Tech ENABLE_SHOW_TOOLPATHS_COG - Show toolpaths center of gravity

src/slic3r/GUI/GCodeViewer.hpp

@@ -380,6 +380,52 @@ class GCodeViewer
         bool visible{ false };
     };
 
+#if ENABLE_SHOW_TOOLPATHS_COG
+    // helper to render center of gravity
+    class COG
+    {
+        GLModel m_model;
+        bool m_visible{ false };
+        // whether or not to render the model with fixed screen size
+        bool m_fixed_size{ true };
+        double m_total_mass{ 0.0 };
+        Vec3d m_position{ Vec3d::Zero() };
+
+    public:
+        void render();
+
+        void reset() {
+            m_position = Vec3d::Zero();
+            m_total_mass = 0.0;
+        }
+
+        bool is_visible() const { return m_visible; }
+        void set_visible(bool visible) { m_visible = visible; }
+
+        void add_segment(const Vec3d& v1, const Vec3d& v2, double mass) {
+            assert(mass > 0.0);
+            m_position += mass * 0.5 * (v1 + v2);
+            m_total_mass += mass;
+        }
+
+        Vec3d cog() const { return (m_total_mass > 0.0) ? (Vec3d)(m_position / m_total_mass) : Vec3d::Zero(); }
+
+    private:
+        void init() {
+            if (m_model.is_initialized())
+                return;
+
+            const float radius = m_fixed_size ? 10.0f : 1.0f;
+
+#if ENABLE_GLBEGIN_GLEND_REMOVAL
+            m_model.init_from(smooth_sphere(32, radius));
+#else
+            m_model.init_from(its_make_sphere(radius, PI / 32.0));
+#endif // ENABLE_GLBEGIN_GLEND_REMOVAL
+        }
+    };
+#endif // ENABLE_SHOW_TOOLPATHS_COG
+
     // helper to render extrusion paths
     struct Extrusions
     {
@@ -734,6 +780,9 @@ private:
     Extrusions m_extrusions;
     SequentialView m_sequential_view;
     Shells m_shells;
+#if ENABLE_SHOW_TOOLPATHS_COG
+    COG m_cog;
+#endif // ENABLE_SHOW_TOOLPATHS_COG
     EViewType m_view_type{ EViewType::FeatureType };
     bool m_legend_enabled{ true };
 #if ENABLE_PREVIEW_LAYOUT
@@ -779,6 +828,9 @@ public:
 
     void reset();
     void render();
+#if ENABLE_SHOW_TOOLPATHS_COG
+    void render_cog() { m_cog.render(); }
+#endif // ENABLE_SHOW_TOOLPATHS_COG
 
     bool has_data() const { return !m_roles.empty(); }
     bool can_export_toolpaths() const;