calculate NPC physics-box correctly

Shared/NPC.cs

@@ -28,7 +28,7 @@ namespace SemiColinGames {
       int desiredX = npc.Position.X + (int) (moveSpeed * npc.Facing * modelTime);
       int testPoint = desiredX + 12 * npc.Facing;
       // TODO: define the box modularly & correctly.
-      AABB npcBox = new AABB(new Vector2(testPoint, npc.Position.Y), new Vector2(1, 33));
+      AABB npcBox = new AABB(new Vector2(testPoint, npc.Position.Y), new Vector2(1, 25));
       Debug.AddRect(npcBox, Color.Cyan);
       bool foundBox = false;
       foreach (AABB box in world.CollisionTargets) {
@@ -49,13 +49,16 @@ namespace SemiColinGames {
   public class NPC {
     private const int spriteWidth = 96;
     private const int spriteHeight = 81;
-    private const int spriteCenterYOffset = 2;
+    private const int spriteCenterYOffset = 10;
     private readonly Vector2 eyeOffset = new Vector2(4, -3);
 
     private readonly FSM<NPC> fsm;
+    private AABB physicsBox;
+    private readonly Vector2 halfSize = new Vector2(12, 24);
 
     public NPC(Point position, int facing) {
       Position = position;
+      physicsBox = new AABB(position.ToVector2(), halfSize);
       Facing = facing;
       fsm = new FSM<NPC>(new Dictionary<string, IState<NPC>> {
         { "idle", new IdleState() },
@@ -93,6 +96,8 @@ namespace SemiColinGames {
 
     public void Update(float modelTime, World world) {
       fsm.Update(this, modelTime, world);
+      physicsBox = new AABB(Position.ToVector2(), halfSize);
+      Debug.AddRect(physicsBox, Color.White);
     }
 
     public void Draw(SpriteBatch spriteBatch) {