Random extruder sequence for MMU.

Related to https://github.com/prusa3d/PrusaSlicer/issues/1866

src/slic3r/GUI/DoubleSlider.cpp

@@ -24,6 +24,7 @@
 
 #include <cmath>
 #include <boost/algorithm/string/replace.hpp>
+#include <random>
 #include "Field.hpp"
 #include "format.hpp"
 #include "NotificationManager.hpp"
@@ -2394,22 +2395,42 @@ void Control::edit_extruder_sequence()
 
     m_ticks.erase_all_ticks_with_code(ToolChange);
 
+    const int extr_cnt = m_extruders_sequence.extruders.size();
+    if (extr_cnt == 1)
+        return;
+
     int tick = 0;
     double value = 0.0;
-    int extruder = 0;
+    int extruder = -1;
-    const int extr_cnt = m_extruders_sequence.extruders.size();
+
+    std::random_device rd;  //Will be used to obtain a seed for the random number engine
+    std::mt19937 gen(rd()); //Standard mersenne_twister_engine seeded with rd()
+    std::uniform_int_distribution<> distrib(0, extr_cnt-1);
 
     while (tick <= m_max_value)
     {
+        bool color_repetition = false;
+        if (m_extruders_sequence.random_sequence) {
+            int rand_extr = distrib(gen);
+            if (m_extruders_sequence.color_repetition)
+                color_repetition = rand_extr == extruder;
+            else
+                while (rand_extr == extruder)
+                    rand_extr = distrib(gen);
+            extruder = rand_extr;
+        }
+        else {
+            extruder++;
+            if (extruder == extr_cnt)
+                extruder = 0;
+        }
+
         const int cur_extruder = m_extruders_sequence.extruders[extruder];
 
         bool meaningless_tick = tick == 0.0 && cur_extruder == extruder;
-        if (!meaningless_tick)
+        if (!meaningless_tick && !color_repetition)
             m_ticks.ticks.emplace(TickCode{tick, ToolChange,cur_extruder + 1, m_extruder_colors[cur_extruder]});
 
-        extruder++;
-        if (extruder == extr_cnt)
-            extruder = 0;
         if (m_extruders_sequence.is_mm_intervals) {
             value += m_extruders_sequence.interval_by_mm;
             tick = get_tick_from_value(value, true);

src/slic3r/GUI/DoubleSlider.hpp

@@ -146,6 +146,8 @@ struct ExtrudersSequence
     bool            is_mm_intervals     = true;
     double          interval_by_mm      = 3.0;
     int             interval_by_layers  = 10;
+    bool            random_sequence     { true };
+    bool            color_repetition    { false };
     std::vector<size_t>  extruders      = { 0 };
 
     bool operator==(const ExtrudersSequence& other) const
@@ -153,19 +155,23 @@ struct ExtrudersSequence
         return  (other.is_mm_intervals      == this->is_mm_intervals    ) &&
                 (other.interval_by_mm       == this->interval_by_mm     ) &&
                 (other.interval_by_layers   == this->interval_by_layers ) &&
+                (other.random_sequence      == this->random_sequence    ) &&
+                (other.color_repetition     == this->color_repetition   ) &&
                 (other.extruders            == this->extruders          ) ;
     }
     bool operator!=(const ExtrudersSequence& other) const
     {
-        return  (other.is_mm_intervals      != this->is_mm_intervals    ) &&
+        return  (other.is_mm_intervals      != this->is_mm_intervals    ) ||
-                (other.interval_by_mm       != this->interval_by_mm     ) &&
+                (other.interval_by_mm       != this->interval_by_mm     ) ||
-                (other.interval_by_layers   != this->interval_by_layers ) &&
+                (other.interval_by_layers   != this->interval_by_layers ) ||
+                (other.random_sequence      != this->random_sequence    ) ||
+                (other.color_repetition     != this->color_repetition   ) ||
                 (other.extruders            != this->extruders          ) ;
     }
 
-    void add_extruder(size_t pos)
+    void add_extruder(size_t pos, size_t extruder_id = size_t(0))
     {
-        extruders.insert(extruders.begin() + pos+1, size_t(0));
+        extruders.insert(extruders.begin() + pos+1, extruder_id);
     }
 
     void delete_extruder(size_t pos)

src/slic3r/GUI/ExtruderSequenceDialog.cpp

@@ -5,6 +5,7 @@
 #include <wx/dialog.h>
 #include <wx/sizer.h>
 #include <wx/bmpcbox.h>
+#include <wx/checkbox.h>
 
 #include <vector>
 #include <set>
@@ -138,6 +139,18 @@ ExtruderSequenceDialog::ExtruderSequenceDialog(const DoubleSlider::ExtrudersSequ
     intervals_box_sizer->Add(m_intervals_grid_sizer, 0, wxLEFT, em);
     option_sizer->Add(intervals_box_sizer, 0, wxEXPAND);
 
+    m_random_sequence = new wxCheckBox(this, wxID_ANY, "Random sequence");
+    m_random_sequence->SetValue(m_sequence.random_sequence);
+    m_random_sequence->SetToolTip(_L("If enabled, random sequence of the selected extruders will be used."));
+    m_random_sequence->Bind(wxEVT_CHECKBOX, [this](wxCommandEvent& e) {
+        m_sequence.random_sequence = e.IsChecked();
+        m_color_repetition->Enable(m_sequence.random_sequence);
+    });
+
+    m_color_repetition = new wxCheckBox(this, wxID_ANY, "Allow next color repetition");
+    m_color_repetition->SetValue(m_sequence.color_repetition);
+    m_color_repetition->SetToolTip(_L("If enabled, a repetition of the next random color will be allowed."));
+    m_color_repetition->Bind(wxEVT_CHECKBOX, [this](wxCommandEvent& e) {m_sequence.color_repetition = e.IsChecked();  });
     
     auto extruders_box = new wxStaticBox(this, wxID_ANY, _(L("Set extruder(tool) sequence"))+ ": ");
     auto extruders_box_sizer = new wxStaticBoxSizer(extruders_box, wxVERTICAL);
@@ -147,6 +160,8 @@ ExtruderSequenceDialog::ExtruderSequenceDialog(const DoubleSlider::ExtrudersSequ
     apply_extruder_sequence();
 
     extruders_box_sizer->Add(m_extruders_grid_sizer, 0, wxALL, em);
+    extruders_box_sizer->Add(m_random_sequence, 0, wxLEFT | wxBOTTOM, em);
+    extruders_box_sizer->Add(m_color_repetition, 0, wxLEFT | wxBOTTOM, em);
     option_sizer->Add(extruders_box_sizer, 0, wxEXPAND | wxTOP, em);
 
     main_sizer->Add(option_sizer, 0, wxEXPAND | wxALL, em);
@@ -197,8 +212,11 @@ void ExtruderSequenceDialog::apply_extruder_sequence()
         auto add_btn = new ScalableButton(this, wxID_ANY, m_bmp_add);
         add_btn->SetToolTip(_(L("Add extruder to sequence")));
 
-        add_btn->Bind(wxEVT_BUTTON, [this, extruder](wxEvent&) {
+        add_btn->Bind(wxEVT_BUTTON, [this, extruder, extruder_selector](wxEvent&) {
-            m_sequence.add_extruder(extruder);
+            size_t extr_cnt = (size_t)extruder_selector->GetCount();
+            size_t seq_extr_cnt = m_sequence.extruders.size();
+            size_t extr_id = seq_extr_cnt - size_t(seq_extr_cnt / extr_cnt) * extr_cnt;
+            m_sequence.add_extruder(extruder, std::min(extr_id, extr_cnt-1));
             apply_extruder_sequence();
         });
 
@@ -208,6 +226,10 @@ void ExtruderSequenceDialog::apply_extruder_sequence()
     }
     m_extruders_grid_sizer->ShowItems(true); // show items hidden in apply_extruder_selector()
 
+    bool show_checkboxes = m_sequence.extruders.size() > 1;
+    m_random_sequence->Enable(show_checkboxes);
+    m_color_repetition->Enable(show_checkboxes && m_sequence.random_sequence);
+
     Fit();
     Refresh();
 }

src/slic3r/GUI/ExtruderSequenceDialog.hpp

@@ -6,6 +6,7 @@
 
 class wxTextCtrl;
 class wxFlexGridSizer;
+class wxCheckBox;
 
 namespace Slic3r {
 namespace GUI {
@@ -22,6 +23,8 @@ class ExtruderSequenceDialog: public DPIDialog
 
     wxTextCtrl* m_interval_by_layers {nullptr}; 
     wxTextCtrl* m_interval_by_mm {nullptr};
+    wxCheckBox* m_random_sequence {nullptr};
+    wxCheckBox* m_color_repetition{nullptr};
 
     wxFlexGridSizer* m_intervals_grid_sizer {nullptr};
     wxFlexGridSizer* m_extruders_grid_sizer {nullptr};