let Scene decide when to draw itself & when to play music

GitOrigin-RevId: 0eac6682b0

Shared/Scene.cs

@@ -1,4 +1,5 @@
 using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Audio;
 using Microsoft.Xna.Framework.Graphics;
 using System;
 
@@ -6,8 +7,6 @@ namespace SemiColinGames {
   class Scene : IDisposable {
     const float DESIRED_ASPECT_RATIO = 1920.0f / 1080.0f;
 
-    public bool Enabled = false;
-
     Color backgroundColor = Color.CornflowerBlue;
 
     readonly GraphicsDevice graphics;
@@ -16,6 +15,12 @@ namespace SemiColinGames {
     readonly RenderTarget2D sceneTarget;
     readonly BasicEffect basicEffect;
     readonly SpriteBatch spriteBatch;
+    readonly SoundEffectInstance music;
+
+    // Draw() needs to be called without IsRunningSlowly this many times before we actually
+    // attempt to draw the scene. This is a workaround for the fact that otherwise the first few
+    // frames can be really slow to draw.
+    int framesToSuppress = 2;
 
     public Scene(GraphicsDevice graphics, Camera camera) {
       this.graphics = graphics;
@@ -32,6 +37,10 @@ namespace SemiColinGames {
       };
 
       spriteBatch = new SpriteBatch(graphics);
+
+      music = SoundEffects.IntroMusic.CreateInstance();
+      music.IsLooped = true;
+      music.Volume = 0.1f;
     }
 
     ~Scene() {
@@ -39,16 +48,22 @@ namespace SemiColinGames {
     }
 
     public void Dispose() {
+      music.Stop();
+      music.Dispose();
       sceneTarget.Dispose();
       basicEffect.Dispose();
       spriteBatch.Dispose();
       GC.SuppressFinalize(this);
     }
 
-    public void Draw(World world, Player player, LinesOfSight linesOfSight, bool paused) {
+    public void Draw(
+        bool isRunningSlowly, World world, Player player, LinesOfSight linesOfSight, bool paused) {
       graphics.SetRenderTarget(null);
       graphics.Clear(backgroundColor);
-      if (!Enabled) {
+
+      // Enable the scene after we've gotten enough non-slow frames.
+      if (framesToSuppress > 0 && !isRunningSlowly) {
+        framesToSuppress--;
         return;
       }
 
@@ -110,6 +125,9 @@ namespace SemiColinGames {
         string text = "Paused";
         Vector2 position = Textures.BannerFont.CenteredOn(text, camera.HalfSize);
         Text.DrawOutlined(spriteBatch, Textures.BannerFont, text, position, Color.White);
+        music.Pause();
+      } else {
+        music.Play();
       }
       spriteBatch.End();
 

Shared/SneakGame.cs

@@ -1,5 +1,4 @@
 using Microsoft.Xna.Framework;
-using Microsoft.Xna.Framework.Audio;
 using Microsoft.Xna.Framework.Graphics;
 using Microsoft.Xna.Framework.Input;
 using MonoGame.Framework.Utilities;
@@ -21,10 +20,6 @@ namespace SemiColinGames {
     readonly FpsCounter fpsCounter = new FpsCounter();
     readonly Timer updateTimer = new Timer(TARGET_FRAME_TIME / 2.0, "UpdateTimer");
     readonly Timer drawTimer = new Timer(TARGET_FRAME_TIME / 2.0, "DrawTimer");
-    // Draw() needs to be called without IsRunningSlowly this many times before we actually
-    // attempt to draw the scene. This is a workaround for the fact that otherwise the first few
-    // frames can be really slow to draw.
-    int framesToSuppress;
     int levelIdx = -1;
 
     Scene scene;
@@ -68,15 +63,10 @@ namespace SemiColinGames {
       SoundEffects.Load(Content);
       Textures.Load(Content);
       linesOfSight = new LinesOfSight(GraphicsDevice);
-      SoundEffectInstance music = SoundEffects.IntroMusic.CreateInstance();
-      music.IsLooped = true;
-      music.Volume = 0.1f;
-      music.Play();
       LoadLevel();
     }
 
     private void LoadLevel() {
-      framesToSuppress = 2;
       camera = new Camera();
       player = new Player();
       levelIdx++;
@@ -143,15 +133,6 @@ namespace SemiColinGames {
     protected override void Draw(GameTime gameTime) {
       drawTimer.Start();
 
-      // Enable the scene after we've gotten enough non-slow frames.
-      // TODO: the Scene should handle this, really.
-      if (framesToSuppress > 0 && !gameTime.IsRunningSlowly) {
-        framesToSuppress--;
-        if (framesToSuppress == 0) {
-          scene.Enabled = true;
-        }
-      }
-
       // We need to update the FPS counter in Draw() since Update() might get called more
       // frequently, especially when gameTime.IsRunningSlowly.
       fpsCounter.Update();
@@ -163,7 +144,7 @@ namespace SemiColinGames {
 
       Debug.SetFpsText(fpsText);
 
-      scene.Draw(world, player, linesOfSight, paused);
+      scene.Draw(gameTime.IsRunningSlowly, world, player, linesOfSight, paused);
 
       base.Draw(gameTime);
       drawTimer.Stop();