Add Input class to group gamepad & keyboard inputs together.

For motion directions (up/down & left/right), have them cancel each other out
if the player attempts to go in opposite directions at once.

Refactor Player & SneakGame to use the new Input class & remove direct access
to Keyboard & GamePad.

GitOrigin-RevId: 80fbed8874

Shared/Input.cs

@@ -0,0 +1,51 @@
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Input;
+
+namespace SemiColinGames {
+  struct Input {
+    public bool Jump;
+    public bool Attack;
+    public Vector2 Motion;
+
+    public bool Exit;
+    public bool FullScreen;
+    public bool Debug;
+
+    public Input(GamePadState gamePad, KeyboardState keyboard) {
+      // First we process normal buttons.
+      Jump = gamePad.IsButtonDown(Buttons.A) || keyboard.IsKeyDown(Keys.J);
+      Attack = gamePad.IsButtonDown(Buttons.X) || keyboard.IsKeyDown(Keys.K);
+
+      // Then special debugging sorts of buttons.
+      Exit = gamePad.IsButtonDown(Buttons.Start) || keyboard.IsKeyDown(Keys.Escape);
+      FullScreen = gamePad.IsButtonDown(Buttons.Back) || keyboard.IsKeyDown(Keys.F12) ||
+          keyboard.IsKeyDown(Keys.OemPlus);
+      Debug = gamePad.IsButtonDown(Buttons.LeftShoulder) || keyboard.IsKeyDown(Keys.OemMinus);
+
+      // Then potential motion directions. If the player attempts to input opposite directions at
+      // once (up & down or left & right), those inputs cancel out, resulting in no motion.
+      Motion = new Vector2();
+      Vector2 leftStick = gamePad.ThumbSticks.Left;
+      bool left = leftStick.X < -0.5 || gamePad.IsButtonDown(Buttons.DPadLeft) ||
+          keyboard.IsKeyDown(Keys.A);
+      bool right = leftStick.X > 0.5 || gamePad.IsButtonDown(Buttons.DPadRight) ||
+          keyboard.IsKeyDown(Keys.D);
+      bool up = leftStick.Y > 0.5 || gamePad.IsButtonDown(Buttons.DPadUp) ||
+          keyboard.IsKeyDown(Keys.W);
+      bool down = leftStick.Y < -0.5 || gamePad.IsButtonDown(Buttons.DPadDown) ||
+          keyboard.IsKeyDown(Keys.S);
+      if (left && !right) {
+        Motion.X = -1;
+      }
+      if (right && !left) {
+        Motion.X = 1;
+      }
+      if (up && !down) {
+        Motion.Y = 1;
+      }
+      if (down && !up) {
+        Motion.Y = -1;
+      }
+    }
+  }
+}

Shared/Player.cs

@@ -35,12 +35,10 @@ namespace SemiColinGames {
       return new Rectangle(position.X - spriteWidth, position.Y - 7, spriteWidth * 2, 26);
     }
 
-    public void Update(
-        GameTime time, History<GamePadState> gamePad, History<KeyboardState> keyboard, 
-        List<Rectangle> collisionTargets) {
+    public void Update(GameTime time, History<Input> input, List<Rectangle> collisionTargets) {
       Point oldPosition = position;
       AirState oldAirState = airState;
-      UpdateFromInput(time, gamePad, keyboard);
+      HandleInput(time, input);
 
       Rectangle oldBbox = Bbox(oldPosition);
       Rectangle playerBbox = Bbox(position);
@@ -97,11 +95,8 @@ namespace SemiColinGames {
       }
     }
     
-    void UpdateFromInput(
-      GameTime time, History<GamePadState> gamePad, History<KeyboardState> keyboard) {
-      if ((gamePad[0].IsButtonDown(Buttons.A) && gamePad[1].IsButtonUp(Buttons.A) ||
-          keyboard[0].IsKeyDown(Keys.J) && keyboard[1].IsKeyUp(Keys.J)) &&
-          airState == AirState.Ground) {
+    void HandleInput(GameTime time, History<Input> input) {
+      if (input[0].Jump && !input[1].Jump && airState == AirState.Ground) {
         pose = Pose.Jumping;
         airState = AirState.Jumping;
         jumpTime = 0.5;
@@ -109,30 +104,23 @@ namespace SemiColinGames {
         return;
       }
 
-      if ((gamePad[0].IsButtonDown(Buttons.X) && gamePad[1].IsButtonUp(Buttons.X) ||
-          keyboard[0].IsKeyDown(Keys.K) && keyboard[1].IsKeyUp(Keys.K))
-          && swordSwingTime <= 0) {
+      if (input[0].Attack && !input[1].Attack && swordSwingTime <= 0) {
         pose = Pose.SwordSwing;
         swordSwingTime = 0.3;
         return;
       }
 
-      Vector2 leftStick = gamePad[0].ThumbSticks.Left;
-      if (gamePad[0].IsButtonDown(Buttons.DPadLeft) || leftStick.X < -0.5 ||
-          keyboard[0].IsKeyDown(Keys.A)) {
+      if (input[0].Motion.X < 0) {
         facing = Facing.Left;
         pose = Pose.Walking;
         position.X -= (int) (moveSpeed * time.ElapsedGameTime.TotalSeconds);
-      } else if (gamePad[0].IsButtonDown(Buttons.DPadRight) || leftStick.X > 0.5 ||
-          keyboard[0].IsKeyDown(Keys.D)) {
+      } else if (input[0].Motion.X > 0) {
         facing = Facing.Right;
         pose = Pose.Walking;
         position.X += (int) (moveSpeed * time.ElapsedGameTime.TotalSeconds);
-      } else if (gamePad[0].IsButtonDown(Buttons.DPadDown) || leftStick.Y < -0.5 ||
-          keyboard[0].IsKeyDown(Keys.S)) {
+      } else if (input[0].Motion.Y < 0) {
         pose = Pose.Crouching;
-      } else if (gamePad[0].IsButtonDown(Buttons.DPadUp) || leftStick.Y > 0.5 ||
-          keyboard[0].IsKeyDown(Keys.W)) {
+      } else if (input[0].Motion.Y > 0) {
         pose = Pose.Stretching;
       } else {
         pose = Pose.Standing;

Shared/Shared.projitems

@@ -10,6 +10,7 @@
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="$(MSBuildThisFileDirectory)Camera.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Input.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Debug.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)FpsCounter.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)History.cs" />

Shared/SneakGame.cs

@@ -17,6 +17,7 @@ namespace SemiColinGames {
 
     History<KeyboardState> keyboard = new History<KeyboardState>(2);
     History<GamePadState> gamePad = new History<GamePadState>(2);
+    History<Input> input = new History<Input>(2);
 
     FpsCounter fpsCounter = new FpsCounter();
     Texture2D grasslandBg1;
@@ -66,27 +67,23 @@ namespace SemiColinGames {
     protected override void Update(GameTime gameTime) {
       Debug.Clear();
 
-      gamePad.Add(GamePad.GetState(PlayerIndex.One));
-      keyboard.Add(Keyboard.GetState());
+      input.Add(new Input(GamePad.GetState(PlayerIndex.One), Keyboard.GetState()));
 
-      if (keyboard[0].IsKeyDown(Keys.Escape) || gamePad[0].IsButtonDown(Buttons.Start)) {
+      if (input[0].Exit) {
         Exit();
       }
 
-      if (keyboard[0].IsKeyDown(Keys.F12) && keyboard[1].IsKeyUp(Keys.F12) ||
-          keyboard[0].IsKeyDown(Keys.OemPlus) && keyboard[1].IsKeyUp(Keys.OemPlus) ||
-          gamePad[0].IsButtonDown(Buttons.Back) && gamePad[1].IsButtonUp(Buttons.Back)) {
+      if (input[0].FullScreen && !input[1].FullScreen) {
         fullScreen = !fullScreen;
         display.SetFullScreen(fullScreen);
       }
 
-      if (gamePad[0].IsButtonDown(Buttons.LeftShoulder) && gamePad[1].IsButtonUp(Buttons.LeftShoulder) ||
-          keyboard[0].IsKeyDown(Keys.OemMinus) && keyboard[1].IsKeyUp(Keys.OemMinus)) {
+      if (input[0].Debug && !input[1].Debug) {
         Debug.Enabled = !Debug.Enabled;
       }
 
       List<Rectangle> collisionTargets = world.CollisionTargets();
-      player.Update(gameTime, gamePad, keyboard, collisionTargets);
+      player.Update(gameTime, input, collisionTargets);
 
       camera.Update(gameTime, player.Position);