Add simple NPC.

GitOrigin-RevId: 47cd7abaf80d7ced14d0b4b92390c8c0edddae1c

Shared/Input.cs

@@ -42,7 +42,7 @@ namespace SemiColinGames {
           keyboard.IsKeyDown(Keys.K);
 
       Debug = gamePad.IsButtonDown(Buttons.Back) || keyboard.IsKeyDown(Keys.OemMinus);
-      Pause = gamePad.IsButtonDown(Buttons.Start) || keyboard.IsKeyDown(Keys.Pause);
+      Pause = gamePad.IsButtonDown(Buttons.Start) || keyboard.IsKeyDown(Keys.P);
 
       // 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.

Shared/NPC.cs

@@ -0,0 +1,46 @@
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+using System;
+using System.Collections.Generic;
+
+namespace SemiColinGames {
+  class NPC {
+    private Point position;
+
+    private const int spriteWidth = 96;
+    private const int spriteHeight = 81;
+    private const int spriteCenterYOffset = 3;
+
+    public NPC(Point position) {
+      this.position = position;
+    }
+
+    public int Facing { get; private set; } = 1;
+
+    public void Update(float modelTime) {
+      if (Facing == 1 && position.X > 16 * 39) {
+        Facing = -1;
+      }
+      if (Facing == -1 && position.X < 16 * 24) {
+        Facing = 1;
+      }
+      position.X += (int) (120 * Facing * modelTime);
+    }
+
+    private int SpriteIndex() {
+      int frameNum = (int) Clock.ModelTime.TotalMilliseconds / 125 % 4;
+      return 35 + frameNum;
+    }
+
+    public void Draw(SpriteBatch spriteBatch) {
+      int index = SpriteIndex();
+      Rectangle textureSource = new Rectangle(index * spriteWidth, 0, spriteWidth, spriteHeight);
+      Vector2 spriteCenter = new Vector2(spriteWidth / 2, spriteHeight / 2 + spriteCenterYOffset);
+      SpriteEffects effect = Facing == 1 ?
+        SpriteEffects.None : SpriteEffects.FlipHorizontally;
+      Color color = Color.White;
+      spriteBatch.Draw(Textures.Executioner.Get, position.ToVector2(), textureSource, color, 0f,
+        spriteCenter, Vector2.One, effect, 0f);
+    }
+  }
+}

Shared/Player.cs

@@ -263,7 +263,7 @@ namespace SemiColinGames {
       Rectangle textureSource = new Rectangle(index * spriteWidth, 0, spriteWidth, spriteHeight);
       Vector2 spriteCenter = new Vector2(spriteWidth / 2, spriteHeight / 2 + spriteCenterYOffset);
       SpriteEffects effect = Facing == 1 ?
-        SpriteEffects.FlipHorizontally : SpriteEffects.None;
+        SpriteEffects.None : SpriteEffects.FlipHorizontally;
       Color color = Color.White;
       if (invincibilityTime > 0 && invincibilityTime % 0.2f > 0.1f) {
         color = new Color(0.5f, 0.5f, 0.5f, 0.5f);

Shared/Shared.projitems

@@ -11,6 +11,7 @@
   <ItemGroup>
     <Compile Include="$(MSBuildThisFileDirectory)Camera.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)ExtensionMethods.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)NPC.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SoundEffects.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Text.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Textures.cs" />

Shared/SneakGame.cs

@@ -121,6 +121,7 @@ namespace SemiColinGames {
         float modelTime = (float) gameTime.ElapsedGameTime.TotalSeconds;
         Clock.AddModelTime(modelTime);
         player.Update(modelTime, input, world.CollisionTargets);
+        world.Update(modelTime);
         linesOfSight.Update(player, world.CollisionTargets);
         camera.Update(player.Position, world.Width);
         if (player.Health <= 0) {

Shared/Textures.cs

@@ -34,6 +34,7 @@ namespace SemiColinGames {
     public static SpriteFont BannerFont;
 
     public static TextureRef Player = new TextureRef("sprites/ccg/ninja_female");
+    public static TextureRef Executioner = new TextureRef("sprites/ccg/executioner_female");
     public static TextureRef Heart = new TextureRef("sprites/semicolin/heart");
 
     // Backgrounds are indexed by draw order; the first element should be drawn furthest back.

Shared/World.cs

@@ -91,6 +91,8 @@ namespace SemiColinGames {
     readonly Tile[] tiles;
     readonly Tile[] decorations;
 
+    readonly NPC[] npcs = new NPC[1];
+
     // Size of World in terms of tile grid.
     private readonly int tileWidth;
     private readonly int tileHeight;
@@ -105,6 +107,7 @@ namespace SemiColinGames {
     }
 
     public World(string levelSpecification) {
+      npcs[0] = new NPC(new Point(16 * 38, 16 * 12));
       var tilesList = new List<Tile>();
       var decorationsList = new List<Tile>();
       string[] worldDesc = levelSpecification.Substring(1).Split('\n');
@@ -152,10 +155,19 @@ namespace SemiColinGames {
           new Vector2(Width + 1, 0), new Vector2(1, float.MaxValue));
     }
 
+    public void Update(float modelTime) {
+      foreach (NPC npc in npcs) {
+        npc.Update(modelTime);
+      }
+    }
+
     public void DrawBackground(SpriteBatch spriteBatch) {
       foreach (Tile t in decorations) {
         t.Draw(spriteBatch);
       }
+      foreach (NPC npc in npcs) {
+        npc.Draw(spriteBatch);
+      }
     }
 
     public void DrawForeground(SpriteBatch spriteBatch) {