_mm;
+        double              expected_floor_mm;
+    };
+
+    auto c = GENERATE(values<Case>({
+        {"objects taller than the nozzle need the full clearance",     {NOZZLE_HEIGHT_MM * 2, NOZZLE_HEIGHT_MM * 2}, 0., CLEARANCE_MM},
+        {"an object exactly at the nozzle height counts as tall",      {NOZZLE_HEIGHT_MM,     NOZZLE_HEIGHT_MM},     0., CLEARANCE_MM},
+        {"one tall object among short ones is enough",                 {NOZZLE_HEIGHT_MM / 2, NOZZLE_HEIGHT_MM * 2}, 0., CLEARANCE_MM},
+        {"objects the nozzle clears keep only the nozzle-width floor", {NOZZLE_HEIGHT_MM / 2, NOZZLE_HEIGHT_MM / 2}, 0., NOZZLE_FLOOR_MM},
+        {"a wide skirt raises the floor for short objects",            {NOZZLE_HEIGHT_MM / 2, NOZZLE_HEIGHT_MM / 2}, 3., 6.},
+    }));
+
+    DYNAMIC_SECTION(c.description)
+    {
+        ArrangePolygons    items = squares_of_heights(c.heights);
+        DynamicPrintConfig cfg   = bed_config();
+        ArrangeParams      p     = seq_print_params(0);
+        p.object_skirt_offset    = float(c.skirt_offset_mm);
+
+        update_selected_items_inflation(items, &cfg, p);
+
+        CHECK(p.min_obj_distance >= scaled(c.expected_floor_mm));
+        CHECK(p.min_obj_distance <= scaled(c.expected_floor_mm + 0.01));
+        // Half each, so a pair ends up a full min_obj_distance apart.
+        CHECK(items.front().inflation == p.min_obj_distance / 2);
+    }
+}
+
+TEST_CASE("Sequential print keeps an object distance already above the floor", "[Arrange]")
+{
+    const coord_t      stored = scaled(CLEARANCE_MM * 2);
+    ArrangePolygons    items  = squares_of_heights({NOZZLE_HEIGHT_MM * 2, NOZZLE_HEIGHT_MM * 2});
+    DynamicPrintConfig cfg    = bed_config();
+    ArrangeParams      p      = seq_print_params(stored);
+
+    update_selected_items_inflation(items, &cfg, p);
+    CHECK(p.min_obj_distance == stored);
+}
+
+TEST_CASE("Layered printing does not floor the object distance", "[Arrange]")
+{
+    ArrangePolygons    items = squares_of_heights({NOZZLE_HEIGHT_MM * 2, NOZZLE_HEIGHT_MM * 2});
+    DynamicPrintConfig cfg   = bed_config();
+    ArrangeParams      p     = seq_print_params(0);
+    p.is_seq_print           = false;
+
+    update_selected_items_inflation(items, &cfg, p);
+    CHECK(p.min_obj_distance == 0);
+}

tests/libslic3r/test_buildvolume.cpp

@@ -0,0 +1,40 @@
+#include <catch2/catch_all.hpp>
+
+#include "libslic3r/BuildVolume.hpp"
+
+using namespace Slic3r;
+
+static std::vector<Vec2d> rect_area(double w, double d)
+{
+    return { { 0., 0. }, { w, 0. }, { w, d }, { 0., d } };
+}
+
+// extruder_printable_height and extruder_printable_area are independent config options, so a
+// profile can leave the heights short. BuildVolume must not index past the end of the heights.
+TEST_CASE("BuildVolume falls back to the bed height when extruder_printable_height is short", "[BuildVolume]")
+{
+    const std::vector<Vec2d>              bed     = rect_area(200., 200.);
+    const std::vector<std::vector<Vec2d>> areas   = { rect_area(200., 200.), rect_area(100., 200.) };
+    const std::vector<double>             heights = { 180. };
+
+    const BuildVolume build_volume(bed, 250., areas, heights);
+
+    REQUIRE(build_volume.get_extruder_area_count() == 2);
+    // The extruder with a height of its own keeps it, and differs from the bed, so it gets its own volume.
+    CHECK_THAT(build_volume.get_extruder_area_volume(0).bboxf.max.z(), Catch::Matchers::WithinAbs(180., 1e-6));
+    // The extruder without one falls back to the bed's printable_height instead of reading out of range.
+    CHECK_THAT(build_volume.get_extruder_area_volume(1).bboxf.max.z(), Catch::Matchers::WithinAbs(250., 1e-6));
+}
+
+TEST_CASE("BuildVolume keeps per-extruder heights when both vectors match", "[BuildVolume]")
+{
+    const std::vector<Vec2d>              bed     = rect_area(200., 200.);
+    const std::vector<std::vector<Vec2d>> areas   = { rect_area(120., 200.), rect_area(100., 200.) };
+    const std::vector<double>             heights = { 180., 200.5 };
+
+    const BuildVolume build_volume(bed, 250., areas, heights);
+
+    REQUIRE(build_volume.get_extruder_area_count() == 2);
+    CHECK_THAT(build_volume.get_extruder_area_volume(0).bboxf.max.z(), Catch::Matchers::WithinAbs(180., 1e-6));
+    CHECK_THAT(build_volume.get_extruder_area_volume(1).bboxf.max.z(), Catch::Matchers::WithinAbs(200.5, 1e-6));
+}

tests/libslic3r/test_config.cpp

@@ -15,6 +15,8 @@
 #include <boost/nowide/fstream.hpp>
 #include <nlohmann/json.hpp>
 
+#include <sstream>
+
 using namespace Slic3r;
 
 SCENARIO("Generic config validation performs as expected.", "[Config]") {
@@ -488,6 +490,59 @@ TEST_CASE("save_to_json round-trips plugin capability references as strings", "[
     CHECK(reloaded.option<ConfigOptionStrings>("slicing_pipeline_plugin")->values == refs);
 }
 
+TEST_CASE("save_to_json writes the same document to a stream as to a file", "[Config]") {
+    DynamicPrintConfig config;
+    config.set_key_value("layer_height", new ConfigOptionFloat(0.2));
+    config.set_key_value("wall_loops", new ConfigOptionInt(3));
+    config.set_key_value("filament_type", new ConfigOptionStrings({ "PLA", "PETG" }));
+    config.set_key_value("machine_start_gcode", new ConfigOptionString("G28\nG1 Z5"));
+
+    ScopedTemporaryFile tmp(".json");
+    config.save_to_json(tmp.string(), "test_preset", "User", "1.0.0.0");
+    std::string file_contents;
+    {
+        boost::nowide::ifstream ifs(tmp.string());
+        file_contents.assign(std::istreambuf_iterator<char>(ifs), std::istreambuf_iterator<char>());
+    }
+    // The file format: one tab per nesting level and a trailing newline.
+    REQUIRE_FALSE(file_contents.empty());
+    CHECK(file_contents.rfind("{\n\t\"", 0) == 0);
+    CHECK(file_contents.back() == '\n');
+
+    std::ostringstream strict, replaced;
+    config.save_to_json(strict, "test_preset", "User", "1.0.0.0");
+    config.save_to_json(replaced, "test_preset", "User", "1.0.0.0", true);
+    CHECK(strict.str() == file_contents);
+    CHECK(replaced.str() == file_contents);
+    CHECK(nlohmann::json::parse(strict.str())["machine_start_gcode"] == "G28\nG1 Z5");
+}
+
+TEST_CASE("save_to_json replaces invalid UTF-8 in a stream only when asked", "[Config]") {
+    DynamicPrintConfig config;
+    config.set_key_value("machine_start_gcode", new ConfigOptionString("G28 ; \xff"));
+
+    std::ostringstream strict, replaced;
+    CHECK_THROWS_AS(config.save_to_json(strict, "test_preset", "User", "1.0.0.0"), nlohmann::json::type_error);
+    REQUIRE_NOTHROW(config.save_to_json(replaced, "test_preset", "User", "1.0.0.0", true));
+    CHECK(nlohmann::json::parse(replaced.str())["machine_start_gcode"] == "G28 ; \xEF\xBF\xBD");
+}
+
+TEST_CASE("save_to_json leaves an existing file untouched when the config cannot be serialized", "[Config]") {
+    DynamicPrintConfig config;
+    config.set_key_value("machine_start_gcode", new ConfigOptionString("G28 ; \xff"));
+
+    ScopedTemporaryFile tmp(".json");
+    {
+        boost::nowide::ofstream ofs(tmp.string());
+        ofs << "previous";
+    }
+    CHECK_THROWS_AS(config.save_to_json(tmp.string(), "test_preset", "User", "1.0.0.0"), nlohmann::json::type_error);
+
+    boost::nowide::ifstream ifs(tmp.string());
+    const std::string contents((std::istreambuf_iterator<char>(ifs)), std::istreambuf_iterator<char>());
+    CHECK(contents == "previous");
+}
+
 TEST_CASE("plugin capability references survive string-map serialization", "[Config][plugins]") {
     const std::vector<std::string> refs = {
         "master_plugin;;header-stamp",
@@ -828,3 +883,391 @@ SCENARIO("ConfigOptionVector::set_to_index throws on incompatible type", "[Confi
         }
     }
 }
+
+TEST_CASE("read_cli applies valid values and collects non-option arguments", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--nozzle-temperature", "210,190", "--reduce-crossing-wall=1", "model.3mf"};
+    REQUIRE(config.read_cli(5, argv, &extra, &keys));
+    REQUIRE(config.opt<ConfigOptionInts>("nozzle_temperature")->values == std::vector<int>{210, 190});
+    REQUIRE(config.opt<ConfigOptionBool>("reduce_crossing_wall")->value);
+    REQUIRE(extra == t_config_option_keys{"model.3mf"});
+    REQUIRE(keys == t_config_option_keys{"nozzle_temperature", "reduce_crossing_wall"});
+}
+
+TEST_CASE("read_cli rejects nil for a non-nullable vector option", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--nozzle-temperature", "nil"};
+    REQUIRE_FALSE(config.read_cli(3, argv, &extra, &keys));
+}
+
+TEST_CASE("read_cli rejects an invalid boolean value", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--reduce-crossing-wall=maybe"};
+    REQUIRE_FALSE(config.read_cli(2, argv, &extra, &keys));
+}
+
+TEST_CASE("read_cli accepts the common spellings of a boolean value", "[Config]") {
+    const auto [text, expected] = GENERATE(table<const char*, bool>({
+        {"--reduce-crossing-wall=1", true},
+        {"--reduce-crossing-wall=true", true},
+        {"--reduce-crossing-wall=Yes", true},
+        {"--reduce-crossing-wall=on", true},
+        {"--reduce-crossing-wall=enabled", true},
+        {"--reduce-crossing-wall=TRUE", true},
+        {"--reduce-crossing-wall=oN", true},
+        {"--reduce-crossing-wall=0", false},
+        {"--reduce-crossing-wall=false", false},
+        {"--reduce-crossing-wall=No", false},
+        {"--reduce-crossing-wall=off", false},
+        {"--reduce-crossing-wall=disabled", false},
+        {"--reduce-crossing-wall=FALSE", false},
+        {"--reduce-crossing-wall=DiSaBlEd", false},
+    }));
+
+    DYNAMIC_SECTION(text) {
+        Slic3r::DynamicPrintConfig config;
+        t_config_option_keys extra, keys;
+        const char* argv[] = {"orca-slicer", text};
+        REQUIRE(config.read_cli(2, argv, &extra, &keys));
+        REQUIRE(config.opt<ConfigOptionBool>("reduce_crossing_wall")->value == expected);
+    }
+}
+
+TEST_CASE("read_cli accepts the common boolean spellings inside a bools vector", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--filament-soluble=true,no,1"};
+    REQUIRE(config.read_cli(2, argv, &extra, &keys));
+    REQUIRE(config.opt<ConfigOptionBools>("filament_soluble")->values == std::vector<unsigned char>{1, 0, 1});
+}
+
+TEST_CASE("read_cli trims whitespace around boolean spellings", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--reduce-crossing-wall= true ", "--filament-soluble= true , no ,1"};
+    REQUIRE(config.read_cli(3, argv, &extra, &keys));
+    REQUIRE(config.opt<ConfigOptionBool>("reduce_crossing_wall")->value);
+    REQUIRE(config.opt<ConfigOptionBools>("filament_soluble")->values == std::vector<unsigned char>{1, 0, 1});
+}
+
+TEST_CASE("read_cli normalizes boolean spellings when a bools vector is repeated", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--filament-soluble=true", "--filament-soluble=off"};
+    REQUIRE(config.read_cli(3, argv, &extra, &keys));
+    REQUIRE(config.opt<ConfigOptionBools>("filament_soluble")->values == std::vector<unsigned char>{1, 0});
+}
+
+TEST_CASE("read_cli keeps nil alongside boolean spellings in a nullable bools vector", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--enable-overhang-speed=nil,yes,off"};
+    REQUIRE(config.read_cli(2, argv, &extra, &keys));
+    auto* opt = config.opt<ConfigOptionBoolsNullable>("enable_overhang_speed");
+    REQUIRE(opt != nullptr);
+    REQUIRE(opt->values.size() == 3);
+    REQUIRE(opt->is_nil(0));
+    REQUIRE(opt->values[1] == 1);
+    REQUIRE(opt->values[2] == 0);
+}
+
+TEST_CASE("read_cli rejects an empty item inside a bools vector", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--filament-soluble=true,,1"};
+    REQUIRE_FALSE(config.read_cli(2, argv, &extra, &keys));
+}
+
+TEST_CASE("read_cli rejects an unknown spelling next to a valid one in a bools vector", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--filament-soluble=true,affirmative"};
+    REQUIRE_FALSE(config.read_cli(2, argv, &extra, &keys));
+}
+
+// The normalization lives in read_cli's boolean branches, so options of other types keep the
+// value verbatim - a path named "on" or a colour named "true" must not turn into "1".
+TEST_CASE("read_cli leaves boolean spellings alone for non-boolean options", "[Config]") {
+    SECTION("string option") {
+        Slic3r::DynamicPrintAndCLIConfig config;
+        t_config_option_keys extra, keys;
+        const char* argv[] = {"orca-slicer", "--logfile=true"};
+        REQUIRE(config.read_cli(2, argv, &extra, &keys));
+        REQUIRE(config.opt<ConfigOptionString>("logfile")->value == "true");
+    }
+    SECTION("strings vector option") {
+        Slic3r::DynamicPrintConfig config;
+        t_config_option_keys extra, keys;
+        const char* argv[] = {"orca-slicer", "--filament-colour=on;off"};
+        REQUIRE(config.read_cli(2, argv, &extra, &keys));
+        REQUIRE(config.opt<ConfigOptionStrings>("filament_colour")->values == std::vector<std::string>{"on", "off"});
+    }
+}
+
+TEST_CASE("read_cli treats a bare boolean flag as true without consuming the next argument", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--reduce-crossing-wall", "model.3mf"};
+    REQUIRE(config.read_cli(3, argv, &extra, &keys));
+    REQUIRE(config.opt<ConfigOptionBool>("reduce_crossing_wall")->value);
+    REQUIRE(extra == t_config_option_keys{"model.3mf"});
+}
+
+TEST_CASE("read_cli rejects an invalid scalar numeric value", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--top-shell-layers", "several"};
+    REQUIRE_FALSE(config.read_cli(3, argv, &extra, &keys));
+}
+
+TEST_CASE("read_cli appends values when a vector option is repeated", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--nozzle-temperature", "210", "--nozzle-temperature", "190,200"};
+    REQUIRE(config.read_cli(5, argv, &extra, &keys));
+    REQUIRE(config.opt<ConfigOptionInts>("nozzle_temperature")->values == std::vector<int>{210, 190, 200});
+    // the key is recorded once, on first use
+    REQUIRE(keys == t_config_option_keys{"nozzle_temperature"});
+}
+
+TEST_CASE("read_cli parses a bools vector given in the --flag=values form", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--filament-soluble=1,0,1"};
+    REQUIRE(config.read_cli(2, argv, &extra, &keys));
+    REQUIRE(config.opt<ConfigOptionBools>("filament_soluble")->values == std::vector<unsigned char>{1, 0, 1});
+}
+
+TEST_CASE("read_cli rejects an invalid value inside a bools vector", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--filament-soluble=1,maybe"};
+    REQUIRE_FALSE(config.read_cli(2, argv, &extra, &keys));
+}
+
+TEST_CASE("read_cli appends true for a bare bools vector flag", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--filament-soluble"};
+    REQUIRE(config.read_cli(2, argv, &extra, &keys));
+    REQUIRE(config.opt<ConfigOptionBools>("filament_soluble")->values == std::vector<unsigned char>{1});
+}
+
+TEST_CASE("read_cli splits a strings vector on semicolons and unescapes quoted items", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--filament-colour", "#FF0000;\"a\\nb\";#00FF00"};
+    REQUIRE(config.read_cli(3, argv, &extra, &keys));
+    auto& values = config.opt<ConfigOptionStrings>("filament_colour")->values;
+    REQUIRE(values == std::vector<std::string>{"#FF0000", "a\nb", "#00FF00"});
+}
+
+TEST_CASE("read_cli rejects a strings vector with an unterminated quote", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--filament-colour", "\"oops"};
+    REQUIRE_FALSE(config.read_cli(3, argv, &extra, &keys));
+}
+
+TEST_CASE("read_cli parses a points vector in the NxM coordinate form", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--printable-area", "0x0,200x0,200x200,0x200"};
+    REQUIRE(config.read_cli(3, argv, &extra, &keys));
+    auto& points = config.opt<ConfigOptionPoints>("printable_area")->values;
+    REQUIRE(points.size() == 4);
+    REQUIRE_THAT(points[1].x(), Catch::Matchers::WithinAbs(200.0, 1e-9));
+    REQUIRE_THAT(points[1].y(), Catch::Matchers::WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(points[3].x(), Catch::Matchers::WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(points[3].y(), Catch::Matchers::WithinAbs(200.0, 1e-9));
+}
+
+// logfile is a CLI-only option, so it needs the config type whose def pulls in cli_misc_config_def.
+TEST_CASE("read_cli stores the log file path as a string", "[Config]") {
+    Slic3r::DynamicPrintAndCLIConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--logfile", "orca.log"};
+    REQUIRE(config.read_cli(3, argv, &extra, &keys));
+    REQUIRE(config.opt<ConfigOptionString>("logfile")->value == "orca.log");
+}
+
+TEST_CASE("read_cli accepts nil entries for a nullable vector option", "[Config]") {
+    Slic3r::DynamicPrintConfig config;
+    t_config_option_keys extra, keys;
+    const char* argv[] = {"orca-slicer", "--filament-retraction-length", "nil,2.5"};
+    REQUIRE(config.read_cli(3, argv, &extra, &keys));
+    auto* opt = config.opt<ConfigOptionFloatsNullable>("filament_retraction_length");
+    REQUIRE(opt != nullptr);
+    REQUIRE(opt->values.size() == 2);
+    REQUIRE(opt->is_nil(0));
+    REQUIRE_FALSE(opt->is_nil(1));
+    REQUIRE_THAT(opt->values[1], Catch::Matchers::WithinAbs(2.5, 1e-9));
+}
+
+// get_at() returns values.front() for an out-of-range index, so calling it on an empty vector
+// option is UB. filament_id and filament_is_support are unpopulated on a CLI from-scratch slice.
+TEST_CASE("get_filament_type treats empty vector options as absent", "[Config][Filament]")
+{
+    DynamicPrintConfig config;
+    std::string displayed;
+
+    SECTION("an empty filament_type yields no type at all")
+    {
+        config.set_key_value("filament_type", new ConfigOptionStrings());
+        REQUIRE(config.get_filament_type(displayed, 0) == "");
+    }
+
+    SECTION("an empty filament_is_support falls back to the plain filament type")
+    {
+        config.set_key_value("filament_type", new ConfigOptionStrings({"PETG"}));
+        config.set_key_value("filament_is_support", new ConfigOptionBools());
+        REQUIRE(config.get_filament_type(displayed, 0) == "PETG");
+        REQUIRE(displayed == "PETG");
+    }
+
+    SECTION("a support filament with an empty filament_id resolves from the type alone")
+    {
+        config.set_key_value("filament_type", new ConfigOptionStrings({"PLA"}));
+        config.set_key_value("filament_is_support", new ConfigOptionBools({true}));
+        config.set_key_value("filament_id", new ConfigOptionStrings());
+        REQUIRE(config.get_filament_type(displayed, 0) == "PLA-S");
+        REQUIRE(displayed == "Sup.PLA");
+    }
+
+    SECTION("a populated filament_id still selects the support type by id")
+    {
+        config.set_key_value("filament_type", new ConfigOptionStrings({"PETG"}));
+        config.set_key_value("filament_is_support", new ConfigOptionBools({true}));
+        config.set_key_value("filament_id", new ConfigOptionStrings({"GFS00"}));
+        REQUIRE(config.get_filament_type(displayed, 0) == "PLA-S");
+        REQUIRE(displayed == "Sup.PLA");
+    }
+}
+
+namespace {
+
+// min_object_distance reads exactly these three options.
+DynamicPrintConfig spacing_config(PrinterTechnology tech, PrintSequence seq, double clearance_radius)
+{
+    DynamicPrintConfig c;
+    c.set_key_value("printer_technology", new ConfigOptionEnum<PrinterTechnology>(tech));
+    c.set_key_value("print_sequence", new ConfigOptionEnum<PrintSequence>(seq));
+    c.set_key_value("extruder_clearance_radius", new ConfigOptionFloat(clearance_radius));
+    return c;
+}
+
+} // namespace
+
+TEST_CASE("min_object_distance floors object spacing per print sequence", "[Config]")
+{
+    struct Case
+    {
+        std::string       description;
+        PrinterTechnology tech;
+        PrintSequence     sequence;
+        double            clearance_radius;
+        double            expected;
+    };
+
+    auto c = GENERATE(values<Case>({
+        {"sequential FFF takes a clearance radius above the floor", ptFFF, PrintSequence::ByObject, 12., 12.},
+        {"sequential FFF holds the floor at the radius",            ptFFF, PrintSequence::ByObject,  6.,  6.},
+        {"sequential FFF holds the floor below the radius",         ptFFF, PrintSequence::ByObject,  4.,  6.},
+        {"layered FFF ignores the clearance radius",                ptFFF, PrintSequence::ByLayer,  12.,  6.},
+        {"SLA is a flat 6mm",                                       ptSLA, PrintSequence::ByObject, 12.,  6.},
+        {"SLA ignores the print sequence too",                      ptSLA, PrintSequence::ByLayer,  12.,  6.},
+    }));
+
+    DYNAMIC_SECTION(c.description)
+    {
+        CHECK_THAT(min_object_distance(spacing_config(c.tech, c.sequence, c.clearance_radius)),
+                   Catch::Matchers::WithinAbs(c.expected, 1e-9));
+    }
+}
+
+TEST_CASE("min_object_distance yields no floor when an FFF config lacks the options", "[Config]")
+{
+    // Missing options yield 0 rather than an error, so a caller gets no floor at all.
+    SECTION("no clearance radius") {
+        DynamicPrintConfig c;
+        c.set_key_value("printer_technology", new ConfigOptionEnum<PrinterTechnology>(ptFFF));
+        c.set_key_value("print_sequence", new ConfigOptionEnum<PrintSequence>(PrintSequence::ByObject));
+        CHECK_THAT(min_object_distance(c), Catch::Matchers::WithinAbs(0., 1e-9));
+    }
+
+    SECTION("no print sequence") {
+        DynamicPrintConfig c;
+        c.set_key_value("printer_technology", new ConfigOptionEnum<PrinterTechnology>(ptFFF));
+        c.set_key_value("extruder_clearance_radius", new ConfigOptionFloat(12.));
+        CHECK_THAT(min_object_distance(c), Catch::Matchers::WithinAbs(0., 1e-9));
+    }
+
+    SECTION("nothing at all") {
+        CHECK_THAT(min_object_distance(DynamicPrintConfig{}), Catch::Matchers::WithinAbs(0., 1e-9));
+    }
+
+    SECTION("an unset printer technology is treated as FFF") {
+        DynamicPrintConfig c;
+        c.set_key_value("print_sequence", new ConfigOptionEnum<PrintSequence>(PrintSequence::ByObject));
+        c.set_key_value("extruder_clearance_radius", new ConfigOptionFloat(12.));
+        CHECK_THAT(min_object_distance(c), Catch::Matchers::WithinAbs(12., 1e-9));
+    }
+}
+
+TEST_CASE("Static print configs compare, order and hash by their option values", "[Config]")
+{
+    // PrintObjectConfig comes from PRINT_CONFIG_CLASS_DEFINE; PrintConfig combines MachineEnvelopeConfig
+    // and GCodeConfig through PRINT_CONFIG_CLASS_DERIVED_DEFINE. Both generate hash(), operator==,
+    // operator< and the option registration from the same option list. The hash inequalities use fixed
+    // inputs, so they are deterministic; they check that hash() covers the changed option.
+    SECTION("default-constructed configs are equal and find their options by key")
+    {
+        PrintObjectConfig a, b;
+        REQUIRE(a == b);
+        REQUIRE(a.hash() == b.hash());
+        REQUIRE_FALSE(a < b);
+        REQUIRE_FALSE(b < a);
+        REQUIRE(a.optptr("layer_height") == &a.layer_height);
+        REQUIRE(a.optptr("brim_object_gap") == &a.brim_object_gap);
+    }
+
+    SECTION("one differing option makes the configs unequal and orders them")
+    {
+        PrintObjectConfig a, b;
+        b.layer_height.value = a.layer_height.value + 0.05;
+        REQUIRE(a != b);
+        REQUIRE(a.hash() != b.hash());
+        REQUIRE(a < b);
+        REQUIRE_FALSE(b < a);
+    }
+
+    SECTION("ordering is decided by the first option in declaration order that differs")
+    {
+        PrintObjectConfig a, b;
+        a.brim_object_gap.value = b.brim_object_gap.value + 1.0;  // declared first
+        a.layer_height.value    = b.layer_height.value - 0.05;    // declared later, points the other way
+        REQUIRE(b < a);
+        REQUIRE_FALSE(a < b);
+    }
+
+    SECTION("a derived config sees differences in its parents and in its own options")
+    {
+        PrintConfig a, b;
+        REQUIRE(a == b);
+        REQUIRE(a.hash() == b.hash());
+
+        b.gcode_flavor.value = b.gcode_flavor.value == gcfMarlinLegacy ? gcfKlipper : gcfMarlinLegacy;  // GCodeConfig parent
+        REQUIRE(a != b);
+        REQUIRE(a.hash() != b.hash());
+
+        PrintConfig c, d;
+        d.skirt_distance.value = c.skirt_distance.value + 1.0;  // PrintConfig's own list
+        REQUIRE(c != d);
+        REQUIRE(c.hash() != d.hash());
+        REQUIRE(c.optptr("skirt_distance") == &c.skirt_distance);
+        REQUIRE(c.optptr("gcode_flavor") == &c.gcode_flavor);
+    }
+}

tests/libslic3r/test_config_variant_expansion.cpp

@@ -130,6 +130,12 @@ TEST_CASE("get_config_index_base resolves (volume type, extruder type, id) to a
     }
 }
 
+TEST_CASE("support interface pattern registry includes spiral inset", "[Config]")
+{
+    const auto &values = ConfigOptionEnum<SupportMaterialInterfacePattern>::get_enum_values();
+    REQUIRE(values.at("spiralinset") == SupportMaterialInterfacePattern::smipSpiralInset);
+}
+
 TEST_CASE("get_extruder_nozzle_volume_count reads the per-extruder volume-type layout", "[Config]")
 {
     std::vector<std::vector<NozzleVolumeType>> nozzle_volume_types;
@@ -478,4 +484,113 @@ TEST_CASE("update_values_to_printer_extruders_for_multiple_filaments resolves pe
         REQUIRE(config.option<ConfigOptionFloats>("filament_max_volumetric_speed")->values == std::vector<double>({12., 21.}));
         REQUIRE(config.option<ConfigOptionInts>("filament_self_index")->values == std::vector<int>({1, 2}));
     }
+
+    SECTION("a variant option shorter than the filament slots keeps its first value instead of zero") {
+        DynamicPrintConfig config;
+        config.option<ConfigOptionEnumsGeneric>("extruder_type", true)->values = {etDirectDrive, etDirectDrive};
+        config.option<ConfigOptionEnumsGeneric>("nozzle_volume_type", true)->values = {nvtStandard, nvtHighFlow};
+        config.option<ConfigOptionStrings>("extruder_variant_list", true)->values = {"Direct Drive Standard,Direct Drive High Flow",
+                                                                                     "Direct Drive Standard,Direct Drive High Flow"};
+        make_filament_arrays(config);
+        config.option<ConfigOptionInts>("filament_map", true)->values = {1, 2};
+        // no loaded preset carries the key, so only its single registered default is present
+        config.option<ConfigOptionFloatsNullable>("filament_cooling_before_tower", true)->values = {10.};
+        // only the first filament's two variant columns were loaded
+        config.option<ConfigOptionFloatsNullable>("filament_ramming_volumetric_speed", true)->values = {-1., -2.};
+
+        std::vector<std::vector<NozzleVolumeType>> nozzle_volume_types;
+        int extruder_count = 2;
+        int count = config.get_extruder_nozzle_volume_count(extruder_count, nozzle_volume_types);
+
+        config.update_values_to_printer_extruders_for_multiple_filaments(config, extruder_count, count, filament_keys,
+            "filament_self_index", "filament_extruder_variant");
+
+        // filament 2 resolves to column 3 (its extruder's High Flow column), past the end of both vectors
+        REQUIRE_THAT(config.option<ConfigOptionFloatsNullable>("filament_cooling_before_tower")->values,
+                     Catch::Matchers::Approx(std::vector<double>({10., 10.})));
+        REQUIRE_THAT(config.option<ConfigOptionFloatsNullable>("filament_ramming_volumetric_speed")->values,
+                     Catch::Matchers::Approx(std::vector<double>({-1., -1.})));
+        REQUIRE(config.option<ConfigOptionFloats>("filament_max_volumetric_speed")->values == std::vector<double>({12., 21.}));
+    }
+}
+
+// update_values_from_multi_to_multi_2 walks the DESTINATION PRINTER's variant list while writing
+// into a row taken from the destination PRINT preset, whose arrays are sized to its own
+// print_extruder_variant. Those two widths disagree until the print preset is re-selected for the
+// new printer -- Tab::load_current_preset() runs this migration first -- so a project authored on
+// a single-variant printer, opened and switched to a wider one, wrote past the end of the row.
+TEST_CASE("update_values_from_multi_to_multi_2 sizes the destination row to the variant count",
+          "[Config][VariantExpansion]")
+{
+    const std::vector<std::string> src_variants{"Direct Drive Standard"};
+    const std::vector<std::string> dst_variants{"Direct Drive Standard", "Direct Drive High Flow",
+                                                "Direct Drive Standard", "Direct Drive High Flow"};
+    const std::set<std::string>    keys{"outer_wall_speed"};
+
+    // The per-object override as authored on the single-variant printer.
+    const auto object_override = [] {
+        DynamicPrintConfig c;
+        c.option<ConfigOptionFloatsNullable>("outer_wall_speed", true)->values = {42.};
+        return c;
+    };
+
+    SECTION("a row narrower than the variant list is grown, not overrun") {
+        DynamicPrintConfig object_config = object_override();
+        DynamicPrintConfig dst;
+        dst.option<ConfigOptionFloatsNullable>("outer_wall_speed", true)->values = {200.};
+
+        REQUIRE(object_config.update_values_from_multi_to_multi_2(src_variants, dst_variants, dst, keys) == 0);
+
+        const auto& out = object_config.option<ConfigOptionFloatsNullable>("outer_wall_speed")->values;
+        REQUIRE(out.size() == dst_variants.size());
+        // Both "Direct Drive Standard" columns match the source variant, so they take the override.
+        CHECK(out[0] == Catch::Approx(42.));
+        CHECK(out[2] == Catch::Approx(42.));
+        // The High Flow columns have no matching source variant: nil, so the destination keeps
+        // tracking the print preset rather than being pinned to another variant's value.
+        CHECK(std::isnan(out[1]));
+        CHECK(std::isnan(out[3]));
+    }
+
+    // The regression guard: where the row already matches the variant list -- every case that was
+    // not corrupting the heap -- the resize is a no-op and the output is unchanged.
+    SECTION("a correctly sized row is untouched") {
+        DynamicPrintConfig object_config = object_override();
+        DynamicPrintConfig dst;
+        dst.option<ConfigOptionFloatsNullable>("outer_wall_speed", true)->values = {200., 500., 210., 510.};
+
+        REQUIRE(object_config.update_values_from_multi_to_multi_2(src_variants, dst_variants, dst, keys) == 0);
+
+        const auto& out = object_config.option<ConfigOptionFloatsNullable>("outer_wall_speed")->values;
+        REQUIRE(out.size() == 4);
+        CHECK(out[0] == Catch::Approx(42.));    // matched -> override
+        CHECK(out[1] == Catch::Approx(500.));   // unmatched -> preset value preserved
+        CHECK(out[2] == Catch::Approx(42.));
+        CHECK(out[3] == Catch::Approx(510.));
+    }
+
+    // is_nil(idx) indexes values[idx] with no bounds check, so a source shorter than its own
+    // variant list read out of range before the guard was added.
+    SECTION("a source shorter than its variant list is read in range") {
+        DynamicPrintConfig object_config = object_override();   // one value...
+        DynamicPrintConfig dst;
+        dst.option<ConfigOptionFloatsNullable>("outer_wall_speed", true)->values = {200., 500.};
+
+        REQUIRE(object_config.update_values_from_multi_to_multi_2(
+            {"Direct Drive Standard", "Direct Drive Standard"},   // ...but two source variants
+            {"Direct Drive Standard", "Direct Drive High Flow"}, dst, keys) == 0);
+
+        const auto& out = object_config.option<ConfigOptionFloatsNullable>("outer_wall_speed")->values;
+        REQUIRE(out.size() == 2);
+        CHECK(out[0] == Catch::Approx(42.));
+        CHECK(out[1] == Catch::Approx(500.));
+    }
+
+    SECTION("an empty destination variant list is refused") {
+        DynamicPrintConfig object_config = object_override();
+        DynamicPrintConfig dst;
+        dst.option<ConfigOptionFloatsNullable>("outer_wall_speed", true)->values = {200.};
+
+        CHECK(object_config.update_values_from_multi_to_multi_2(src_variants, {}, dst, keys) == -1);
+    }
 }

tests/libslic3r/test_lay_on_face.cpp

@@ -0,0 +1,205 @@
+#include <catch2/catch_all.hpp>
+
+#include "libslic3r/LayOnFace.hpp"
+#include "libslic3r/Model.hpp"
+
+using namespace Slic3r;
+using Catch::Matchers::WithinAbs;
+
+namespace {
+
+// Adds a box part spanning `origin` to `origin + size`, in object coordinates.
+void add_box(ModelObject &object, const Vec3d &size, const Vec3d &origin = Vec3d::Zero())
+{
+    TriangleMesh mesh = make_cube(size.x(), size.y(), size.z());
+    mesh.translate(origin.cast<float>());
+    object.add_volume(std::move(mesh), ModelVolumeType::MODEL_PART, false);
+}
+
+ModelObject &add_box_object(Model &model, const Vec3d &size)
+{
+    ModelObject *object = model.add_object();
+    add_box(*object, size);
+    object->add_instance();
+    return *object;
+}
+
+// A 30 x 30 x 2 plate with three 1 mm thick, 20 mm tall ribs along Y. The rib sides facing -X add up
+// to more area than the plate's bottom, but only the bottom is a face of the convex hull.
+ModelObject &add_ribbed_plate(Model &model)
+{
+    ModelObject *object = model.add_object();
+    add_box(*object, { 30, 30, 2 });
+    for (double x : { 5., 14.5, 24. })
+        add_box(*object, { 1, 30, 20 }, { x, 0, 2 });
+    object->add_instance();
+    return *object;
+}
+
+std::vector<LayOnFacePlane> instance_planes(const ModelObject &object)
+{
+    return lay_on_face_planes(object, object.instances.front()->get_matrix_no_offset());
+}
+
+void lay_on_largest_face(ModelObject &object)
+{
+    const std::vector<LayOnFacePlane> planes = instance_planes(object);
+    const int                         idx    = find_largest_plane(planes);
+    REQUIRE(idx >= 0);
+    lay_on_face(object, 0, planes[idx].normal);
+}
+
+void check_size(const ModelObject &object, const Vec3d &expected)
+{
+    const Vec3d size = object.instance_bounding_box(0).size();
+    CHECK_THAT(size.x(), WithinAbs(expected.x(), 1e-3));
+    CHECK_THAT(size.y(), WithinAbs(expected.y(), 1e-3));
+    CHECK_THAT(size.z(), WithinAbs(expected.z(), 1e-3));
+}
+
+void check_on_bed(const ModelObject &object) { CHECK_THAT(object.instance_bounding_box(0).min.z(), WithinAbs(0., 1e-3)); }
+
+} // namespace
+
+TEST_CASE("A tilted box is laid on its largest face and dropped onto the bed", "[LayOnFace]")
+{
+    Model        model;
+    ModelObject &box = add_box_object(model, { 40, 20, 10 }); // the 40 x 20 faces are the largest
+    box.instances.front()->set_rotation({ 0.3, 0.5, 0.2 });
+    box.instances.front()->set_offset({ 0, 0, 50 });
+    REQUIRE(box.instance_bounding_box(0).size().z() > 11.);
+
+    const std::vector<LayOnFacePlane> planes = instance_planes(box);
+    REQUIRE(planes.size() == 6);
+    CHECK_THAT(planes.front().area, WithinAbs(40. * 20., 1e-2));
+
+    lay_on_largest_face(box);
+    CHECK_THAT(box.instance_bounding_box(0).size().z(), WithinAbs(10., 1e-3));
+    check_on_bed(box);
+}
+
+TEST_CASE("A box lying on one of its equally large faces is not flipped", "[LayOnFace]")
+{
+    // A half turn about X puts the other large face down, so the two cases expect different faces
+    // and neither can pass on the order in which the hull lists them.
+    const double rotation_x = GENERATE(0., PI);
+    Model        model;
+    ModelObject &box = add_box_object(model, { 40, 20, 10 }); // the bottom and top are both 40 x 20
+    box.instances.front()->set_rotation({ rotation_x, 0, 0 });
+    const Transform3d before = box.instances.front()->get_matrix_no_offset();
+
+    const std::vector<LayOnFacePlane> planes = instance_planes(box);
+    const int                         idx    = find_largest_plane(planes);
+    REQUIRE(idx >= 0);
+    // The face down on the plate is the object's -Z face, or its +Z face after the half turn.
+    CHECK_THAT(planes[idx].normal.z(), WithinAbs(rotation_x == 0. ? -1. : 1., 1e-6));
+
+    lay_on_face(box, 0, planes[idx].normal);
+    CHECK(box.instances.front()->get_matrix_no_offset().isApprox(before, 1e-9));
+}
+
+TEST_CASE("Faces are chosen from the orientation left by an earlier part rotation", "[LayOnFace]")
+{
+    Model        model;
+    ModelObject &box = add_box_object(model, { 40, 20, 10 });
+    box.rotate(PI / 2., X); // what --rotate-x 90 does: rotates the parts, not the instance
+    check_size(box, { 40, 10, 20 });
+
+    SECTION("the largest face") {
+        lay_on_largest_face(box);
+        check_size(box, { 40, 20, 10 });
+        check_on_bed(box);
+    }
+
+    SECTION("the face pointing along +X") {
+        const std::vector<LayOnFacePlane> planes = instance_planes(box);
+        const int                         idx    = find_plane_by_normal(planes, { 1, 0, 0 });
+        REQUIRE(idx >= 0);
+        CHECK_THAT(planes[idx].normal.x(), WithinAbs(1., 1e-6));
+        lay_on_face(box, 0, planes[idx].normal);
+        check_size(box, { 20, 10, 40 });
+        check_on_bed(box);
+    }
+}
+
+TEST_CASE("Objects are laid on their own faces independently", "[LayOnFace]")
+{
+    Model model;
+    // Standing on end through its instance rotation.
+    ModelObject &standing = add_box_object(model, { 40, 20, 10 });
+    standing.instances.front()->set_rotation({ 0, PI / 2., 0 });
+    // Standing on edge through a part rotation, lifted above the bed.
+    ModelObject &on_edge = add_box_object(model, { 30, 20, 5 });
+    on_edge.rotate(PI / 2., X);
+    on_edge.instances.front()->set_offset({ 100, 0, 30 });
+    check_size(standing, { 10, 20, 40 });
+    check_size(on_edge, { 30, 5, 20 });
+
+    for (ModelObject *object : model.objects)
+        lay_on_largest_face(*object);
+
+    check_size(standing, { 40, 20, 10 });
+    check_on_bed(standing);
+    check_size(on_edge, { 30, 20, 5 });
+    check_on_bed(on_edge);
+}
+
+TEST_CASE("A part rests on its largest hull face even when parallel inner faces add up to more area", "[LayOnFace]")
+{
+    Model        model;
+    ModelObject &plate = add_ribbed_plate(model);
+
+    double area_facing_minus_x = 0.;
+    for (const ModelVolume *volume : plate.volumes) {
+        const indexed_triangle_set &its = volume->mesh().its;
+        for (const Vec3i32 &face : its.indices) {
+            const Vec3d cross = (its.vertices[face[1]] - its.vertices[face[0]]).cast<double>().cross(
+                (its.vertices[face[2]] - its.vertices[face[0]]).cast<double>());
+            if (cross.normalized().x() < -0.999)
+                area_facing_minus_x += 0.5 * cross.norm();
+        }
+    }
+    // Summing triangle area per normal would pick a rib side over the 900 mm² bottom.
+    REQUIRE(area_facing_minus_x > 30. * 30.);
+
+    plate.instances.front()->set_rotation({ 0, PI / 2., 0 }); // stand the plate on its side
+    check_size(plate, { 22, 30, 30 });
+
+    const std::vector<LayOnFacePlane> planes = instance_planes(plate);
+    const int                         idx    = find_largest_plane(planes);
+    REQUIRE(idx >= 0);
+    CHECK_THAT(planes[idx].area, WithinAbs(30. * 30., 1e-2));
+    CHECK_THAT(planes[idx].normal.z(), WithinAbs(-1., 1e-6));
+
+    lay_on_face(plate, 0, planes[idx].normal);
+    check_size(plate, { 30, 30, 22 });
+    check_on_bed(plate);
+}
+
+TEST_CASE("Faces are selected in object coordinates whatever the instance rotation", "[LayOnFace]")
+{
+    Model        model;
+    ModelObject &plate = add_ribbed_plate(model);
+    plate.instances.front()->set_rotation({ 0, 0, PI / 2. });
+    const Transform3d                 instance_matrix = plate.instances.front()->get_matrix_no_offset();
+    const std::vector<LayOnFacePlane> planes          = lay_on_face_planes(plate, instance_matrix);
+    REQUIRE_FALSE(planes.empty());
+
+    // Every face center, as --inspect-mesh reports it, selects its own face.
+    for (size_t i = 0; i < planes.size(); ++i)
+        CHECK(find_plane_at_point(planes, instance_matrix, planes[i].center, 0.01) == int(i));
+
+    const int bottom = find_plane_at_point(planes, instance_matrix, { 15, 15, 0 }, 0.01);
+    REQUIRE(bottom >= 0);
+    CHECK_THAT(planes[bottom].normal.z(), WithinAbs(-1., 1e-6));
+    CHECK(find_plane_by_normal(planes, { 0, 0, -1 }) == bottom);
+    // Above the bottom plane, and on a rib side that lies inside the hull.
+    CHECK(find_plane_at_point(planes, instance_matrix, { 15, 15, 0.5 }, 0.01) == -1);
+    CHECK(find_plane_at_point(planes, instance_matrix, { 14.5, 15, 12 }, 0.01) == -1);
+}
+
+TEST_CASE("A part too small to rest on offers no faces", "[LayOnFace]")
+{
+    Model model;
+    CHECK(instance_planes(add_box_object(model, { 2, 2, 2 })).empty()); // every face is 4 mm², under the 5 mm² minimum
+}

tests/libslic3r/test_marchingsquares.cpp

@@ -1,4 +1,6 @@
+#ifndef NOMINMAX
 #define NOMINMAX
+#endif
 
 #include <catch2/catch_all.hpp>
 #include "test_utils.hpp"

tests/libslic3r/test_minimum_spanning_tree.cpp

@@ -0,0 +1,66 @@
+#include <catch2/catch_all.hpp>
+
+#include <algorithm>
+
+#include "libslic3r/MinimumSpanningTree.hpp"
+#include "libslic3r/Point.hpp"
+
+using namespace Slic3r;
+
+// A 5x5 lattice: at every step of Prim's algorithm several candidates sit at the same
+// distance from the tree, so the tie-break decides the tree's shape.
+static std::vector<Point> lattice()
+{
+    std::vector<Point> vertices;
+    for (int y = 0; y < 5; ++y)
+        for (int x = 0; x < 5; ++x)
+            vertices.emplace_back(Point::new_scale(x, y));
+    return vertices;
+}
+
+static std::vector<Point> sorted_neighbours(const MinimumSpanningTree &mst, const Point &vertex)
+{
+    std::vector<Point> neighbours = mst.adjacent_nodes(vertex);
+    std::sort(neighbours.begin(), neighbours.end());
+    return neighbours;
+}
+
+TEST_CASE("Minimum spanning tree connects every vertex", "[MinimumSpanningTree]")
+{
+    const std::vector<Point> vertices = lattice();
+    const MinimumSpanningTree mst(vertices);
+
+    REQUIRE(mst.vertices().size() == vertices.size());
+    size_t adjacency_entries = 0;
+    for (const Point &vertex : vertices) {
+        const std::vector<Point> neighbours = mst.adjacent_nodes(vertex);
+        REQUIRE(! neighbours.empty());
+        adjacency_entries += neighbours.size();
+    }
+    // A tree on n vertices has n - 1 edges, each listed from both ends.
+    REQUIRE(adjacency_entries == 2 * (vertices.size() - 1));
+}
+
+TEST_CASE("Minimum spanning tree does not depend on the order of the non-root vertices", "[MinimumSpanningTree][Regression]")
+{
+    const std::vector<Point> vertices = lattice();
+    const MinimumSpanningTree reference(vertices);
+
+    // The root stays first: Prim's tree legitimately depends on where it starts.
+    // Every other order of the remaining vertices must give the same tree.
+    std::vector<std::vector<Point>> orders;
+    orders.emplace_back(vertices);
+    std::reverse(orders.back().begin() + 1, orders.back().end());
+    for (size_t shift = 1; shift + 1 < vertices.size(); ++shift) {
+        orders.emplace_back(vertices);
+        std::rotate(orders.back().begin() + 1, orders.back().begin() + 1 + shift, orders.back().end());
+    }
+
+    for (const std::vector<Point> &order : orders) {
+        const MinimumSpanningTree mst(order);
+        for (const Point &vertex : vertices) {
+            INFO("vertex " << vertex.x() << "," << vertex.y());
+            REQUIRE(sorted_neighbours(mst, vertex) == sorted_neighbours(reference, vertex));
+        }
+    }
+}

tests/libslic3r/test_preset_diff.cpp

@@ -33,3 +33,20 @@ TEST_CASE("deep_diff flags new vector entries that duplicate values[0]", "[Prese
     // specific to new indices rather than flagging the whole vector.
     REQUIRE(std::find(diff.begin(), diff.end(), "nozzle_diameter#0") == diff.end());
 }
+
+TEST_CASE("deep_diff distinguishes absolute and percentage speeds for each variant", "[PresetDiff][Config]")
+{
+    const size_t changed_index = GENERATE(size_t(0), size_t(1));
+    Preset reference(Preset::TYPE_PRINT, "ref");
+    reference.config.set_key_value("small_perimeter_speed", new ConfigOptionFloatsOrPercents{{50., false}, {50., false}});
+
+    Preset edited = reference;
+    edited.config.option<ConfigOptionFloatsOrPercents>("small_perimeter_speed")->values[changed_index].percent = true;
+
+    const auto diff = PresetCollection::dirty_options(&edited, &reference, /*deep_compare=*/true);
+    REQUIRE(diff == std::vector<std::string>{"small_perimeter_speed#" + std::to_string(changed_index)});
+
+    DynamicPrintConfig transferred = reference.config;
+    transferred.apply_only(edited.config, diff);
+    REQUIRE(*transferred.option("small_perimeter_speed") == *edited.config.option("small_perimeter_speed"));
+}

tests/libslic3r/test_preset_options.cpp

@@ -0,0 +1,70 @@
+// Regression test for the "option in def + UI but missing from preset key list"
+// crash class.
+//
+// The print preset's DynamicPrintConfig is seeded with only the keys returned by
+// Preset::print_options() (PresetBundle.cpp). A field added to PrintRegionConfig
+// or PrintObjectConfig and registered via print_config_def plus a TabPrint
+// optgroup, but left out of print_options(), still gets its control built; on tab
+// activation reload_config -> get_config_value dispatches to opt_bool/opt_int on a
+// DynamicPrintConfig with no entry for the key, and the accessor null-derefs the
+// result of option<T>(key).
+//
+// The invariant asserted here is the inverse: every key declared on
+// PrintRegionConfig and PrintObjectConfig appears in Preset::print_options() or
+// Preset::filament_options(), the two preset key lists that seed a print preset's
+// DynamicConfig.
+
+#include <catch2/catch_all.hpp>
+
+#include "libslic3r/Preset.hpp"
+#include "libslic3r/PrintConfig.hpp"
+
+#include <set>
+
+using namespace Slic3r;
+
+namespace {
+
+// Deprecated keys renamed in handle_legacy() (ironing_direction ->
+// ironing_angle, wall_infill_order -> wall_sequence); neither is in a
+// preset list. Register new options in a preset list, not here.
+const std::set<std::string> kDeprecatedRegionFields = {
+    "ironing_direction",
+    "wall_infill_order",
+};
+
+void check_keys_are_in_a_preset(const t_config_option_keys& keys, const std::string& class_name)
+{
+    REQUIRE_FALSE(keys.empty());
+    const auto& print_options    = Preset::print_options();
+    const auto& filament_options = Preset::filament_options();
+    const std::set<std::string> in_print(print_options.begin(), print_options.end());
+    const std::set<std::string> in_filament(filament_options.begin(), filament_options.end());
+    for (const std::string& key : keys) {
+        DYNAMIC_SECTION(class_name << "::" << key)
+        {
+            INFO("'" << key << "' on " << class_name
+                     << " is missing from "
+                        "Preset::print_options()/filament_options(); add it to "
+                        "s_Preset_print_options (or s_Preset_filament_options) in Preset.cpp.");
+            const bool registered = in_print.count(key) || in_filament.count(key) || kDeprecatedRegionFields.count(key);
+            REQUIRE(registered);
+        }
+    }
+}
+
+} // namespace
+
+// Bodies are laid out like the rest of the test suite rather than collapsed
+// onto the brace line.
+// clang-format off
+TEST_CASE("Every PrintRegionConfig field is registered in a preset key list", "[Preset][Config]")
+{
+    check_keys_are_in_a_preset(PrintRegionConfig::defaults().keys(), "PrintRegionConfig");
+}
+
+TEST_CASE("Every PrintObjectConfig field is registered in a preset key list", "[Preset][Config]")
+{
+    check_keys_are_in_a_preset(PrintObjectConfig::defaults().keys(), "PrintObjectConfig");
+}
+// clang-format on

tests/libslic3r/test_preset_setting_id.cpp

@@ -5,10 +5,10 @@
 using namespace Slic3r;
 
 // Golden vectors from the Python reference generate_preset_setting_id (defined in
-// scripts/assign_vendor_setting_ids.py). The C++ generate_preset_setting_id() MUST stay
-// byte-identical to it, otherwise app-side on-the-fly ids would diverge from the
+// scripts/orca_profile_tool.py). The C++ generate_preset_setting_id() MUST stay byte-identical
+// to it, otherwise app-side on-the-fly ids would diverge from the
 // script-assigned ones in the profiles. Regenerate a vector with:
-//   python3 -c "from assign_vendor_setting_ids import generate_preset_setting_id as g; print(g('Afinia','filament','Afinia ABS @Afinia H400'))"
+//   python3 -c "import sys; sys.path.insert(0, 'scripts'); from orca_profile_tool import generate_preset_setting_id as g; print(g('Afinia','filament','Afinia ABS @Afinia H400'))"
 TEST_CASE("preset setting_id matches the Python reference", "[Preset][setting_id]") {
     struct Vec { const char* vendor; const char* type; const char* name; const char* expected; };
     const Vec vectors[] = {

tests/libslic3r/test_sketchconstraints.cpp

@@ -0,0 +1,396 @@
+#include <catch2/catch_all.hpp>   // mainline OrcaSlicer ships Catch2 v3 (v2 was catch2/catch.hpp)
+#include "libslic3r/CAD/SketchConstraints.hpp"
+#include "libslic3r/CAD/SketchEngine.hpp"
+
+using namespace Slic3r;
+
+namespace {
+SketchEntity mk_line(double x0, double y0, double x1, double y1)
+{
+    SketchEntity e; e.type = SketchEntity::Type::Line;
+    e.p0 = Vec2d(x0, y0); e.p1 = Vec2d(x1, y1); return e;
+}
+SketchEntity mk_point(double x, double y)
+{
+    SketchEntity e; e.type = SketchEntity::Type::Point; e.p0 = Vec2d(x, y); return e;
+}
+SketchEntity mk_circle(double cx, double cy, double r)
+{
+    SketchEntity e; e.type = SketchEntity::Type::Circle;
+    e.center = Vec2d(cx, cy); e.radius = r; return e;
+}
+}
+
+TEST_CASE("Coincident with anchor", "[SketchConstraints]")
+{
+    SketchConstraints sc;
+    int a = sc.add_point(0, 0);
+    int b = sc.add_point(5, 5);
+    sc.fix_point(a);
+    sc.coincident(a, b);
+    REQUIRE(sc.solve());
+    Vec2d pb = sc.get_point(b);
+    REQUIRE_THAT(pb.x(), Catch::Matchers::WithinAbs(0.0, 1e-4));
+    REQUIRE_THAT(pb.y(), Catch::Matchers::WithinAbs(0.0, 1e-4));
+}
+
+TEST_CASE("Horizontal + distance", "[SketchConstraints]")
+{
+    SketchConstraints sc;
+    int a = sc.add_point(0, 0);
+    int b = sc.add_point(5, 3);
+    sc.fix_point(a);
+    sc.horizontal(a, b);
+    sc.distance(a, b, 10);
+    REQUIRE(sc.solve());
+    Vec2d pb = sc.get_point(b);
+    REQUIRE_THAT(pb.y(), Catch::Matchers::WithinAbs(0.0, 1e-3));
+    REQUIRE_THAT(std::abs(pb.x()), Catch::Matchers::WithinAbs(10.0, 1e-3));
+}
+
+TEST_CASE("Rectangle", "[SketchConstraints]")
+{
+    SketchConstraints sc;
+    int p0 = sc.add_point(0, 0);
+    int p1 = sc.add_point(8, 1);
+    int p2 = sc.add_point(9, 5);
+    int p3 = sc.add_point(-1, 4);
+    sc.fix_point(p0);
+    sc.lock_x(p0, 0);
+    sc.lock_y(p0, 0);
+    sc.horizontal(p0, p1);
+    sc.vertical(p1, p2);
+    sc.horizontal(p2, p3);
+    sc.vertical(p3, p0);
+    sc.distance(p0, p1, 10);
+    sc.distance(p1, p2, 6);
+    REQUIRE(sc.solve());
+    Vec2d pp1 = sc.get_point(p1);
+    Vec2d pp2 = sc.get_point(p2);
+    Vec2d pp3 = sc.get_point(p3);
+    REQUIRE_THAT(pp1.x(), Catch::Matchers::WithinAbs(10.0, 1e-3));
+    REQUIRE_THAT(pp1.y(), Catch::Matchers::WithinAbs(0.0, 1e-3));
+    REQUIRE_THAT(pp2.x(), Catch::Matchers::WithinAbs(10.0, 1e-3));
+    REQUIRE_THAT(pp2.y(), Catch::Matchers::WithinAbs(6.0, 1e-3));
+    REQUIRE_THAT(pp3.x(), Catch::Matchers::WithinAbs(0.0, 1e-3));
+    REQUIRE_THAT(pp3.y(), Catch::Matchers::WithinAbs(6.0, 1e-3));
+}
+
+TEST_CASE("residual_norm after each solve", "[SketchConstraints]")
+{
+    SECTION("coincident case")
+    {
+        SketchConstraints sc;
+        int a = sc.add_point(0, 0);
+        int b = sc.add_point(5, 5);
+        sc.fix_point(a);
+        sc.coincident(a, b);
+        REQUIRE(sc.solve());
+        REQUIRE(sc.residual_norm() < 1e-5);
+    }
+    SECTION("horizontal+distance case")
+    {
+        SketchConstraints sc;
+        int a = sc.add_point(0, 0);
+        int b = sc.add_point(5, 3);
+        sc.fix_point(a);
+        sc.horizontal(a, b);
+        sc.distance(a, b, 10);
+        REQUIRE(sc.solve());
+        REQUIRE(sc.residual_norm() < 1e-5);
+    }
+    SECTION("rectangle case")
+    {
+        SketchConstraints sc;
+        int p0 = sc.add_point(0, 0);
+        int p1 = sc.add_point(8, 1);
+        int p2 = sc.add_point(9, 5);
+        int p3 = sc.add_point(-1, 4);
+        sc.fix_point(p0);
+        sc.lock_x(p0, 0);
+        sc.lock_y(p0, 0);
+        sc.horizontal(p0, p1);
+        sc.vertical(p1, p2);
+        sc.horizontal(p2, p3);
+        sc.vertical(p3, p0);
+        sc.distance(p0, p1, 10);
+        sc.distance(p1, p2, 6);
+        REQUIRE(sc.solve());
+        REQUIRE(sc.residual_norm() < 1e-5);
+    }
+}
+
+TEST_CASE("midpoint", "[SketchConstraints]")
+{
+    SketchConstraints sc;
+    int a = sc.add_point(0, 0);
+    int b = sc.add_point(10, 0);
+    int m = sc.add_point(3, 7);
+    sc.fix_point(a);
+    sc.fix_point(b);
+    sc.midpoint(m, a, b);
+    REQUIRE(sc.solve());
+    Vec2d pm = sc.get_point(m);
+    REQUIRE_THAT(pm.x(), Catch::Matchers::WithinAbs(5.0, 1e-3));
+    REQUIRE_THAT(pm.y(), Catch::Matchers::WithinAbs(0.0, 1e-3));
+}
+
+TEST_CASE("symmetric across Y axis", "[SketchConstraints]")
+{
+    SketchConstraints sc;
+    int a = sc.add_point(2, 3);
+    int b = sc.add_point(-1, 1);
+    int c = sc.add_point(0, 0);
+    int d = sc.add_point(0, 1);
+    sc.fix_point(a);
+    sc.fix_point(c);
+    sc.fix_point(d);
+    sc.symmetric(a, b, c, d);
+    REQUIRE(sc.solve());
+    Vec2d pb = sc.get_point(b);
+    REQUIRE_THAT(pb.x(), Catch::Matchers::WithinAbs(-2.0, 1e-3));
+    REQUIRE_THAT(pb.y(), Catch::Matchers::WithinAbs(3.0, 1e-3));
+}
+
+TEST_CASE("angle 90 degrees", "[SketchConstraints]")
+{
+    SketchConstraints sc;
+    int a = sc.add_point(0, 0);
+    int b = sc.add_point(1, 0);
+    int c = sc.add_point(0, 0);
+    int d = sc.add_point(1, 1);
+    sc.fix_point(a);
+    sc.fix_point(b);
+    sc.fix_point(c);
+    sc.angle(a, b, c, d, M_PI / 2);
+    REQUIRE(sc.solve());
+    Vec2d pd = sc.get_point(d);
+    Vec2d pc = sc.get_point(c);
+    REQUIRE_THAT(pd.x() - pc.x(), Catch::Matchers::WithinAbs(0.0, 1e-3));
+    REQUIRE(pd.y() > pc.y());
+}
+
+TEST_CASE("point-line distance", "[SketchConstraints]")
+{
+    SketchConstraints sc;
+    int a = sc.add_point(0, 0);
+    int b = sc.add_point(10, 0);
+    int p = sc.add_point(3, 1);
+    sc.fix_point(a);
+    sc.fix_point(b);
+    sc.lock_x(p, 3.0);
+    sc.point_line_distance(p, a, b, 5.0);
+    REQUIRE(sc.solve());
+    Vec2d pp = sc.get_point(p);
+    REQUIRE_THAT(std::abs(pp.y()), Catch::Matchers::WithinAbs(5.0, 1e-3));
+    REQUIRE_THAT(pp.x(), Catch::Matchers::WithinAbs(3.0, 1e-3));
+}
+
+// ---- entity-constraint planner (kernel port of DesignPanel::apply_entity_constraint) ----
+
+TEST_CASE("sketch_entity_ends exposes real roles only", "[SketchConstraints]")
+{
+    std::pair<SketchPointRole, Vec2d> out[2];
+    REQUIRE(sketch_entity_ends(mk_point(3, 4), out) == 1);
+    REQUIRE(out[0].first == SketchPointRole::P0);
+    REQUIRE(sketch_entity_ends(mk_circle(1, 2, 5), out) == 1);
+    REQUIRE(out[0].first == SketchPointRole::Center);
+    REQUIRE_THAT(out[0].second.x(), Catch::Matchers::WithinAbs(1.0, 1e-9));
+    REQUIRE_THAT(out[0].second.y(), Catch::Matchers::WithinAbs(2.0, 1e-9));
+    REQUIRE(sketch_entity_ends(mk_line(0, 0, 10, 0), out) == 2);
+    REQUIRE(out[0].first == SketchPointRole::P0);
+    REQUIRE(out[1].first == SketchPointRole::P1);
+}
+
+TEST_CASE("Coincident on two Points binds P0/P0, not phantom p1", "[SketchConstraints]")
+{
+    std::vector<SketchEntity> ents = { mk_point(0, 0), mk_point(5, 5) };
+    ConstraintPlan p = plan_entity_constraint(ents, 0, 1, -1, SketchConstraintType::Coincident);
+    REQUIRE(p.kind == ConstraintPlan::Kind::Apply);
+    REQUIRE(p.defs.size() == 1);
+    REQUIRE(p.defs[0].type == SketchConstraintType::Coincident);
+    REQUIRE(p.defs[0].ea == 0);
+    REQUIRE(p.defs[0].ra == SketchPointRole::P0);
+    REQUIRE(p.defs[0].eb == 1);
+    REQUIRE(p.defs[0].rb == SketchPointRole::P0);
+}
+
+TEST_CASE("DistanceX on two Points binds real roles with non-negative prefill", "[SketchConstraints]")
+{
+    // e0 is right of e1, so the raw projected delta is negative: the plan must swap the
+    // refs so accepting the shown (positive) value is a no-op, not a sign flip.
+    std::vector<SketchEntity> ents = { mk_point(5, 1), mk_point(2, 3) };
+    ConstraintPlan p = plan_entity_constraint(ents, 0, 1, -1, SketchConstraintType::DistanceX);
+    REQUIRE(p.kind == ConstraintPlan::Kind::AskValue);
+    REQUIRE(p.defs.size() == 1);
+    REQUIRE(p.defs[0].type == SketchConstraintType::DistanceX);
+    REQUIRE(p.defs[0].ra == SketchPointRole::P0);
+    REQUIRE(p.defs[0].rb == SketchPointRole::P0);
+    REQUIRE(p.prefill >= 0.0);
+    REQUIRE(p.defs[0].ea == 1);
+    REQUIRE(p.defs[0].eb == 0);
+}
+
+TEST_CASE("Horizontal on a Point rejects with NeedALine", "[SketchConstraints]")
+{
+    std::vector<SketchEntity> ents = { mk_point(1, 2) };
+    ConstraintPlan p = plan_entity_constraint(ents, 0, -1, -1, SketchConstraintType::Horizontal);
+    REQUIRE(p.kind == ConstraintPlan::Kind::Reject);
+    REQUIRE(p.reason == ConstraintReject::NeedALine);
+}
+
+TEST_CASE("Angle on two Circles rejects with NeedTwoLines", "[SketchConstraints]")
+{
+    std::vector<SketchEntity> ents = { mk_circle(0, 0, 1), mk_circle(5, 0, 1) };
+    ConstraintPlan p = plan_entity_constraint(ents, 0, 1, -1, SketchConstraintType::Angle);
+    REQUIRE(p.kind == ConstraintPlan::Kind::Reject);
+    REQUIRE(p.reason == ConstraintReject::NeedTwoLines);
+}
+
+TEST_CASE("Parallel on a Line + Circle rejects with NeedTwoLines (new guard)", "[SketchConstraints]")
+{
+    std::vector<SketchEntity> ents = { mk_line(0, 0, 1, 0), mk_circle(5, 0, 1) };
+    ConstraintPlan p = plan_entity_constraint(ents, 0, 1, -1, SketchConstraintType::Parallel);
+    REQUIRE(p.kind == ConstraintPlan::Kind::Reject);
+    REQUIRE(p.reason == ConstraintReject::NeedTwoLines);
+}
+
+TEST_CASE("Equal on two Circles promotes to EqualRadius", "[SketchConstraints]")
+{
+    std::vector<SketchEntity> ents = { mk_circle(0, 0, 1), mk_circle(5, 0, 2) };
+    ConstraintPlan p = plan_entity_constraint(ents, 0, 1, -1, SketchConstraintType::EqualLength);
+    REQUIRE(p.kind == ConstraintPlan::Kind::Apply);
+    REQUIRE(p.defs.size() == 1);
+    REQUIRE(p.defs[0].type == SketchConstraintType::EqualRadius);
+    REQUIRE(p.defs[0].ea == 0);
+    REQUIRE(p.defs[0].eb == 1);
+}
+
+TEST_CASE("Symmetric on two Lines returns two defs with ec set to the axis", "[SketchConstraints]")
+{
+    std::vector<SketchEntity> ents = { mk_line(0, 1, 5, 1), mk_line(0, -1, 5, -1), mk_line(0, 0, 0, 1) };
+    ConstraintPlan p = plan_entity_constraint(ents, 0, 1, 2, SketchConstraintType::Symmetric);
+    REQUIRE(p.kind == ConstraintPlan::Kind::Apply);
+    REQUIRE(p.defs.size() == 2);
+    for (const auto& d : p.defs) {
+        REQUIRE(d.type == SketchConstraintType::Symmetric);
+        REQUIRE(d.ea == 0);
+        REQUIRE(d.eb == 1);
+        REQUIRE(d.ec == 2);
+    }
+    REQUIRE(p.defs[0].ra == SketchPointRole::P0);
+    REQUIRE(p.defs[0].rb == SketchPointRole::P0);
+    REQUIRE(p.defs[1].ra == SketchPointRole::P1);
+    REQUIRE(p.defs[1].rb == SketchPointRole::P1);
+}
+
+TEST_CASE("Symmetric with no axis rejects with NeedAxisLine", "[SketchConstraints]")
+{
+    std::vector<SketchEntity> ents = { mk_point(0, 0), mk_point(5, 0) };
+    ConstraintPlan p = plan_entity_constraint(ents, 0, 1, -1, SketchConstraintType::Symmetric);
+    REQUIRE(p.kind == ConstraintPlan::Kind::Reject);
+    REQUIRE(p.reason == ConstraintReject::NeedAxisLine);
+}
+
+TEST_CASE("SymmetricAboutY on two Points returns one def with ec == kSketchRefAxisY", "[SketchConstraints]")
+{
+    std::vector<SketchEntity> ents = { mk_point(1, 0), mk_point(-2, 0) };
+    ConstraintPlan p = plan_entity_constraint(ents, 0, 1, -1, SketchConstraintType::SymmetricAboutY);
+    REQUIRE(p.kind == ConstraintPlan::Kind::Apply);
+    REQUIRE(p.defs.size() == 1);
+    REQUIRE(p.defs[0].type == SketchConstraintType::SymmetricAboutY);
+    REQUIRE(p.defs[0].ec == kSketchRefAxisY);
+    REQUIRE(p.defs[0].ea == 0);
+    REQUIRE(p.defs[0].eb == 1);
+}
+
+TEST_CASE("constraint planner apply/askvalue matrix", "[SketchConstraints]")
+{
+    struct C {
+        const char* name; SketchConstraintType type; std::vector<SketchEntity> ents;
+        int e0, e1, e2; ConstraintPlan::Kind kind;
+    };
+    const std::vector<C> cases = {
+        { "Fix",              SketchConstraintType::Fix,              { mk_point(1, 2) },                      0, -1, -1, ConstraintPlan::Kind::Apply },
+        { "Coincident",       SketchConstraintType::Coincident,       { mk_point(0, 0), mk_point(5, 5) },      0,  1, -1, ConstraintPlan::Kind::Apply },
+        { "Horizontal",       SketchConstraintType::Horizontal,       { mk_line(0, 0, 5, 0) },                 0, -1, -1, ConstraintPlan::Kind::Apply },
+        { "Vertical",         SketchConstraintType::Vertical,         { mk_line(0, 0, 0, 5) },                 0, -1, -1, ConstraintPlan::Kind::Apply },
+        { "Parallel",         SketchConstraintType::Parallel,         { mk_line(0, 0, 1, 0), mk_line(0, 1, 1, 1) }, 0, 1, -1, ConstraintPlan::Kind::Apply },
+        { "Perpendicular",    SketchConstraintType::Perpendicular,    { mk_line(0, 0, 1, 0), mk_line(0, 0, 0, 1) }, 0, 1, -1, ConstraintPlan::Kind::Apply },
+        { "EqualLength",      SketchConstraintType::EqualLength,      { mk_line(0, 0, 1, 0), mk_line(0, 1, 2, 1) }, 0, 1, -1, ConstraintPlan::Kind::Apply },
+        { "Concentric",       SketchConstraintType::Concentric,       { mk_circle(0, 0, 1), mk_circle(5, 0, 1) }, 0, 1, -1, ConstraintPlan::Kind::Apply },
+        { "Tangent",          SketchConstraintType::Tangent,          { mk_line(0, 0, 1, 0), mk_circle(0, 1, 1) }, 0, 1, -1, ConstraintPlan::Kind::Apply },
+        { "Midpoint",         SketchConstraintType::Midpoint,         { mk_point(2, 0), mk_line(0, 0, 5, 0) },   0, 1, -1, ConstraintPlan::Kind::Apply },
+        { "Symmetric",        SketchConstraintType::Symmetric,        { mk_point(0, 0), mk_point(5, 0), mk_line(0, -1, 0, 1) }, 0, 1, 2, ConstraintPlan::Kind::Apply },
+        { "SymmetricAboutY",  SketchConstraintType::SymmetricAboutY,  { mk_point(1, 0), mk_point(-2, 0) },       0, 1, -1, ConstraintPlan::Kind::Apply },
+        { "SymmetricAboutX",  SketchConstraintType::SymmetricAboutX,  { mk_point(0, 1), mk_point(0, -2) },       0, 1, -1, ConstraintPlan::Kind::Apply },
+        { "EqualRadius",      SketchConstraintType::EqualRadius,      { mk_circle(0, 0, 1), mk_circle(5, 0, 2) }, 0, 1, -1, ConstraintPlan::Kind::Apply },
+        { "Collinear",        SketchConstraintType::Collinear,        { mk_line(0, 0, 1, 0), mk_line(2, 0, 3, 0) }, 0, 1, -1, ConstraintPlan::Kind::Apply },
+        { "Angle",            SketchConstraintType::Angle,            { mk_line(0, 0, 1, 0), mk_line(0, 0, 0, 1) }, 0, 1, -1, ConstraintPlan::Kind::AskValue },
+        { "Radius",           SketchConstraintType::Radius,           { mk_circle(0, 0, 2.5) },                  0, -1, -1, ConstraintPlan::Kind::AskValue },
+        { "Diameter",         SketchConstraintType::Diameter,         { mk_circle(0, 0, 2.5) },                  0, -1, -1, ConstraintPlan::Kind::AskValue },
+        { "DistanceX",        SketchConstraintType::DistanceX,        { mk_point(0, 0), mk_point(5, 3) },        0,  1, -1, ConstraintPlan::Kind::AskValue },
+        { "DistanceY",        SketchConstraintType::DistanceY,        { mk_point(0, 0), mk_point(5, 3) },        0,  1, -1, ConstraintPlan::Kind::AskValue },
+    };
+    for (const C& c : cases) {
+        DYNAMIC_SECTION("apply " << c.name) {
+            ConstraintPlan p = plan_entity_constraint(c.ents, c.e0, c.e1, c.e2, c.type);
+            REQUIRE(p.kind == c.kind);
+            REQUIRE(p.defs.size() >= 1);
+            for (const auto& d : p.defs) REQUIRE(d.type == c.type);
+        }
+    }
+}
+
+TEST_CASE("constraint planner reject matrix", "[SketchConstraints]")
+{
+    struct C {
+        const char* name; SketchConstraintType type; std::vector<SketchEntity> ents;
+        int e0, e1, e2; ConstraintReject reason;
+    };
+    const std::vector<C> cases = {
+        { "Fix",              SketchConstraintType::Fix,              {},                                 0, -1, -1, ConstraintReject::NeedOneEntity },
+        { "Coincident",       SketchConstraintType::Coincident,       { mk_point(0, 0) },                 0, -1, -1, ConstraintReject::NeedTwoEntities },
+        { "Horizontal",       SketchConstraintType::Horizontal,       { mk_point(1, 2) },                 0, -1, -1, ConstraintReject::NeedALine },
+        { "Vertical",         SketchConstraintType::Vertical,         { mk_circle(0, 0, 1) },             0, -1, -1, ConstraintReject::NeedALine },
+        { "Parallel",         SketchConstraintType::Parallel,         { mk_line(0, 0, 1, 0), mk_circle(5, 0, 1) }, 0, 1, -1, ConstraintReject::NeedTwoLines },
+        { "Perpendicular",    SketchConstraintType::Perpendicular,    { mk_circle(0, 0, 1), mk_line(0, 0, 1, 0) }, 0, 1, -1, ConstraintReject::NeedTwoLines },
+        { "EqualLength",      SketchConstraintType::EqualLength,      { mk_line(0, 0, 1, 0), mk_circle(5, 0, 1) }, 0, 1, -1, ConstraintReject::NeedTwoLines },
+        { "Concentric",       SketchConstraintType::Concentric,       { mk_line(0, 0, 1, 0), mk_circle(5, 0, 1) }, 0, 1, -1, ConstraintReject::NeedTwoRounds },
+        { "Tangent",          SketchConstraintType::Tangent,          { mk_line(0, 0, 1, 0), mk_line(0, 1, 1, 1) }, 0, 1, -1, ConstraintReject::NeedTangentPair },
+        { "Midpoint",         SketchConstraintType::Midpoint,         { mk_line(0, 0, 1, 0), mk_line(0, 1, 1, 1) }, 0, 1, -1, ConstraintReject::NeedPointAndLine },
+        { "Symmetric",        SketchConstraintType::Symmetric,        { mk_line(0, 0, 1, 0), mk_point(1, 1), mk_line(0, -1, 0, 1) }, 0, 1, 2, ConstraintReject::NeedTwoPointsOrLines },
+        { "SymmetricAboutY",  SketchConstraintType::SymmetricAboutY,  { mk_line(0, 0, 1, 0), mk_point(1, 1) },     0, 1, -1, ConstraintReject::NeedTwoPointsOrLines },
+        { "SymmetricAboutX",  SketchConstraintType::SymmetricAboutX,  { mk_point(1, 1), mk_line(0, 0, 1, 0) },     0, 1, -1, ConstraintReject::NeedTwoPointsOrLines },
+        { "EqualRadius",      SketchConstraintType::EqualRadius,      { mk_line(0, 0, 1, 0), mk_circle(5, 0, 1) }, 0, 1, -1, ConstraintReject::NeedTwoRounds },
+        { "Collinear",        SketchConstraintType::Collinear,        { mk_line(0, 0, 1, 0), mk_circle(5, 0, 1) }, 0, 1, -1, ConstraintReject::NeedTwoLines },
+        { "Angle",            SketchConstraintType::Angle,            { mk_circle(0, 0, 1), mk_circle(5, 0, 1) }, 0, 1, -1, ConstraintReject::NeedTwoLines },
+        { "Radius",           SketchConstraintType::Radius,           { mk_line(0, 0, 1, 0) },             0, -1, -1, ConstraintReject::NeedRound },
+        { "Diameter",         SketchConstraintType::Diameter,         { mk_point(1, 2) },                 0, -1, -1, ConstraintReject::NeedRound },
+        { "DistanceX",        SketchConstraintType::DistanceX,        { mk_point(0, 0) },                 0, -1, -1, ConstraintReject::NeedTwoEntities },
+        { "DistanceY",        SketchConstraintType::DistanceY,        { mk_point(0, 0) },                 0, -1, -1, ConstraintReject::NeedTwoEntities },
+    };
+    for (const C& c : cases) {
+        DYNAMIC_SECTION("reject " << c.name) {
+            ConstraintPlan p = plan_entity_constraint(c.ents, c.e0, c.e1, c.e2, c.type);
+            REQUIRE(p.kind == ConstraintPlan::Kind::Reject);
+            REQUIRE(p.reason == c.reason);
+        }
+    }
+}
+
+TEST_CASE("constraint planner rejects types with no entity binding", "[SketchConstraints]")
+{
+    const SketchConstraintType unsupported[] = {
+        SketchConstraintType::Distance, SketchConstraintType::LockX, SketchConstraintType::LockY,
+        SketchConstraintType::PointOnLine, SketchConstraintType::PointOnObject,
+    };
+    std::vector<SketchEntity> ents = { mk_point(0, 0), mk_point(1, 1) };
+    for (SketchConstraintType t : unsupported) {
+        DYNAMIC_SECTION("unsupported " << int(t)) {
+            ConstraintPlan p = plan_entity_constraint(ents, 0, 1, -1, t);
+            REQUIRE(p.kind == ConstraintPlan::Kind::Reject);
+            REQUIRE(p.reason == ConstraintReject::Unsupported);
+        }
+    }
+}

tests/libslic3r/test_sketchedit.cpp

@@ -0,0 +1,730 @@
+#include <catch2/catch_all.hpp>   // mainline OrcaSlicer ships Catch2 v3 (v2 was catch2/catch.hpp)
+#include "libslic3r/CAD/SketchEngine.hpp"
+#include <cmath>
+#include <algorithm>
+#include <TopExp_Explorer.hxx>
+#include <TopAbs.hxx>
+
+using namespace Slic3r;
+
+using Catch::Matchers::WithinAbs;
+
+// CONTRACT: mirror_entities hands the reflected half back REVERSED — the order of the entities
+// and the direction of each — because a reflection reverses orientation and the result has to
+// CONTINUE the chain it was made from. So a mirrored line's p0 is the reflection of the source's
+// p1, not its p0. See [SketchProfile] "a mirrored half continues the original chain".
+TEST_CASE("Mirror Line across Y axis (reversed: p0 is the reflection of the source p1)", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type = SketchEntity::Type::Line;
+    e.p0   = Vec2d(3, 2);
+    e.p1   = Vec2d(5, 4);
+
+    Vec2d a(0, -1);
+    Vec2d b(0, 1);
+
+    auto result = SketchEngine::mirror_entities({e}, a, b);
+    REQUIRE(result.size() == 1);
+
+    const auto& m = result[0];
+    REQUIRE(m.type == SketchEntity::Type::Line);
+    REQUIRE_THAT(m.p0.x(), WithinAbs(-5.0, 1e-9));   // reflection of the SOURCE p1
+    REQUIRE_THAT(m.p0.y(), WithinAbs(4.0, 1e-9));
+    REQUIRE_THAT(m.p1.x(), WithinAbs(-3.0, 1e-9));   // reflection of the SOURCE p0
+    REQUIRE_THAT(m.p1.y(), WithinAbs(2.0, 1e-9));
+}
+
+TEST_CASE("Mirror Circle across Y axis", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type   = SketchEntity::Type::Circle;
+    e.center = Vec2d(5, 0);
+    e.p0     = Vec2d(5, 0);
+    e.radius = 3;
+
+    Vec2d a(0, -1);
+    Vec2d b(0, 1);
+
+    auto result = SketchEngine::mirror_entities({e}, a, b);
+    REQUIRE(result.size() == 1);
+
+    const auto& m = result[0];
+    REQUIRE(m.type == SketchEntity::Type::Circle);
+    REQUIRE_THAT(m.center.x(), WithinAbs(-5.0, 1e-9));
+    REQUIRE_THAT(m.center.y(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(m.radius, WithinAbs(3.0, 1e-9));
+    REQUIRE_THAT(m.p0.x(), WithinAbs(-5.0, 1e-9));
+    REQUIRE_THAT(m.p0.y(), WithinAbs(0.0, 1e-9));
+}
+
+TEST_CASE("Mirror Arc across X axis", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type        = SketchEntity::Type::Arc;
+    e.center      = Vec2d(0, 0);
+    e.radius      = 1.0;
+    e.start_angle = 0.0;
+    e.end_angle   = M_PI / 2.0;
+    e.p0          = Vec2d(1, 0);
+    e.p1          = Vec2d(0, 1);
+
+    Vec2d a(-1, 0);
+    Vec2d b(1, 0);
+
+    auto result = SketchEngine::mirror_entities({e}, a, b);
+    REQUIRE(result.size() == 1);
+
+    const auto& m = result[0];
+    REQUIRE(m.type == SketchEntity::Type::Arc);
+
+    // Reversed with the rest of the half: the mirrored arc STARTS where the reflection of the
+    // source's end is, and finishes at the reflection of its start.
+    REQUIRE_THAT(m.p0.x(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(m.p0.y(), WithinAbs(-1.0, 1e-9));
+    REQUIRE_THAT(m.p1.x(), WithinAbs(1.0, 1e-9));
+    REQUIRE_THAT(m.p1.y(), WithinAbs(0.0, 1e-9));
+
+    // The reflection alone would negate the sweep; walking the arc the other way negates it
+    // again, so a mirrored CCW arc is CCW once more and a mirrored CCW loop stays CCW.
+    double sweep = m.end_angle - m.start_angle;
+    double orig_sweep = e.end_angle - e.start_angle;
+    REQUIRE(orig_sweep > 0.0);
+    REQUIRE(sweep > 0.0);
+}
+
+TEST_CASE("Offset Line by positive d", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type = SketchEntity::Type::Line;
+    e.p0   = Vec2d(0, 0);
+    e.p1   = Vec2d(10, 0);
+
+    auto result = SketchEngine::offset_entities({e}, 2.0);
+    REQUIRE(result.size() == 1);
+
+    const auto& o = result[0];
+    REQUIRE(o.type == SketchEntity::Type::Line);
+    REQUIRE_THAT(o.p0.x(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(o.p0.y(), WithinAbs(2.0, 1e-9));
+    REQUIRE_THAT(o.p1.x(), WithinAbs(10.0, 1e-9));
+    REQUIRE_THAT(o.p1.y(), WithinAbs(2.0, 1e-9));
+}
+
+TEST_CASE("Offset Circle: expand and collapse", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type   = SketchEntity::Type::Circle;
+    e.center = Vec2d(0, 0);
+    e.p0     = Vec2d(0, 0);
+    e.radius = 5;
+
+    auto expanded = SketchEngine::offset_entities({e}, 2.0);
+    REQUIRE(expanded.size() == 1);
+    REQUIRE_THAT(expanded[0].radius, WithinAbs(7.0, 1e-9));
+
+    auto collapsed = SketchEngine::offset_entities({e}, -5.0);
+    REQUIRE(collapsed.empty());
+}
+
+// CONTRACT CHANGED: +d used to mean "radius + d" for every arc regardless of its sweep, while
+// for a line it meant "left of the direction of travel". The two disagreed, so a profile made
+// of lines AND arcs (any slot outline) offset with its straights going one way and its caps the
+// other, and could never come back closed. The arc now follows the line's rule: +d is left of
+// travel, which for this CCW quarter-arc is inward -> r = 3. See [SketchProfile].
+TEST_CASE("Offset Arc by positive d (left of travel: a CCW arc shrinks)", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type        = SketchEntity::Type::Arc;
+    e.center      = Vec2d(0, 0);
+    e.radius      = 4.0;
+    e.start_angle = 0.0;
+    e.end_angle   = M_PI / 2.0;
+    e.p0          = Vec2d(4, 0);
+    e.p1          = Vec2d(0, 4);
+
+    auto result = SketchEngine::offset_entities({e}, 1.0);
+    REQUIRE(result.size() == 1);
+
+    const auto& o = result[0];
+    REQUIRE(o.type == SketchEntity::Type::Arc);
+    REQUIRE_THAT(o.radius, WithinAbs(3.0, 1e-9));
+    REQUIRE_THAT(o.p0.x(), WithinAbs(3.0, 1e-9));
+    REQUIRE_THAT(o.p0.y(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(o.p1.x(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(o.p1.y(), WithinAbs(3.0, 1e-9));
+}
+
+TEST_CASE("Fillet right-angle corner", "[SketchEdit]")
+{
+    SketchEntity a;
+    a.type = SketchEntity::Type::Line;
+    a.p0   = Vec2d(0, 0);
+    a.p1   = Vec2d(10, 0);
+
+    SketchEntity b;
+    b.type = SketchEntity::Type::Line;
+    b.p0   = Vec2d(10, 0);
+    b.p1   = Vec2d(10, 10);
+
+    SketchEntity a_out, b_out, arc_out;
+    bool ok = SketchEngine::fillet_lines(a, b, 2.0, a_out, b_out, arc_out);
+    REQUIRE(ok);
+
+    REQUIRE_THAT(a_out.p0.x(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(a_out.p0.y(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(a_out.p1.x(), WithinAbs(8.0, 1e-9));
+    REQUIRE_THAT(a_out.p1.y(), WithinAbs(0.0, 1e-9));
+
+    REQUIRE_THAT(b_out.p0.x(), WithinAbs(10.0, 1e-9));
+    REQUIRE_THAT(b_out.p0.y(), WithinAbs(2.0, 1e-9));
+    REQUIRE_THAT(b_out.p1.x(), WithinAbs(10.0, 1e-9));
+    REQUIRE_THAT(b_out.p1.y(), WithinAbs(10.0, 1e-9));
+
+    REQUIRE(arc_out.type == SketchEntity::Type::Arc);
+    REQUIRE_THAT(arc_out.radius, WithinAbs(2.0, 1e-9));
+    REQUIRE_THAT(arc_out.center.x(), WithinAbs(8.0, 1e-9));
+    REQUIRE_THAT(arc_out.center.y(), WithinAbs(2.0, 1e-9));
+    REQUIRE_THAT((arc_out.p0 - arc_out.center).norm(), WithinAbs(2.0, 1e-9));
+    REQUIRE_THAT((arc_out.p1 - arc_out.center).norm(), WithinAbs(2.0, 1e-9));
+}
+
+TEST_CASE("Fillet parallel lines returns false", "[SketchEdit]")
+{
+    SketchEntity a;
+    a.type = SketchEntity::Type::Line;
+    a.p0   = Vec2d(0, 0);
+    a.p1   = Vec2d(10, 0);
+
+    SketchEntity b;
+    b.type = SketchEntity::Type::Line;
+    b.p0   = Vec2d(0, 5);
+    b.p1   = Vec2d(10, 5);
+
+    SketchEntity a_out, b_out, arc_out;
+    REQUIRE_FALSE(SketchEngine::fillet_lines(a, b, 1.0, a_out, b_out, arc_out));
+}
+
+TEST_CASE("Fillet arc too big returns false", "[SketchEdit]")
+{
+    SketchEntity a;
+    a.type = SketchEntity::Type::Line;
+    a.p0   = Vec2d(0, 0);
+    a.p1   = Vec2d(1, 0);
+
+    SketchEntity b;
+    b.type = SketchEntity::Type::Line;
+    b.p0   = Vec2d(1, 0);
+    b.p1   = Vec2d(1, 1);
+
+    SketchEntity a_out, b_out, arc_out;
+    REQUIRE_FALSE(SketchEngine::fillet_lines(a, b, 5.0, a_out, b_out, arc_out));
+}
+
+TEST_CASE("Trim right arm", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type = SketchEntity::Type::Line;
+    e.p0   = Vec2d(-5, 0);
+    e.p1   = Vec2d(5, 0);
+
+    SketchEntity vc;
+    vc.type = SketchEntity::Type::Line;
+    vc.p0   = Vec2d(0, -5);
+    vc.p1   = Vec2d(0, 5);
+
+    bool ok = SketchEngine::trim_entity(e, {vc}, Vec2d(3, 0));
+    REQUIRE(ok);
+    REQUIRE_THAT(e.p0.x(), WithinAbs(-5.0, 1e-9));
+    REQUIRE_THAT(e.p0.y(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(e.p1.x(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(e.p1.y(), WithinAbs(0.0, 1e-9));
+}
+
+TEST_CASE("Trim left arm", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type = SketchEntity::Type::Line;
+    e.p0   = Vec2d(-5, 0);
+    e.p1   = Vec2d(5, 0);
+
+    SketchEntity vc;
+    vc.type = SketchEntity::Type::Line;
+    vc.p0   = Vec2d(0, -5);
+    vc.p1   = Vec2d(0, 5);
+
+    bool ok = SketchEngine::trim_entity(e, {vc}, Vec2d(-3, 0));
+    REQUIRE(ok);
+    REQUIRE_THAT(e.p0.x(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(e.p0.y(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(e.p1.x(), WithinAbs(5.0, 1e-9));
+    REQUIRE_THAT(e.p1.y(), WithinAbs(0.0, 1e-9));
+}
+
+TEST_CASE("Trim no cut (u out of range)", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type = SketchEntity::Type::Line;
+    e.p0   = Vec2d(-5, 0);
+    e.p1   = Vec2d(5, 0);
+
+    SketchEntity other;
+    other.type = SketchEntity::Type::Line;
+    other.p0   = Vec2d(0, 3);
+    other.p1   = Vec2d(0, 8);
+
+    REQUIRE_FALSE(SketchEngine::trim_entity(e, {other}, Vec2d(3, 0)));
+}
+
+TEST_CASE("Extend forward to line", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type = SketchEntity::Type::Line;
+    e.p0   = Vec2d(0, 0);
+    e.p1   = Vec2d(2, 0);
+
+    SketchEntity other;
+    other.type = SketchEntity::Type::Line;
+    other.p0   = Vec2d(5, -5);
+    other.p1   = Vec2d(5, 5);
+
+    bool ok = SketchEngine::extend_entity(e, {other}, Vec2d(2, 0));
+    REQUIRE(ok);
+    REQUIRE_THAT(e.p0.x(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(e.p0.y(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(e.p1.x(), WithinAbs(5.0, 1e-9));
+    REQUIRE_THAT(e.p1.y(), WithinAbs(0.0, 1e-9));
+}
+
+TEST_CASE("Extend forward to circle", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type = SketchEntity::Type::Line;
+    e.p0   = Vec2d(0, 0);
+    e.p1   = Vec2d(2, 0);
+
+    SketchEntity other;
+    other.type   = SketchEntity::Type::Circle;
+    other.center = Vec2d(10, 0);
+    other.p0     = Vec2d(10, 0);
+    other.radius = 3;
+
+    bool ok = SketchEngine::extend_entity(e, {other}, Vec2d(2, 0));
+    REQUIRE(ok);
+    REQUIRE_THAT(e.p0.x(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(e.p0.y(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(e.p1.x(), WithinAbs(7.0, 1e-9));
+    REQUIRE_THAT(e.p1.y(), WithinAbs(0.0, 1e-9));
+}
+
+TEST_CASE("Extend backward", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type = SketchEntity::Type::Line;
+    e.p0   = Vec2d(0, 0);
+    e.p1   = Vec2d(2, 0);
+
+    SketchEntity other;
+    other.type = SketchEntity::Type::Line;
+    other.p0   = Vec2d(-3, -5);
+    other.p1   = Vec2d(-3, 5);
+
+    bool ok = SketchEngine::extend_entity(e, {other}, Vec2d(0, 0));
+    REQUIRE(ok);
+    REQUIRE_THAT(e.p0.x(), WithinAbs(-3.0, 1e-9));
+    REQUIRE_THAT(e.p0.y(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(e.p1.x(), WithinAbs(2.0, 1e-9));
+    REQUIRE_THAT(e.p1.y(), WithinAbs(0.0, 1e-9));
+}
+
+TEST_CASE("Extend no target", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type = SketchEntity::Type::Line;
+    e.p0   = Vec2d(0, 0);
+    e.p1   = Vec2d(2, 0);
+
+    SketchEntity other;
+    other.type = SketchEntity::Type::Line;
+    other.p0   = Vec2d(5, -5);
+    other.p1   = Vec2d(5, -1);
+
+    REQUIRE_FALSE(SketchEngine::extend_entity(e, {other}, Vec2d(2, 0)));
+}
+
+// --- Arc/Circle subject trim & extend (Fase 4.5 kernel) -------------------
+
+TEST_CASE("Trim arc drops the picked (start) side", "[SketchEdit]")
+{
+    // Upper semicircle r=5, ccw from (5,0) to (-5,0); cutter = vertical axis.
+    SketchEntity e;
+    e.type        = SketchEntity::Type::Arc;
+    e.center      = Vec2d(0, 0);
+    e.radius      = 5;
+    e.start_angle = 0.0;
+    e.end_angle   = M_PI;
+
+    SketchEntity cut;
+    cut.type = SketchEntity::Type::Line;
+    cut.p0   = Vec2d(0, -10);
+    cut.p1   = Vec2d(0, 10);
+
+    // Pick the right quarter (phi=pi/4) -> it is removed, left quarter kept.
+    bool ok = SketchEngine::trim_entity(e, {cut}, Vec2d(5 * std::cos(M_PI/4), 5 * std::sin(M_PI/4)));
+    REQUIRE(ok);
+    REQUIRE(e.type == SketchEntity::Type::Arc);
+    REQUIRE_THAT(e.radius, WithinAbs(5.0, 1e-9));
+    REQUIRE_THAT(e.start_angle, WithinAbs(M_PI / 2.0, 1e-9));
+    REQUIRE_THAT(e.end_angle,   WithinAbs(M_PI, 1e-9));
+}
+
+TEST_CASE("Trim arc drops the picked (end) side", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type        = SketchEntity::Type::Arc;
+    e.center      = Vec2d(0, 0);
+    e.radius      = 5;
+    e.start_angle = 0.0;
+    e.end_angle   = M_PI;
+
+    SketchEntity cut;
+    cut.type = SketchEntity::Type::Line;
+    cut.p0   = Vec2d(0, -10);
+    cut.p1   = Vec2d(0, 10);
+
+    // Pick the left quarter (phi=3pi/4) -> removed, right quarter kept.
+    bool ok = SketchEngine::trim_entity(e, {cut}, Vec2d(5 * std::cos(3*M_PI/4), 5 * std::sin(3*M_PI/4)));
+    REQUIRE(ok);
+    REQUIRE(e.type == SketchEntity::Type::Arc);
+    REQUIRE_THAT(e.start_angle, WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(e.end_angle,   WithinAbs(M_PI / 2.0, 1e-9));
+}
+
+TEST_CASE("Trim circle opens into an arc excluding the pick", "[SketchEdit]")
+{
+    // Full circle r=5; vertical axis cuts it at (0,+-5). Pick the right side
+    // (5,0): the kept arc is the left half, sweeping pi and centred on (-5,0).
+    SketchEntity e;
+    e.type   = SketchEntity::Type::Circle;
+    e.center = Vec2d(0, 0);
+    e.p0     = Vec2d(5, 0);
+    e.radius = 5;
+
+    SketchEntity cut;
+    cut.type = SketchEntity::Type::Line;
+    cut.p0   = Vec2d(0, -10);
+    cut.p1   = Vec2d(0, 10);
+
+    bool ok = SketchEngine::trim_entity(e, {cut}, Vec2d(5, 0));
+    REQUIRE(ok);
+    REQUIRE(e.type == SketchEntity::Type::Arc);
+    REQUIRE_THAT(e.radius, WithinAbs(5.0, 1e-9));
+    REQUIRE_THAT(e.end_angle - e.start_angle, WithinAbs(M_PI, 1e-9));
+    // Midpoint of the kept arc must point left (away from the pick).
+    double mid = 0.5 * (e.start_angle + e.end_angle);
+    REQUIRE_THAT(5 * std::cos(mid), WithinAbs(-5.0, 1e-9));
+    REQUIRE_THAT(5 * std::sin(mid), WithinAbs(0.0, 1e-9));
+}
+
+TEST_CASE("Extend arc forward (end) to a crossing", "[SketchEdit]")
+{
+    // Quarter arc (5,0)->(0,5); cutter crosses the circle at (-5,0). Picking
+    // near the end grows the sweep ccw to pi.
+    SketchEntity e;
+    e.type        = SketchEntity::Type::Arc;
+    e.center      = Vec2d(0, 0);
+    e.radius      = 5;
+    e.start_angle = 0.0;
+    e.end_angle   = M_PI / 2.0;
+
+    SketchEntity cut;
+    cut.type = SketchEntity::Type::Line;
+    cut.p0   = Vec2d(-10, 0);
+    cut.p1   = Vec2d(0, 0);
+
+    bool ok = SketchEngine::extend_entity(e, {cut}, Vec2d(0, 5));
+    REQUIRE(ok);
+    REQUIRE(e.type == SketchEntity::Type::Arc);
+    REQUIRE_THAT(e.start_angle, WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(e.end_angle,   WithinAbs(M_PI, 1e-9));
+}
+
+TEST_CASE("Extend arc backward (start) to a crossing", "[SketchEdit]")
+{
+    // Quarter arc (0,5)->(-5,0); cutter crosses at (5,0). Picking near the
+    // start grows the sweep cw to start_angle 0.
+    SketchEntity e;
+    e.type        = SketchEntity::Type::Arc;
+    e.center      = Vec2d(0, 0);
+    e.radius      = 5;
+    e.start_angle = M_PI / 2.0;
+    e.end_angle   = M_PI;
+
+    SketchEntity cut;
+    cut.type = SketchEntity::Type::Line;
+    cut.p0   = Vec2d(10, 0);
+    cut.p1   = Vec2d(0, 0);
+
+    bool ok = SketchEngine::extend_entity(e, {cut}, Vec2d(0, 5));
+    REQUIRE(ok);
+    REQUIRE_THAT(e.start_angle, WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(e.end_angle,   WithinAbs(M_PI, 1e-9));
+}
+
+TEST_CASE("Extend circle returns false (closed)", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type   = SketchEntity::Type::Circle;
+    e.center = Vec2d(0, 0);
+    e.p0     = Vec2d(5, 0);
+    e.radius = 5;
+
+    SketchEntity cut;
+    cut.type = SketchEntity::Type::Line;
+    cut.p0   = Vec2d(0, -10);
+    cut.p1   = Vec2d(0, 10);
+
+    REQUIRE_FALSE(SketchEngine::extend_entity(e, {cut}, Vec2d(5, 0)));
+}
+
+TEST_CASE("Trim arc with no crossing returns false", "[SketchEdit]")
+{
+    SketchEntity e;
+    e.type        = SketchEntity::Type::Arc;
+    e.center      = Vec2d(0, 0);
+    e.radius      = 5;
+    e.start_angle = 0.0;
+    e.end_angle   = M_PI / 2.0;
+
+    SketchEntity cut;          // far away, never reaches the r=5 circle
+    cut.type = SketchEntity::Type::Line;
+    cut.p0   = Vec2d(20, -5);
+    cut.p1   = Vec2d(20, 5);
+
+    REQUIRE_FALSE(SketchEngine::trim_entity(e, {cut}, Vec2d(5 * std::cos(M_PI/4), 5 * std::sin(M_PI/4))));
+}
+
+// Regression guard: BEFORE the weld fix this test failed with 4 edges instead of 6.
+// BRepLib_MakeWire::Add silently DROPS a disconnected edge (BRepLib_DisconnectedWire + NotDone)
+// yet every successful Add ends with BRepLib_WireDone + Done(), so IsDone() reported only whether
+// the LAST edge connected. This sketch is a real user loop (2 arcs + 4 lines) given in
+// creation order, which is NOT traversal order, and its joint between the 3rd and 4th entity
+// below is open by 2.28e-5 mm — larger than OCCT's default vertex tolerance.
+TEST_CASE("entities_to_wires keeps every edge of a loop drawn out of order", "[SketchEngine]")
+{
+    std::vector<SketchEntity> ents(6);
+
+    ents[0].type = SketchEntity::Type::Line;
+    ents[0].p0   = Vec2d(-0.537697713190522, -0.0009077462579133498);
+    ents[0].p1   = Vec2d(99.46230228680926, -0.0009141694814321626);
+
+    ents[1].type        = SketchEntity::Type::Arc;
+    ents[1].p0          = Vec2d(-0.537697713190522, -0.0009077462579133498);
+    ents[1].p1          = Vec2d(-100.14602636660666, -0.27673132181233495);
+    ents[1].center      = Vec2d(-50.313868583115394, -10.248112903179617);
+    ents[1].radius      = 50.81999999999999;
+    ents[1].start_angle = 0.20302922018398933;
+    ents[1].end_angle   = 2.944101582158999;
+
+    ents[2].type = SketchEntity::Type::Line;
+    ents[2].p0   = Vec2d(99.46228668626469, -39.22091416947833);
+    ents[2].p1   = Vec2d(-0.537864366432629, -39.22420589376945);
+
+    ents[3].type        = SketchEntity::Type::Arc;
+    ents[3].p0          = Vec2d(-100.14602636694521, -38.94673132181234);
+    ents[3].p1          = Vec2d(-0.5378420354900413, -39.22421049164698);
+    ents[3].center      = Vec2d(-50.31377078666179, -28.975499083790503);
+    ents[3].radius      = 50.82006659345552;
+    ents[3].start_angle = -2.944104841286737;
+    ents[3].end_angle   = -0.20305921095748136;
+
+    ents[4].type = SketchEntity::Type::Line;
+    ents[4].p0   = Vec2d(99.46228668626469, -39.22091416947833);
+    ents[4].p1   = Vec2d(99.46230228680926, -0.0009141694814321626);
+
+    ents[5].type = SketchEntity::Type::Line;
+    ents[5].p0   = Vec2d(-100.14602636694521, -38.94673132181234);
+    ents[5].p1   = Vec2d(-100.14602636660666, -0.27673132181233495);
+
+    auto wires = SketchEngine::entities_to_wires(ents, SketchPlane::XY());
+
+    REQUIRE(wires.size() == 1);
+
+    int edge_count = 0;
+    for (TopExp_Explorer ex(wires[0], TopAbs_EDGE); ex.More(); ex.Next())
+        ++edge_count;
+    REQUIRE(edge_count == 6);
+
+    REQUIRE(wires[0].Closed());
+}
+
+// Regression guard: this fails at 1e-4 (the wire builder refuses a joint the viewport had
+// already shaded closed) and passes at kSketchJoinTol. A 20x10 quad with one joint left open
+// by 9e-4 mm — just inside kSketchJoinTol, exactly the case the viewport shades closed — given
+// in an order that is NOT traversal order, so the ordering path is covered too.
+TEST_CASE("a loop the viewport shades closed is buildable by the kernel", "[SketchEngine]")
+{
+    std::vector<SketchEntity> ents(4);
+
+    // (0,0) -> (20,0) -> (20,10) -> (0,10) -> (0.0009, 0): last endpoint misses (0,0) by 9e-4.
+    ents[0].type = SketchEntity::Type::Line;
+    ents[0].p0   = Vec2d(0, 0);
+    ents[0].p1   = Vec2d(20, 0);
+
+    // Index 1 is the FAR side, not the neighbour of index 0: creation order here is
+    // deliberately not traversal order, so a partial wire would reject it without the
+    // traversal walk.
+    ents[1].type = SketchEntity::Type::Line;
+    ents[1].p0   = Vec2d(20, 10);
+    ents[1].p1   = Vec2d(0, 10);
+
+    ents[2].type = SketchEntity::Type::Line;
+    ents[2].p0   = Vec2d(20, 0);
+    ents[2].p1   = Vec2d(20, 10);
+
+    ents[3].type = SketchEntity::Type::Line;
+    ents[3].p0   = Vec2d(0, 10);
+    ents[3].p1   = Vec2d(0.0009, 0);
+
+    auto wires = SketchEngine::entities_to_wires(ents, SketchPlane::XY());
+
+    REQUIRE(wires.size() == 1);
+
+    int edge_count = 0;
+    for (TopExp_Explorer ex(wires[0], TopAbs_EDGE); ex.More(); ex.Next())
+        ++edge_count;
+    REQUIRE(edge_count == 4);
+
+    REQUIRE(wires[0].Closed());
+}
+
+// Regression guard for the auto-close preference. Same 20x10 quad, one joint open by 9e-4 mm
+// and given out of traversal order, as "a loop the viewport shades closed is buildable by the
+// kernel". With auto-close ON the gap welds (one closed wire); with auto-close OFF it must not.
+TEST_CASE("auto-close off makes the kernel demand an exact joint", "[SketchEngine]")
+{
+    std::vector<SketchEntity> ents(4);
+
+    ents[0].type = SketchEntity::Type::Line;
+    ents[0].p0   = Vec2d(0, 0);
+    ents[0].p1   = Vec2d(20, 0);
+
+    ents[1].type = SketchEntity::Type::Line;
+    ents[1].p0   = Vec2d(20, 10);
+    ents[1].p1   = Vec2d(0, 10);
+
+    ents[2].type = SketchEntity::Type::Line;
+    ents[2].p0   = Vec2d(20, 0);
+    ents[2].p1   = Vec2d(20, 10);
+
+    ents[3].type = SketchEntity::Type::Line;
+    ents[3].p0   = Vec2d(0, 10);
+    ents[3].p1   = Vec2d(0.0009, 0);
+
+    auto edge_count = [](const TopoDS_Wire& w) {
+        int n = 0;
+        for (TopExp_Explorer ex(w, TopAbs_EDGE); ex.More(); ex.Next()) ++n;
+        return n;
+    };
+
+    // ON: the 9e-4 mm gap is inside kSketchJoinTol, so the loop welds into one closed wire.
+    Slic3r::set_sketch_auto_close(true);
+    auto wires_on = SketchEngine::entities_to_wires(ents, SketchPlane::XY());
+    REQUIRE(wires_on.size() == 1);
+    REQUIRE(edge_count(wires_on[0]) == 4);
+    REQUIRE(wires_on[0].Closed());
+
+    // OFF: the joint is not exact, so the gap is NOT welded. entities_to_wires legitimately
+    // returns open chains (a sweep path is open), so the observable is an OPEN wire — the
+    // kernel no longer hands back the closed loop the viewport would have shaded.
+    Slic3r::set_sketch_auto_close(false);
+    auto wires_off = SketchEngine::entities_to_wires(ents, SketchPlane::XY());
+    REQUIRE(wires_off.size() == 1);
+    REQUIRE(edge_count(wires_off[0]) == 4);
+    REQUIRE_FALSE(wires_off[0].Closed());
+
+    // OFF + an EXACT joint (last endpoint exactly (0,0)): the quad still builds closed,
+    // proving "off" means exact rather than broken.
+    ents[3].p1 = Vec2d(0, 0);
+    auto wires_exact = SketchEngine::entities_to_wires(ents, SketchPlane::XY());
+    REQUIRE(wires_exact.size() == 1);
+    REQUIRE(edge_count(wires_exact[0]) == 4);
+    REQUIRE(wires_exact[0].Closed());
+
+    // Restore the default so test order cannot leak OFF into the other cases.
+    Slic3r::set_sketch_auto_close(true);
+}
+
+// A stray open segment touching nothing must not break a closed profile: the viewport
+// discards open chains when it shades a region extrudable, so with closed_only the kernel
+// must discard them too — otherwise Revolve/Extrude fail on a sketch that looks perfect.
+TEST_CASE("a stray open segment does not break a closed profile", "[SketchEngine]")
+{
+    auto line = [](double x0, double y0, double x1, double y1) {
+        SketchEntity e;
+        e.type = SketchEntity::Type::Line;
+        e.p0   = Vec2d(x0, y0);
+        e.p1   = Vec2d(x1, y1);
+        return e;
+    };
+
+    std::vector<SketchEntity> ents;
+    ents.push_back(line(0, 0, 20, 0));     // 20x10 quad
+    ents.push_back(line(20, 0, 20, 10));
+    ents.push_back(line(20, 10, 0, 10));
+    ents.push_back(line(0, 10, 0, 0));
+    ents.push_back(line(5, 5, 6, 5.2));    // stray, touches nothing
+
+    auto edge_count = [](const TopoDS_Wire& w) {
+        int n = 0;
+        for (TopExp_Explorer ex(w, TopAbs_EDGE); ex.More(); ex.Next()) ++n;
+        return n;
+    };
+
+    // Unchanged behaviour: the stray line is its own open wire.
+    auto wires_all = SketchEngine::entities_to_wires(ents, SketchPlane::XY(), /*closed_only=*/false);
+    REQUIRE(wires_all.size() == 2);
+
+    // closed_only drops the open chain: one closed quad survives.
+    auto wires_closed = SketchEngine::entities_to_wires(ents, SketchPlane::XY(), /*closed_only=*/true);
+    REQUIRE(wires_closed.size() == 1);
+    REQUIRE(edge_count(wires_closed[0]) == 4);
+    REQUIRE(wires_closed[0].Closed());
+
+    // The Revolve path (entities_to_wire) finds the single closed loop.
+    TopoDS_Wire w = SketchEngine::entities_to_wire(ents, SketchPlane::XY(), /*closed_only=*/true);
+    REQUIRE_FALSE(w.IsNull());
+    REQUIRE(edge_count(w) == 4);
+}
+
+// sketch_open_ends names the two free endpoints of an open chain, so the "does not form a
+// single closed wire" failure can say WHERE the sketch is open.
+TEST_CASE("sketch_open_ends names where a chain fails to close", "[SketchEngine]")
+{
+    auto line = [](double x0, double y0, double x1, double y1) {
+        SketchEntity e;
+        e.type = SketchEntity::Type::Line;
+        e.p0   = Vec2d(x0, y0);
+        e.p1   = Vec2d(x1, y1);
+        return e;
+    };
+
+    // Open C shape: three lines, free endpoints at (0,0) and (0,10).
+    std::vector<SketchEntity> ents;
+    ents.push_back(line(0, 0, 10, 0));
+    ents.push_back(line(10, 0, 10, 10));
+    ents.push_back(line(10, 10, 0, 10));
+
+    auto got = sketch_open_ends(ents, SketchPlane::XY());
+    REQUIRE(got.size() == 2);
+
+    std::sort(got.begin(), got.end(), [](const Vec2d& a, const Vec2d& b) {
+        if (a.x() < b.x()) return true;
+        if (a.x() > b.x()) return false;
+        return a.y() < b.y();
+    });
+
+    REQUIRE_THAT(got[0].x(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(got[0].y(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(got[1].x(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT(got[1].y(), WithinAbs(10.0, 1e-9));
+}

tests/libslic3r/test_sketchimport.cpp

@@ -0,0 +1,103 @@
+#include <catch2/catch_all.hpp>   // mainline OrcaSlicer ships Catch2 v3 (v2 was catch2/catch.hpp)
+
+#include "libslic3r/CAD/SketchImport.hpp"
+#include "libslic3r/Utils.hpp"   // resources_dir
+#include "test_utils.hpp"        // ScopedTemporaryFile
+
+#include <fstream>
+#include <string>
+
+using namespace Slic3r;
+
+// A 10x10 mm filled square, on disk because nanosvg reads from a file. The path
+// must come from the system temp dir: a hardcoded /tmp is not writable on
+// Windows, where the stream fails silently and the parse then sees no file.
+static void write_square_svg(const std::string& path)
+{
+    std::ofstream f(path);
+    f << "<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"10mm\" height=\"10mm\" "
+         "viewBox=\"0 0 10 10\">"
+         "<path d=\"M0,0 L10,0 L10,10 L0,10 Z\" fill=\"#000000\"/></svg>";
+    REQUIRE(f.good());
+}
+
+TEST_CASE("svg_to_regions parses a filled path into a region", "[SketchImport]")
+{
+    ScopedTemporaryFile square(".svg");
+    write_square_svg(square.string());
+
+    ImportRegions regs = svg_to_regions(square.string(), 1.0);
+    REQUIRE(regs.size() >= 1);
+    // Outer contour present with at least a few vertices.
+    REQUIRE(regs[0].size() >= 1);
+    REQUIRE(regs[0][0].size() >= 4);
+
+    // Centred on the origin: bbox half-extent ~5 mm on each side.
+    double hi = 0.0;
+    for (const auto& region : regs)
+        for (const auto& contour : region)
+            for (const Vec2d& p : contour)
+                hi = std::max(hi, std::max(std::abs(p.x()), std::abs(p.y())));
+    REQUIRE(hi > 3.0);    // not collapsed
+    REQUIRE(hi < 8.0);    // ~5 mm half-size after centring
+}
+
+TEST_CASE("svg_to_regions rejects bad input gracefully", "[SketchImport]")
+{
+    ScopedTemporaryFile square(".svg");
+    write_square_svg(square.string());
+    ScopedTemporaryFile missing(".svg");   // name reserved, never written
+
+    REQUIRE(svg_to_regions("", 1.0).empty());
+    REQUIRE(svg_to_regions(missing.string(), 1.0).empty());
+    REQUIRE(svg_to_regions(square.string(), 0.0).empty()); // scale<=0
+}
+
+TEST_CASE("transform_regions moves and scales independently", "[SketchImport]")
+{
+    ImportRegions r = {{ {Vec2d(-1,-1), Vec2d(1,-1), Vec2d(1,1), Vec2d(-1,1)} }};
+    ImportRegions t = transform_regions(r, Vec2d(10, 20), 2.0, 3.0);
+    REQUIRE(t.size() == 1);
+    REQUIRE(t[0][0].size() == 4);
+    // (-1,-1) -> (-1*2+10, -1*3+20) = (8, 17)
+    REQUIRE_THAT(t[0][0][0].x(), Catch::Matchers::WithinAbs(8.0, 1e-9));
+    REQUIRE_THAT(t[0][0][0].y(), Catch::Matchers::WithinAbs(17.0, 1e-9));
+    // (1,1) -> (1*2+10, 1*3+20) = (12, 23)
+    REQUIRE_THAT(t[0][0][2].x(), Catch::Matchers::WithinAbs(12.0, 1e-9));
+    REQUIRE_THAT(t[0][0][2].y(), Catch::Matchers::WithinAbs(23.0, 1e-9));
+    // identity is a no-op
+    ImportRegions id = transform_regions(r, Vec2d(0,0), 1.0, 1.0);
+    REQUIRE_THAT(id[0][0][1].x(), Catch::Matchers::WithinAbs(1.0, 1e-9));
+}
+
+TEST_CASE("text_to_regions vectorizes glyphs with counters", "[SketchImport]")
+{
+    // Locate the bundled font; resources_dir() may be unset under ctest, so
+    // fall back to a cwd-relative path (tests run from the repo root).
+    std::string font = resources_dir().empty()
+                           ? std::string("resources/fonts/HarmonyOS_Sans_SC_Regular.ttf")
+                           : resources_dir() + "/fonts/HarmonyOS_Sans_SC_Regular.ttf";
+    {
+        std::ifstream probe(font);
+        if (!probe.good()) {
+            SUCCEED("bundled font not reachable in this environment; covered live on :10");
+            return;
+        }
+    }
+
+    // Bad input is rejected without throwing.
+    REQUIRE(text_to_regions("", 10.0, font).empty());
+    REQUIRE(text_to_regions("A", 0.0, font).empty());
+
+    // 'A' has one triangular counter -> a region with an outer + 1 hole.
+    ImportRegions a = text_to_regions("A", 12.0, font);
+    REQUIRE(a.size() >= 1);
+    bool has_hole = false;
+    for (const auto& region : a)
+        if (region.size() >= 2) has_hole = true;
+    REQUIRE(has_hole);
+
+    // Two letters produce more regions than one.
+    ImportRegions ab = text_to_regions("AB", 12.0, font);
+    REQUIRE(ab.size() >= a.size());
+}

tests/libslic3r/test_sketchinference.cpp

@@ -0,0 +1,174 @@
+#include <catch2/catch_all.hpp>   // mainline OrcaSlicer ships Catch2 v3 (v2 was catch2/catch.hpp)
+using Catch::Approx;   // v3 scopes Approx into the Catch namespace; v2 had it at global scope
+
+#include "libslic3r/CAD/SketchInference.hpp"
+
+using namespace Slic3r;
+using K = InferenceSnap::Kind;
+
+static SketchEntity line(Vec2d a, Vec2d b)
+{
+    SketchEntity e; e.type = SketchEntity::Type::Line; e.p0 = a; e.p1 = b; return e;
+}
+static SketchEntity circle(Vec2d c, double r)
+{
+    SketchEntity e; e.type = SketchEntity::Type::Circle; e.center = c; e.p0 = c; e.radius = r; return e;
+}
+
+TEST_CASE("inference: cursor near a line endpoint snaps Coincident-able to it", "[inference]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {10, 0}) };
+    auto s = infer_point_snap(ents, {10.3, 0.2}, 1.0);
+    REQUIRE(s.kind == K::Endpoint);
+    CHECK(s.entity == 0);
+    CHECK(s.role == SketchPointRole::P1);
+    CHECK((s.point - Vec2d(10, 0)).norm() == Approx(0.0).margin(1e-9));
+}
+
+TEST_CASE("inference: endpoint beats midpoint when both are in range", "[inference]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {2, 0}) };
+    // Query equidistant-ish but closer to the endpoint: endpoint tier wins regardless.
+    auto s = infer_point_snap(ents, {1.9, 0.0}, 5.0);
+    CHECK(s.kind == K::Endpoint);
+    CHECK(s.role == SketchPointRole::P1);
+}
+
+TEST_CASE("inference: midpoint of a line is detected", "[inference]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {10, 0}) };
+    auto s = infer_point_snap(ents, {5.1, 0.1}, 0.5, /*include_origin=*/false);
+    REQUIRE(s.kind == K::Midpoint);
+    CHECK((s.point - Vec2d(5, 0)).norm() == Approx(0.0).margin(1e-9));
+}
+
+TEST_CASE("inference: circle centre and rim", "[inference]")
+{
+    std::vector<SketchEntity> ents = { circle({0, 0}, 5.0) };
+    auto c = infer_point_snap(ents, {0.2, 0.1}, 1.0, false);
+    CHECK(c.kind == K::Center);
+    auto r = infer_point_snap(ents, {5.1, 0.0}, 1.0, false);
+    REQUIRE(r.kind == K::OnEdge);
+    CHECK((r.point - Vec2d(5, 0)).norm() == Approx(0.0).margin(1e-9));
+}
+
+TEST_CASE("inference: origin snap when nothing else is near", "[inference]")
+{
+    std::vector<SketchEntity> ents = { line({20, 20}, {30, 20}) };
+    auto s = infer_point_snap(ents, {0.1, 0.1}, 1.0);
+    REQUIRE(s.kind == K::Origin);
+    CHECK(s.entity == -1);
+    CHECK((s.point - Vec2d(0, 0)).norm() == Approx(0.0).margin(1e-9));
+}
+
+TEST_CASE("inference: nothing in range returns None and the raw query", "[inference]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {10, 0}) };
+    auto s = infer_point_snap(ents, {50, 50}, 1.0, /*include_origin=*/false);
+    CHECK(s.kind == K::None);
+    CHECK((s.point - Vec2d(50, 50)).norm() == Approx(0.0).margin(1e-9));
+}
+
+TEST_CASE("inference: axis inference flags horizontal / vertical segments", "[inference]")
+{
+    CHECK(infer_axis_constraint({0, 0}, {10, 0.05}).value() == SketchConstraintType::Horizontal);
+    CHECK(infer_axis_constraint({0, 0}, {0.05, 10}).value() == SketchConstraintType::Vertical);
+    CHECK_FALSE(infer_axis_constraint({0, 0}, {10, 10}).has_value());   // 45 deg
+    CHECK_FALSE(infer_axis_constraint({0, 0}, {0, 0}).has_value());     // degenerate
+}
+
+TEST_CASE("inference: perpendicular inferred for a connected square corner", "[inference]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {10, 0}), line({10, 0}, {10, 7}) };
+    auto r = infer_relations(ents, 1);
+    REQUIRE(r.size() == 1);
+    CHECK(r[0].type == SketchConstraintType::Perpendicular);
+    CHECK(r[0].ea == 0);
+    CHECK(r[0].eb == 1);
+}
+
+TEST_CASE("inference: parallel inferred for connected collinear-ish lines", "[inference]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {10, 0}), line({10, 0}, {21, 0.1}) };
+    auto r = infer_relations(ents, 1);
+    REQUIRE(r.size() == 1);
+    CHECK(r[0].type == SketchConstraintType::Parallel);
+    CHECK(r[0].ea == 0);
+    CHECK(r[0].eb == 1);
+}
+
+TEST_CASE("inference: two unconnected parallel lines infer nothing", "[inference]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {10, 0}), line({0, 5}, {10, 5}) };
+    auto r = infer_relations(ents, 1);
+    CHECK(r.empty());
+}
+
+TEST_CASE("inference: a corner outside tolerance infers nothing", "[inference]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {10, 0}), line({10, 0}, {15, 7}) };
+    auto r = infer_relations(ents, 1);
+    CHECK(r.empty());
+}
+
+TEST_CASE("inference: equal radius inferred for near-equal circles", "[inference]")
+{
+    auto r = infer_relations({ circle({0, 0}, 5.0), circle({30, 0}, 5.02) }, 1);
+    REQUIRE(r.size() == 1);
+    CHECK(r[0].type == SketchConstraintType::EqualRadius);
+    CHECK(r[0].ea == 0);
+    CHECK(r[0].eb == 1);
+
+    auto r2 = infer_relations({ circle({0, 0}, 5.0), circle({30, 0}, 6.0) }, 1);
+    CHECK(r2.empty());
+}
+
+TEST_CASE("inference: tangent inferred for a line meeting a circle tangentially", "[inference]")
+{
+    std::vector<SketchEntity> ents = { circle({0, 0}, 5.0), line({0, 5}, {10, 5}) };
+    auto r = infer_relations(ents, 1);
+    REQUIRE(r.size() == 1);
+    CHECK(r[0].type == SketchConstraintType::Tangent);
+    CHECK(r[0].ea == 0);
+    CHECK(r[0].eb == 1);
+
+    std::vector<SketchEntity> off = { circle({0, 0}, 5.0), line({0, 5}, {10, 9}) };
+    CHECK(infer_relations(off, 1).empty());
+}
+
+TEST_CASE("inference: nothing inferred against a higher index", "[inference]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {10, 0}), line({10, 0}, {10, 7}) };
+    auto r = infer_relations(ents, 0);
+    CHECK(r.empty());
+}
+
+TEST_CASE("inference: degenerate entities are ignored", "[inference]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {10, 0}), line({10, 0}, {10, 0}) };
+    auto r = infer_relations(ents, 1);
+    CHECK(r.empty());
+}
+
+// The cap that keeps infer_relations linear rather than quadratic. Without it a drawing with
+// many equal holes yields a constraint per PAIR: 200 equal circles produced ~20000 candidates,
+// the batch was rejected as over-constrained, and the caller's one-at-a-time fallback then ran
+// a solve per constraint -- which pinned the app at 95% of a core with the MCP socket
+// unresponsive, and is what the corpus rung caught.
+TEST_CASE("inference: at most one relation per rule per new entity", "[inference]")
+{
+    // 40 circles of the same radius; the 41st must not produce 40 EqualRadius constraints.
+    std::vector<SketchEntity> ents;
+    for (int i = 0; i < 41; ++i) {
+        SketchEntity c;
+        c.type = SketchEntity::Type::Circle;
+        c.center = Vec2d(i * 20.0, 0.0);
+        c.p0 = c.center;
+        c.radius = 5.0;
+        ents.push_back(c);
+    }
+    auto rels = infer_relations(ents, 40);
+    CHECK(rels.size() == 1);
+    CHECK(rels[0].type == SketchConstraintType::EqualRadius);
+    CHECK(rels[0].eb == 40);
+}

tests/libslic3r/test_sketchprofile.cpp

@@ -0,0 +1,209 @@
+// Closed-profile harness for the 2D sketch layer.
+//
+// The existing [SketchEdit] cases check one entity at a time — offset ONE line, mirror ONE
+// arc — and every one of them passes while the feature they belong to is unusable. What a
+// user actually does is combine 2D features into a CLOSED PROFILE and extrude it, and the
+// property that makes that work is topological, not per-entity: after the operation, do the
+// pieces still form a single closed loop?
+//
+// So these cases assert the loop, not the coordinates. That is the invariant every sketch
+// operation has to preserve and the only one that predicts whether the GUI can build a solid
+// out of the result.
+#include <catch2/catch_all.hpp>   // mainline OrcaSlicer ships Catch2 v3 (v2 was catch2/catch.hpp)
+#include "libslic3r/CAD/SketchEngine.hpp"
+#include <BRepGProp.hxx>
+#include <GProp_GProps.hxx>
+#include <cmath>
+
+using namespace Slic3r;
+using Catch::Matchers::WithinAbs;
+
+namespace {
+
+SketchPlane xy_plane() { return SketchPlane::XY(); }
+
+SketchEntity line(const Vec2d& a, const Vec2d& b)
+{
+    SketchEntity e;
+    e.type = SketchEntity::Type::Line;
+    e.p0 = a; e.p1 = b;
+    return e;
+}
+
+// A CCW rectangle as four Line entities sharing endpoints exactly.
+std::vector<SketchEntity> rect(double w, double h)
+{
+    return { line({0, 0}, {w, 0}), line({w, 0}, {w, h}),
+             line({w, h}, {0, h}), line({0, h}, {0, 0}) };
+}
+
+// How many of the wires the sketch resolves to are CLOSED.
+int closed_wires(const std::vector<SketchEntity>& ents)
+{
+    const auto ws = SketchEngine::entities_to_wires(ents, xy_plane());
+    int n = 0;
+    for (const auto& w : ws)
+        if (!w.IsNull() && w.Closed()) ++n;
+    return n;
+}
+
+// Enclosed area of the single closed loop the sketch resolves to. -1 when it is not one
+// closed loop — the failure the whole file exists to catch.
+double profile_area(const std::vector<SketchEntity>& ents)
+{
+    const auto ws = SketchEngine::entities_to_wires(ents, xy_plane());
+    if (ws.size() != 1 || ws[0].IsNull() || !ws[0].Closed()) return -1.0;
+    const TopoDS_Face f = SketchEngine::wires_to_face(ws, xy_plane());
+    GProp_GProps props;
+    BRepGProp::SurfaceProperties(f, props);
+    return props.Mass();
+}
+
+SketchEntity arc(const Vec2d& c, double r, double a0, double a1)
+{
+    SketchEntity e;
+    e.type        = SketchEntity::Type::Arc;
+    e.center      = c;
+    e.radius      = r;
+    e.start_angle = a0;
+    e.end_angle   = a1;
+    e.p0 = c + r * Vec2d(std::cos(a0), std::sin(a0));
+    e.p1 = c + r * Vec2d(std::cos(a1), std::sin(a1));
+    return e;
+}
+
+} // namespace
+
+TEST_CASE("profile baseline: a hand-built rectangle is one closed loop", "[SketchProfile]")
+{
+    REQUIRE(closed_wires(rect(40, 20)) == 1);
+}
+
+TEST_CASE("profile: mirroring a closed rectangle keeps it closed", "[SketchProfile]")
+{
+    const auto m = SketchEngine::mirror_entities(rect(40, 20), Vec2d(-10, 0), Vec2d(-10, 1));
+    REQUIRE(m.size() == 4);
+    REQUIRE(closed_wires(m) == 1);
+}
+
+TEST_CASE("profile: mirroring an open half-profile closes it against the axis", "[SketchProfile]")
+{
+    // Half a rectangle, open along x=0 — the classic "draw half, mirror it" gesture.
+    const std::vector<SketchEntity> half = {
+        line({0, 0}, {20, 0}), line({20, 0}, {20, 10}), line({20, 10}, {0, 10}) };
+    auto all = half;
+    for (const auto& e : SketchEngine::mirror_entities(half, Vec2d(0, 0), Vec2d(0, 1)))
+        all.push_back(e);
+    REQUIRE(all.size() == 6);
+    REQUIRE(closed_wires(all) == 1);
+}
+
+TEST_CASE("profile: offsetting a closed rectangle keeps it closed", "[SketchProfile]")
+{
+    const auto out = SketchEngine::offset_entities(rect(40, 20), 5.0);
+    REQUIRE(out.size() == 4);
+    REQUIRE(closed_wires(out) == 1);
+}
+
+TEST_CASE("profile: offset outward grows the enclosed area by the right amount", "[SketchProfile]")
+{
+    // A rectangle offset outward by d is (w+2d) x (h+2d) with the corners rounded at r=d,
+    // so its area is w*h + 2d(w+h) + pi*d^2 whichever way the corners are healed... except
+    // for a sharp-corner offset, which is exactly (w+2d)*(h+2d). Either healing is defensible;
+    // a set of four disconnected segments is not, and that is what this measures.
+    const double w = 40, h = 20, d = 5;
+    const auto out = SketchEngine::offset_entities(rect(w, h), d);
+    const auto ws  = SketchEngine::entities_to_wires(out, xy_plane());
+    REQUIRE(ws.size() == 1);
+    REQUIRE(ws[0].Closed());
+}
+
+TEST_CASE("profile: offset sign is left-of-travel, so +d shrinks a CCW rectangle", "[SketchProfile]")
+{
+    // The convention has to be pinned by a test, because it is the one thing a caller cannot
+    // read off the geometry: +d = left of the direction of travel = inward for a CCW loop.
+    // Miter join on a rectangle keeps the corners sharp, so the result is exact.
+    const double w = 40, h = 20, d = 5;
+    REQUIRE_THAT(profile_area(SketchEngine::offset_entities(rect(w, h), d)),
+                 WithinAbs((w - 2 * d) * (h - 2 * d), 1e-6));
+    REQUIRE_THAT(profile_area(SketchEngine::offset_entities(rect(w, h), -d)),
+                 WithinAbs((w + 2 * d) * (h + 2 * d), 1e-6));
+}
+
+TEST_CASE("profile: offsetting a stadium (two lines + two arcs) stays closed", "[SketchProfile]")
+{
+    // A slot outline: straight top and bottom joined by half-circle caps. This is the case the
+    // per-entity offset could never repair, because both seams are line-to-arc.
+    const double L = 30, r = 8, d = 3;
+    const std::vector<SketchEntity> slot = {
+        line({0, -r}, {L, -r}),
+        arc({L, 0}, r, -M_PI / 2, M_PI / 2),
+        line({L, r}, {0, r}),
+        arc({0, 0}, r, M_PI / 2, 3 * M_PI / 2),
+    };
+    REQUIRE(closed_wires(slot) == 1);
+    const auto out = SketchEngine::offset_entities(slot, -d);   // -d = outward for this CCW loop
+    REQUIRE(closed_wires(out) == 1);
+    // Offsetting a stadium outward by d gives the stadium with radius r+d: L*2(r+d) + pi(r+d)^2.
+    // Lines and caps must move the SAME way — that is the assertion this case exists for.
+    const double rr = r + d;
+    REQUIRE_THAT(profile_area(out), WithinAbs(L * 2 * rr + M_PI * rr * rr, 1e-6));
+}
+
+TEST_CASE("profile: an open chain offsets without being forced closed", "[SketchProfile]")
+{
+    // A sweep path is legitimately open; the repair must join its interior seams and leave
+    // the two free ends alone.
+    const std::vector<SketchEntity> open_chain = {
+        line({0, 0}, {20, 0}), line({20, 0}, {20, 10}) };
+    const auto out = SketchEngine::offset_entities(open_chain, 4.0);
+    REQUIRE(out.size() == 2);
+    REQUIRE(closed_wires(out) == 0);
+    // The interior seam is repaired: the two offset segments still meet.
+    REQUIRE_THAT((out[0].p1 - out[1].p0).norm(), WithinAbs(0.0, 1e-9));
+}
+
+TEST_CASE("profile: a mirrored half offsets as one loop, not two", "[SketchProfile]")
+{
+    // The classic "draw half, mirror it" gesture on a stadium. mirror_entities emits a half
+    // that travels the opposite way round, so the concatenation must still chain as ONE closed
+    // loop and its mirrored cap must offset outward like the original, not inward.
+    const double L = 30, R = 15, d = 4;
+    const std::vector<SketchEntity> half = {
+        line({0, -R}, {L, -R}),
+        arc({L, 0}, R, -M_PI / 2, M_PI / 2),
+        line({L, R}, {0, R}),
+    };
+    std::vector<SketchEntity> all = half;
+    for (const auto& e : SketchEngine::mirror_entities(half, Vec2d(0, 0), Vec2d(0, 1)))
+        all.push_back(e);
+    REQUIRE(closed_wires(all) == 1);
+
+    const auto out = SketchEngine::offset_entities(all, -d);   // -d = outward for this loop
+    REQUIRE(closed_wires(out) == 1);
+    for (const auto& o : out)
+        if (o.type == SketchEntity::Type::Arc)
+            REQUIRE_THAT(o.radius, WithinAbs(R + d, 1e-9));
+}
+
+TEST_CASE("profile: a mirrored half continues the original chain", "[SketchProfile]")
+{
+    // The point of emitting the reflected half reversed: appending it to the source must give a
+    // chain you can WALK, head-to-tail, with no consumer having to notice that half of it came
+    // from a mirror. The end of the last source entity must be the start of the first mirrored
+    // one, and the end of the last mirrored one must close back to the very first start.
+    const std::vector<SketchEntity> half = {
+        line({0, -15}, {50, -15}), line({50, -15}, {50, 15}), line({50, 15}, {0, 15}) };
+    const auto m = SketchEngine::mirror_entities(half, Vec2d(0, 0), Vec2d(0, 1));
+    REQUIRE(m.size() == 3);
+
+    REQUIRE_THAT((half.back().p1 - m.front().p0).norm(), WithinAbs(0.0, 1e-9));
+    REQUIRE_THAT((m.back().p1   - half.front().p0).norm(), WithinAbs(0.0, 1e-9));
+
+    for (size_t i = 0; i + 1 < m.size(); ++i)
+        REQUIRE_THAT((m[i].p1 - m[i + 1].p0).norm(), WithinAbs(0.0, 1e-9));
+
+    auto all = half;
+    for (const auto& e : m) all.push_back(e);
+    REQUIRE(closed_wires(all) == 1);
+}

tests/libslic3r/test_slvs_constraints.cpp

@@ -0,0 +1,401 @@
+#include <catch2/catch_all.hpp>   // mainline OrcaSlicer ships Catch2 v3 (v2 was catch2/catch.hpp)
+using Catch::Approx;   // v3 scopes Approx into the Catch namespace; v2 had it at global scope
+
+#include "libslic3r/CAD/SketchSolver.hpp"
+#include "libslic3r/CAD/SketchEngine.hpp"
+
+using namespace Slic3r;
+using CT = SketchConstraintType;
+using R  = SketchPointRole;
+
+static SketchEntity line(Vec2d a, Vec2d b)
+{
+    SketchEntity e; e.type = SketchEntity::Type::Line; e.p0 = a; e.p1 = b; return e;
+}
+static SketchEntity circle(Vec2d c, double r)
+{
+    SketchEntity e; e.type = SketchEntity::Type::Circle; e.center = c; e.p0 = c; e.radius = r; return e;
+}
+static SketchEntityConstraintDef con(CT t, int ea, R ra, int eb, R rb, double v = 0.0)
+{
+    SketchEntityConstraintDef c; c.type = t; c.ea = ea; c.ra = ra; c.eb = eb; c.rb = rb; c.value = v; return c;
+}
+
+TEST_CASE("slvs: distance + horizontal + fix solves a line length", "[slvs]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {5, 1}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::Fix,        0, R::P0, 0, R::P0),
+        con(CT::Horizontal, 0, R::P0, 0, R::P1),
+        con(CT::Distance,   0, R::P0, 0, R::P1, 10.0),
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK((ents[0].p1 - ents[0].p0).norm() == Approx(10.0).margin(1e-6));
+    CHECK(ents[0].p0.x() == Approx(0.0).margin(1e-6));
+    CHECK(ents[0].p0.y() == Approx(0.0).margin(1e-6));
+    CHECK(ents[0].p1.y() == Approx(0.0).margin(1e-6));   // horizontal
+}
+
+TEST_CASE("slvs: coincident joins two line endpoints (loop closes)", "[slvs]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {10, 0}), line({10.3, 0.2}, {10, 10}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::Coincident, 0, R::P1, 1, R::P0),
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK((ents[0].p1 - ents[1].p0).norm() == Approx(0.0).margin(1e-6));
+}
+
+TEST_CASE("slvs: parallel + perpendicular on lines", "[slvs]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {10, 1}), line({0, 5}, {10, 5.5}), line({0, 0}, {0.5, 10}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::Fix,           0, R::P0, 0, R::P0),
+        con(CT::Horizontal,    0, R::P0, 0, R::P1),
+        con(CT::Parallel,      0, R::P0, 1, R::P0),     // line1 parallel to line0
+        con(CT::Perpendicular, 0, R::P0, 2, R::P0),     // line2 perpendicular to line0
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK(ents[1].p1.y() - ents[1].p0.y() == Approx(0.0).margin(1e-6));            // line1 horizontal
+    CHECK(ents[2].p1.x() - ents[2].p0.x() == Approx(0.0).margin(1e-6));            // line2 vertical
+}
+
+TEST_CASE("slvs: circle radius constraint", "[slvs]")
+{
+    std::vector<SketchEntity> ents = { circle({2, 2}, 3.0) };
+    std::vector<SketchEntityConstraintDef> cons = { con(CT::Radius, 0, R::P0, -1, R::P0, 7.0) };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK(ents[0].radius == Approx(7.0).margin(1e-6));
+}
+
+TEST_CASE("slvs: degrees of freedom reported", "[slvs]")
+{
+    // One free line with only a Fix on the start: 4 DoF total minus 2 (fix) = 2 remaining.
+    std::vector<SketchEntity> ents = { line({0, 0}, {3, 4}) };
+    std::vector<SketchEntityConstraintDef> cons = { con(CT::Fix, 0, R::P0, 0, R::P0) };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK(res.dof == 2);
+}
+
+TEST_CASE("slvs: drag pulls a point while constraints hold", "[slvs]")
+{
+    // A vertical line of fixed length 10, P0 pinned at the origin. Dragging P1 toward
+    // (10,0) must keep the length (Distance constraint) but rotate the line so the end
+    // follows the cursor into positive x — the dragged param wins the under-constrained DoF.
+    std::vector<SketchEntity> ents = { line({0, 0}, {0, 10}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::Fix,      0, R::P0, 0, R::P0),
+        con(CT::Distance, 0, R::P0, 0, R::P1, 10.0),
+    };
+    ents[0].p1 = Vec2d(10, 0);   // user dropped the endpoint here
+    auto res = sketch_solve_drag(ents, cons, 0, R::P1);
+    REQUIRE(res.ok);
+    CHECK((ents[0].p1 - ents[0].p0).norm() == Approx(10.0).margin(1e-6));  // length held
+    CHECK(ents[0].p0.x() == Approx(0.0).margin(1e-6));                     // P0 still pinned
+    CHECK(ents[0].p0.y() == Approx(0.0).margin(1e-6));
+    CHECK(ents[0].p1.x() > 1.0);   // end followed the drag toward +x (not stuck vertical)
+}
+
+TEST_CASE("slvs: over-constrained / inconsistent is detected", "[slvs]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {5, 0}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::Fix,      0, R::P0, 0, R::P0),
+        con(CT::Fix,      0, R::P1, 0, R::P1),
+        con(CT::Distance, 0, R::P0, 0, R::P1, 99.0),   // contradicts the pinned endpoints
+    };
+    auto res = sketch_solve(ents, cons);
+    CHECK_FALSE(res.ok);   // SLVS_RESULT_INCONSISTENT
+}
+
+// yww4. libslvs sizes its System with a compile-time `MAX_UNKNOWNS = 1024`, and the
+// solver is handed every entity in the sketch at 2 params per point — so a sketch of about 480
+// lines is the last one that fits and the next comes back TOO_MANY_UNKNOWNS. Because
+// try_add_constraints rolls a failed batch back, that turned into: every auto-inferred constraint
+// on a large sketch silently dropped, and from then on no dimension could ever be applied to it.
+// Constraints only couple entities that share a point, so the sketch is solved component by
+// component when the whole system does not fit.
+TEST_CASE("slvs: a sketch past the solver's unknown limit still solves", "[slvs]")
+{
+    // 300 disjoint squares: 1200 lines, 4800 unknowns whole, 8 per component.
+    const int N = 300;
+    std::vector<SketchEntity> ents;
+    std::vector<SketchEntityConstraintDef> cons;
+    for (int i = 0; i < N; ++i) {
+        const double x = (i % 30) * 10.0, y = (i / 30) * 10.0;
+        const int b = int(ents.size());
+        ents.push_back(line({x, y},         {x + 4.0, y}));
+        ents.push_back(line({x + 4.0, y},   {x + 4.0, y + 4.0}));
+        ents.push_back(line({x + 4.0, y + 4.0}, {x, y + 4.0}));
+        ents.push_back(line({x, y + 4.0},   {x, y}));
+        for (int k = 0; k < 4; ++k)
+            cons.push_back(con(CT::Coincident, b + k, R::P1, b + (k + 1) % 4, R::P0));
+    }
+    REQUIRE(ents.size() == size_t(4 * N));
+
+    std::vector<SketchEntity> before = ents;
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    for (size_t i = 0; i < ents.size(); ++i) {         // already satisfied: nothing may move
+        CHECK(ents[i].p0.x() == Approx(before[i].p0.x()).margin(1e-9));
+        CHECK(ents[i].p0.y() == Approx(before[i].p0.y()).margin(1e-9));
+        CHECK(ents[i].p1.x() == Approx(before[i].p1.x()).margin(1e-9));
+        CHECK(ents[i].p1.y() == Approx(before[i].p1.y()).margin(1e-9));
+    }
+
+    // And a dimension typed onto one of them lands exactly, which is what stopped working.
+    cons.push_back(con(CT::Distance, 0, R::P0, 0, R::P1, 7.0));
+    auto res2 = sketch_solve(ents, cons);
+    REQUIRE(res2.ok);
+    CHECK((ents[0].p1 - ents[0].p0).norm() == Approx(7.0).margin(1e-9));
+
+    // A conflict inside ONE component must still be caught, not swallowed by the split.
+    cons.push_back(con(CT::Distance, 0, R::P0, 0, R::P1, 99.0));
+    auto res3 = sketch_solve(ents, cons);
+    CHECK_FALSE(res3.ok);
+}
+
+TEST_CASE("slvs: equal radius drives two circles to one radius", "[slvs][CadDocument]")
+{
+    std::vector<SketchEntity> ents = { circle({0, 0}, 5.0), circle({10, 0}, 12.0) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::EqualRadius, 0, R::P0, 1, R::P0),
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK(ents[0].radius == Approx(ents[1].radius).margin(1e-9));
+    CHECK(ents[0].radius > 1e-6);   // equal-at-zero would satisfy the line above trivially
+}
+
+TEST_CASE("slvs: equal radius plus a radius dimension pins both", "[slvs][CadDocument]")
+{
+    std::vector<SketchEntity> ents = { circle({0, 0}, 5.0), circle({10, 0}, 12.0) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::EqualRadius, 0, R::P0, 1, R::P0),
+        con(CT::Radius, 0, R::P0, -1, R::P0, 8.0),
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK(ents[0].radius == Approx(8.0).margin(1e-9));
+    CHECK(ents[1].radius == Approx(8.0).margin(1e-9));
+}
+
+TEST_CASE("slvs: collinear makes two offset lines share one line", "[slvs][CadDocument]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {10, 0}), line({0, 4}, {10, 4}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::Collinear, 0, R::P0, 1, R::P0),
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    const Vec2d& a0 = ents[0].p0;
+    const Vec2d  ad = ents[0].p1 - ents[0].p0;
+    for (int k = 0; k <= 1; ++k) {
+        const Vec2d& pk = (k == 0) ? ents[1].p0 : ents[1].p1;
+        const double cross = ad.x() * (pk.y() - a0.y()) - ad.y() * (pk.x() - a0.x());
+        CHECK(cross == Approx(0.0).margin(1e-9));
+    }
+    // A line collapsed to a point is trivially collinear with anything, so the cross
+    // products above would pass on a degenerate solve. Both lines must survive intact.
+    CHECK(ad.norm() == Approx(10.0).margin(1e-9));
+    CHECK((ents[1].p1 - ents[1].p0).norm() == Approx(10.0).margin(1e-9));
+}
+
+TEST_CASE("slvs: collinear on already-collinear lines moves nothing", "[slvs][CadDocument]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {10, 0}), line({20, 0}, {30, 0}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::Collinear, 0, R::P0, 1, R::P0),
+    };
+    std::vector<SketchEntity> before = ents;
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    for (size_t i = 0; i < ents.size(); ++i) {         // already satisfied: nothing may move
+        CHECK(ents[i].p0.x() == Approx(before[i].p0.x()).margin(1e-9));
+        CHECK(ents[i].p0.y() == Approx(before[i].p0.y()).margin(1e-9));
+        CHECK(ents[i].p1.x() == Approx(before[i].p1.x()).margin(1e-9));
+        CHECK(ents[i].p1.y() == Approx(before[i].p1.y()).margin(1e-9));
+    }
+}
+
+TEST_CASE("slvs: distance-x drives the horizontal gap and leaves Y alone", "[slvs][CadDocument]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {3, 7}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::Fix,       0, R::P0, 0, R::P0),
+        con(CT::DistanceX, 0, R::P0, 0, R::P1, 10.0),
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    // SIGNED, not abs. PROJ_PT_DISTANCE constrains (pB - pA).dot(unit(dir)), and a
+    // LINE_SEGMENT's direction is point[0] - point[1] (slvs entity.cpp), so the reference
+    // line is built head-first to mean +X. Assert on abs and a flipped reference passes
+    // while every dimension lands the point on the wrong side of its anchor.
+    CHECK(ents[0].p1.x() - ents[0].p0.x() == Approx(10.0).margin(1e-9));
+    CHECK(ents[0].p1.y() == Approx(7.0).margin(1e-9));   // Y must not be disturbed
+}
+
+TEST_CASE("slvs: distance-y drives the vertical gap and leaves X alone", "[slvs][CadDocument]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {3, 7}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::Fix,       0, R::P0, 0, R::P0),
+        con(CT::DistanceY, 0, R::P0, 0, R::P1, 10.0),
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK(ents[0].p1.y() - ents[0].p0.y() == Approx(10.0).margin(1e-9));   // signed: see above
+    CHECK(ents[0].p1.x() == Approx(3.0).margin(1e-9));   // X must not be disturbed
+}
+
+TEST_CASE("slvs: distance-x is not the straight-line distance", "[slvs][CadDocument]")
+{
+    // B is at straight-line distance 10 from A; DistanceX = 6 is already satisfied, so a
+    // correct projection leaves B untouched. This is the case that fails if the constraint
+    // were wired to SLVS_C_PT_PT_DISTANCE, which would drag B onto the radius-6 circle.
+    std::vector<SketchEntity> ents = { line({0, 0}, {6, 8}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::Fix,       0, R::P0, 0, R::P0),
+        con(CT::DistanceX, 0, R::P0, 0, R::P1, 6.0),
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK(ents[0].p1.x() == Approx(6.0).margin(1e-9));
+    CHECK(ents[0].p1.y() == Approx(8.0).margin(1e-9));
+}
+
+TEST_CASE("slvs: distance-x plus distance-y fully locates a point", "[slvs][CadDocument]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {1, 1}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::Fix,       0, R::P0, 0, R::P0),
+        con(CT::DistanceX, 0, R::P0, 0, R::P1, 4.0),
+        con(CT::DistanceY, 0, R::P0, 0, R::P1, 3.0),
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK(ents[0].p1.x() - ents[0].p0.x() == Approx(4.0).margin(1e-9));   // signed: see above
+    CHECK(ents[0].p1.y() - ents[0].p0.y() == Approx(3.0).margin(1e-9));
+}
+
+// The property the GUI's ref-ordering exists to preserve: DistanceX is SIGNED, so applying
+// the CURRENT projected delta as the target must not move anything. If the refs are ordered
+// so the shown value is positive while the actual signed delta is negative, accepting the
+// value a dimension opens with teleports the point to the other side of its anchor.
+TEST_CASE("slvs: applying a point's own distance-x is a no-op", "[slvs][CadDocument]")
+{
+    // p1 sits to the LEFT of p0, so the signed delta p1 - p0 is negative.
+    std::vector<SketchEntity> ents = { line({0, 0}, {-4, 7}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::Fix,       0, R::P0, 0, R::P0),
+        con(CT::DistanceX, 0, R::P0, 0, R::P1, -4.0),   // the CURRENT signed delta
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK(ents[0].p1.x() == Approx(-4.0).margin(1e-9));   // stayed left, did not flip to +4
+    CHECK(ents[0].p1.y() == Approx(7.0).margin(1e-9));
+}
+
+static SketchEntity point(Vec2d p)
+{
+    SketchEntity e; e.type = SketchEntity::Type::Point; e.p0 = p; return e;
+}
+
+TEST_CASE("slvs: coincident onto the origin sentinel pins a point", "[slvs][CadDocument]")
+{
+    std::vector<SketchEntity> ents = { point({5, 5}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::Coincident, 0, R::P0, kSketchRefOrigin, R::P0),
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK(ents[0].p0.x() == Approx(0.0).margin(1e-9));
+    CHECK(ents[0].p0.y() == Approx(0.0).margin(1e-9));
+}
+
+// NOTE on why these pin the free direction instead of asserting "the other coordinate is
+// left alone". sys.dragged[] is populated only while a drag is in progress, so a plain
+// sketch_solve of an UNDER-constrained system is free to move any parameter -- solvespace
+// runs a Newton iteration, it does not minimise movement. PointOnLine alone is one equation
+// in two unknowns, and the point measurably slides along the axis (from (7,4) to (4,0)).
+// That is legal, not a defect, so the well-posed test states both coordinates.
+TEST_CASE("slvs: point-on-line onto the X axis, located along it from the origin", "[slvs][CadDocument]")
+{
+    std::vector<SketchEntity> ents = { point({7, 4}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::PointOnLine, 0, R::P0, kSketchRefAxisX, R::P0),
+        con(CT::DistanceX,   kSketchRefOrigin, R::P0, 0, R::P0, 7.0),   // both sentinels at once
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK(ents[0].p0.y() == Approx(0.0).margin(1e-9));   // driven onto the X axis
+    CHECK(ents[0].p0.x() == Approx(7.0).margin(1e-9));   // and located along it
+}
+
+TEST_CASE("slvs: point-on-line onto the Y axis, located along it from the origin", "[slvs][CadDocument]")
+{
+    std::vector<SketchEntity> ents = { point({4, 7}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::PointOnLine, 0, R::P0, kSketchRefAxisY, R::P0),
+        con(CT::DistanceY,   kSketchRefOrigin, R::P0, 0, R::P0, 7.0),
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK(ents[0].p0.x() == Approx(0.0).margin(1e-9));   // driven onto the Y axis
+    CHECK(ents[0].p0.y() == Approx(7.0).margin(1e-9));   // and located along it
+}
+
+TEST_CASE("slvs: parallel to the X axis levels a line without collapsing it", "[slvs][CadDocument]")
+{
+    std::vector<SketchEntity> ents = { line({0, 0}, {10, 3}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::Fix,      0, R::P0, 0, R::P0),
+        con(CT::Parallel, 0, R::P0, kSketchRefAxisX, R::P0),
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK(ents[0].p1.y() == Approx(0.0).margin(1e-9));   // leveled onto y = 0
+    // A bare Parallel leaves length free; the solver preserves the endpoint's free
+    // x-coordinate, so the line lands at (10,0) — length 10, not the original sqrt(109).
+    // Assert that free coordinate rather than abs(): a flipped/collapsed line would not
+    // land exactly here.
+    CHECK(ents[0].p1.x() == Approx(10.0).margin(1e-9));
+    CHECK((ents[0].p1 - ents[0].p0).norm() == Approx(10.0).margin(1e-6));   // did not collapse
+}
+
+TEST_CASE("slvs: symmetric-about-Y mirrors two points across x = 0", "[slvs][CadDocument]")
+{
+    std::vector<SketchEntity> ents = { point({3, 5}), point({9, 5}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::SymmetricAboutY, 0, R::P0, 1, R::P0),
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK(ents[0].p0.x() == Approx(-ents[1].p0.x()).margin(1e-9));   // mirror across x = 0
+    // Neither x may be 0: a both-collapsed-to-the-axis solution also satisfies the mirror
+    // trivially. Squared, not abs(), so a near-zero x still fails cleanly.
+    CHECK(ents[0].p0.x() * ents[0].p0.x() > 1e-12);
+    CHECK(ents[1].p0.x() * ents[1].p0.x() > 1e-12);
+    CHECK(ents[0].p0.y() == Approx(5.0).margin(1e-9));   // Y values untouched
+    CHECK(ents[1].p0.y() == Approx(5.0).margin(1e-9));
+}
+
+TEST_CASE("slvs: reference-based constraint adds no degrees of freedom", "[slvs][CadDocument]")
+{
+    // A free line with Fix on P0 and Parallel to the X axis: 4 DoF - 2 (fix) - 1 (angle)
+    // = 1 (length still free). If the G_FIXED reference entities leaked unknowns into the
+    // solved group, this figure would be wrong.
+    std::vector<SketchEntity> ents = { line({0, 0}, {3, 4}) };
+    std::vector<SketchEntityConstraintDef> cons = {
+        con(CT::Fix,      0, R::P0, 0, R::P0),
+        con(CT::Parallel, 0, R::P0, kSketchRefAxisX, R::P0),
+    };
+    auto res = sketch_solve(ents, cons);
+    REQUIRE(res.ok);
+    CHECK(res.dof == 1);
+}

tests/libslic3r/test_toolordering_nozzle_group.cpp

@@ -163,6 +163,50 @@ TEST_CASE("H2C multi-nozzle: filaments get distinct nozzles on the 6-nozzle extr
     }
 }
 
+TEST_CASE("Grouping context spans the filament count with mis-sized config arrays", "[ToolOrdering][H2C]")
+{
+    // FilamentGroup indexes the grouping context's filament_info by filament id, so a short
+    // per-filament array must not shorten it: the reads run off the end.
+    DynamicPrintConfig config = DynamicPrintConfig::full_print_config();
+    // Single 6-nozzle extruder: opens the grouping engine without needing a BBL multi-extruder.
+    config.option<ConfigOptionFloats>("nozzle_diameter", true)->values = {0.4};
+    config.option<ConfigOptionIntsNullable>("extruder_max_nozzle_count", true)->values = {6};
+    config.option<ConfigOptionStrings>("extruder_nozzle_stats", true)->values = {"Standard#6"};
+
+    // Four filaments, with filament_type / filament_is_support left short on purpose.
+    config.option<ConfigOptionStrings>("filament_colour", true)->values = {"#FF0000", "#00FF00", "#0000FF", "#FFFF00"};
+    config.option<ConfigOptionStrings>("filament_type", true)->values = {"PLA"};
+    config.option<ConfigOptionBools>("filament_is_support", true)->values = {0};
+    config.option<ConfigOptionFloats>("filament_diameter", true)->values = {1.75, 1.75, 1.75, 1.75};
+    config.option<ConfigOptionInts>("filament_map", true)->values = {1, 1, 1, 1};
+    config.option<ConfigOptionFloats>("flush_volumes_matrix", true)->values = std::vector<double>(16, 140.);
+    config.option<ConfigOptionFloats>("flush_multiplier", true)->values = {1.};
+
+    Model model;
+    model.add_object("cube", "", make_cube(20, 20, 20))->add_instance();
+
+    Print print;
+    print.apply(model, config);
+    // apply() does not pad the per-filament arrays, so the mis-sizing survives into the engine.
+    REQUIRE(print.config().filament_type.values.size() < print.config().filament_colour.values.size());
+
+    std::vector<std::vector<unsigned int>> layer_filaments = {{0, 1}, {1, 2}, {2, 3}};
+
+    SECTION("short per-filament arrays still yield one entry per filament") {
+        auto result = ToolOrdering::get_recommended_filament_maps(layer_filaments, &print, FilamentMapMode::fmmAutoForFlush, {}, {});
+        REQUIRE(result.get_extruder_map(false).size() == 4);
+        for (int f = 0; f < 4; ++f)
+            REQUIRE(result.get_extruder_id(f) == 0);
+    }
+
+    SECTION("filament_ids longer than the filament count is truncated, not paired past the end") {
+        config.option<ConfigOptionStrings>("filament_ids", true)->values = {"a", "b", "c", "d", "e", "f"};
+        print.apply(model, config);
+        auto result = ToolOrdering::get_recommended_filament_maps(layer_filaments, &print, FilamentMapMode::fmmAutoForFlush, {}, {});
+        REQUIRE(result.get_extruder_map(false).size() == 4);
+    }
+}
+
 TEST_CASE("H2C dynamic selector: per-layer nozzle ids reach the g-code surface", "[ToolOrdering][H2C][Dynamic]")
 {
     // The per-layer regroup engine
@@ -981,3 +1025,41 @@ TEST_CASE("Selector slicing keeps the result valid across re-apply", "[Print][H2
     REQUIRE(status != PrintBase::APPLY_STATUS_INVALIDATED);
     REQUIRE(print.is_step_done(psSlicingFinished));
 }
+
+TEST_CASE("parse_cyclic_order parses user cyclic toolchange sequences", "[ToolOrdering][Cyclic]")
+{
+    // Filament numbers are 1-based in the UI; the parser returns 0-based indices.
+    SECTION("well-formed sequence") {
+        REQUIRE(parse_cyclic_order("3,2,1,4", 4) == std::vector<unsigned int>({2, 1, 0, 3}));
+    }
+
+    SECTION("surrounding whitespace is tolerated") {
+        REQUIRE(parse_cyclic_order(" 3 , 2 ,1, 4 ", 4) == std::vector<unsigned int>({2, 1, 0, 3}));
+    }
+
+    SECTION("out-of-range and non-positive entries are dropped") {
+        // 0 is below the 1-based range, 5 is above it for a 4-filament setup, -1 is invalid.
+        REQUIRE(parse_cyclic_order("0,5,-1,2", 4) == std::vector<unsigned int>({1}));
+    }
+
+    SECTION("duplicates keep only the first occurrence") {
+        REQUIRE(parse_cyclic_order("2,2,1,2", 4) == std::vector<unsigned int>({1, 0}));
+    }
+
+    SECTION("garbage tokens are ignored") {
+        REQUIRE(parse_cyclic_order("3,abc,,2,x1", 4) == std::vector<unsigned int>({2, 1}));
+    }
+
+    SECTION("tokens that only start with a number are ignored") {
+        // "2x" must be dropped rather than parsed as filament 2.
+        REQUIRE(parse_cyclic_order("3,2x,1", 4) == std::vector<unsigned int>({2, 0}));
+    }
+
+    SECTION("empty string yields an empty order") {
+        REQUIRE(parse_cyclic_order("", 4).empty());
+    }
+
+    SECTION("a partial sequence only names the filaments it lists") {
+        REQUIRE(parse_cyclic_order("3,1", 4) == std::vector<unsigned int>({2, 0}));
+    }
+}

tests/libslic3r/test_utils.cpp

@@ -2,6 +2,15 @@
 
 #include "libslic3r/Utils.hpp"
 
+#include "test_utils.hpp"
+
+#include <boost/filesystem.hpp>
+
+#include <algorithm>
+#include <cctype>
+#include <fstream>
+#include <string>
+
 #ifndef _WIN32
 #include <unistd.h>     // getuid
 #endif
@@ -52,3 +61,94 @@ TEST_CASE("per-user temp root is unchanged on Windows, isolated elsewhere", "[ut
     REQUIRE_THAT(root, Catch::Matchers::StartsWith(base + "/orcaslicer_"));
 #endif
 }
+
+TEST_CASE("copy_file reports the OS error when the destination cannot be written", "[utils]") {
+    ScopedTemporaryFile source(".txt");
+    {
+        std::ofstream ofs(source.string(), std::ios::binary);
+        ofs << "orca";
+    }
+    REQUIRE(boost::filesystem::exists(source.path()));
+
+    // A directory that was never created, so the copy fails on every platform.
+    const boost::filesystem::path destination = source.path().parent_path() / "orca-missing-dir" / "copy.txt";
+    REQUIRE_FALSE(boost::filesystem::exists(destination.parent_path()));
+
+    std::string error_message;
+    REQUIRE(copy_file(source.string(), destination.string(), error_message) == FAIL_COPY_FILE);
+    REQUIRE_FALSE(error_message.empty());
+
+#ifdef _WIN32
+    // The Windows branch formats GetLastError() itself. Writing that as
+    // "Error: " + errCode adds an integer to a string literal, which indexes into the
+    // literal instead of appending and runs off its end for any code above 7.
+    const std::string prefix = "Error: ";
+    REQUIRE(error_message.rfind(prefix, 0) == 0);
+
+    const std::string code = error_message.substr(prefix.size());
+    REQUIRE_FALSE(code.empty());
+    REQUIRE(std::all_of(code.begin(), code.end(), [](unsigned char c) { return std::isdigit(c) != 0; }));
+#endif // _WIN32
+}
+
+TEST_CASE("A resolved input path still names the same file after the working directory changes", "[utils]") {
+    ScopedTemporaryFile model(".3mf");
+    { std::ofstream out(model.string()); out << "3mf"; }
+    const std::string name = model.path().filename().string();
+
+    // Resolve the bare name from the directory holding the file, then move away from it. The guard
+    // restores the directory the test started in, wherever this leaves it.
+    ScopedWorkingDirectory cwd(model.path().parent_path());
+    const std::string resolved = resolve_cli_input_path(name);
+    boost::filesystem::current_path(boost::filesystem::path(TEST_DATA_DIR));
+
+    REQUIRE(boost::filesystem::exists(resolved));
+    REQUIRE(boost::filesystem::equivalent(resolved, model.path()));
+    // Control: the bare name finds nothing from here, so resolving it this late would have failed.
+    REQUIRE_FALSE(boost::filesystem::exists(name));
+}
+
+TEST_CASE("resolve_cli_input_path completes a relative path against the working directory", "[utils]") {
+    ScopedWorkingDirectory cwd(boost::filesystem::temp_directory_path());
+    // Read back rather than reusing temp_directory_path(): changing to it resolves any symlink.
+    const boost::filesystem::path here = boost::filesystem::current_path();
+
+    SECTION("a bare name") {
+        REQUIRE(resolve_cli_input_path("model.3mf") == (here / "model.3mf").make_preferred().string());
+    }
+    SECTION("a ./ prefix is dropped") {
+        REQUIRE(resolve_cli_input_path("./model.3mf") == (here / "model.3mf").make_preferred().string());
+    }
+    SECTION("a ../ traversal is collapsed") {
+        REQUIRE(resolve_cli_input_path("../model.3mf") == (here.parent_path() / "model.3mf").make_preferred().string());
+    }
+}
+
+TEST_CASE("resolve_cli_input_path leaves inputs that must not be completed unchanged", "[utils]") {
+    SECTION("an absolute path") {
+        const boost::filesystem::path absolute = (boost::filesystem::temp_directory_path() / "model.3mf").make_preferred();
+        REQUIRE(resolve_cli_input_path(absolute.string()) == absolute.string());
+    }
+#ifdef _WIN32
+    // Every absolute form Windows accepts opens today, so each must come back byte for byte:
+    // normalizing them would rewrite the forward slashes and rebuild the \\?\ and UNC prefixes.
+    SECTION("an absolute Windows path of any form") {
+        for (const std::string absolute : {R"(C:\models\model.3mf)",
+                                           R"(C:/models/model.3mf)",
+                                           R"(\\server\share\model.3mf)",
+                                           R"(\\?\C:\models\model.3mf)"})
+            REQUIRE(resolve_cli_input_path(absolute) == absolute);
+    }
+#endif
+    // These are downloaded rather than opened, and completing one would produce a path, not a URL.
+    SECTION("a custom open protocol URL") {
+        for (const std::string url : {"orcaslicer://open/?file=https://example.com/model.3mf",
+                                      "prusaslicer://open/?file=https://example.com/model.3mf",
+                                      "bambustudio://open/?file=https://example.com/model.3mf",
+                                      "cura://open/?file=https://example.com/model.3mf"})
+            REQUIRE(resolve_cli_input_path(url) == url);
+    }
+    SECTION("an empty argument") {
+        REQUIRE(resolve_cli_input_path("").empty());
+    }
+}

tests/libslic3r/test_wipe_tower.cpp

@@ -0,0 +1,289 @@
+#include <catch2/catch_all.hpp>
+
+#include <cmath>
+
+#include "libslic3r/BoundingBox.hpp"
+#include "libslic3r/ClipperUtils.hpp"
+#include "libslic3r/GCode/WipeTower.hpp"
+#include "libslic3r/GCode/WipeTower2.hpp"
+#include "libslic3r/Print.hpp"
+#include "libslic3r/PrintConfig.hpp"
+
+using namespace Slic3r;
+using Catch::Matchers::WithinAbs;
+
+// A Bambu P1S project that reproduced the off-plate brim: two PLAs priming 30 and 45 mm3 in
+// separate adhesiveness categories on a 35 mm tower, 0.21 mm layers, 0.4 nozzle (0.5 mm lines),
+// 150 % infill gap (0.75 mm line pitch), rib width 8, 16 mm tall.
+static std::vector<WipeTower::PurgeEstimate> cube_purges(int first_category = 100)
+{
+    return {{30.f, first_category}, {45.f, 0}};
+}
+
+TEST_CASE("Cone base polygon bulges past the body box", "[WipeTower]") {
+    // Zero angle: plain body box.
+    const Polygon box = WipeTower2::cone_base_polygon(35., 20., 100., 0.);
+    CHECK(box.points.size() == 4);
+    CHECK(get_extents(box).size() == Point::new_scale(Vec2d(35., 20.)));
+    // A 25-degree cone on a 100 mm tower: base radius R = tan(12.5deg)*100 = 22.2 mm,
+    // which exceeds the body half-depth, so the footprint bulges to center +- R in y
+    // (support_scale keeps the x extent compressed near the body).
+    const Polygon     base = WipeTower2::cone_base_polygon(35., 20., 100., 25.);
+    const BoundingBox bb   = get_extents(base);
+    const double      R    = std::tan(25. / 2. * M_PI / 180.) * 100.;
+    CHECK_THAT(unscaled(bb.min.y()), WithinAbs(10. - R, 0.1));
+    CHECK_THAT(unscaled(bb.max.y()), WithinAbs(10. + R, 0.1));
+    // The footprint always contains the body box.
+    CHECK(diff(Polygons{box}, Polygons{base}).empty());
+}
+
+TEST_CASE("Type1 block-stack depth quantizes each purge to whole lines", "[WipeTower]") {
+    // A 0.5 mm line at 0.21 mm carries 0.0955 mm3 per mm, so across the 34 mm between the
+    // perimeters 30 mm3 is 10 lines and 45 mm3 is 14: 7.5 + 10.5 at the 0.75 mm pitch behind
+    // one perimeter width. The generated mesh of the project measured exactly this.
+    CHECK_THAT(WipeTower::estimate_tower_blocks_depth(cube_purges(), 35.f, 0.21f, 0.4f, 1.5f), WithinAbs(18.5f, 0.01f));
+    // Sharing one category, a layer can never purge into every filament (one of them starts
+    // the layer), so the block is sized by its worst layer and the 10-line purge drops out.
+    CHECK_THAT(WipeTower::estimate_tower_blocks_depth(cube_purges(0), 35.f, 0.21f, 0.4f, 1.5f), WithinAbs(11.0f, 0.01f));
+    CHECK_THAT(WipeTower::estimate_tower_blocks_depth({}, 35.f, 0.2f, 0.4f, 1.f), WithinAbs(0.f, 1e-6f));
+    // A width narrower than two perimeter widths cannot hold purge lines.
+    CHECK_THAT(WipeTower::estimate_tower_blocks_depth({{45.f, 0}}, 0.9f, 0.2f, 0.4f, 1.f), WithinAbs(0.f, 1e-6f));
+}
+
+TEST_CASE("A nozzle change adds its ramming lines to the block", "[WipeTower]") {
+    // 10 mm of 1.75 mm filament (24.05 mm3) laid as 1.0 mm nozzle-change lines at 0.2 mm
+    // (0.1914 mm2 each) is 125.7 mm; across the 48.5 mm available that is 3 lines of 1.0 mm.
+    std::vector<WipeTower::PurgeEstimate> purges{{100.f, 0}, {100.f, 0}};
+    const float without_change = WipeTower::estimate_tower_blocks_depth(purges, 50.f, 0.2f, 0.4f, 1.f);
+    purges.front().filament_change_length = 10.f;
+    CHECK_THAT(WipeTower::estimate_tower_blocks_depth(purges, 50.f, 0.2f, 0.4f, 1.f) - without_change, WithinAbs(3.f, 1e-4f));
+}
+
+TEST_CASE("Rib tower footprint estimate covers the generated footprint", "[WipeTower]") {
+    // The generated first-layer wall bbox of the project measured 29.56 mm from the sliced
+    // G-code; the volume-only estimate said 23.585 mm.
+    const float side = WipeTower::estimate_rib_tower_bbox_side(cube_purges(), 35.f, 0.21f, 0.4f, 1.5f, 8.f, 0.f, 16.f);
+    CHECK(side >= 29.56f);
+    CHECK(side <= 29.56f + 4.f); // without grossly over-reserving plate space
+    // Separate categories stack their blocks, so the footprint must not shrink when they differ.
+    CHECK(side >= WipeTower::estimate_rib_tower_bbox_side(cube_purges(0), 35.f, 0.21f, 0.4f, 1.5f, 8.f, 0.f, 16.f));
+    CHECK_THAT(WipeTower::estimate_rib_tower_bbox_side({}, 35.f, 0.2f, 0.4f, 1.f, 8.f, 0.f, 16.f), WithinAbs(0.f, 1e-6f));
+}
+
+TEST_CASE("Rib footprint extends the ribs, not the body, below the stability minimum", "[WipeTower]") {
+    // A 10 mm body under a 90 mm print: the ribs stretch to the minimum depth's diagonal, and
+    // the rib width is capped at half the body, so the square grows to minimum + 5 / sqrt(2).
+    const float min_depth = WipeTower::get_limit_depth_by_height(90.f);
+    REQUIRE(min_depth > 10.f);
+    CHECK_THAT(WipeTower::rib_footprint_side(10.f, 10.f, 8.f, 0.f, 90.f), WithinAbs(min_depth + 5.f / std::sqrt(2.f), 1e-4f));
+    // The extra rib length runs along the diagonal, so it shows as its projection on each axis.
+    const float plain = WipeTower::rib_footprint_side(30.f, 30.f, 8.f, 0.f, 5.f);
+    CHECK_THAT(plain, WithinAbs(30.f + 8.f / std::sqrt(2.f), 1e-4f));
+    CHECK_THAT(WipeTower::rib_footprint_side(30.f, 30.f, 8.f, 4.f, 5.f) - plain, WithinAbs(4.f / std::sqrt(2.f), 1e-4f));
+    // A negative extra length cannot pull the ribs inside the diagonal.
+    CHECK_THAT(WipeTower::rib_footprint_side(30.f, 30.f, 8.f, -4.f, 5.f), WithinAbs(plain, 1e-4f));
+    CHECK_THAT(WipeTower::rib_footprint_side(0.f, 30.f, 8.f, 0.f, 5.f), WithinAbs(0.f, 1e-6f));
+}
+
+TEST_CASE("Brim width estimate matches each generator's loop quantization", "[WipeTower]") {
+    // 3 mm configured, 0.4 nozzle, 0.2 first layer: 0.4571 mm spacing, 7 loops. WipeTower2
+    // prints and reports the 7 loops; WipeTower reports half a spacing of line width on top.
+    const float spacing = 0.5f - 0.2f * float(1. - M_PI_4);
+    CHECK_THAT(WipeTower::estimate_brim_real_width(3.f, 0.4f, 0.2f, true), WithinAbs(7.f * spacing, 1e-4f));
+    CHECK_THAT(WipeTower::estimate_brim_real_width(3.f, 0.4f, 0.2f, false), WithinAbs(7.5f * spacing, 1e-4f));
+    CHECK_THAT(WipeTower::estimate_brim_real_width(0.f, 0.4f, 0.2f, true), WithinAbs(0.f, 1e-6f));
+}
+
+// ---------------------------------------------------------------------------------------------
+// "No sparse layers": the compaction rule and the clearance it demands of the plate.
+// ---------------------------------------------------------------------------------------------
+
+// A square of side mm centred on (cx, cy), in bed coordinates.
+static Polygon centered_square(double cx, double cy, double side)
+{
+    const double h = 0.5 * side;
+    Polygon      poly;
+    poly.points = {Point::new_scale(cx - h, cy - h), Point::new_scale(cx + h, cy - h),
+                   Point::new_scale(cx + h, cy + h), Point::new_scale(cx - h, cy + h)};
+    return poly;
+}
+
+static WipeTower::ToolChangeResult make_tcr(int initial_tool, int new_tool, float layer_height)
+{
+    WipeTower::ToolChangeResult tcr{};
+    tcr.initial_tool = initial_tool;
+    tcr.new_tool     = new_tool;
+    tcr.layer_height = layer_height;
+    return tcr;
+}
+
+// A 20 mm square tower at the bed origin, no spiral z-hop, so the keep-out zone is the bare
+// footprint and every distance below is one the test sets.
+static PrintConfig clearance_config()
+{
+    PrintConfig cfg;
+    cfg.extruder_clearance_radius.value       = 40.;
+    cfg.extruder_clearance_dist_to_rod.value  = 20.;
+    cfg.extruder_clearance_height_to_rod.value = 25.;
+    cfg.extruder_clearance_height_to_lid.value = 120.;
+    cfg.nozzle_height.value                   = 5.;
+    cfg.nozzle_diameter.values                = {0.4};
+    cfg.z_hop.values                          = {0.};
+    cfg.travel_slope.values                   = {3.};
+    return cfg;
+}
+
+TEST_CASE("Sparse layers are skipped only when nothing else needs a tower on every layer", "[WipeTower][NoSparseLayers]") {
+    PrintConfig cfg;
+    cfg.timelapse_type.value            = TimelapseType::tlTraditional;
+    cfg.enable_wrapping_detection.value = false;
+
+    cfg.wipe_tower_no_sparse_layers.value = false;
+    CHECK_FALSE(wipe_tower_sparse_layers_skipped(cfg));
+    cfg.wipe_tower_no_sparse_layers.value = true;
+    CHECK(wipe_tower_sparse_layers_skipped(cfg));
+
+    // Both park the nozzle on the tower every layer, so no layer is ever dropped and the option
+    // must read as off everywhere rather than compact in one place and not another.
+    cfg.timelapse_type.value = TimelapseType::tlSmooth;
+    CHECK_FALSE(wipe_tower_sparse_layers_skipped(cfg));
+    cfg.timelapse_type.value            = TimelapseType::tlTraditional;
+    cfg.enable_wrapping_detection.value = true;
+    CHECK_FALSE(wipe_tower_sparse_layers_skipped(cfg));
+}
+
+TEST_CASE("A planned layer is sparse only when its single tool change keeps the filament", "[WipeTower][NoSparseLayers]") {
+    CHECK(wipe_tower_layer_is_sparse({make_tcr(1, 1, 0.2f)}));
+    CHECK_FALSE(wipe_tower_layer_is_sparse({make_tcr(0, 1, 0.2f)}));
+    // A second entry means the layer carries real work whatever the tools are.
+    CHECK_FALSE(wipe_tower_layer_is_sparse({make_tcr(1, 1, 0.2f), make_tcr(1, 1, 0.2f)}));
+    CHECK_FALSE(wipe_tower_layer_is_sparse({}));
+}
+
+TEST_CASE("The compacted tower falls one layer height behind the object per sparse layer", "[WipeTower][NoSparseLayers]") {
+    // Five 0.2 mm layers off a 0.1 mm z offset, the middle two sparse. The object reaches
+    // 0.1 + 5 * 0.2 = 1.1; the tower only grows on the three printed layers, so it ends at
+    // 0.1 + 3 * 0.2 = 0.7 and a sparse layer carries the previous value rather than its own.
+    const std::vector<std::vector<WipeTower::ToolChangeResult>> tool_changes{
+        {make_tcr(0, 1, 0.2f)}, {make_tcr(1, 1, 0.2f)}, {make_tcr(1, 1, 0.2f)},
+        {make_tcr(1, 0, 0.2f)}, {make_tcr(0, 1, 0.2f)}};
+
+    const std::vector<float> tower_z = compute_compacted_wipe_tower_z(tool_changes, 0.1f);
+    REQUIRE(tower_z.size() == tool_changes.size());
+    CHECK_THAT(tower_z[0], WithinAbs(0.3f, 1e-5f));
+    CHECK_THAT(tower_z[1], WithinAbs(0.3f, 1e-5f));
+    CHECK_THAT(tower_z[2], WithinAbs(0.3f, 1e-5f));
+    CHECK_THAT(tower_z[3], WithinAbs(0.5f, 1e-5f));
+    CHECK_THAT(tower_z[4], WithinAbs(0.7f, 1e-5f));
+    CHECK_THAT(1.1f - tower_z.back(), WithinAbs(2 * 0.2f, 1e-5f));
+
+    // Without a base the tower starts at the bed, and an empty layer carries over like a sparse one.
+    const std::vector<float> no_offset = compute_compacted_wipe_tower_z({{make_tcr(0, 1, 0.2f)}, {}}, 0.f);
+    CHECK_THAT(no_offset[0], WithinAbs(0.2f, 1e-5f));
+    CHECK_THAT(no_offset[1], WithinAbs(0.2f, 1e-5f));
+}
+
+TEST_CASE("The tower keep-out zone grows by the spiral z-hop envelope", "[WipeTower][NoSparseLayers]") {
+    PrintConfig   cfg       = clearance_config();
+    const Polygon footprint = centered_square(0., 0., 20.);
+
+    // No lift, no envelope: the zone works on the bare footprint.
+    CHECK_THAT(unscaled(compacted_wipe_tower_zone(cfg, footprint).hull.bounding_box().max.x()), WithinAbs(10., 1e-6));
+
+    // A spiral lift leaves the outline at low z, so it counts as tower. The circle reaches
+    // 2 * lift / (2*pi*atan(slope)) past the outline, matching GCodeWriter: 2*2/(2*pi*atan(3)) = 0.51 mm.
+    cfg.z_hop.values = {2.};
+    const CompactedTowerZone lifted = compacted_wipe_tower_zone(cfg, footprint);
+    CHECK_THAT(unscaled(lifted.hull.bounding_box().max.x()), WithinAbs(10.51, 0.02));
+    CHECK_THAT(unscaled(lifted.hull.bounding_box().min.y()), WithinAbs(-10.51, 0.02));
+    CHECK(diff(Polygons{footprint}, Polygons{lifted.hull}).empty());
+
+    // z_hop is capped at 5 mm by the option, so a taller lift cannot widen the zone further.
+    cfg.z_hop.values = {10.};
+    const double capped = unscaled(compacted_wipe_tower_zone(cfg, footprint).hull.bounding_box().max.x());
+    CHECK_THAT(capped, WithinAbs(10. + 2. * 5. / (2. * M_PI * std::atan(3.)), 0.02));
+
+    // The rod sweeps the whole X axis, so its band is the tower's y span plus half the rod offset.
+    CHECK_THAT(unscaled(lifted.bbox_rod.max.y()), WithinAbs(10.51 + 10., 0.02));
+}
+
+TEST_CASE("An object beside a compacted tower is limited by the nearest part of the toolhead", "[WipeTower][NoSparseLayers]") {
+    const PrintConfig        cfg  = clearance_config();
+    const CompactedTowerZone zone = compacted_wipe_tower_zone(cfg, centered_square(0., 0., 20.));
+
+    // Each side carries half its clearance less 0.1 mm slack, so the two outlines meet when the
+    // objects are a full clearance apart: 2 * (4 - 0.2) / 2 = 3.8 mm for the bare nozzle cone,
+    // 2 * (40 - 0.2) / 2 = 39.8 mm for the head body. A 10 mm object at x leaves a gap of x - 15.
+    const double tall = 50., shortish = 3.;
+
+    // Gap 1 mm, inside the nozzle cone: the object may not rise above the tower at all.
+    const CompactedTowerClearance touching = compacted_wipe_tower_clearance(cfg, zone, centered_square(16., 0., 10.), tall);
+    CHECK_THAT(touching.allowed_rise, WithinAbs(0., 1e-9));
+
+    // Gap 10 mm: clear of the cone but inside the head body, which starts at nozzle_height.
+    const CompactedTowerClearance near_body = compacted_wipe_tower_clearance(cfg, zone, centered_square(25., 0., 10.), tall);
+    CHECK(near_body.near_body);
+    CHECK_THAT(near_body.allowed_rise, WithinAbs(5., 1e-9));
+    CHECK_THAT(near_body.body_clearance, WithinAbs(40., 1e-9));
+
+    // The same spot, but an object that never rises past the cone. The body sits above the cone, so
+    // it cannot reach this object however close it stands, and only the narrow tier applies.
+    const CompactedTowerClearance low = compacted_wipe_tower_clearance(cfg, zone, centered_square(25., 0., 10.), shortish);
+    CHECK_FALSE(low.near_body);
+    CHECK_THAT(low.body_clearance, WithinAbs(4., 1e-9));
+    CHECK_THAT(low.allowed_rise, WithinAbs(25., 1e-9));
+
+    // Gap 55 mm, clear of the head entirely: the rod is the obstacle, since the object shares the
+    // tower's y band and the rod spans the whole x axis however far apart the two stand.
+    const CompactedTowerClearance far_in_band = compacted_wipe_tower_clearance(cfg, zone, centered_square(70., 0., 10.), tall);
+    CHECK_FALSE(far_in_band.near_body);
+    CHECK_THAT(far_in_band.far_clearance, WithinAbs(25., 1e-9));
+    CHECK_THAT(far_in_band.allowed_rise, WithinAbs(25., 1e-9));
+
+    // Out of the band the rod passes over it and only the lid is left.
+    const CompactedTowerClearance out_of_band = compacted_wipe_tower_clearance(cfg, zone, centered_square(70., 60., 10.), tall);
+    CHECK_THAT(out_of_band.allowed_rise, WithinAbs(120., 1e-9));
+}
+
+TEST_CASE("The ring drawn around the tower meets the outline drawn around an offender", "[WipeTower][NoSparseLayers]") {
+    const PrintConfig        cfg  = clearance_config();
+    const CompactedTowerZone zone = compacted_wipe_tower_zone(cfg, centered_square(0., 0., 20.));
+
+    // What the plater draws has to be what the check tested, otherwise a user moves an object until
+    // the outlines part and slicing still refuses the plate. Both halves of the 3.8 mm nozzle
+    // clearance: at a 3 mm gap the rings overlap and the rise limit is zero, at 5 mm neither holds.
+    for (const auto &c : {std::make_pair(18., true), std::make_pair(20., false)}) {
+        DYNAMIC_SECTION("object at x = " << c.first) {
+            const Polygon                 hull      = centered_square(c.first, 0., 10.);
+            const CompactedTowerClearance clearance = compacted_wipe_tower_clearance(cfg, zone, hull, 3.);
+            const Polygons                rings     = compacted_wipe_tower_rings(zone, compacted_tower_body_tier(clearance));
+            const Polygon                 outline   = compacted_wipe_tower_offender_outline(hull, clearance.body_clearance);
+            const bool                    outlines_meet = ! intersection(rings, Polygons{outline}).empty();
+            const bool                    rise_denied   = clearance.allowed_rise < EPSILON;
+            CHECK(outlines_meet == c.second);
+            CHECK(rise_denied == c.second);
+        }
+    }
+}
+
+TEST_CASE("Only the keep-out ring an object is measured against is drawn", "[WipeTower][NoSparseLayers]") {
+    const PrintConfig        cfg  = clearance_config();
+    const CompactedTowerZone zone = compacted_wipe_tower_zone(cfg, centered_square(0., 0., 20.));
+
+    // Drawing the wide ring when no object is judged on it would show a keep-out zone the check can
+    // never trip, so it is added only once some object reaches past the nozzle cone.
+    CHECK(compacted_wipe_tower_rings(zone, false).size() == zone.grown_nozzle.size());
+    CHECK(compacted_wipe_tower_rings(zone, true).size() == zone.grown_nozzle.size() + zone.grown_body.size());
+    CHECK_THAT(unscaled(get_extents(zone.grown_nozzle).max.x()), WithinAbs(10. + 0.5 * (4. - 0.2), 0.02));
+    CHECK_THAT(unscaled(get_extents(zone.grown_body).max.x()), WithinAbs(10. + 0.5 * (40. - 0.2), 0.02));
+}
+
+TEST_CASE("Footprint padding covers the brim and the extrusion half width on each side", "[WipeTower][NoSparseLayers]") {
+    // A nominal outline hulls extrusion centre lines and is re-centred once the real wall is known,
+    // so a line width per side on top of the brim is what keeps an estimate enclosing the real tower.
+    const PrintConfig cfg = clearance_config();
+    CHECK_THAT(compacted_tower_footprint_padding(cfg, 2.), WithinAbs(2. + 2. * 0.4, 1e-9));
+    CHECK_THAT(compacted_tower_footprint_padding(cfg, 0.), WithinAbs(2. * 0.4, 1e-9));
+    // Callers whose outline already carries the brim pass zero, and a negative one cannot shrink it.
+    CHECK_THAT(compacted_tower_footprint_padding(cfg, -5.), WithinAbs(2. * 0.4, 1e-9));
+}

tests/libslic3r/test_wipe_tower_estimate.cpp

@@ -0,0 +1,351 @@
+#include <catch2/catch_all.hpp>
+
+#include "libslic3r/BoundingBox.hpp"
+#include "libslic3r/ClipperUtils.hpp"
+#include "libslic3r/GCode/WipeTower.hpp"
+#include "libslic3r/GCode/WipeTower2.hpp"
+#include "libslic3r/GCode/WipeTowerEstimate.hpp"
+#include "libslic3r/PrintConfig.hpp"
+
+#include <cmath>
+#include <numeric>
+#include <string>
+
+using namespace Slic3r;
+using Catch::Matchers::WithinAbs;
+
+// Rectangle wall, one nozzle, 100 mm3 prime volume on a 50 mm wide tower at 0.2 mm layers: one
+// purge is 10 mm of depth. The flush matrix is off here; the shipped-default case covers it.
+// Built as PresetBundle::full_config builds the GUI's: apply() creates each enum as a
+// ConfigOptionEnumGeneric, where full_print_config() would clone the static defaults'
+// ConfigOptionEnum<T>. The estimate has to read either.
+static DynamicPrintConfig preset_shaped_defaults()
+{
+    DynamicPrintConfig config;
+    config.apply(FullPrintConfig::defaults());
+    return config;
+}
+
+static DynamicPrintConfig make_config(const char *wall_type = "rectangle")
+{
+    DynamicPrintConfig config = preset_shaped_defaults();
+    config.set_key_value("prime_tower_width", new ConfigOptionFloat(50.));
+    config.set_key_value("prime_volume", new ConfigOptionFloat(100.));
+    config.set_key_value("filament_prime_volume", new ConfigOptionFloats({100.}));
+    config.set_key_value("filament_adhesiveness_category", new ConfigOptionInts({0}));
+    config.set_key_value("prime_tower_infill_gap", new ConfigOptionPercent(100.));
+    config.set_key_value("wipe_tower_extra_spacing", new ConfigOptionPercent(100.));
+    config.set_key_value("prime_tower_brim_width", new ConfigOptionFloat(3.));
+    config.set_deserialize_strict("wipe_tower_wall_type", wall_type);
+    config.set_key_value("wipe_tower_rib_width", new ConfigOptionFloat(8.));
+    config.set_key_value("wipe_tower_extra_rib_length", new ConfigOptionFloat(0.));
+    config.set_key_value("nozzle_diameter", new ConfigOptionFloats({0.4}));
+    config.set_key_value("initial_layer_print_height", new ConfigOptionFloat(0.2));
+    config.set_deserialize_strict("timelapse_type", "0");
+    config.set_key_value("enable_wrapping_detection", new ConfigOptionBool(false));
+    config.set_key_value("raft_layers", new ConfigOptionInt(0));
+    config.set_key_value("purge_in_prime_tower", new ConfigOptionBool(false));
+    config.set_key_value("single_extruder_multi_material", new ConfigOptionBool(false));
+    return config;
+}
+
+static std::vector<unsigned int> filaments(size_t count)
+{
+    std::vector<unsigned int> ids(count);
+    std::iota(ids.begin(), ids.end(), 0u);
+    return ids;
+}
+
+// The first `count` filaments on the given planner; Type2 unless a case says otherwise.
+static WipeTowerFootprint estimate(const ConfigBase &config, size_t count, double layer_height, double height, WipeTowerType type = WipeTowerType::Type2)
+{
+    return estimate_wipe_tower_footprint(config, type, filaments(count), layer_height, height);
+}
+
+// What both planners print for a 3 mm brim at 0.4 nozzle and 0.2 first layer (0.4571 mm loops).
+static double printed_brim(double configured, WipeTowerType type)
+{
+    return WipeTower::estimate_brim_real_width(float(configured), 0.4f, 0.2f, type == WipeTowerType::Type2);
+}
+
+TEST_CASE("A rectangle wall tower is sized by the purge volume", "[WipeTowerEstimate]") {
+    const DynamicPrintConfig config = make_config();
+    // Three filaments purge twice per layer; a 5 mm object keeps the stability floor at 5 mm.
+    const WipeTowerFootprint fp = estimate(config, 3, 0.2, 5.);
+    CHECK_THAT(fp.width, WithinAbs(50., 1e-9));
+    CHECK_THAT(fp.depth, WithinAbs(20., 1e-9));
+    CHECK_THAT(fp.height, WithinAbs(5., 1e-9));
+    CHECK_THAT(fp.brim_width, WithinAbs(printed_brim(3., WipeTowerType::Type2), 1e-6));
+    // Thinner layers need more depth for the same volume.
+    CHECK_THAT(estimate(config, 3, 0.1, 5.).depth, WithinAbs(40., 1e-9));
+}
+
+TEST_CASE("Each planner spaces its purge lines by its own option", "[WipeTowerEstimate]") {
+    // Type2 reads wipe_tower_extra_spacing and Type1 prime_tower_infill_gap; neither sees the
+    // other's key. Type2's extra flow cancels out of its depth.
+    DynamicPrintConfig config = make_config();
+    config.set_key_value("wipe_tower_extra_flow", new ConfigOptionPercent(250.));
+    CHECK_THAT(estimate(config, 3, 0.2, 5.).depth, WithinAbs(20., 1e-9));
+    config.set_key_value("wipe_tower_extra_spacing", new ConfigOptionPercent(150.));
+    CHECK_THAT(estimate(config, 3, 0.2, 5.).depth, WithinAbs(30., 1e-9));
+    const double type1_spaced = estimate(config, 3, 0.2, 5., WipeTowerType::Type1).depth;
+    config.set_key_value("prime_tower_infill_gap", new ConfigOptionPercent(150.));
+    CHECK_THAT(estimate(config, 3, 0.2, 5.).depth, WithinAbs(30., 1e-9));
+    // Type1 stacks whole lines behind one 0.5 mm perimeter width, so only the stack scales.
+    CHECK_THAT(estimate(config, 3, 0.2, 5., WipeTowerType::Type1).depth - 0.5, WithinAbs(1.5 * (type1_spaced - 0.5), 1e-6));
+}
+
+TEST_CASE("Type1 sizes the tower from each filament's own prime volume", "[WipeTowerEstimate]") {
+    // The Bambu P1S project of the WipeTower cases: 30 and 45 mm3 in two categories on a 35 mm
+    // tower at 0.21 mm, 150 % gap, is 18.5 mm of stacked blocks (11 mm sharing one category).
+    DynamicPrintConfig config = make_config();
+    config.set_key_value("prime_tower_width", new ConfigOptionFloat(35.));
+    config.set_key_value("prime_tower_infill_gap", new ConfigOptionPercent(150.));
+    config.set_key_value("initial_layer_print_height", new ConfigOptionFloat(0.21));
+    config.set_key_value("filament_prime_volume", new ConfigOptionFloats({30., 45.}));
+    config.set_key_value("filament_adhesiveness_category", new ConfigOptionInts({100, 0}));
+    const std::vector<WipeTower::PurgeEstimate> purges{{30.f, 100}, {45.f, 0}};
+    const double blocks = WipeTower::estimate_tower_blocks_depth(purges, 35.f, 0.21f, 0.4f, 1.5f);
+    REQUIRE_THAT(blocks, WithinAbs(18.5, 0.01));
+    CHECK_THAT(estimate(config, 2, 0.21, 5., WipeTowerType::Type1).depth, WithinAbs(blocks, 1e-4));
+    // The ids pick the volumes, so their order does not matter and a lone filament has no purge.
+    CHECK_THAT(estimate_wipe_tower_footprint(config, WipeTowerType::Type1, {1, 0}, 0.21, 5.).depth, WithinAbs(blocks, 1e-4));
+    CHECK_THAT(estimate(config, 1, 0.21, 5., WipeTowerType::Type1).depth, WithinAbs(0., 1e-9));
+    config.set_key_value("filament_adhesiveness_category", new ConfigOptionInts({0, 0}));
+    CHECK_THAT(estimate(config, 2, 0.21, 5., WipeTowerType::Type1).depth, WithinAbs(11., 0.01));
+    // A rib wall squares the same stack.
+    config.set_deserialize_strict("wipe_tower_wall_type", "rib");
+    const WipeTowerFootprint rib = estimate(config, 2, 0.21, 5., WipeTowerType::Type1);
+    CHECK_THAT(rib.width, WithinAbs(rib.depth, 1e-9));
+    CHECK_THAT(rib.depth, WithinAbs(WipeTower::estimate_rib_tower_bbox_side({{30.f, 0}, {45.f, 0}}, 35.f, 0.21f, 0.4f, 1.5f, 8.f, 0.f, 5.f), 1e-4));
+}
+
+TEST_CASE("A second nozzle adds the ramming of one nozzle change per layer", "[WipeTowerEstimate]") {
+    // Two filaments on two nozzles: the tool order crosses once per layer, and Type1 rams 10 mm
+    // of filament as three 1.0 mm nozzle-change lines (see the WipeTower case).
+    DynamicPrintConfig config = make_config();
+    config.set_key_value("nozzle_diameter", new ConfigOptionFloats({0.4, 0.4}));
+    config.set_key_value("filament_change_length", new ConfigOptionFloats({10., 10.}));
+    config.set_key_value("filament_diameter", new ConfigOptionFloats({1.75, 1.75}));
+    config.set_key_value("filament_map", new ConfigOptionInts({1, 1}));
+    const double same_nozzle = estimate(config, 2, 0.2, 5., WipeTowerType::Type1).depth;
+    config.set_key_value("filament_map", new ConfigOptionInts({1, 2}));
+    CHECK_THAT(estimate(config, 2, 0.2, 5., WipeTowerType::Type1).depth - same_nozzle, WithinAbs(3., 1e-4));
+}
+
+TEST_CASE("The tower is sized for the first layer when it is the thinnest", "[WipeTowerEstimate]") {
+    // Both planners reserve the worst layer: a 0.28 mm print with a 0.2 mm first layer needs
+    // the 0.2 mm depth, while a thicker first layer changes nothing.
+    DynamicPrintConfig config = make_config();
+    const double at_thinnest = estimate(config, 3, 0.2, 5.).depth;
+    CHECK_THAT(estimate(config, 3, 0.28, 5.).depth, WithinAbs(at_thinnest, 1e-9));
+    config.set_key_value("initial_layer_print_height", new ConfigOptionFloat(0.3));
+    CHECK(estimate(config, 3, 0.28, 5.).depth < at_thinnest);
+}
+
+TEST_CASE("Object height sets the stability floor and the auto brim", "[WipeTowerEstimate]") {
+    DynamicPrintConfig config = make_config();
+    // Two filaments purge once: 10 mm, lifted to the 20 mm floor of a 100 mm tower.
+    CHECK_THAT(estimate(config, 2, 0.2, 100.).depth, WithinAbs(20., 1e-9));
+    config.set_key_value("prime_tower_brim_width", new ConfigOptionFloat(-1.));
+    const double auto_brim = WipeTower::get_auto_brim_by_height(50.f);
+    CHECK_THAT(estimate(config, 2, 0.2, 50.).brim_width, WithinAbs(printed_brim(auto_brim, WipeTowerType::Type2), 1e-6));
+    CHECK_THAT(estimate(config, 2, 0.2, 50., WipeTowerType::Type1).brim_width, WithinAbs(printed_brim(auto_brim, WipeTowerType::Type1), 1e-6));
+}
+
+TEST_CASE("A single filament only gets a tower when one is printed anyway", "[WipeTowerEstimate]") {
+    DynamicPrintConfig config = make_config();
+    CHECK_THAT(estimate(config, 1, 0.2, 100.).depth, WithinAbs(0., 1e-9));
+    CHECK_THAT(estimate(config, 0, 0.2, 100.).width, WithinAbs(0., 1e-9));
+
+    // Wrapping detection prints a tower on the first layers whatever the filament count: the
+    // Type1 planner's fixed 10 mm, the stability floor otherwise.
+    config.set_key_value("enable_wrapping_detection", new ConfigOptionBool(true));
+    CHECK_THAT(estimate(config, 1, 0.2, 100.).depth, WithinAbs(20., 1e-9));
+    CHECK_THAT(estimate(config, 1, 0.2, 100., WipeTowerType::Type1).depth, WithinAbs(WipeTower::get_wrapping_detection_depth(), 1e-9));
+    config.set_key_value("enable_wrapping_detection", new ConfigOptionBool(false));
+
+    // A raft is not one of them: normalize_fdm_2 clears enable_prime_tower for a plate that
+    // purges one filament unless smooth timelapse or wrapping detection is on, so a raft
+    // alone leaves no tower to reserve for.
+    config.set_key_value("raft_layers", new ConfigOptionInt(3));
+    CHECK_THAT(estimate(config, 1, 0.2, 100.).depth, WithinAbs(0., 1e-9));
+    config.set_key_value("raft_layers", new ConfigOptionInt(0));
+
+    config.set_deserialize_strict("timelapse_type", "1");
+    // A tower printed with no tool change is exactly the planner's idle depth: there is
+    // nothing to purge, and WipeTower2 sizes it at the stability floor.
+    CHECK_THAT(estimate(config, 1, 0.2, 100.).depth, WithinAbs(20., 1e-9));
+    CHECK_THAT(estimate(config, 1, 0.2, 5.).depth, WithinAbs(WipeTower::get_limit_depth_by_height(5.f), 1e-9));
+}
+
+TEST_CASE("A tool change reserves a tower even with nothing to purge", "[WipeTowerEstimate]") {
+    // The purge volumes are configurable down to zero, but the tool changes are still printed
+    // on the tower and both planners still floor it - so the estimate has to floor it too.
+    // Type1 plans per filament and already reserves one; Type2 has only the volume to go on.
+    const double     height = GENERATE(5., 100.);
+    const float      floor  = WipeTower::get_limit_depth_by_height(float(height));
+    const char      *wall   = GENERATE("rectangle", "rib");
+    DynamicPrintConfig config = make_config(wall);
+    config.set_key_value("prime_volume", new ConfigOptionFloat(0.));
+    config.set_key_value("filament_prime_volume", new ConfigOptionFloats({0.}));
+
+    CHECK(estimate(config, 3, 0.2, height, WipeTowerType::Type2).depth >= floor);
+    CHECK(estimate(config, 3, 0.2, height, WipeTowerType::Type1).depth >= floor);
+    // Still nothing for a lone filament with no other reason.
+    CHECK_THAT(estimate(config, 1, 0.2, height, WipeTowerType::Type2).depth, WithinAbs(0., 1e-9));
+    CHECK_THAT(estimate(config, 1, 0.2, height, WipeTowerType::Type1).depth, WithinAbs(0., 1e-9));
+}
+
+TEST_CASE("Both wall types agree on whether there is a tower at all", "[WipeTowerEstimate]") {
+    // A wall type may only change the shape of the tower, never whether one is reserved:
+    // reporting no tower for one that is built collapses the validation hull to a point.
+    const double height = GENERATE(5., 100.);
+    DynamicPrintConfig rect = make_config();
+    DynamicPrintConfig rib  = make_config("rib");
+
+    // No tool change and nothing else that prints a tower - neither wall type reserves one.
+    CHECK_THAT(estimate(rect, 1, 0.2, height).depth, WithinAbs(0., 1e-9));
+    CHECK_THAT(estimate(rib, 1, 0.2, height).depth, WithinAbs(0., 1e-9));
+
+    // Not even on a dual-nozzle printer, where a lone filament still needs no purge.
+    rect.set_key_value("nozzle_diameter", new ConfigOptionFloats({0.4, 0.4}));
+    rib.set_key_value("nozzle_diameter", new ConfigOptionFloats({0.4, 0.4}));
+    CHECK_THAT(estimate(rect, 1, 0.2, height).depth, WithinAbs(0., 1e-9));
+    CHECK_THAT(estimate(rib, 1, 0.2, height).depth, WithinAbs(0., 1e-9));
+
+    // With a tool change both reserve one, and both respect the stability floor.
+    CHECK(estimate(rect, 2, 0.2, height).depth >= WipeTower::get_limit_depth_by_height(float(height)));
+    CHECK(estimate(rib, 2, 0.2, height).depth >= WipeTower::get_limit_depth_by_height(float(height)));
+}
+
+TEST_CASE("A rib wall squares the tower and caps the rib width", "[WipeTowerEstimate]") {
+    DynamicPrintConfig config = make_config("rib");
+    // sqrt(200 / 0.2) = 31.62 mm square, plus the 8 mm rib bulge along the diagonal.
+    const double body = std::sqrt(1000.);
+    WipeTowerFootprint fp = estimate(config, 3, 0.2, 5.);
+    CHECK_THAT(fp.depth, WithinAbs(8. / std::sqrt(2.) + body, 1e-5));
+    CHECK_THAT(fp.width, WithinAbs(fp.depth, 1e-9));
+    // The extra rib length runs along the diagonal and grows the footprint by its projection.
+    config.set_key_value("wipe_tower_extra_rib_length", new ConfigOptionFloat(4.));
+    CHECK_THAT(estimate(config, 3, 0.2, 5.).depth, WithinAbs((8. + 4.) / std::sqrt(2.) + body, 1e-5));
+    // A tiny tower caps the rib width at half its depth: 5 mm body, 2.5 mm rib.
+    config.set_key_value("wipe_tower_extra_rib_length", new ConfigOptionFloat(0.));
+    config.set_key_value("prime_volume", new ConfigOptionFloat(5.));
+    CHECK_THAT(estimate(config, 2, 0.2, 5.).depth, WithinAbs(2.5 / std::sqrt(2.) + 5., 1e-5));
+}
+
+TEST_CASE("Every wall and tower type is read the same from a preset and a static config", "[WipeTowerEstimate]") {
+    // The GUI, arrange and the CLI pass a DynamicPrintConfig whose enums are
+    // ConfigOptionEnumGeneric; Print passes a static config whose enums are ConfigOptionEnum<T>.
+    // Both the wall type and the planner selection are read by value, so both give the same shape.
+    const char *wall_type  = GENERATE("rectangle", "cone", "rib");
+    const char *tower_type = GENERATE("type1", "type2");
+    DynamicPrintConfig preset = make_config(wall_type);
+    preset.set_deserialize_strict("wipe_tower_type", tower_type);
+    REQUIRE(dynamic_cast<const ConfigOptionEnumGeneric *>(preset.option("wipe_tower_wall_type")) != nullptr);
+
+    FullPrintConfig static_config;
+    static_config.apply(preset, true);
+    REQUIRE(static_config.wipe_tower_wall_type.serialize() == wall_type);
+    REQUIRE(static_config.wipe_tower_type.serialize() == tower_type);
+
+    const WipeTowerType type = resolve_wipe_tower_type(preset);
+    CHECK(type == (std::string(tower_type) == "type1" ? WipeTowerType::Type1 : WipeTowerType::Type2));
+    CHECK(resolve_wipe_tower_type(static_config) == type);
+
+    // Three filaments purge twice per layer on a 5 mm object.
+    const WipeTowerFootprint fp          = estimate(preset, 3, 0.2, 5., type);
+    const WipeTowerFootprint from_static = estimate(static_config, 3, 0.2, 5., type);
+    CHECK(fp.depth > 0.);
+    if (std::string(wall_type) == "rib")
+        CHECK_THAT(fp.width, WithinAbs(fp.depth, 1e-9));
+    else
+        CHECK_THAT(fp.width, WithinAbs(50., 1e-9));
+    CHECK_THAT(from_static.width, WithinAbs(fp.width, 1e-9));
+    CHECK_THAT(from_static.depth, WithinAbs(fp.depth, 1e-9));
+    CHECK_THAT(from_static.brim_width, WithinAbs(fp.brim_width, 1e-9));
+
+    // Smooth timelapse is the other enum the estimate reads: a lone filament gets a tower
+    // through both storages too.
+    preset.set_deserialize_strict("timelapse_type", "1");
+    static_config.apply(preset, true);
+    CHECK(estimate(preset, 1, 0.2, 5., type).depth > 0.);
+    CHECK(estimate(static_config, 1, 0.2, 5., type).depth > 0.);
+}
+
+TEST_CASE("The first-layer outline bulges only for a Type2 cone wall", "[WipeTowerEstimate]") {
+    // Read off a preset-shaped config, whose enums are ConfigOptionEnumGeneric: a cast to
+    // ConfigOptionEnum<T> sees no wall type there and would never find the cone.
+    DynamicPrintConfig config = make_config("cone");
+    config.set_key_value("wipe_tower_cone_angle", new ConfigOptionFloat(25.));
+    REQUIRE(dynamic_cast<const ConfigOptionEnumGeneric *>(config.option("wipe_tower_wall_type")) != nullptr);
+    const Polygon box = Polygon::new_scale({{0., 0.}, {35., 0.}, {35., 20.}, {0., 20.}});
+    auto is_box = [&box](const Polygon &outline) { return diff(Polygons{outline}, Polygons{box}).empty(); };
+
+    // A 25-degree cone on a 100 mm tower has a 22 mm base radius, past the 10 mm half-depth.
+    const Polygon cone = estimate_wipe_tower_first_layer_outline(config, WipeTowerType::Type2, 35., 20., 100.);
+    CHECK(unscaled(get_extents(cone).max.y()) > 20. + 1.);
+    CHECK(diff(Polygons{box}, Polygons{cone}).empty());
+    // Type1 ignores the cone option, and the other wall types have no cone.
+    CHECK(is_box(estimate_wipe_tower_first_layer_outline(config, WipeTowerType::Type1, 35., 20., 100.)));
+    for (const char *wall_type : {"rectangle", "rib"}) {
+        config.set_deserialize_strict("wipe_tower_wall_type", wall_type);
+        CHECK(is_box(estimate_wipe_tower_first_layer_outline(config, WipeTowerType::Type2, 35., 20., 100.)));
+    }
+    // The static config Print holds gives the same outline.
+    config.set_deserialize_strict("wipe_tower_wall_type", "cone");
+    FullPrintConfig static_config;
+    static_config.apply(config, true);
+    const Polygon from_static = estimate_wipe_tower_first_layer_outline(static_config, WipeTowerType::Type2, 35., 20., 100.);
+    CHECK(from_static.points == cone.points);
+}
+
+TEST_CASE("A Bambu Lab printer always gets the Type1 planner", "[WipeTowerEstimate]") {
+    DynamicPrintConfig config = make_config();
+    config.set_deserialize_strict("wipe_tower_type", "type2");
+    config.set_key_value("printer_model", new ConfigOptionString("Bambu Lab X1 Carbon"));
+    CHECK(resolve_wipe_tower_type(config) == WipeTowerType::Type1);
+    config.set_key_value("printer_model", new ConfigOptionString("Voron 2.4"));
+    CHECK(resolve_wipe_tower_type(config) == WipeTowerType::Type2);
+    config.erase("wipe_tower_type");
+    CHECK(resolve_wipe_tower_type(config) == WipeTowerType::Type2);
+}
+
+TEST_CASE("A dual nozzle purges every filament plus the filament change", "[WipeTowerEstimate]") {
+    DynamicPrintConfig config = make_config();
+    config.set_key_value("nozzle_diameter", new ConfigOptionFloats({0.4, 0.4}));
+    config.set_key_value("filament_change_length", new ConfigOptionFloats({10., 10.}));
+    config.set_key_value("filament_diameter", new ConfigOptionFloats({1.75, 1.75}));
+    // Two purges of 100 mm3 plus one 10 mm filament change: (200 + 10 * pi * 1.75^2 / 4) / (0.2 * 50).
+    const double change_volume = 10. * PI * 1.75 * 1.75 / 4.;
+    CHECK_THAT(estimate(config, 2, 0.2, 5.).depth, WithinAbs((200. + change_volume) / 10., 1e-9));
+}
+
+TEST_CASE("The shipped defaults size the tower from the flush matrix", "[WipeTowerEstimate]") {
+    // Both keys default to true, so the shipped configuration purges the flush volumes rather
+    // than the prime volume, with no infill gap on top - the flush volumes already hold it.
+    DynamicPrintConfig config = preset_shaped_defaults();
+    REQUIRE(config.opt_bool("purge_in_prime_tower"));
+    REQUIRE(config.opt_bool("single_extruder_multi_material"));
+    config.set_key_value("prime_tower_width", new ConfigOptionFloat(50.));
+    config.set_deserialize_strict("wipe_tower_wall_type", "rectangle");
+    config.set_key_value("nozzle_diameter", new ConfigOptionFloats({0.4}));
+
+    const double flush_volume = WipeTower2::estimate_semm_flush_volume(config, 2);
+    const double expected     = std::max(double(WipeTower::get_limit_depth_by_height(5.f)), flush_volume / (0.2 * 50.));
+    CHECK_THAT(estimate(config, 2, 0.2, 5.).depth, WithinAbs(expected, 1e-6));
+}
+
+TEST_CASE("A config missing a tower key falls back to that key's default", "[WipeTowerEstimate]") {
+    // The signature takes any ConfigBase: an absent key must read as its declared default.
+    const DynamicPrintConfig full = make_config();
+    DynamicPrintConfig       partial = full;
+    partial.erase("wipe_tower_extra_spacing");
+    REQUIRE(partial.option("wipe_tower_extra_spacing") == nullptr);
+
+    DynamicPrintConfig defaulted = full;
+    defaulted.set_key_value("wipe_tower_extra_spacing",
+                            print_config_def.get("wipe_tower_extra_spacing")->default_value->clone());
+    CHECK_THAT(estimate(partial, 3, 0.2, 5.).depth, WithinAbs(estimate(defaulted, 3, 0.2, 5.).depth, 1e-9));
+}