Add shallow copy semantics to Camera's, Object's, and Scene's.

5 files changed, 98 insertions, 22 deletions

diff --git a/libdimensionxx/dimensionxx/camera.hpp b/libdimensionxx/dimensionxx/camera.hpp
index 950e16d..a883969 100644
--- a/libdimensionxx/dimensionxx/camera.hpp
+++ b/libdimensionxx/dimensionxx/camera.hpp
@@ -29,12 +29,15 @@ namespace Dimension
   class Camera
   {
   public:
-    // No-op, made pure virtual
-    virtual ~Camera() = 0;
+    // No-op
+    virtual ~Camera();
 
     // Camera callback
     virtual Line ray(const Canvas& canvas, unsigned int x, unsigned int y);
 
+    // Shallow-copy a derived camera
+    virtual Camera* copy() const = 0;
+
     // Access the wrapped C camera.
     dmnsn_camera*       dmnsn();
     const dmnsn_camera* dmnsn() const;
@@ -42,15 +45,22 @@ namespace Dimension
   protected:
     // No-op
     Camera();
+    // Shallow-copy
+    Camera(const Camera& camera);
     // Wrap an existing camera
     explicit Camera(dmnsn_camera* camera);
 
-    dmnsn_camera* m_camera;
+    // Is m_camera unique?
+    bool unique() const;
+
+    // Set the wrapped C camera
+    void dmnsn(dmnsn_camera* camera);
 
   private:
-    // Copying prohibited
-    Camera(const Camera&);
+    // Copy-assignment prohibited
     Camera& operator=(const Camera&);
+
+    std::tr1::shared_ptr<dmnsn_camera*> m_camera;
   };
 
   // A custom camera abstract base class, for creating your own camera types
diff --git a/libdimensionxx/dimensionxx/cameras.hpp b/libdimensionxx/dimensionxx/cameras.hpp
index 4e67d64..cabae97 100644
--- a/libdimensionxx/dimensionxx/cameras.hpp
+++ b/libdimensionxx/dimensionxx/cameras.hpp
@@ -30,10 +30,17 @@ namespace Dimension
   {
   public:
     Perspective_Camera(const Matrix& trans);
-    virtual ~Perspective_Camera();
+    ~Perspective_Camera();
 
     Matrix trans();
     void trans(const Matrix& trans);
+
+    Camera* copy() const;
+
+  private:
+    // Copying prohibited, but used internally
+    Perspective_Camera(const Perspective_Camera& camera);
+    Perspective_Camera& operator=(const Perspective_Camera&);
   };
 }
 
diff --git a/libdimensionxx/dimensionxx/object.hpp b/libdimensionxx/dimensionxx/object.hpp
index 1b9c848..c56d358 100644
--- a/libdimensionxx/dimensionxx/object.hpp
+++ b/libdimensionxx/dimensionxx/object.hpp
@@ -29,8 +29,8 @@ namespace Dimension
   class Object
   {
   public:
-    // No-op, made pure virtual
-    virtual ~Object() = 0;
+    // No-op
+    virtual ~Object();
 
     // Get/set the transformation matrix
     Matrix trans();
@@ -40,6 +40,9 @@ namespace Dimension
     virtual Array<double> intersections(const Line& l);
     virtual bool inside(const Vector& point);
 
+    // Shallow-copy a derived
+    virtual Object* copy() const = 0;
+
     // Access the wrapped C object.
     dmnsn_object*       dmnsn();
     const dmnsn_object* dmnsn() const;
@@ -47,15 +50,22 @@ namespace Dimension
   protected:
     // No-op
     Object();
+    // Shallow copy
+    Object(const Object& object);
     // Wrap an existing object.
     explicit Object(dmnsn_object* object);
 
-    dmnsn_object* m_object;
+    // Is m_object unique?
+    bool unique() const;
+
+    // Set the wrapped object
+    void dmnsn(dmnsn_object* object);
 
   private:
-    // Copying prohibited
-    Object(const Object&);
+    // Copy-assignment prohibited
     Object& operator=(const Object&);
+
+    std::tr1::shared_ptr<dmnsn_object*> m_object;
   };
 
   // A custom object abstract base class, for creating your own object types
diff --git a/libdimensionxx/dimensionxx/objects.hpp b/libdimensionxx/dimensionxx/objects.hpp
index 89aab14..5b43dc4 100644
--- a/libdimensionxx/dimensionxx/objects.hpp
+++ b/libdimensionxx/dimensionxx/objects.hpp
@@ -30,7 +30,14 @@ namespace Dimension
   {
   public:
     Sphere();
-    virtual ~Sphere();
+    ~Sphere();
+
+    Object* copy() const;
+
+  private:
+    // Copying prohibited, but used internally
+    Sphere(const Sphere& sphere);
+    Sphere& operator=(const Sphere&);
   };
 
   // A cube
@@ -38,7 +45,14 @@ namespace Dimension
   {
   public:
     Cube();
-    virtual ~Cube();
+    ~Cube();
+
+    Object* copy() const;
+
+  private:
+    // Copying prohibited, but used internally
+    Cube(const Cube& cube);
+    Cube& operator=(const Cube&);
   };
 }
 
diff --git a/libdimensionxx/dimensionxx/scene.hpp b/libdimensionxx/dimensionxx/scene.hpp
index 256de29..b5adde0 100644
--- a/libdimensionxx/dimensionxx/scene.hpp
+++ b/libdimensionxx/dimensionxx/scene.hpp
@@ -25,14 +25,20 @@
 
 namespace Dimension
 {
+  // Iterator class for scene objects
+  class Scene_Iterator;
+
   // Base scene class.  Wraps a dmnsn_scene*.
   class Scene
   {
   public:
-    // Allocate a dmnsn_scene
+    typedef Scene_Iterator Iterator;
+
+    // Allocate a dmnsn_scene*
     Scene(const Color& background, Camera& camera, Canvas& canvas);
-    // Wrap an existing scene
-    explicit Scene(dmnsn_scene* scene);
+
+    // Scene(const Scene& scene);
+
     // Delete the scene
     ~Scene();
 
@@ -43,7 +49,11 @@ namespace Dimension
     Canvas&       canvas();
     const Canvas& canvas() const;
 
-    // Add objects
+    // Object access
+
+    Iterator begin();
+    Iterator end();
+
     void push_object(Object& object);
 
     // Access the wrapped C object.
@@ -51,13 +61,38 @@ namespace Dimension
     const dmnsn_scene* dmnsn() const;
 
   private:
-    // Copying prohibited
-    Scene(const Scene&);
+    // Copy-assignment prohibited
     Scene& operator=(const Scene&);
 
-    dmnsn_scene* m_scene;
-    Camera* m_camera;
-    Canvas* m_canvas;
+    std::tr1::shared_ptr<dmnsn_scene*> m_scene;
+    std::tr1::shared_ptr<Camera> m_camera;
+    std::tr1::shared_ptr<Canvas> m_canvas;
+    std::list<std::tr1::shared_ptr<Object> > m_objects;
+  };
+
+  class Scene_Iterator
+  {
+  public:
+    Scene_Iterator(std::list<std::tr1::shared_ptr<Object> >::iterator i)
+      : m_i(i) { }
+    // Scene_Iterator(const Scene_Iterator& i);
+    // ~Scene_Iterator();
+
+    // Scene_Iterator& operator=(const Scene_Iterator& i);
+
+    Object& operator*() const { return **m_i; }
+    Object* operator->() const { return &**m_i; }
+
+    bool operator==(Scene_Iterator i) const { return m_i == i.m_i; }
+    bool operator!=(Scene_Iterator i) const { return m_i != i.m_i; }
+
+    Scene_Iterator& operator++()    { ++m_i; return *this; }
+    Scene_Iterator  operator++(int) { return Scene_Iterator(m_i++); }
+    Scene_Iterator& operator--()    { --m_i; return *this; }
+    Scene_Iterator  operator--(int) { return Scene_Iterator(m_i--); }
+
+  private:
+    std::list<std::tr1::shared_ptr<Object> >::iterator m_i;
   };
 }