add basic shmup game

Shared/Shared.projitems

@@ -17,6 +17,8 @@
     <Compile Include="$(MSBuildThisFileDirectory)MusicPlayer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)NPC.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)ProfilingList.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)ShmupScene.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)ShmupWorld.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SneakScene.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SneakWorld.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SoundEffects.cs" />

Shared/ShmupScene.cs

@@ -0,0 +1,76 @@
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+using System;
+using System.Collections.Generic;
+
+namespace SemiColinGames {
+  public sealed class ShmupScene : IScene {
+
+    const float DESIRED_ASPECT_RATIO = 1920.0f / 1080.0f;
+
+    private readonly Color backgroundColor = Color.DarkBlue;
+
+    private readonly GraphicsDevice graphics;
+    private readonly RenderTarget2D sceneTarget;
+    private readonly SpriteBatch spriteBatch;
+
+    public ShmupScene(GraphicsDevice graphics) {
+      this.graphics = graphics;
+
+      sceneTarget = new RenderTarget2D(
+        graphics, 1920 / 4, 1080 / 4, false /* mipmap */,
+        graphics.PresentationParameters.BackBufferFormat, DepthFormat.Depth24);
+      spriteBatch = new SpriteBatch(graphics);
+    }
+
+    ~ShmupScene() {
+      Dispose();
+    }
+
+    public void Dispose() {
+      GC.SuppressFinalize(this);
+    }
+
+    public void Draw(bool isRunningSlowly, IWorld iworld, bool paused) {
+      ShmupWorld world = (ShmupWorld) iworld;
+      graphics.SetRenderTarget(null);
+      graphics.Clear(backgroundColor);
+
+      // Draw scene to sceneTarget.
+      graphics.SetRenderTarget(sceneTarget);
+      graphics.Clear(backgroundColor);
+
+      spriteBatch.Begin(SpriteSortMode.Deferred, BlendState.AlphaBlend,
+          SamplerState.PointClamp, DepthStencilState.Default,
+          RasterizerState.CullNone);
+      spriteBatch.Draw(Textures.SilverBlue1.Get, Vector2.Floor(world.Player.Position), Color.White);
+      spriteBatch.End();
+
+      // Get ready to draw sceneTarget to screen.
+      graphics.SetRenderTarget(null);
+
+
+      // Letterbox the scene if needed.
+      float aspectRatio = 1.0f * graphics.Viewport.Width / graphics.Viewport.Height;
+      Rectangle drawRect;
+      if (aspectRatio > DESIRED_ASPECT_RATIO) {
+        // Need to letterbox the sides.
+        int desiredWidth = (int) (graphics.Viewport.Height * DESIRED_ASPECT_RATIO);
+        int padding = (graphics.Viewport.Width - desiredWidth) / 2;
+        drawRect = new Rectangle(padding, 0, desiredWidth, graphics.Viewport.Height);
+      } else {
+        // Need to letterbox the top / bottom.
+        int desiredHeight = (int) (graphics.Viewport.Width / DESIRED_ASPECT_RATIO);
+        int padding = (graphics.Viewport.Height - desiredHeight) / 2;
+        drawRect = new Rectangle(0, padding, graphics.Viewport.Width, desiredHeight);
+      }
+
+      // Actually draw to screen.
+      spriteBatch.Begin(SpriteSortMode.Deferred, BlendState.AlphaBlend,
+          SamplerState.PointClamp, DepthStencilState.Default,
+          RasterizerState.CullNone);
+      spriteBatch.Draw(sceneTarget, drawRect, Color.White);
+      spriteBatch.End();
+    }
+  }
+}

Shared/ShmupWorld.cs

@@ -0,0 +1,33 @@
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+using System;
+using System.Collections.Generic;
+
+namespace SemiColinGames {
+  public sealed class ShmupWorld : IWorld {
+    public struct ShmupPlayer {
+      // Center of player sprite.
+      public Vector2 Position;
+    }
+
+    public ShmupPlayer Player;
+
+    public ShmupWorld() {
+      Player = new ShmupPlayer();
+    }
+
+    ~ShmupWorld() {
+      Dispose();
+    }
+
+    public void Dispose() {
+      GC.SuppressFinalize(this);
+    }
+
+    public void Update(float modelTime, History<Input> input) {
+      float speed = 150f;
+      Vector2 motion = Vector2.Multiply(input[0].Motion, modelTime * speed);
+      Player.Position = Vector2.Add(Player.Position, motion);
+    }
+  }
+}

Shared/SneakGame.cs

@@ -64,11 +64,13 @@ namespace SemiColinGames {
 
     private void LoadLevel() {
       world?.Dispose();
-      world = new SneakWorld(GraphicsDevice, Content.LoadString("levels/demo.json"));
+      // world = new SneakWorld(GraphicsDevice, Content.LoadString("levels/demo.json"));
       // world = new TreeWorld();
+      world = new ShmupWorld();
       scene?.Dispose();
-      scene = new SneakScene(GraphicsDevice, ((SneakWorld) world).Camera);
+      // scene = new SneakScene(GraphicsDevice, ((SneakWorld) world).Camera);
       // scene = new TreeScene(GraphicsDevice);
+      scene = new ShmupScene(GraphicsDevice);
 
       GC.Collect();
       GC.WaitForPendingFinalizers();

Shared/Textures.cs

@@ -40,6 +40,9 @@ namespace SemiColinGames {
     // UI sprites.
     public static TextureRef Heart = new TextureRef("sprites/semicolin/heart");
 
+    // Ship sprites.
+    public static TextureRef SilverBlue1 = new TextureRef("sprites/dylestorm/SilverBlue-1");
+
     // Backgrounds are indexed by draw order; the first element should be drawn furthest back.
     public static TextureRef[] Backgrounds = new TextureRef[] {
       new TextureRef("backgrounds/szadiart/pf4/background1_day"),