feat: Adding resource handling Chapter 2, changed game.cpp so it comfors to the new way of handling textures

SFMLEngine/makingAGameTick/game.cpp

@@ -1,8 +1,14 @@
+#ifndef GAME_CPP
+#define GAME_CPP
+
 #include <vector>
 #include <SFML/Graphics.hpp>
 #include "constants.hpp"
+#include "resources.cpp"
 #include "basic.cpp"
 
+
+
 class Game
 {
   public:
@@ -20,18 +26,16 @@ class Game
     bool mIsMovingDown = false;
   private:
     sf::RenderWindow mWindow;
-    sf::Texture mTexture;
+    TextureHolder mTexture;
     sf::Sprite mPlayer;
 };
 
 Game::Game() : mWindow(sf::VideoMode(640, 480), "SFML Application"), mTexture(), mPlayer()
 {
-  if (!mTexture.loadFromFile(PATH_TO_PLAYER_TEXTURE))
-  {
-    std::cout << "NO FILE: " << PATH_TO_PLAYER_TEXTURE << std::endl;
-    mWindow.close();
-  }
-  mPlayer.setTexture(mTexture);
+  //TextureHolder textures;
+  mTexture.load(Textures::Airplane, PATH_TO_PLAYER_TEXTURE);
+
+  mPlayer.setTexture(mTexture.get(Textures::Airplane));
   mPlayer.setPosition(PLAYER_X_POSITION, PLAYER_Y_POSITION);
 }
 
@@ -124,3 +128,5 @@ int main()
   Game game;
   game.run();
 }
+
+#endif // GAME_CPP

SFMLEngine/makingAGameTick/resources.cpp

@@ -0,0 +1,41 @@
+#ifndef RESOURCES_CPP
+#define RESOURCES_CPP
+// Mostly Chapter 2
+// Handles resource management
+namespace Textures // This gives us a scope for the enumerators which allows us to write Textures::Airplane instead of just Airplane to avoid name collisions in the global scope
+{
+  enum ID { Landscape, Airplane, Missile };
+}
+
+class TextureHolder
+{
+  public:
+    void load(Textures::ID id, const std::string& filename);
+    sf::Texture& get(Textures::ID id);
+    const sf::Texture& get(Textures::ID id) const;
+  private:
+    std::map< Textures::ID, std::unique_ptr<sf::Texture> > mTextureMap;
+    // unique_ptr are class templates that act like pointers, this allows us to work with heavyweight objects without copying them all the time, or we can store classes that are non-cpyable like sf::Shader
+};
+
+void TextureHolder::load(Textures::ID id, const std::string& filename)
+// Function to load a resource, it takes one parameter for filename and one for identifier
+{
+  std::unique_ptr<sf::Texture> texture(new sf::Texture()); // Create sf:Texture and store it in the unique pointer
+  texture -> loadFromFile(filename); // Load the texture from the filename
+  mTextureMap.insert(std::make_pair(id, std::move(texture))); // Insert texture into map mTextureMap, std::move used to take ownership from texture variable and transfer it to std::make_pair(), std::move moves the resource into a new place and removes it from earlier place https://en.cppreference.com/w/cpp/utility/move
+}
+
+sf::Texture& TextureHolder::get(Textures::ID id) // returns a reference to a texture
+{
+  auto found = mTextureMap.find(id); // find returns an iterator to the found element or end() if nothing was found
+  return *found -> second; // We have to access the second member of the pointer, then we deference it and get a texture
+}
+
+const sf::Texture& TextureHolder::get(Textures::ID id) const // we need to be able to invoke get() also if we only have a pointer/reference to the const TextureHolder, it returns const sf::Texture so the texture cannot be changed by caller
+{
+  auto found = mTextureMap.find(id); // find returns an iterator to the found element or end() if nothing was found
+  return *found -> second; // We have to access the second member of the pointer, then we deference it and get a texture
+}
+
+#endif //RESOUIRCES_CPP