SLA gizmo keeps track of current status of the points, enables the user to erase all points

src/libslic3r/Model.cpp

@@ -592,6 +592,7 @@ ModelObject& ModelObject::assign_copy(const ModelObject &rhs)
     this->input_file                  = rhs.input_file;
     this->config                      = rhs.config;
     this->sla_support_points          = rhs.sla_support_points;
+    this->sla_points_status           = rhs.sla_points_status;
     this->layer_height_ranges         = rhs.layer_height_ranges;
     this->layer_height_profile        = rhs.layer_height_profile;
     this->origin_translation          = rhs.origin_translation;
@@ -625,6 +626,7 @@ ModelObject& ModelObject::assign_copy(ModelObject &&rhs)
     this->input_file                  = std::move(rhs.input_file);
     this->config                      = std::move(rhs.config);
     this->sla_support_points          = std::move(rhs.sla_support_points);
+    this->sla_points_status           = std::move(rhs.sla_points_status);
     this->layer_height_ranges         = std::move(rhs.layer_height_ranges);
     this->layer_height_profile        = std::move(rhs.layer_height_profile);
     this->origin_translation          = std::move(rhs.origin_translation);
@@ -1130,6 +1132,7 @@ ModelObjectPtrs ModelObject::cut(size_t instance, coordf_t z, bool keep_upper, b
     if (keep_upper) {
         upper->set_model(nullptr);
         upper->sla_support_points.clear();
+        upper->sla_points_status = sla::PointsStatus::None;
         upper->clear_volumes();
         upper->input_file = "";
     }
@@ -1137,6 +1140,7 @@ ModelObjectPtrs ModelObject::cut(size_t instance, coordf_t z, bool keep_upper, b
     if (keep_lower) {
         lower->set_model(nullptr);
         lower->sla_support_points.clear();
+        lower->sla_points_status = sla::PointsStatus::None;
         lower->clear_volumes();
         lower->input_file = "";
     }

src/libslic3r/Model.hpp

@@ -180,6 +180,9 @@ public:
     // saved in mesh coordinates to allow using them for several instances.
     // The format is (x, y, z, point_size, supports_island)
     std::vector<sla::SupportPoint>      sla_support_points;
+    // To keep track of where the points came from (used for synchronization between
+    // the SLA gizmo and the backend).
+    sla::PointsStatus sla_points_status = sla::PointsStatus::None;
 
     /* This vector accumulates the total translation applied to the object by the
         center_around_origin() method. Callers might want to apply the same translation

src/libslic3r/SLA/SLACommon.hpp

@@ -15,6 +15,14 @@ class TriangleMesh;
 
 namespace sla {
     
+// An enum to keep track of where the current points on the ModelObject came from.
+enum class PointsStatus {
+    None,           // No points were generated so far.
+    Generating,     // The autogeneration algorithm triggered, but not yet finished.
+    AutoGenerated,  // Points were autogenerated (i.e. copied from the backend).
+    UserModified    // User has done some edits.
+};
+
 struct SupportPoint {
     Vec3f pos;
     float head_front_radius;

src/libslic3r/SLAPrint.cpp

@@ -342,6 +342,17 @@ SLAPrint::ApplyStatus SLAPrint::apply(const Model &model, const DynamicPrintConf
                 if (it_print_object_status != print_object_status.end())
                     update_apply_status(it_print_object_status->print_object->invalidate_step(slaposSupportPoints));
             }
+            if (model_object.sla_points_status != model_object_new.sla_points_status) {
+                // Change of this status should invalidate support points. The points themselves are not enough, there are none
+                // in case that nothing was generated OR that points were autogenerated already and not copied to the front-end.
+                // These cases can only be differentiated by checking the status change. However, changing from 'Generating' should NOT
+                // invalidate - that would keep stopping the background processing without a reason.
+                if (model_object.sla_points_status != sla::PointsStatus::Generating)
+                    if (it_print_object_status != print_object_status.end())
+                        update_apply_status(it_print_object_status->print_object->invalidate_step(slaposSupportPoints));
+                model_object.sla_points_status = model_object_new.sla_points_status;
+            }
+
             // Copy the ModelObject name, input_file and instances. The instances will compared against PrintObject instances in the next step.
             model_object.name       = model_object_new.name;
             model_object.input_file = model_object_new.input_file;
@@ -630,10 +641,11 @@ void SLAPrint::process()
         BOOST_LOG_TRIVIAL(debug) << "Support point count "
                                  << mo.sla_support_points.size();
 
-        // If there are no points on the front-end, we will do the
+        // Unless the user modified the points or we already did the calculation, we will do
-        // autoplacement. Otherwise we will just blindly copy the frontend data
+        // the autoplacement. Otherwise we will just blindly copy the frontend data
         // into the backend cache.
-        if(mo.sla_support_points.empty()) {
+        if (mo.sla_points_status != sla::PointsStatus::UserModified) {
+
             // calculate heights of slices (slices are calculated already)
             double lh = po.m_config.layer_height.getFloat();
 
@@ -645,7 +657,9 @@ void SLAPrint::process()
             this->throw_if_canceled();
             SLAAutoSupports::Config config;
             const SLAPrintObjectConfig& cfg = po.config();
-            config.density_relative = float(cfg.support_points_density_relative / 100.f); // the config value is in percents
+
+            // the density config value is in percents:
+            config.density_relative = float(cfg.support_points_density_relative / 100.f);
             config.minimal_distance = float(cfg.support_points_minimal_distance);
 
             // Construction of this object does the calculation.
@@ -669,7 +683,7 @@ void SLAPrint::process()
             report_status(*this, -1, L("Generating support points"), SlicingStatus::RELOAD_SLA_SUPPORT_POINTS);
         }
         else {
-            // There are some points on the front-end, no calculation will be done.
+            // There are either some points on the front-end, or the user removed them on purpose. No calculation will be done.
             po.m_supportdata->support_points = po.transformed_support_points();
         }
     };

src/slic3r/GUI/GLGizmo.cpp

@@ -1789,12 +1789,12 @@ void GLGizmoSlaSupports::set_sla_support_data(ModelObject* model_object, const G
         if (is_mesh_update_necessary())
             update_mesh();
 
-        // If there are no points, let's ask the backend if it calculated some.
-        if (m_editing_mode_cache.empty())
-            get_data_from_backend();
-
         if (m_model_object != m_old_model_object)
             m_editing_mode = false;
+
+        if (m_editing_mode_cache.empty() && m_model_object->sla_points_status != sla::PointsStatus::UserModified)
+            get_data_from_backend();
+
         if (m_state == On) {
             m_parent.toggle_model_objects_visibility(false);
             m_parent.toggle_model_objects_visibility(true, m_model_object, m_active_instance);
@@ -2296,8 +2296,7 @@ RENDER_AGAIN:
 
         m_imgui->text(" "); // vertical gap
 
-        bool apply_changes = m_imgui->button(_(L("Apply changes")));
+        if (m_imgui->button(_(L("Apply changes")))) {
-        if (apply_changes) {
             editing_mode_apply_changes();
             force_refresh = true;
         }
@@ -2308,24 +2307,28 @@ RENDER_AGAIN:
             force_refresh = true;
         }
     }
-    else {
+    else { // not in editing mode:
-       /* ImGui::PushItemWidth(50.0f);
+        /*ImGui::PushItemWidth(100.0f);
         m_imgui->text(_(L("Minimal points distance: ")));
         ImGui::SameLine();
-        bool value_changed = ImGui::InputDouble("mm", &m_minimal_point_distance, 0.0f, 0.0f, "%.2f");
+        bool value_changed = ImGui::SliderFloat("", &m_minimal_point_distance, 0.f, 20.f, "%.f mm");
         m_imgui->text(_(L("Support points density: ")));
         ImGui::SameLine();
-        value_changed |= ImGui::InputDouble("%", &m_density, 0.0f, 0.0f, "%.f");*/
+        value_changed |= ImGui::SliderFloat(" ", &m_density, 0.f, 200.f, "%.f %%");*/
 
         bool generate = m_imgui->button(_(L("Auto-generate points [A]")));
 
         if (generate)
             auto_generate();
 
-        m_imgui->text("");
         m_imgui->text("");
         if (m_imgui->button(_(L("Manual editing [M]"))))
             switch_to_editing_mode();
+
+        m_imgui->text(m_model_object->sla_points_status == sla::PointsStatus::None ? "No points  (will be autogenerated)" :
+                     (m_model_object->sla_points_status == sla::PointsStatus::AutoGenerated ? "Autogenerated points (no modifications)" :
+                     (m_model_object->sla_points_status == sla::PointsStatus::UserModified ? "User-modified points" :
+                     (m_model_object->sla_points_status == sla::PointsStatus::Generating ? "Generation in progress..." : "UNKNOWN STATUS"))));
     }
 
     m_imgui->end();
@@ -2448,16 +2451,18 @@ void GLGizmoSlaSupports::editing_mode_apply_changes()
     // If there are no changes, don't touch the front-end. The data in the cache could have been
     // taken from the backend and copying them to ModelObject would needlessly invalidate them.
     if (m_unsaved_changes) {
+        m_model_object->sla_points_status = sla::PointsStatus::UserModified;
         m_model_object->sla_support_points.clear();
         for (const std::pair<sla::SupportPoint, bool>& point_and_selection : m_editing_mode_cache)
             m_model_object->sla_support_points.push_back(point_and_selection.first);
+
+        // Recalculate support structures once the editing mode is left.
+        // m_parent.post_event(SimpleEvent(EVT_GLCANVAS_SCHEDULE_BACKGROUND_PROCESS));
+        // m_parent.post_event(SimpleEvent(EVT_GLCANVAS_SCHEDULE_BACKGROUND_PROCESS));
+        wxGetApp().plater()->reslice_SLA_supports(*m_model_object);
     }
     m_editing_mode = false;
     m_unsaved_changes = false;
-
-    // Recalculate support structures once the editing mode is left.
-    // m_parent.post_event(SimpleEvent(EVT_GLCANVAS_SCHEDULE_BACKGROUND_PROCESS));
-    wxGetApp().plater()->reslice_SLA_supports(*m_model_object);
 }
 
 
@@ -2476,10 +2481,15 @@ void GLGizmoSlaSupports::get_data_from_backend()
 {
     for (const SLAPrintObject* po : m_parent.sla_print()->objects()) {
         if (po->model_object()->id() == m_model_object->id() && po->is_step_done(slaposSupportPoints)) {
+            m_editing_mode_cache.clear();
             const std::vector<sla::SupportPoint>& points = po->get_support_points();
             auto mat = po->trafo().inverse().cast<float>();
             for (unsigned int i=0; i<points.size();++i)
                 m_editing_mode_cache.emplace_back(sla::SupportPoint(mat * points[i].pos, points[i].head_front_radius, points[i].is_new_island), false);
+
+            if (m_model_object->sla_points_status != sla::PointsStatus::UserModified)
+                m_model_object->sla_points_status = sla::PointsStatus::AutoGenerated;
+
             break;
         }
     }
@@ -2497,8 +2507,9 @@ void GLGizmoSlaSupports::auto_generate()
                 "Are you sure you want to do it?\n"
                 )), _(L("Warning")), wxICON_WARNING | wxYES | wxNO);
 
-    if (m_model_object->sla_support_points.empty() || dlg.ShowModal() == wxID_YES) {
+    if (m_model_object->sla_points_status != sla::PointsStatus::UserModified || dlg.ShowModal() == wxID_YES) {
         m_model_object->sla_support_points.clear();
+        m_model_object->sla_points_status = sla::PointsStatus::Generating;
         m_editing_mode_cache.clear();
         wxGetApp().plater()->reslice_SLA_supports(*m_model_object);
     }

src/slic3r/GUI/GLGizmo.hpp

@@ -489,19 +489,19 @@ private:
 #endif // not ENABLE_IMGUI
 
     bool m_lock_unique_islands = false;
-    bool m_editing_mode = false;
+    bool m_editing_mode = false;            // Is editing mode active?
-    bool m_old_editing_state = false;
+    bool m_old_editing_state = false;       // To keep track of whether the user toggled between the modes (needed for imgui refreshes).
-    float m_new_point_head_diameter = 0.4f;
+    float m_new_point_head_diameter = 0.4f; // Size of a new point.
-    double m_minimal_point_distance = 20.;
+    float m_minimal_point_distance = 20.f;
-    double m_density = 100.;
+    float m_density = 100.f;
     std::vector<std::pair<sla::SupportPoint, bool>> m_editing_mode_cache; // a support point and whether it is currently selected
 
     bool m_selection_rectangle_active = false;
     Vec2d m_selection_rectangle_start_corner;
     Vec2d m_selection_rectangle_end_corner;
     bool m_ignore_up_event = false;
-    bool m_combo_box_open = false;
+    bool m_combo_box_open = false;  // To ensure proper rendering of the imgui combobox.
-    bool m_unsaved_changes = false;
+    bool m_unsaved_changes = false; // Are there unsaved changes in manual mode?
     bool m_selection_empty = true;
     EState m_old_state = Off; // to be able to see that the gizmo has just been closed (see on_set_state)
     int m_canvas_width;