1 files changed, 48 insertions, 11 deletions

diff --git a/xs/src/libslic3r/Model.hpp b/xs/src/libslic3r/Model.hpp
index f10707457..cb0ab05f2 100644
--- a/xs/src/libslic3r/Model.hpp
+++ b/xs/src/libslic3r/Model.hpp
@@ -27,10 +27,18 @@ typedef std::vector<ModelObject*> ModelObjectPtrs;
 typedef std::vector<ModelVolume*> ModelVolumePtrs;
 typedef std::vector<ModelInstance*> ModelInstancePtrs;
 
+// The print bed content.
+// Description of a triangular model with multiple materials, multiple instances with various affine transformations
+// and with multiple modifier meshes.
+// A model groups multiple objects, each object having possibly multiple instances,
+// all objects may share mutliple materials.
 class Model
 {
-    public:
+public:
+    // Materials are owned by a model and referenced by objects through t_model_material_id.
+    // Single material may be shared by multiple models.
     ModelMaterialMap materials;
+    // Objects are owned by a model. Each model may have multiple instances, each instance having its own transformation (shift, scale, rotation).
     ModelObjectPtrs objects;
     
     Model();
@@ -63,34 +71,48 @@ class Model
     void duplicate_objects_grid(size_t x, size_t y, coordf_t dist);
 };
 
+// Material, which may be shared across multiple ModelObjects of a single Model.
 class ModelMaterial
 {
     friend class Model;
-    public:
+public:
+    // Attributes are defined by the AMF file format, but they don't seem to be used by Slic3r for any purpose.
     t_model_material_attributes attributes;
+    // Dynamic configuration storage for the object specific configuration values, overriding the global configuration.
     DynamicPrintConfig config;
 
     Model* get_model() const { return this->model; };
     void apply(const t_model_material_attributes &attributes);
     
-    private:
+private:
+    // Parent, owning this material.
     Model* model;
     
     ModelMaterial(Model *model);
     ModelMaterial(Model *model, const ModelMaterial &other);
 };
 
+// A printable object, possibly having multiple print volumes (each with its own set of parameters and materials),
+// and possibly having multiple modifier volumes, each modifier volume with its set of parameters and materials.
+// Each ModelObject may be instantiated mutliple times, each instance having different placement on the print bed,
+// different rotation and different uniform scaling.
 class ModelObject
 {
     friend class Model;
-    public:
+public:
     std::string name;
     std::string input_file;
+    // Instances of this ModelObject. Each instance defines a shift on the print bed, rotation around the Z axis and a uniform scaling.
+    // Instances are owned by this ModelObject.
     ModelInstancePtrs instances;
+    // Printable and modifier volumes, each with its material ID and a set of override parameters.
+    // ModelVolumes are owned by this ModelObject.
     ModelVolumePtrs volumes;
+    // Configuration parameters specific to a single ModelObject, overriding the global Slic3r settings.
     DynamicPrintConfig config;
+    // Variation of a layer thickness for spans of Z coordinates.
     t_layer_height_ranges layer_height_ranges;
-    
+
     /* This vector accumulates the total translation applied to the object by the
         center_around_origin() method. Callers might want to apply the same translation
         to new volumes before adding them to this object in order to preserve alignment
@@ -134,7 +156,8 @@ class ModelObject
     void split(ModelObjectPtrs* new_objects);
     void update_bounding_box();   // this is a private method but we expose it until we need to expose it via XS
     
-    private:
+private:
+    // Parent object, owning this ModelObject.
     Model* model;
     
     ModelObject(Model *model);
@@ -144,15 +167,22 @@ class ModelObject
     ~ModelObject();
 };
 
+// An object STL, or a modifier volume, over which a different set of parameters shall be applied.
+// ModelVolume instances are owned by a ModelObject.
 class ModelVolume
 {
     friend class ModelObject;
-    public:
+public:
     std::string name;
+    // The triangular model.
     TriangleMesh mesh;
+    // Configuration parameters specific to an object model geometry or a modifier volume, 
+    // overriding the global Slic3r settings and the ModelObject settings.
     DynamicPrintConfig config;
+    // Is it an object to be printed, or a modifier volume?
     bool modifier;
     
+    // A parent object owning this modifier volume.
     ModelObject* get_object() const { return this->object; };
     t_model_material_id material_id() const;
     void material_id(t_model_material_id material_id);
@@ -161,7 +191,8 @@ class ModelVolume
     
     ModelMaterial* assign_unique_material();
     
-    private:
+private:
+    // Parent object owning this ModelVolume.
     ModelObject* object;
     t_model_material_id _material_id;
     
@@ -169,19 +200,25 @@ class ModelVolume
     ModelVolume(ModelObject *object, const ModelVolume &other);
 };
 
+// A single instance of a ModelObject.
+// Knows the affine transformation of an object.
 class ModelInstance
 {
     friend class ModelObject;
-    public:
-    double rotation;            // in radians around mesh center point
+public:
+    double rotation;            // Rotation around the Z axis, in radians around mesh center point
     double scaling_factor;
     Pointf offset;              // in unscaled coordinates
     
     ModelObject* get_object() const { return this->object; };
+
+    // To be called on an external mesh
     void transform_mesh(TriangleMesh* mesh, bool dont_translate = false) const;
+    // To be called on an external polygon. It does not translate the polygon, only rotates and scales.
     void transform_polygon(Polygon* polygon) const;
     
-    private:
+private:
+    // Parent object, owning this instance.
     ModelObject* object;
     
     ModelInstance(ModelObject *object);