add method to clear texture list to sprite class, add comments explaining model class's private member vars

src/Model.hpp

@@ -40,8 +40,17 @@ namespace sb
 
     private:
 
+        /* When a texture is copied, it copies its shared pointer to its ID that identifies the texture memory on the GPU. Therefore, when
+         * this object is copied, its textures are copied with reference to the same GPU memory preserved. */
         std::vector<sb::Texture> _textures;
+
+        /* The attributes are associated with vertex data copied on the GPU. Shared pointers are used to store the attributes, so that if a
+         * copy of this object is made, each attributes in the copied object will point to its originally constructed attributes object, preserving
+         * the association with the vertex data on the GPU. */
         std::map<std::string, std::shared_ptr<sb::Attributes>> _attributes;
+
+        /* The model keeps a single transformation matrix. Specific types of transformation, like scale, translate, etc, can be combined into this
+         * transformation. */
         glm::mat4 _transformation {1.0f};
 
     public:

src/Sprite.hpp

@@ -149,14 +149,20 @@ namespace sb
 
         /*!
          * Get a constant reference to the texture attached to the sprite's plane object at the object's current texture index.
-         *
-         * @param index   index of texture to get
          */
         const sb::Texture& texture() const
         {
             return plane.texture(_texture_index);
         }
 
+        /*!
+         * Remove all textures from the sprite object's plane.
+         */
+        void clear_textures()
+        {
+            plane.textures() = {};
+        }
+
         /*!
          * @param index    set the object's texture index
          * @return         constant reference to the texture at the given index