Add constructors from existing SDL2 objects

SDL2pp/Renderer.cc

@@ -30,6 +30,9 @@
 
 namespace SDL2pp {
 
+Renderer::Renderer(SDL_Renderer* renderer) : renderer_(renderer) {
+}
+
 Renderer::Renderer(Window& window, int index, Uint32 flags) {
 	if ((renderer_ = SDL_CreateRenderer(window.Get(), index, flags)) == nullptr)
 		throw Exception("SDL_CreateRenderer failed");

SDL2pp/Renderer.hh

@@ -51,6 +51,14 @@ private:
 	SDL_Renderer* renderer_; ///< Contained SDL_Renderer structure
 
 public:
+	////////////////////////////////////////////////////////////
+	/// \brief Construct from existing SDL_Renderer structure
+	///
+	/// \param renderer Existing SDL_Renderer to manage
+	///
+	////////////////////////////////////////////////////////////
+	Renderer(SDL_Renderer* renderer);
+
 	////////////////////////////////////////////////////////////
 	/// \brief Create renderer
 	///

SDL2pp/Surface.hh

@@ -148,16 +148,15 @@ public:
 		const SDL_PixelFormat& GetFormat() const;
 	};
 
-private:
+public:
 	////////////////////////////////////////////////////////////
-	/// \brief Create surface taking existing SDL_surface structure
+	/// \brief Construct from existing SDL_Surface structure
 	///
-	/// \param surface Existing SDL_surface to manage
+	/// \param surface Existing SDL_Surface to manage
 	///
 	////////////////////////////////////////////////////////////
 	Surface(SDL_Surface* surface);
 
-public:
 	////////////////////////////////////////////////////////////
 	/// \brief Create RGB surface
 	///

SDL2pp/Texture.cc

@@ -40,6 +40,9 @@
 
 namespace SDL2pp {
 
+Texture::Texture(SDL_Texture* texture) : texture_(texture) {
+}
+
 Texture::Texture(Renderer& renderer, Uint32 format, int access, int w, int h) {
 	if ((texture_ = SDL_CreateTexture(renderer.Get(), format, access, w, h)) == nullptr)
 		throw Exception("SDL_CreateTexture failed");

SDL2pp/Texture.hh

@@ -172,6 +172,14 @@ public:
 	};
 
 public:
+    ////////////////////////////////////////////////////////////
+	/// \brief Construct from existing SDL_Texture structure
+	///
+	/// \param texture Existing SDL_Texture to manage
+	///
+	////////////////////////////////////////////////////////////
+	Texture(SDL_Texture* texture);
+
 	////////////////////////////////////////////////////////////
 	/// \brief Create empty texture
 	///

SDL2pp/Window.cc

@@ -26,6 +26,9 @@
 
 namespace SDL2pp {
 
+Window::Window(SDL_Window* window) : window_(window) {
+}
+
 Window::Window(const std::string& title, int x, int y, int w, int h, Uint32 flags) {
 	if ((window_ = SDL_CreateWindow(title.c_str(), x, y, w, h, flags)) == nullptr)
 		throw Exception("SDL_CreateWindow failed");

SDL2pp/Window.hh

@@ -64,6 +64,14 @@ private:
 	SDL_Window* window_; ///< Contained SDL2_Window structure
 
 public:
+	////////////////////////////////////////////////////////////
+	/// \brief Construct from existing SDL_Window structure
+	///
+	/// \param window Existing SDL_Window to manage
+	///
+	////////////////////////////////////////////////////////////
+	Window(SDL_Window* window);
+
 	////////////////////////////////////////////////////////////
 	/// \brief Create window with specified title and fimensions
 	///