move LinesOfSight into World

Shared/Camera.cs

@@ -4,7 +4,7 @@ using System;
 // Good background reading, eventually:
 // https://gamasutra.com/blogs/ItayKeren/20150511/243083/Scroll_Back_The_Theory_and_Practice_of_Cameras_in_SideScrollers.php
 namespace SemiColinGames {
-  class Camera {
+  public class Camera {
     // Screen size in pixels is 1920x1080 divided by 4.
     private Rectangle bbox = new Rectangle(0, 0, 480, 270);
     public int Width { get => bbox.Width; }

Shared/LinesOfSight.cs

@@ -3,7 +3,7 @@ using Microsoft.Xna.Framework.Graphics;
 using System;
 
 namespace SemiColinGames {
-  class LinesOfSight : IDisposable {
+  public sealed class LinesOfSight : IDisposable {
 
     const int NUM_EDGE_VERTICES = 60;
 

Shared/Scene.cs

@@ -4,7 +4,7 @@ using Microsoft.Xna.Framework.Graphics;
 using System;
 
 namespace SemiColinGames {
-  class Scene : IDisposable {
+  public sealed class Scene : IDisposable {
     const float DESIRED_ASPECT_RATIO = 1920.0f / 1080.0f;
 
     Color backgroundColor = Color.CornflowerBlue;
@@ -56,7 +56,7 @@ namespace SemiColinGames {
       GC.SuppressFinalize(this);
     }
 
-    public void Draw(bool isRunningSlowly, World world, LinesOfSight linesOfSight, bool paused) {
+    public void Draw(bool isRunningSlowly, World world, bool paused) {
       graphics.SetRenderTarget(null);
       graphics.Clear(backgroundColor);
 
@@ -87,7 +87,7 @@ namespace SemiColinGames {
       // Draw lines of sight.
       basicEffect.Projection = camera.Projection;
       if (Debug.Enabled) {
-        linesOfSight.Draw(graphics, basicEffect);
+        world.LinesOfSight.Draw(graphics, basicEffect);
       }
 
       // Set up transformation matrix for drawing world objects.

Shared/SneakGame.cs

@@ -23,7 +23,6 @@ namespace SemiColinGames {
 
     Scene scene;
     World world;
-    LinesOfSight linesOfSight;
     Camera camera = new Camera();
 
     public SneakGame() {
@@ -61,14 +60,13 @@ namespace SemiColinGames {
       SoundEffects.Load(Content);
       Textures.Load(Content);
       Sprites.Load(Content);
-      // TODO: move this into World.
-      linesOfSight = new LinesOfSight(GraphicsDevice);
       LoadLevel();
     }
 
     private void LoadLevel() {
       camera = new Camera();
-      world = new World(Content.LoadString("levels/demo.json"));
+      world?.Dispose();
+      world = new World(GraphicsDevice, Content.LoadString("levels/demo.json"));
       scene?.Dispose();
       scene = new Scene(GraphicsDevice, camera);
 
@@ -114,7 +112,6 @@ namespace SemiColinGames {
         float modelTime = (float) gameTime.ElapsedGameTime.TotalSeconds;
         Clock.AddModelTime(modelTime);
         world.Update(modelTime, input);
-        linesOfSight.Update(world.Player, world.CollisionTargets);
         camera.Update(world.Player.Position, world.Width);
       }
 
@@ -137,7 +134,7 @@ namespace SemiColinGames {
 
       Debug.SetFpsText(fpsText);
 
-      scene.Draw(gameTime.IsRunningSlowly, world, linesOfSight, paused);
+      scene.Draw(gameTime.IsRunningSlowly, world, paused);
 
       base.Draw(gameTime);
       drawTimer.Stop();

Shared/World.cs

@@ -6,7 +6,7 @@ using System.Collections.Generic;
 
 namespace SemiColinGames {
 
-  public class World {
+  public sealed class World : IDisposable {
 
     public const int TileSize = 16;
 
@@ -21,6 +21,7 @@ namespace SemiColinGames {
 
     public Player Player { get; private set; }
     public AABB[] CollisionTargets { get; }
+    public LinesOfSight LinesOfSight { get; private set; }
 
     // Size of World in pixels.
     public int Width {
@@ -31,7 +32,9 @@ namespace SemiColinGames {
       get { return gridHeight * TileSize; }
     }
 
-    public World(string json) {
+    public World(GraphicsDevice graphics, string json) {
+      LinesOfSight = new LinesOfSight(graphics);
+
       JObject root = JObject.Parse(json);
 
       List<Tile> hazardTiles = new List<Tile>();
@@ -86,6 +89,15 @@ namespace SemiColinGames {
           new Vector2(Width + 1, 0), new Vector2(1, float.MaxValue));
     }
 
+    ~World() {
+      Dispose();
+    }
+
+    public void Dispose() {
+      LinesOfSight.Dispose();
+      GC.SuppressFinalize(this);
+    }
+
     private List<Tile> ParseLayer(JToken layer) {
       string layerName = layer.SelectToken("name").Value<string>();
 
@@ -149,6 +161,7 @@ namespace SemiColinGames {
       if (Player.Health <= 0) {
         Reset();
       }
+      LinesOfSight.Update(Player, CollisionTargets);
     }
 
     // Draws everything that's behind the player, from back to front.
@@ -174,8 +187,8 @@ namespace SemiColinGames {
       return t1.Position.X.CompareTo(t2.Position.X);
     }
 
-    private TextureRef texture;
+    private readonly TextureRef texture;
-    private Rectangle textureSource;
+    private readonly Rectangle textureSource;
 
     public Tile(TextureRef texture, Rectangle textureSource, Rectangle position, bool isHazard) {
       Position = position;