Fix issue #10971 (#12108)

Sorry had to re-create the PR as I did some chaos in my repo with CLI. xD

Fixes issue https://github.com/OrcaSlicer/OrcaSlicer/issues/10971

Description:
Fix wipe tower filament selection and clean up tool ordering. Added wipe_tower_filament handling to WipeTower2 (store config, mark non-selected tools as “soluble,” and use it in toolchange selection) and ensured the configured wipe‑tower extruder is included in the extruder list for ordering. Removed duplicated/merged tool‑ordering code (extra insert_wipe_tower_extruder definition, duplicate declaration, and redundant reorder block) so the tool order logic runs only once.

<img width="1819" height="799" alt="image" src="https://github.com/user-attachments/assets/cef39026-cf6a-46da-a87a-ef895774699f" />

src/libslic3r/GCode/ToolOrdering.cpp

@@ -306,6 +306,26 @@ void ToolOrdering::handle_dontcare_extruder(unsigned int last_extruder_id)
     }
 }
 
+bool ToolOrdering::insert_wipe_tower_extruder()
+{
+    if (!m_print_config_ptr || !m_print_config_ptr->enable_prime_tower)
+        return false;
+    if (m_print_config_ptr->wipe_tower_filament == 0)
+        return false;
+
+    bool changed = false;
+    const unsigned int wipe_extruder = (unsigned int)(m_print_config_ptr->wipe_tower_filament - 1);
+    for (LayerTools &lt : m_layer_tools) {
+        if (lt.wipe_tower_partitions > 0) {
+            if (std::find(lt.extruders.begin(), lt.extruders.end(), wipe_extruder) == lt.extruders.end()) {
+                lt.extruders.emplace_back(wipe_extruder);
+                changed = true;
+            }
+        }
+    }
+    return changed;
+}
+
 void ToolOrdering::sort_and_build_data(const Print& print, unsigned int first_extruder, bool prime_multi_material)
 {
     // if first extruder is -1, we can decide the first layer tool order before doing reorder function
@@ -328,9 +348,13 @@ void ToolOrdering::sort_and_build_data(const Print& print, unsigned int first_ex
 
     max_layer_height = calc_max_layer_height(print.config(), max_layer_height);
 
-    this->collect_extruder_statistics(prime_multi_material);
-
     this->fill_wipe_tower_partitions(print.config(), object_bottom_z, max_layer_height);
+    if (this->insert_wipe_tower_extruder()) {
+        reorder_extruders_for_minimum_flush_volume(reorder_first_layer);
+        this->fill_wipe_tower_partitions(print.config(), object_bottom_z, max_layer_height);
+    }
+
+    this->collect_extruder_statistics(prime_multi_material);
 }
 
 void ToolOrdering::sort_and_build_data(const PrintObject& object , unsigned int first_extruder, bool prime_multi_material)
@@ -343,9 +367,13 @@ void ToolOrdering::sort_and_build_data(const PrintObject& object , unsigned int
 
     double max_layer_height = calc_max_layer_height(object.print()->config(), object.config().layer_height);
 
-    this->collect_extruder_statistics(prime_multi_material);
-
     this->fill_wipe_tower_partitions(object.print()->config(), object.layers().front()->print_z - object.layers().front()->height, max_layer_height);
+    if (this->insert_wipe_tower_extruder()) {
+        reorder_extruders_for_minimum_flush_volume(reorder_first_layer);
+        this->fill_wipe_tower_partitions(object.print()->config(), object.layers().front()->print_z - object.layers().front()->height, max_layer_height);
+    }
+
+    this->collect_extruder_statistics(prime_multi_material);
 }
 
 

src/libslic3r/GCode/ToolOrdering.hpp

@@ -258,6 +258,7 @@ private:
     void				initialize_layers(std::vector<coordf_t> &zs);
     void 				collect_extruders(const PrintObject &object, const std::vector<std::pair<double, unsigned int>> &per_layer_extruder_switches);
     void 				fill_wipe_tower_partitions(const PrintConfig &config, coordf_t object_bottom_z, coordf_t max_layer_height);
+    bool                insert_wipe_tower_extruder();
     void                mark_skirt_layers(const PrintConfig &config, coordf_t max_layer_height);
     void 				collect_extruder_statistics(bool prime_multi_material);
     void                reorder_extruders_for_minimum_flush_volume(bool reorder_first_layer);

src/libslic3r/GCode/WipeTower.cpp

@@ -1540,7 +1540,7 @@ void WipeTower::set_extruder(size_t idx, const PrintConfig& config)
     m_filpar.push_back(FilamentParameters());
 
     m_filpar[idx].material = config.filament_type.get_at(idx);
-    m_filpar[idx].is_soluble = config.filament_soluble.get_at(idx);
+    m_filpar[idx].is_soluble = config.wipe_tower_filament == 0 ? config.filament_soluble.get_at(idx) : (idx != size_t(config.wipe_tower_filament - 1));
     // BBS
     m_filpar[idx].is_support = config.filament_is_support.get_at(idx);
     m_filpar[idx].nozzle_temperature = config.nozzle_temperature.get_at(idx);

src/libslic3r/GCode/WipeTower2.cpp

@@ -1227,6 +1227,7 @@ WipeTower::ToolChangeResult WipeTower2::construct_tcr(WipeTowerWriter2& writer,
 WipeTower2::WipeTower2(const PrintConfig& config, const PrintRegionConfig& default_region_config,int plate_idx, Vec3d plate_origin, const std::vector<std::vector<float>>& wiping_matrix, size_t initial_tool) :
     m_semm(config.single_extruder_multi_material.value),
     m_enable_filament_ramming(config.enable_filament_ramming.value),
+    m_wipe_tower_filament(config.wipe_tower_filament.value),
     m_wipe_tower_pos(config.wipe_tower_x.get_at(plate_idx), config.wipe_tower_y.get_at(plate_idx)),
     m_wipe_tower_width(float(config.prime_tower_width)),
     m_wipe_tower_rotation_angle(float(config.wipe_tower_rotation_angle)),
@@ -1309,7 +1310,10 @@ void WipeTower2::set_extruder(size_t idx, const PrintConfig& config)
     m_filpar.push_back(FilamentParameters());
 
     m_filpar[idx].material = config.filament_type.get_at(idx);
-    m_filpar[idx].is_soluble = config.filament_soluble.get_at(idx);
+    if (m_wipe_tower_filament > 0)
+        m_filpar[idx].is_soluble = (idx != size_t(m_wipe_tower_filament - 1));
+    else
+        m_filpar[idx].is_soluble = config.filament_soluble.get_at(idx);
     m_filpar[idx].temperature = config.nozzle_temperature.get_at(idx);
     m_filpar[idx].first_layer_temperature = config.nozzle_temperature_initial_layer.get_at(idx);
     m_filpar[idx].filament_minimal_purge_on_wipe_tower = config.filament_minimal_purge_on_wipe_tower.get_at(idx);
@@ -2224,14 +2228,16 @@ void WipeTower2::save_on_last_wipe()
 int WipeTower2::first_toolchange_to_nonsoluble(
         const std::vector<WipeTowerInfo::ToolChange>& tool_changes) const
 {
-    // Orca: allow calculation of the required depth and wipe volume for soluable toolchanges as well
-    // NOTE: it's not clear if this is the right way, technically we should disable wipe tower if soluble filament is used as it
-    // will will make the wipe tower unstable. Need to revist this in the future.
+    // If a specific wipe tower filament is forced, use it to decide where to finish the layer.
+    if (m_wipe_tower_filament > 0) {
+        for (size_t idx = 0; idx < tool_changes.size(); ++idx) {
+            if (!m_filpar[tool_changes[idx].new_tool].is_soluble)
+                return idx;
+        }
+        return -1;
+    }
+    // Orca: allow calculation of the required depth and wipe volume for soluble toolchanges as well.
     return tool_changes.empty() ? -1 : 0;
-    //for (size_t idx=0; idx<tool_changes.size(); ++idx)
-    //    if (! m_filpar[tool_changes[idx].new_tool].is_soluble)
-    //        return idx;
-    //return -1;
 }
 
 static WipeTower::ToolChangeResult merge_tcr(WipeTower::ToolChangeResult& first,

src/libslic3r/GCode/WipeTower2.hpp

@@ -187,6 +187,7 @@ private:
 	bool   m_semm               = true; // Are we using a single extruder multimaterial printer?
 	bool   m_enable_filament_ramming = true;
 	bool   m_is_mk4mmu3         = false;
+    int    m_wipe_tower_filament = 0;   // 1-based config value, 0 means auto
     Vec2f  m_wipe_tower_pos; 			// Left front corner of the wipe tower in mm.
 	float  m_wipe_tower_width; 			// Width of the wipe tower.
 	float  m_wipe_tower_depth 	= 0.f; 	// Depth of the wipe tower

src/libslic3r/Print.cpp

@@ -520,6 +520,12 @@ std::vector<unsigned int> Print::extruders(bool conside_custom_gcode) const
         }
     }
 
+    // If a wipe tower filament is explicitly set, ensure it participates in tool ordering.
+    if (has_wipe_tower() && config().wipe_tower_filament != 0 && extruders.size() > 1) {
+        assert(config().wipe_tower_filament > 0 && config().wipe_tower_filament < int(config().nozzle_diameter.size()));
+        extruders.emplace_back(config().wipe_tower_filament - 1); // config value is 1-based
+    }
+
     sort_remove_duplicates(extruders);
     return extruders;
 }