add restarting mechanism with scenes (scuffed)

Core/Game.cs

@@ -8,15 +8,17 @@ namespace Core;
 
 public abstract class Game : Microsoft.Xna.Framework.Game
 {
+    private readonly Type[] scenes = null;
     private static Game instance = null;
+    private Scene scene;
     private bool initialized = false;
     private bool loadedContent = false;
 
     internal static Game Instance => instance ?? throw new NullReferenceException("Tried to get the game's instance before the game has been made");
 
-    internal readonly ObjectRegistry objectRegistry;
     internal bool Initialized => initialized;
     internal bool LoadedContent => loadedContent;
+    public Scene Scene => scene;
 
     protected abstract SpriteBatch SpriteBatch { get; set; }
 
@@ -25,25 +27,37 @@ public Game()
         if (instance != null) throw new InvalidOperationException("there is only allowed to be one game!");
         instance = this;
 
-        objectRegistry = new();
+        scenes = GetScenes();
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static IEnumerable<T> GetObjectsOfType<T>() where T : class
     {
-        return Instance.objectRegistry.GetObjectsOfType<T>();
+        return Instance.scene.objectRegistry.GetObjectsOfType<T>();
+    }
+
+    public void LoadScene(int i, params object[] args)
+    {
+        if (scenes[i].IsSubclassOf(typeof(Scene)) == false)
+            throw new InvalidCastException($"the scene '{i}' is not derrived from '{typeof(Scene).FullName}'!");
+
+        scene?.Dispose();
+        scene = (Scene)Activator.CreateInstance(scenes[i], args);
+        if (initialized) scene.Initialize();
+        if (loadedContent) scene.LoadContent(Content);
     }
 
     // executes the scheduled actions DO NOT CALL UNLESS YOU KNOW WHAT YOU'RE DOING
     protected void ExecuteScheduled()
     {
-        objectRegistry.CreateGameObjects();
-        objectRegistry.DisposeGameObjects();
+        scene.objectRegistry.CreateGameObjects();
+        scene.objectRegistry.DisposeGameObjects();
     }
 
     protected override void Initialize()
     {
         initialized = true;
+        scene.Initialize();
         foreach (IInitialize initialize in GetObjectsOfType<IInitialize>())
             initialize.Initialize();
 
@@ -55,6 +69,7 @@ protected override void Initialize()
     protected override void LoadContent()
     {
         loadedContent = true;
+        scene.LoadContent(Content);
         foreach (ILoadContent loadContent in GetObjectsOfType<ILoadContent>())
             loadContent.LoadContent(Content);
 
@@ -65,6 +80,7 @@ protected override void LoadContent()
 
     protected override void Update(GameTime gameTime)
     {
+        scene.Update();
         foreach (IUpdate update in GetObjectsOfType<IUpdate>())
             update.Update();
 
@@ -73,9 +89,5 @@ protected override void Update(GameTime gameTime)
         base.Update(gameTime);
     }
 
-    protected void DrawObjects()
-    {
-        foreach (IDraw draw in GetObjectsOfType<IDraw>())
-            draw.Draw(SpriteBatch);
-    }
+    protected abstract Type[] GetScenes();
 }

Core/GameObject.cs

@@ -12,7 +12,7 @@ public GameObject()
     {
         // initialize public variables with their default values
         transform = new();
-        Game.Instance.objectRegistry.AddGameObject(this);
+        Game.Instance.Scene.objectRegistry.AddGameObject(this);
     }
 
     // to get rid of the gameobject
@@ -23,7 +23,7 @@ public void Dispose()
             return;
 
         GC.SuppressFinalize(this);
-        Game.Instance.objectRegistry.RemoveGameObject(this);
+        Game.Instance.Scene.objectRegistry.RemoveGameObject(this);
         disposed = true;
         OnDispose();
     }

Core/ObjectRegistry.cs

@@ -4,7 +4,7 @@
 
 namespace Core;
 
-internal class ObjectRegistry
+internal class ObjectRegistry : IDisposable
 {
     // using linked lists instead of a List, because it's faster when creating new objects
     // removing makes no difference, as it only needs to climb till the correct gameObject. Where in a list it'd need to move all the elements after one forward.
@@ -119,4 +119,26 @@ public IEnumerable<T> GetObjectsOfType<T>() where T : class
                 yield return t;
         }
     }
+
+    public void Dispose()
+    {
+        GC.SuppressFinalize(this);
+
+        // call dispose on all the gameObjects
+        while (objectRegistry.First != null)
+        {
+            objectRegistry.First.Value.Dispose();
+            objectRegistry.RemoveFirst();
+        }
+
+        // clear other lists
+        initializes.Clear();
+        loadContents.Clear();
+        updates.Clear();
+        draws.Clear();
+
+        // clear queues
+        createQueue.Clear();
+        disposeQueue.Clear();
+    }
 }

Core/Scene.cs

@@ -0,0 +1,53 @@
+using System;
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+using Microsoft.Xna.Framework.Content;
+using Microsoft.Xna.Framework.Graphics;
+
+namespace Core;
+
+public abstract class Scene : IDisposable, IInitialize, ILoadContent, IUpdate, IDraw
+{
+    private bool disposed = false;
+    internal readonly ObjectRegistry objectRegistry;
+
+    public Scene()
+    {
+        objectRegistry = new();
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public IEnumerable<T> GetObjectsOfType<T>() where T : class
+    {
+        return objectRegistry.GetObjectsOfType<T>();
+    }
+
+    public void DrawObjects(SpriteBatch spriteBatch)
+    {
+        Draw(spriteBatch);
+        foreach (IDraw draw in GetObjectsOfType<IDraw>())
+            draw.Draw(spriteBatch);
+    }
+
+    public void Dispose()
+    {
+        // ignore extra dispose calls; we've already disposed.
+        if (disposed)
+            return;
+
+        GC.SuppressFinalize(this);
+
+        // dispose of the object registry
+        objectRegistry.Dispose();
+
+        disposed = true;
+        OnDispose();
+    }
+
+    public virtual void OnDispose() { }
+
+    public abstract void Draw(SpriteBatch spriteBatch);
+    public abstract void Update();
+    public abstract void LoadContent(ContentManager content);
+    public abstract void Initialize();
+}

SpaceShooter2/SpaceShooter.cs

@@ -3,6 +3,7 @@
 using Microsoft.Xna.Framework.Input;
 using SpaceShooter2.Src;
 using SpaceShooter2.Src.Data;
+using SpaceShooter2.Src.Scenes;
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
@@ -86,6 +87,12 @@ private void DebugKeybinds()
             glob.player.Damage(glob.player.Health);
     }
 
+    protected override void Initialize()
+    {
+        LoadScene(0, glob);
+        base.Initialize();
+    }
+
     // loads all the assets we will use for the game
     // aditionally, it initializes the objects used in the game
     protected override void LoadContent()
@@ -104,11 +111,8 @@ protected override void LoadContent()
         glob.assets.destroyAsteroid = Content.Load<SoundEffect>(Const.SFX_DESTROY_ASTEROID);
         glob.assets.lose = Content.Load<SoundEffect>(Const.SFX_LOSE);
 
-        // init game objects (some aren't stored in globalstate, because theglob.spawnery're automatically added to the game object registry)
-        glob.player = new Player(glob);
         glob.pcl = new(GraphicsDevice);
-        _ = new Spawner(glob);
-        _ = new UI(glob);
+
         base.LoadContent();
     }
 
@@ -122,9 +126,12 @@ protected override void Update(GameTime gameTime)
         // excute the debug keybinds to perform debug actions
         DebugKeybinds();
 
-        // if the game has been lost, check if the enter key has been pressed, exit if so
-        if (glob.lose == true && glob.keyboard.IsKeyDown(Keys.Enter))
-            Exit();
+        // if the game has been lost, check if the enter key has been pressed, restart if so
+        if (glob.lose && glob.keyboard.IsKeyDown(Keys.Enter))
+        {
+            glob.lose = false;
+            LoadScene(0, glob);
+        }
 
         base.Update(gameTime);
     }
@@ -138,7 +145,7 @@ protected override void Draw(GameTime gameTime)
         // draw everything
         SpriteBatch.Begin(samplerState: SamplerState.PointClamp, sortMode: SpriteSortMode.FrontToBack);
         glob.pcl.Draw(SpriteBatch);     // draw the pixel control layer
-        DrawObjects();                  // draw all the gameObjects with IDraw implemented
+        Scene.DrawObjects(SpriteBatch); // draw all the gameObjects with IDraw implemented
         SpriteBatch.End();
 
         // clear pcl's internal buffer *after* drawing, otherwise it won't know what to draw
@@ -158,4 +165,11 @@ protected override void OnExiting(object sender, EventArgs args)
 
         base.OnExiting(sender, args);
     }
+
+    protected override Type[] GetScenes()
+    {
+        return new Type[] {
+            typeof(GameScene),
+        };
+    }
 }

SpaceShooter2/Src/Scenes/GameScene.cs

@@ -0,0 +1,30 @@
+using Core;
+using Microsoft.Xna.Framework.Content;
+using Microsoft.Xna.Framework.Graphics;
+using SpaceShooter2.Src.Data;
+
+namespace SpaceShooter2.Src.Scenes;
+
+internal class GameScene : Scene
+{
+    private readonly GlobalState glob;
+
+    public GameScene(GlobalState glob)
+    {
+        this.glob = glob;
+    }
+
+    public override void Initialize()
+    {
+        _ = new Spawner(glob);
+        _ = new UI(glob);
+    }
+
+    public override void LoadContent(ContentManager content)
+    {
+        glob.player = new Player(glob);
+
+    }
+    public override void Update() { }
+    public override void Draw(SpriteBatch spriteBatch) { }
+}

SpaceShooter2/Src/UI.cs

@@ -38,7 +38,7 @@ public void Draw(SpriteBatch spriteBatch)
         {
             spriteBatch.DrawString(glob.assets.font, "YOU LOST", new Vector2(Const.SCREEN_CENTRE_X, Const.SCREEN_CENTRE_Y), Color.Red, centre, 1.0F, 1.0F);
             spriteBatch.DrawString(glob.assets.font, $"Score: {score}\nHigh Score: {highscore}", new Vector2(Const.SCREEN_CENTRE_X, 10), Color.White, topCentre, 0.5F, 1.0F);
-            spriteBatch.DrawString(glob.assets.font, "press [enter] to exit", new Vector2(Const.SCREEN_CENTRE_X, Const.SCREEN_CENTRE_Y + 40), Color.Red, centre, 0.5F, 1.0F);
+            spriteBatch.DrawString(glob.assets.font, "press [enter] to restart", new Vector2(Const.SCREEN_CENTRE_X, Const.SCREEN_CENTRE_Y + 40), Color.Red, centre, 0.5F, 1.0F);
             return;
         }