use History for handling gamepad & keyboard state

GitOrigin-RevId: 87aa91b212

Jumpy.Shared/JumpyGame.cs

@@ -2,22 +2,27 @@
 using Microsoft.Xna.Framework.Graphics;
 using Microsoft.Xna.Framework.Input;
 
+using System;
 using System.Collections.Generic;
 
 namespace Jumpy {
   public class JumpyGame : Game {
     GraphicsDeviceManager graphics;
 
+    // TODO: use a History<RenderTarget2D> but implement functions that let us re-use the
+    // RenderTargets instead of re-creating them every frame?
     const int numRenderTargets = 1;
     RenderTarget2D[] renderTargets = new RenderTarget2D[numRenderTargets];
     int renderTargetIdx = 0;
 
     SpriteBatch spriteBatch;
     SpriteFont font;
-    KeyboardInput keyboardInput = new KeyboardInput();
     bool fullScreen = false;
     IDisplay display;
 
+    History<KeyboardState> keyboardHistory = new History<KeyboardState>(2);
+    History<GamePadState> gamePadHistory = new History<GamePadState>(2);
+
     FpsCounter fpsCounter = new FpsCounter();
     Player player;
 
@@ -56,21 +61,20 @@ namespace Jumpy {
 
     // Updates the game world.
     protected override void Update(GameTime gameTime) {
-      keyboardInput.Update();
-      GamePadState gamePadState = GamePad.GetState(PlayerIndex.One);
-      List<Keys> keysDown = keyboardInput.NewKeysDown();
+      gamePadHistory.Add(GamePad.GetState(PlayerIndex.One));
+      keyboardHistory.Add(Keyboard.GetState());
 
-      if (keysDown.Contains(Keys.F12)) {
-        fullScreen = !fullScreen;
-        display.SetFullScreen(fullScreen);
+      if (gamePadHistory[0].Buttons.Start == ButtonState.Pressed ||
+          keyboardHistory[0].IsKeyDown(Keys.Escape)) {
+        Exit();
       }
 
-      if (gamePadState.Buttons.Start == ButtonState.Pressed ||
-          keysDown.Contains(Keys.Escape)) {
-        Exit();
+      if (keyboardHistory[0].IsKeyDown(Keys.F12) && keyboardHistory[1].IsKeyUp(Keys.F12)) {
+        fullScreen = !fullScreen;
+        display.SetFullScreen(fullScreen);
       }
 
-      player.Update(gameTime, gamePadState);
+      player.Update(gameTime, gamePadHistory);
 
       base.Update(gameTime);
     }

Jumpy.Shared/Player.cs

@@ -29,7 +29,8 @@ namespace Jumpy {
       this.texture = texture;
     }
 
-    public void Update(GameTime time, GamePadState gamePad) {
+    public void Update(GameTime time, History<GamePadState> gamePadHistory) {
+      GamePadState gamePad = gamePadHistory[0];
       if (gamePad.Buttons.A == ButtonState.Pressed && airState == AirState.Ground) {
         pose = Pose.Jumping;
         airState = AirState.Jumping;