Allow Array's of non-POD types through specialized Array_Element class.

9 files changed, 351 insertions, 104 deletions

diff --git a/libdimensionxx/dimensionxx/array.hpp b/libdimensionxx/dimensionxx/array.hpp
index 84bc06b..aa1f805 100644
--- a/libdimensionxx/dimensionxx/array.hpp
+++ b/libdimensionxx/dimensionxx/array.hpp
@@ -25,9 +25,38 @@
 
 #include <tr1/memory> // For tr1::shared_ptr
 #include <cstdlib>    // For size_t
+#include <vector>
 
 namespace Dimension
 {
+  // Class to store POD types, and wrapped dmnsn_* types, including polymorphic
+  // types.  The non-specialized version will only handle POD types; specialize
+  // it to allow storage of classes in Array's.
+  template <typename T>
+  class Array_Element
+  {
+  public:
+    typedef T C_Type;
+
+    inline Array_Element();
+    inline Array_Element(T t);
+
+    // Specializations should implement this constructor if C_Type differs from
+    // T - but it should throw if T is a polymorphic type
+    // Array_Element(C_Type c);
+
+    // Array_Element(const Array_Element& ae);
+    // ~Array_Element();
+
+    // Array_Element& operator=(const Array_Element& ae);
+
+    C_Type dmnsn() const { return m_t; }
+    T& object(C_Type* c) const { return *c; }
+
+  private:
+    T m_t;
+  };
+
   // Array template class, wraps a dmnsn_array*.  Copying is possible, but
   // copies refer to the same object, which is reference counted.  T must be
   // a POD type.
@@ -35,32 +64,95 @@ namespace Dimension
   class Array
   {
   public:
-    Array();
-    explicit Array(dmnsn_array* array);
+    inline Array();
+    explicit inline Array(dmnsn_array* array);
     // Array(const Array& a);
     ~Array()
-    { if (m_array && m_array.unique()) { dmnsn_delete_array(dmnsn()); } }
+      { if (m_array && m_array.unique()) { dmnsn_delete_array(dmnsn()); } }
 
     // Array& operator=(const Array& a);
 
-    T& operator[](std::size_t i)
-    { return *reinterpret_cast<T*>(dmnsn_array_at(dmnsn(), i)); }
-    const T& operator[](std::size_t i) const
-    { return *reinterpret_cast<const T*>(dmnsn_array_at(dmnsn(), i)); }
+    inline T&       operator[](std::size_t i);
+    inline const T& operator[](std::size_t i) const;
 
     std::size_t size() const { return dmnsn_array_size(dmnsn()); }
-    void resize(std::size_t size) { dmnsn_array_resize(dmnsn(), size); }
+    inline void resize(std::size_t size);
+
+    inline void push(T& object);
+    inline void push(const T& object); // Not valid for polymorphic types
+    inline void pop();
 
     // Access the wrapped C object.
-    dmnsn_array*       dmnsn();
-    const dmnsn_array* dmnsn() const;
+    inline dmnsn_array*       dmnsn();
+    inline const dmnsn_array* dmnsn() const;
 
     // Release ownership of the dmnsn_array*, needed for returning a
     // dmnsn_array* from a function.
-    dmnsn_array* release();
+    inline dmnsn_array* release();
 
   private:
+    typedef typename Array_Element<T>::C_Type C_Type;
+
     std::tr1::shared_ptr<dmnsn_array*> m_array;
+    std::vector<Array_Element<T> > m_elements;
+  };
+
+  // Base class for non-polymorphic wrappers
+  template <typename T, typename C>
+  class DMNSN_Array_Element
+  {
+  public:
+    typedef C C_Type;
+
+    DMNSN_Array_Element() {
+      throw Dimension_Error("Couldn't default-construct an array element.");
+    }
+
+    DMNSN_Array_Element(const T& object) : m_object(new T(object)) { }
+    DMNSN_Array_Element(C_Type c) : m_object(new T(c)) { }
+    // DMNSN_Array_Element(const DMNSN_Array_Element& ae);
+    // ~DMNSN_Array_Element();
+
+    // DMNSN_Array_Element& operator=(const DMNSN_Array_Element& ae);
+
+    C_Type dmnsn() const { return m_object->dmnsn(); }
+    T& object(C_Type* c) const { return *m_object; }
+
+  private:
+    std::tr1::shared_ptr<T> m_object;
+  };
+
+  // Base class for polymorphic wrappers
+  template <typename T, typename C>
+  class Polymorphic_Array_Element
+  {
+  public:
+    typedef C C_Type;
+
+    Polymorphic_Array_Element()
+    {
+      throw Dimension_Error("Cannot default-construct a polymorphic array"
+                            " object.");
+    }
+
+    Polymorphic_Array_Element(T& object) : m_object(object.copy()) { }
+
+    Polymorphic_Array_Element(C_Type c)
+    {
+      throw Dimension_Error("Cannot wrap existing dmnsn_array* elements in"
+                            " polymorphic class.");
+    }
+
+    // Polymorphic_Array_Element(const Polymorphic_Array_Element& ae);
+    // ~Polymorphic_Array_Element();
+
+    // Polymorphic_Array_Element& operator=(const Polymorphic_Array_Element& e);
+
+    C_Type dmnsn() const { return m_object->dmnsn(); }
+    T& object(C_Type* c) const { return *m_object; }
+
+  private:
+    std::tr1::shared_ptr<T> m_object;
   };
 
   // A constraint enforcing that T is a POD type by making it part of a union.
@@ -77,26 +169,110 @@ namespace Dimension
     static_cast<void>(constraint); // Silence unused variable warning
   }
 
+  // Array_Element
+
   template <typename T>
-  Array<T>::Array()
-    : m_array(new dmnsn_array*(dmnsn_new_array(sizeof(T))))
+  inline
+  Array_Element<T>::Array_Element()
   {
     void (*constraint)() = &POD_constraint<T>;
     static_cast<void>(constraint); // Silence unused variable warning
   }
 
   template <typename T>
-  Array<T>::Array(dmnsn_array* array)
-    : m_array(new dmnsn_array*(array))
+  inline
+  Array_Element<T>::Array_Element(T t)
+    : m_t(t)
   {
     void (*constraint)() = &POD_constraint<T>;
     static_cast<void>(constraint); // Silence unused variable warning
   }
 
+  // Array constructors
+
+  template <typename T>
+  inline
+  Array<T>::Array()
+    : m_array(new dmnsn_array*(dmnsn_new_array(sizeof(T)))) { }
+
+  template <typename T>
+  inline
+  Array<T>::Array(dmnsn_array* array)
+    : m_array(new dmnsn_array*(array))
+  {
+    m_elements.reserve(dmnsn_array_size(dmnsn()));
+    for (std::size_t i = 0; i < dmnsn_array_size(dmnsn()); ++i) {
+      C_Type* c = reinterpret_cast<C_Type*>(dmnsn_array_at(dmnsn(), i));
+      m_elements.push_back(Array_Element<T>(*c));
+    }
+  }
+
+  // Array element access
+
+  template <typename T>
+  inline T&
+  Array<T>::operator[](std::size_t i)
+  {
+    if (i >= m_elements.size()) {
+      m_elements.resize(i + 1);
+    }
+    C_Type* c = reinterpret_cast<C_Type*>(dmnsn_array_at(dmnsn(), i));
+    return m_elements[i].object(c);
+  }
+
+  template <typename T>
+  inline const T&
+  Array<T>::operator[](std::size_t i) const
+  {
+    if (i >= m_elements.size()) {
+      m_elements.resize(i + 1);
+    }
+    C_Type* c = reinterpret_cast<C_Type*>(dmnsn_array_at(dmnsn(), i));
+    return m_elements[i].object(c);
+  }
+
+  template <typename T>
+  inline void
+  Array<T>::resize(std::size_t size)
+  {
+    m_elements.resize(size);
+    dmnsn_array_resize(dmnsn(), size);
+  }
+
+  template <typename T>
+  inline void
+  Array<T>::push(T& object)
+  {
+    Array_Element<T> ae(object);
+    m_elements.push_back(ae);
+
+    C_Type c = ae.dmnsn();
+    dmnsn_array_push(dmnsn(), &c);
+  }
+
+  template <typename T>
+  inline void
+  Array<T>::push(const T& object)
+  {
+    Array_Element<T> ae(object);
+    m_elements.push_back(ae);
+
+    C_Type c = ae.dmnsn();
+    dmnsn_array_push(dmnsn(), &c);
+  }
+
+  template <typename T>
+  inline void
+  Array<T>::pop()
+  {
+    m_elements.pop();
+    dmnsn_array_resize(dmnsn_array_size(dmnsn()) - 1);
+  }
+
   // Access the underlying dmnsn_array*
 
   template <typename T>
-  dmnsn_array*
+  inline dmnsn_array*
   Array<T>::dmnsn()
   {
     if (!m_array) {
@@ -107,7 +283,7 @@ namespace Dimension
   }
 
   template <typename T>
-  const dmnsn_array*
+  inline const dmnsn_array*
   Array<T>::dmnsn() const
   {
     if (!m_array) {
@@ -119,7 +295,7 @@ namespace Dimension
 
   // Release the dmnsn_array*, if we are the only Array holding it
   template <typename T>
-  dmnsn_array*
+  inline dmnsn_array*
   Array<T>::release()
   {
     dmnsn_array* array = dmnsn();
diff --git a/libdimensionxx/dimensionxx/camera.hpp b/libdimensionxx/dimensionxx/camera.hpp
index 9b717ff..d8743ce 100644
--- a/libdimensionxx/dimensionxx/camera.hpp
+++ b/libdimensionxx/dimensionxx/camera.hpp
@@ -72,6 +72,25 @@ namespace Dimension
 
     virtual Line ray(const Canvas& canvas, unsigned int x, unsigned int y) = 0;
   };
+
+  // Array_Element specialization
+  template <>
+  class Array_Element<Camera>
+    : public Polymorphic_Array_Element<Camera, dmnsn_camera*>
+  {
+  public:
+    typedef dmnsn_camera* C_Type;
+
+    Array_Element() { }
+    Array_Element(Camera& camera)
+      : Polymorphic_Array_Element<Camera, dmnsn_camera*>(camera) { }
+    Array_Element(C_Type c)
+      : Polymorphic_Array_Element<Camera, dmnsn_camera*>(c) { }
+    // Array_Element(const Array_Element& ae);
+    // ~Array_Element();
+
+    // Array_Element& operator=(const Array_Element& ae);
+  };
 }
 
 #endif /* DIMENSIONXX_CAMERA_HPP */
diff --git a/libdimensionxx/dimensionxx/canvas.hpp b/libdimensionxx/dimensionxx/canvas.hpp
index c75b100..321e1c7 100644
--- a/libdimensionxx/dimensionxx/canvas.hpp
+++ b/libdimensionxx/dimensionxx/canvas.hpp
@@ -60,6 +60,25 @@ namespace Dimension
 
     std::tr1::shared_ptr<dmnsn_canvas*> m_canvas;
   };
+
+  // Array_Element specialization
+  template <>
+  class Array_Element<Canvas>
+    : public DMNSN_Array_Element<Canvas, dmnsn_canvas*>
+  {
+  public:
+    typedef dmnsn_canvas* C_Type;
+
+    Array_Element() { }
+    Array_Element(Canvas& canvas)
+      : DMNSN_Array_Element<Canvas, dmnsn_canvas*>(canvas) { }
+    Array_Element(C_Type c)
+      : DMNSN_Array_Element<Canvas, dmnsn_canvas*>(c) { }
+    // Array_Element(const Array_Element& ae);
+    // ~Array_Element();
+
+    // Array_Element& operator=(const Array_Element& ae);
+  };
 }
 
 #endif /* DIMENSIONXX_CANVAS_HPP */
diff --git a/libdimensionxx/dimensionxx/color.hpp b/libdimensionxx/dimensionxx/color.hpp
index 635e141..7d804f5 100644
--- a/libdimensionxx/dimensionxx/color.hpp
+++ b/libdimensionxx/dimensionxx/color.hpp
@@ -200,6 +200,26 @@ namespace Dimension
     dmnsn_sRGB m_RGB;
   };
 
+  // Array_Element specialization
+  template <>
+  class Array_Element<Color>
+    : public DMNSN_Array_Element<Color, dmnsn_color>
+  {
+  public:
+    typedef dmnsn_color C_Type;
+
+    Array_Element()
+      : DMNSN_Array_Element<Color, dmnsn_color>(Color()) { }
+    Array_Element(Color& color)
+      : DMNSN_Array_Element<Color, dmnsn_color>(color) { }
+    Array_Element(C_Type c)
+      : DMNSN_Array_Element<Color, dmnsn_color>(c) { }
+    // Array_Element(const Array_Element& ae);
+    // ~Array_Element();
+
+    // Array_Element& operator=(const Array_Element& ae);
+  };
+
   // Color inline constructors
 
   inline Color::Color(const CIE_XYZ& XYZ)
diff --git a/libdimensionxx/dimensionxx/geometry.hpp b/libdimensionxx/dimensionxx/geometry.hpp
index fdeccf0..4da6f47 100644
--- a/libdimensionxx/dimensionxx/geometry.hpp
+++ b/libdimensionxx/dimensionxx/geometry.hpp
@@ -134,6 +134,65 @@ namespace Dimension
     dmnsn_line m_line;
   };
 
+  // Array_Element specializations
+
+  template <>
+  class Array_Element<Matrix>
+    : public DMNSN_Array_Element<Matrix, dmnsn_matrix>
+  {
+  public:
+    typedef dmnsn_matrix C_Type;
+
+    Array_Element()
+      : DMNSN_Array_Element<Matrix, dmnsn_matrix>(Matrix()) { }
+    Array_Element(Matrix& matrix)
+      : DMNSN_Array_Element<Matrix, dmnsn_matrix>(matrix) { }
+    Array_Element(C_Type c)
+      : DMNSN_Array_Element<Matrix, dmnsn_matrix>(c) { }
+    // Array_Element(const Array_Element& ae);
+    // ~Array_Element();
+
+    // Array_Element& operator=(const Array_Element& ae);
+  };
+
+  template <>
+  class Array_Element<Vector>
+    : public DMNSN_Array_Element<Vector, dmnsn_vector>
+  {
+  public:
+    typedef dmnsn_vector C_Type;
+
+    Array_Element()
+      : DMNSN_Array_Element<Vector, dmnsn_vector>(Vector()) { }
+    Array_Element(Vector& vector)
+      : DMNSN_Array_Element<Vector, dmnsn_vector>(vector) { }
+    Array_Element(C_Type c)
+      : DMNSN_Array_Element<Vector, dmnsn_vector>(c) { }
+    // Array_Element(const Array_Element& ae);
+    // ~Array_Element();
+
+    // Array_Element& operator=(const Array_Element& ae);
+  };
+
+  template <>
+  class Array_Element<Line>
+    : public DMNSN_Array_Element<Line, dmnsn_line>
+  {
+  public:
+    typedef dmnsn_line C_Type;
+
+    Array_Element()
+      : DMNSN_Array_Element<Line, dmnsn_line>(Line()) { }
+    Array_Element(Line& line)
+      : DMNSN_Array_Element<Line, dmnsn_line>(line) { }
+    Array_Element(C_Type c)
+      : DMNSN_Array_Element<Line, dmnsn_line>(c) { }
+    // Array_Element(const Array_Element& ae);
+    // ~Array_Element();
+
+    // Array_Element& operator=(const Array_Element& ae);
+  };
+
   // Matrix operators
 
   inline Matrix
diff --git a/libdimensionxx/dimensionxx/object.hpp b/libdimensionxx/dimensionxx/object.hpp
index 8283c9c..30dadf8 100644
--- a/libdimensionxx/dimensionxx/object.hpp
+++ b/libdimensionxx/dimensionxx/object.hpp
@@ -78,6 +78,25 @@ namespace Dimension
     virtual Array<double> intersections(const Line& l) = 0;
     virtual bool inside(const Vector& point) = 0;
   };
+
+  // Array_Element specialization
+  template <>
+  class Array_Element<Object>
+    : public Polymorphic_Array_Element<Object, dmnsn_object*>
+  {
+  public:
+    typedef dmnsn_object* C_Type;
+
+    Array_Element() { }
+    Array_Element(Object& object)
+      : Polymorphic_Array_Element<Object, dmnsn_object*>(object) { }
+    Array_Element(C_Type c)
+      : Polymorphic_Array_Element<Object, dmnsn_object*>(c) { }
+    // Array_Element(const Array_Element& ae);
+    // ~Array_Element();
+
+    // Array_Element& operator=(const Array_Element& ae);
+  };
 }
 
 #endif /* DIMENSIONXX_OBJECT_HPP */
diff --git a/libdimensionxx/dimensionxx/scene.hpp b/libdimensionxx/dimensionxx/scene.hpp
index acb2cb1..8b5270c 100644
--- a/libdimensionxx/dimensionxx/scene.hpp
+++ b/libdimensionxx/dimensionxx/scene.hpp
@@ -25,15 +25,10 @@
 
 namespace Dimension
 {
-  // Iterator class for scene objects - never invalidated unless removed
-  class Scene_Iterator;
-
   // Base scene class.  Wraps a dmnsn_scene*.
   class Scene
   {
   public:
-    typedef Scene_Iterator Iterator;
-
     // Allocate a dmnsn_scene*
     Scene(const Color& background, Camera& camera, Canvas& canvas);
 
@@ -43,19 +38,13 @@ namespace Dimension
     ~Scene();
 
     // Element access
-    Color background() const;
-    Camera&       camera();
-    const Camera& camera() const;
-    Canvas&       canvas();
-    const Canvas& canvas() const;
-
-    // Object access
-
-    Iterator begin();
-    Iterator end();
-
-    void push_object(Object& object);
-    void remove_object(Iterator i);
+    Color                background() const;
+    Camera&              camera();
+    const Camera&        camera() const;
+    Canvas&              canvas();
+    const Canvas&        canvas() const;
+    Array<Object>&       objects();
+    const Array<Object>& objects() const;
 
     // Access the wrapped C object.
     dmnsn_scene*       dmnsn();
@@ -68,36 +57,7 @@ namespace Dimension
     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
-  {
-    typedef std::list<std::tr1::shared_ptr<Object> >::iterator Iterator;
-
-  public:
-    Scene_Iterator(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--); }
-
-    Iterator iterator() const { return m_i; }
-
-  private:
-    Iterator m_i;
+    Array<Object> m_objects;
   };
 }
 
diff --git a/libdimensionxx/scene.cpp b/libdimensionxx/scene.cpp
index 1bff351..f41f3b5 100644
--- a/libdimensionxx/scene.cpp
+++ b/libdimensionxx/scene.cpp
@@ -25,7 +25,7 @@ namespace Dimension
   // Allocate a dmnsn_scene
   Scene::Scene(const Color& background, Camera& camera, Canvas& canvas)
     : m_scene(new dmnsn_scene*(dmnsn_new_scene())), m_camera(camera.copy()),
-      m_canvas(new Canvas(canvas))
+      m_canvas(new Canvas(canvas)), m_objects(dmnsn()->objects)
   {
     if (!dmnsn()) {
       throw Dimension_Error("Couldn't allocate scene.");
@@ -40,6 +40,7 @@ namespace Dimension
   Scene::~Scene()
   {
     if (m_scene.unique()) {
+      m_objects.release();
       dmnsn_delete_scene(dmnsn());
     }
   }
@@ -76,44 +77,16 @@ namespace Dimension
     return *m_canvas;
   }
 
-  // An iterator to the beginning of the object list
-  Scene::Iterator
-  Scene::begin()
+  Array<Object>&
+  Scene::objects()
   {
-    return Iterator(m_objects.begin());
+    return m_objects;
   }
 
-  // An iterator one past the end of the object list
-  Scene::Iterator
-  Scene::end()
+  const Array<Object>&
+  Scene::objects() const
   {
-    return Iterator(m_objects.end());
-  }
-
-  // Add an object
-  void
-  Scene::push_object(Object& object)
-  {
-    m_objects.push_back(std::tr1::shared_ptr<Object>(object.copy()));
-    dmnsn_object* cobject = object.dmnsn();
-    dmnsn_array_push(dmnsn()->objects, &cobject);
-  }
-
-  // Remove an object
-  void
-  Scene::remove_object(Iterator i)
-  {
-    // Find it in the dmnsn_array* of objects and remove it
-    for (unsigned int j = 0; j < dmnsn_array_size(dmnsn()->objects); ++j) {
-      dmnsn_object* cobject;
-      dmnsn_array_get(dmnsn()->objects, j, &cobject);
-      if (cobject == i->dmnsn()) {
-        dmnsn_array_remove(dmnsn()->objects, j);
-        break;
-      }
-    }
-    // Remove it from the std::list
-    m_objects.erase(i.iterator());
+    return m_objects;
   }
 
   // Access the wrapped C object.
diff --git a/tests/testsxx.cpp b/tests/testsxx.cpp
index aaeb546..b4c28d9 100644
--- a/tests/testsxx.cpp
+++ b/tests/testsxx.cpp
@@ -38,7 +38,9 @@ namespace Dimension
         Matrix::rotation(Vector(0.0, 1.0, 0.0))
         * Matrix::translation(Vector(0.0, 0.0, -4.0))
         * Matrix::scale(
-            Vector(static_cast<double>(canvas.width())/canvas.height(), 1.0, 1.0)
+            Vector(static_cast<double>(canvas.width())/canvas.height(),
+                   1.0,
+                   1.0)
           )
       );
 
@@ -49,11 +51,11 @@ namespace Dimension
 
       Sphere sphere;
       sphere.trans(inverse(Matrix::scale(Vector(1.25, 1.25, 1.25))));
-      scene.push_object(sphere);
+      scene.objects().push(sphere);
 
       Cube cube;
       cube.trans(inverse(Matrix::rotation(Vector(0.75, 0.0, 0.0))));
-      scene.push_object(cube);
+      scene.objects().push(cube);
 
       return scene;
     }