Added Screen system

src/example/main.cpp

@@ -4,11 +4,35 @@
 
 using namespace sf;
 
-int Callback(void* userdata, SDL_Event* event)
+class MyScreen : public IScreen
 {
-	std::cout << event->type << std::endl;
-	return 0;
-}
+public:
+	virtual void OnFocus() override
+	{
+		printf("Received Focus\n");
+	}
+
+	virtual void OnDefocus() override
+	{
+		printf("Lost Focus\n");
+	}
+
+	virtual void OnRender(SDL_Renderer* renderer) override
+	{
+		SDL_SetRenderDrawColor(renderer, 0, 0, 255, 255);
+		SDL_RenderClear(renderer);
+	}
+
+	static MyScreen* Get() 
+	{
+		static MyScreen* instance = new MyScreen;
+		return instance;
+	}
+private:
+	MyScreen() = default;
+};
+
+
 
 class MyWindow : public IWindow
 {
@@ -22,6 +46,7 @@ public:
 private:
 	virtual bool OnCreate() override
 	{
+		SwitchScreen(MyScreen::Get());
 		printf("On Create\n");
 		return true;
 	}
@@ -38,12 +63,13 @@ private:
 	}
 };
 
+
+
 int main(int argc, char* argv[])
 {
 	SDL_Init(SDL_INIT_VIDEO);
 
 	MyWindow window;
-	window.AddEventCallback(Callback, nullptr);
 
 	try
 	{

src/sdlf/Screen.hpp

@@ -7,15 +7,15 @@ namespace sf
 	class IScreen
 	{
 	public:
+		virtual void OnFocus() {}							// Called when the screen is being switched to
+		virtual void OnDefocus() {}							// Called when the screen is being switched from
+		virtual bool OnUpdate(double frametime) { return true; }			// Called every frame
+		virtual void OnEvent(const SDL_Event& event) {}		// Called after an event occurs
+		virtual void OnRender(SDL_Renderer* renderer) {}	// Called for rendering
 
 	protected:
-		IScreen();
+		IScreen() = default;
 
-		virtual void OnFocus() = 0;							// Called when the screen is being switched to
-		virtual void OnDefocus() = 0;						// Called when the screen is being switched from
-		virtual void OnUpdate(double frametime) = 0;		// Called every frame
-		virtual void OnEvent(const SDL_Event& event) = 0;	// Called after an event occurs
-	
 	private:
 	};
 }

src/sdlf/Window.cpp

@@ -33,6 +33,10 @@ namespace sf
 			THROW_IF_NULLPTR(m_pRenderer);
 		}
 
+		m_oEventFunction = std::bind(&IWindow::OnEvent, this, std::placeholders::_1);
+		m_oUpdateFunction = std::bind<bool>(&IWindow::OnUpdate, this, std::placeholders::_1);
+		m_oRenderFunction = std::bind(&IWindow::OnRender, this, std::placeholders::_1);
+
 	}
 
 	void IWindow::Destroy()
@@ -67,10 +71,38 @@ namespace sf
 		SDL_AddEventWatch(*(callback.target<SDL_EventFilter>()), userdata);
 	}
 
+	void IWindow::SwitchScreen(IScreen* screen)
+	{
+		if (m_pCurrentScreen == screen)
+			return;
+
+		if (IS_NOT_NULLPTR(m_pCurrentScreen))
+			m_pCurrentScreen->OnDefocus();
+		
+		m_pCurrentScreen = screen;
+
+		if (IS_NOT_NULLPTR(m_pCurrentScreen))
+		{
+			m_oEventFunction = std::bind(&IScreen::OnEvent, m_pCurrentScreen, std::placeholders::_1);
+			m_oUpdateFunction = std::bind<bool>(&IScreen::OnUpdate, m_pCurrentScreen, std::placeholders::_1);
+			m_oRenderFunction = std::bind(&IScreen::OnRender, m_pCurrentScreen, std::placeholders::_1);
+
+			m_pCurrentScreen->OnFocus();
+		}
+		else
+		{
+			m_oEventFunction = std::bind(&IWindow::OnEvent, this, std::placeholders::_1);
+			m_oUpdateFunction = std::bind<bool>(&IWindow::OnUpdate, this, std::placeholders::_1);
+			m_oRenderFunction = std::bind(&IWindow::OnRender, this, std::placeholders::_1);
+
+		}
+	}
+
 	IWindow::IWindow(Vector2u size, Vector2i position, std::string title,
 		Uint32 flags /*= SDL_WINDOW_RESIZABLE*/) :
 		m_pWindow(nullptr), m_pRenderer(nullptr), m_oEvent(),
-		m_oSize(size), m_oPosition(position), m_strTitle(title), m_uFlags(flags)
+		m_oSize(size), m_oPosition(position), m_strTitle(title), m_uFlags(flags),
+		m_pCurrentScreen(nullptr)
 	{
 		
 	}
@@ -88,7 +120,7 @@ namespace sf
 		{
 			while (SDL_PollEvent(&m_oEvent))
 			{
-				OnEvent(m_oEvent);
+				m_oEventFunction(m_oEvent);
 
 				if (m_oEvent.type == SDL_QUIT)
 				{
@@ -100,11 +132,10 @@ namespace sf
 				std::chrono::steady_clock::now() - pastTime
 				).count();
 			pastTime = std::chrono::steady_clock::now();
-			if (!OnUpdate(frametime))
+			if (!m_oUpdateFunction(frametime))
 				m_atomWindowOpen = false;
 
-			SDL_SetRenderDrawColor(m_pRenderer, 0, 0, 0, 255);
-			SDL_RenderClear(m_pRenderer);
+			m_oRenderFunction(m_pRenderer);
 
 			SDL_RenderPresent(m_pRenderer);
 		}

src/sdlf/Window.hpp

@@ -7,6 +7,7 @@
 
 #include "SDL.h"
 #include "util/Vector2.hpp"
+#include "Screen.hpp"
 
 #define SDLF_REQUIRED_SUBSYSTEMS SDL_INIT_VIDEO
 
@@ -26,6 +27,8 @@ namespace sf
 
 		void AddEventCallback(EventCallback callback, void* userdata);
 
+		void SwitchScreen(IScreen* screen);
+
 	protected:
 		IWindow(Vector2u size, Vector2i position, std::string title, Uint32 flags = SDL_WINDOW_RESIZABLE);
 
@@ -33,6 +36,7 @@ namespace sf
 		virtual void OnClose() { }
 		virtual void OnEvent(const SDL_Event& event) { }
 		virtual bool OnUpdate(double frametime) { return true; }
+		virtual void OnRender(SDL_Renderer* renderer) { }
 
 	protected:
 		SDL_Window* m_pWindow;
@@ -49,7 +53,13 @@ namespace sf
 		std::string m_strTitle;
 		Uint32 m_uFlags;
 
+		IScreen* m_pCurrentScreen;
+
 		std::thread m_oMsgLoopThread;
 		std::atomic_bool m_atomWindowOpen;
+
+		std::function<void( SDL_Event& )> m_oEventFunction;
+		std::function<bool( double )>			m_oUpdateFunction;
+		std::function<void( SDL_Renderer* )>	m_oRenderFunction;
 	};
 }

src/sdlf/util/util.hpp

@@ -1,3 +1,5 @@
 #include "Vector2.hpp"
 
-#define THROW_IF_NULLPTR(x) { if(x == nullptr) throw SDL_GetError(); }
+#define THROW_IF_NULLPTR(x) { if(x == nullptr) throw SDL_GetError(); }
+#define IS_NULLPTR(x) ( x == nullptr ? true : false )
+#define IS_NOT_NULLPTR(x) !IS_NULLPTR(x)