generate Shots on user input & reap them once offscreen

Shared/ShmupScene.cs

@@ -8,7 +8,8 @@ namespace SemiColinGames {
 
     const float DESIRED_ASPECT_RATIO = 1920.0f / 1080.0f;
 
-    private readonly Color backgroundColor = Color.DarkBlue;
+    private readonly Color letterboxColor = Color.DarkSlateBlue;
+    private readonly Color backgroundColor = Color.Black;
 
     private readonly GraphicsDevice graphics;
     private readonly RenderTarget2D sceneTarget;
@@ -35,8 +36,6 @@ namespace SemiColinGames {
 
     public void Draw(bool isRunningSlowly, IWorld iworld, bool paused) {
       ShmupWorld world = (ShmupWorld) iworld;
-      graphics.SetRenderTarget(null);
-      graphics.Clear(Color.Black);
 
       // Draw scene to sceneTarget.
       graphics.SetRenderTarget(sceneTarget);
@@ -64,6 +63,7 @@ namespace SemiColinGames {
 
       // Get ready to draw sceneTarget to screen.
       graphics.SetRenderTarget(null);
+      graphics.Clear(letterboxColor);
 
       // Letterbox the scene if needed.
       float aspectRatio = 1.0f * graphics.Viewport.Width / graphics.Viewport.Height;

Shared/ShmupWorld.cs

@@ -16,26 +16,33 @@ namespace SemiColinGames {
     public class Shot {
       public TextureRef Texture = Textures.Projectile1;
       public Vector2 Position;
-      public Vector2 HalfSize = new Vector2(11, 8);
+      public Vector2 HalfSize = new Vector2(11, 4);
+      public Rectangle Bounds;
       public Vector2 Velocity;
       public Shot(Vector2 position, Vector2 velocity) {
         Position = position;
         Velocity = velocity;
+        Update(0);  // set Bounds
+      }
+
+      public void Update(float modelTime) {
+        Position = Vector2.Add(Position, Vector2.Multiply(Velocity, modelTime));
+        Bounds = new Rectangle(
+            (int) (Position.X - HalfSize.X),
+            (int) (Position.Y - HalfSize.Y),
+            (int) HalfSize.X * 2,
+            (int) HalfSize.Y * 2);
       }
     }
 
-    public readonly Point Size;
+    public readonly Rectangle Bounds;
     public readonly ShmupPlayer Player;
     public readonly ProfilingList<Shot> Shots;
 
     public ShmupWorld() {
-      Size = new Point(1920 / 4, 1080 / 4);
+      Bounds = new Rectangle(0, 0, 1920 / 4, 1080 / 4);
       Player = new ShmupPlayer();
       Shots = new ProfilingList<Shot>(100, "shots");
-      Vector2 velocity = new Vector2(100, 0);
-      Shots.Add(new Shot(new Vector2(96, 1080 / 8), velocity));
-      Shots.Add(new Shot(new Vector2(96 * 2, 1080 / 8), velocity));
-      Shots.Add(new Shot(new Vector2(96 * 4, 1080 / 8), velocity));
     }
 
     ~ShmupWorld() {
@@ -50,19 +57,22 @@ namespace SemiColinGames {
       Vector2 motion = Vector2.Multiply(input[0].Motion, modelTime * Player.Speed);
       Player.Position = Vector2.Add(Player.Position, motion);
       Player.Position.X = Math.Max(Player.Position.X, Player.HalfSize.X);
-      Player.Position.X = Math.Min(Player.Position.X, Size.X - Player.HalfSize.X);
+      Player.Position.X = Math.Min(Player.Position.X, Bounds.Size.X - Player.HalfSize.X);
       Player.Position.Y = Math.Max(Player.Position.Y, Player.HalfSize.Y);
-      Player.Position.Y = Math.Min(Player.Position.Y, Size.Y - Player.HalfSize.Y);
+      Player.Position.Y = Math.Min(Player.Position.Y, Bounds.Size.Y - Player.HalfSize.Y);
 
       foreach (Shot shot in Shots) {
-        shot.Position = Vector2.Add(shot.Position, Vector2.Multiply(shot.Velocity, modelTime));
+        shot.Update(modelTime);
-        shot.Position.X = Math.Max(shot.Position.X, shot.HalfSize.X);
-        shot.Position.X = Math.Min(shot.Position.X, Size.X - shot.HalfSize.X);
-        shot.Position.X = Math.Max(shot.Position.X, shot.HalfSize.X);
-        shot.Position.X = Math.Min(shot.Position.X, Size.X - shot.HalfSize.X);
       }
 
-      // Shots.RemoveAll(shot => shot.Position.X > Size.X);
+      if (input[0].Attack && !input[1].Attack) {
+        Vector2 shotOffset = new Vector2(12, 2);
+        Vector2 shotPosition = Vector2.Add(Player.Position, shotOffset);
+        Shot shot = new Shot(shotPosition, new Vector2(300, 0));
+        Shots.Add(shot);
+      }
+
+      Shots.RemoveAll(shot => !Bounds.Intersects(shot.Bounds));
     }
   }
 }

Shared/SneakGame.cs

@@ -70,7 +70,7 @@ namespace SemiColinGames {
       scene?.Dispose();
       // scene = new SneakScene(GraphicsDevice, ((SneakWorld) world).Camera);
       // scene = new TreeScene(GraphicsDevice);
-      scene = new ShmupScene(GraphicsDevice, ((ShmupWorld) world).Size);
+      scene = new ShmupScene(GraphicsDevice, ((ShmupWorld) world).Bounds.Size);
 
       GC.Collect();
       GC.WaitForPendingFinalizers();