Minor bug fixes.

FreedomFighter/Game1.cs

@@ -17,6 +17,7 @@ public class Game1 : Game
     SpriteBatch _sb = null!;
     SpriteFont _font12 = null!;
     SpriteFont _font20 = null!;
+    RenderTarget2D _virtualScreen = null!;   // fixed 800x600 scene, stretched to the window
 
     bool _paused;
     string _enteredName = "";
@@ -44,6 +45,18 @@ public class Game1 : Game
         IsFixedTimeStep = true;
         TargetElapsedTime = TimeSpan.FromSeconds(1 / 120.0);
         Window.Title = "Freedom Fighter";
+        Window.AllowUserResizing = true;
+        Window.ClientSizeChanged += (_, _) =>
+        {
+            int w = Window.ClientBounds.Width, h = Window.ClientBounds.Height;
+            if (w > 0 && h > 0 &&
+                (w != _graphics.PreferredBackBufferWidth || h != _graphics.PreferredBackBufferHeight))
+            {
+                _graphics.PreferredBackBufferWidth = w;
+                _graphics.PreferredBackBufferHeight = h;
+                _graphics.ApplyChanges();
+            }
+        };
     }
 
     protected override void LoadContent()
@@ -51,6 +64,13 @@ public class Game1 : Game
         _sb = new SpriteBatch(GraphicsDevice);
         _font12 = Content.Load<SpriteFont>("Verdana12");
         _font20 = Content.Load<SpriteFont>("Verdana20");
+        _virtualScreen = new RenderTarget2D(GraphicsDevice, G.ScreenWidth, G.ScreenHeight);
+
+        // the Delphi form's Width/Height were the OUTER window size (800x600, sizeable border);
+        // as a DPI-unaware app it was also stretched by Windows, so scale by the current DPI
+        if (System.Windows.Forms.Control.FromHandle(Window.Handle) is System.Windows.Forms.Form form)
+            form.Size = new System.Drawing.Size(
+                G.ScreenWidth * form.DeviceDpi / 96, G.ScreenHeight * form.DeviceDpi / 96);
 
         string contentDir = Path.Combine(AppContext.BaseDirectory, "Content");
 
@@ -109,36 +129,45 @@ public class Game1 : Game
 
         if (G.Input.PauseClicked)
             _paused = !_paused;
-        if (_paused)
+
+        if (!_paused)
         {
-            base.Draw(gameTime);
-            return;
+            GraphicsDevice.SetRenderTarget(_virtualScreen);
+            GraphicsDevice.Clear(Color.Black);
+            _sb.Begin(SpriteSortMode.Deferred, BlendState.NonPremultiplied, SamplerState.PointClamp);
+
+            G.Sprites.Move(0);
+
+            switch (G.State)
+            {
+                case GameState.Intro: DoIntro(); break;
+                case GameState.Idle: DrawMenu(); break;
+                case GameState.Intermission: DoIntermission(); break;
+                case GameState.Playing: GameLoop(); break;
+                case GameState.Stats: DoStats(); break;
+                case GameState.Shop: DoShop(); break;
+                case GameState.GameOver: DoGameOver(); break;
+                case GameState.Credits: DoCredits(); break;
+                case GameState.HighScore: DoHighScore(); break;
+                case GameState.EnterName: DoEnterName(); break;
+            }
+
+            G.Sprites.Collision();
+            G.Sprites.RemoveDead();
+            G.Sprites.Draw(_sb);
+
+            _sb.End();
+            GraphicsDevice.SetRenderTarget(null);
         }
 
+        // stretch the 800x600 scene to the window, as DirectX presentation did
         GraphicsDevice.Clear(Color.Black);
-        _sb.Begin(SpriteSortMode.Deferred, BlendState.NonPremultiplied, SamplerState.PointClamp);
-
-        G.Sprites.Move(0);
-
-        switch (G.State)
-        {
-            case GameState.Intro: DoIntro(); break;
-            case GameState.Idle: DrawMenu(); break;
-            case GameState.Intermission: DoIntermission(); break;
-            case GameState.Playing: GameLoop(); break;
-            case GameState.Stats: DoStats(); break;
-            case GameState.Shop: DoShop(); break;
-            case GameState.GameOver: DoGameOver(); break;
-            case GameState.Credits: DoCredits(); break;
-            case GameState.HighScore: DoHighScore(); break;
-            case GameState.EnterName: DoEnterName(); break;
-        }
-
-        G.Sprites.Collision();
-        G.Sprites.RemoveDead();
-        G.Sprites.Draw(_sb);
-
+        _sb.Begin(SpriteSortMode.Deferred, BlendState.Opaque, SamplerState.LinearClamp);
+        _sb.Draw(_virtualScreen, new Rectangle(0, 0,
+            GraphicsDevice.PresentationParameters.BackBufferWidth,
+            GraphicsDevice.PresentationParameters.BackBufferHeight), Color.White);
         _sb.End();
+
         base.Draw(gameTime);
 
         if (ShotFile != null && --ShotFrames <= 0)
@@ -151,14 +180,9 @@ public class Game1 : Game
 
     void SaveScreenshot(string file)
     {
-        int w = GraphicsDevice.PresentationParameters.BackBufferWidth;
-        int h = GraphicsDevice.PresentationParameters.BackBufferHeight;
-        var data = new Color[w * h];
-        GraphicsDevice.GetBackBufferData(data);
-        using var tex = new Texture2D(GraphicsDevice, w, h);
-        tex.SetData(data);
+        // capture the virtual screen so debug shots are always 800x600
         using var fs = File.Create(file);
-        tex.SaveAsPng(fs, w, h);
+        _virtualScreen.SaveAsPng(fs, _virtualScreen.Width, _virtualScreen.Height);
     }
 
     // ================================================================ helpers

FreedomFighter/OmegaImage.cs

@@ -64,8 +64,10 @@ public class OmegaImage
     }
 
     /// <summary>
-    /// Full Omega draw. X,Y is the top-left of the pattern; rotation (degrees, clockwise)
-    /// pivots around (centerX, centerY) as a fraction of the pattern size.
+    /// Full Omega draw. X,Y is the top-left of the unscaled pattern; rotation and scale
+    /// are applied around the pivot (centerX, centerY), which stays at its unscaled
+    /// position — matching DirectX-era Draw semantics (a half-scaled 64px sprite at X
+    /// with center 0.5 still has its pivot at X+32).
     /// </summary>
     public void Draw(SpriteBatch sb, float x, float y, float rotation = 0,
         float centerX = 0, float centerY = 0, float scaleX = 1, float scaleY = 1,
@@ -73,7 +75,7 @@ public class OmegaImage
     {
         var src = PatternRect(pattern);
         var origin = new Vector2(centerX * TileWidth, centerY * TileHeight);
-        var pos = new Vector2(x + origin.X * scaleX, y + origin.Y * scaleY);
+        var pos = new Vector2(x + origin.X, y + origin.Y);
         var color = new Color(red, green, blue, alpha);
         sb.Draw(Texture, pos, src, color, MathHelper.ToRadians(rotation), origin,
             new Vector2(scaleX, scaleY), SpriteEffects.None, 0);

FreedomFighter/Sprites.cs

@@ -112,8 +112,9 @@ public class SpriteManager
 
     public void Draw(SpriteBatch sb)
     {
-        int n = Items.Count;
-        for (int i = 0; i < n; i++)
+        // Omega drew newest sprites first, so earlier-created sprites appear on top
+        // (e.g. the missile turret gun is spawned before its base and must cover it)
+        for (int i = Items.Count - 1; i >= 0; i--)
             if (!Items[i].IsDead)
                 Items[i].Draw(sb);
     }