Player now takes damage from spikes.

GitOrigin-RevId: e9096316218f2590aac74ce1055a0829f71bdff8

Shared/Geometry.cs

@@ -83,10 +83,15 @@ namespace SemiColinGames {
   public readonly struct AABB {
     public readonly Vector2 Position;  // centroid
     public readonly Vector2 HalfSize;
+    public readonly Terrain Terrain;
 
-    public AABB(Vector2 position, Vector2 halfSize) {
+    public AABB(Vector2 position, Vector2 halfSize) : this(position, halfSize, Terrain.Empty) {
+    }
+
+    public AABB(Vector2 position, Vector2 halfSize, Terrain terrain) {
       Position = position;
       HalfSize = halfSize;
+      Terrain = terrain;
     }
 
     public float Top {

Shared/Player.cs

@@ -34,12 +34,13 @@ namespace SemiColinGames {
     private const int swordSwingMax = 6;
     private float ySpeed = 0;
     private double jumpTime = 0;
+    private float invincibilityTime = 0;
 
     public Player() {
       Health = MaxHealth;
     }
 
-    public int MaxHealth { get; private set; } = 5;
+    public int MaxHealth { get; private set; } = 3;
 
     public int Health { get; private set; }
 
@@ -56,6 +57,8 @@ namespace SemiColinGames {
         return BoxOffset(position, 0);
       }
 
+      invincibilityTime -= modelTime;
+
       Vector2 movement = HandleInput(modelTime, input);
 
       // Broad test: remove all collision targets nowhere near the player.
@@ -71,11 +74,12 @@ namespace SemiColinGames {
         new Vector2(halfSize.X + Math.Abs(movement.X) + 1, halfSize.Y + Math.Abs(movement.Y) + 1));
       foreach (var box in collisionTargets) {
         if (box.Intersect(largeBox) != null) {
-          Debug.AddRect(box, Color.Green);
+          // Debug.AddRect(box, Color.Green);
           candidates.Add(box);
         }
       }
 
+      bool harmedByCollision = false;
       Point[] movePoints = Line.Rasterize(0, 0, (int) movement.X, (int) movement.Y);
       for (int i = 1; i < movePoints.Length; i++) {
         int dx = movePoints[i].X - movePoints[i - 1].X;
@@ -86,8 +90,12 @@ namespace SemiColinGames {
           bool reject = false;
           foreach (var box in candidates) {
             if (box.Intersect(player) != null) {
+              Debug.AddRect(box, Color.Cyan);
               reject = true;
-              break;
+              if (box.Terrain.IsHarmful) {
+                Debug.AddRect(box, Color.Red);
+                harmedByCollision = true;
+              }
             }
           }
           if (!reject) {
@@ -100,8 +108,12 @@ namespace SemiColinGames {
           bool reject = false;
           foreach (var box in candidates) {
             if (box.Intersect(player) != null) {
+              Debug.AddRect(box, Color.Cyan);
               reject = true;
-              break;
+              if (box.Terrain.IsHarmful) {
+                Debug.AddRect(box, Color.Red);
+                harmedByCollision = true;
+              }
             }
           }
           if (!reject) {
@@ -114,8 +126,12 @@ namespace SemiColinGames {
       AABB groundIntersect = BoxOffset(position, 1);
       foreach (var box in candidates) {
         if (groundIntersect.Intersect(box) != null) {
+          Debug.AddRect(box, Color.Cyan);
           standingOnGround = true;
-          break;
+          if (box.Terrain.IsHarmful) {
+            Debug.AddRect(box, Color.Red);
+            harmedByCollision = true;
+          }
         }
       }
 
@@ -133,6 +149,11 @@ namespace SemiColinGames {
         Debug.AddRect(Box(position), Color.Orange);
       }
 
+      if (harmedByCollision && invincibilityTime <= 0) {
+        Health -= 1;
+        invincibilityTime = 0.6f;
+      }
+
       if (movement.X > 0) {
         Facing = 1;
       } else if (movement.X < 0) {
@@ -242,7 +263,11 @@ namespace SemiColinGames {
       Vector2 spriteCenter = new Vector2(spriteWidth / 2, spriteHeight / 2 + spriteCenterYOffset);
       SpriteEffects effect = Facing == 1 ?
         SpriteEffects.FlipHorizontally : SpriteEffects.None;
-      spriteBatch.Draw(Textures.Player.Get, position.ToVector2(), textureSource, Color.White, 0f,
+      Color color = Color.White;
+      if (invincibilityTime > 0 && invincibilityTime % 0.2f > 0.1f) {
+        color = new Color(0.5f, 0.5f, 0.5f, 0.5f);
+      }
+      spriteBatch.Draw(Textures.Player.Get, position.ToVector2(), textureSource, color, 0f,
         spriteCenter, Vector2.One, effect, 0f);
     }
   }

Shared/SneakGame.cs

@@ -24,7 +24,7 @@ namespace SemiColinGames {
     // 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 = 0;
+    int levelIdx = -1;
 
     Scene scene;
     Player player;
@@ -73,10 +73,10 @@ namespace SemiColinGames {
       framesToSuppress = 2;
       camera = new Camera();
       player = new Player();
+      levelIdx++;
       world = new World(Levels.ALL_LEVELS[levelIdx % Levels.ALL_LEVELS.Length]);
       scene?.Dispose();
       scene = new Scene(GraphicsDevice, camera);
-      levelIdx++;
 
       GC.Collect();
       GC.WaitForPendingFinalizers();
@@ -122,6 +122,10 @@ namespace SemiColinGames {
         player.Update(modelTime, input, world.CollisionTargets);
         linesOfSight.Update(player, world.CollisionTargets);
         camera.Update(player.Position, world.Width);
+        if (player.Health <= 0) {
+          world = new World(Levels.ALL_LEVELS[levelIdx % Levels.ALL_LEVELS.Length]);
+          player = new Player();
+        }
       }
 
       base.Update(gameTime);

Shared/Textures.cs

@@ -5,7 +5,7 @@ using System.Collections.Generic;
 
 namespace SemiColinGames {
 
-  class TextureRef {
+  public class TextureRef {
     private static readonly List<TextureRef> allTextures = new List<TextureRef>();
 
     public static void LoadAll(ContentManager content) {
@@ -28,7 +28,7 @@ namespace SemiColinGames {
     }
   }
 
-  static class Textures {
+  public static class Textures {
 
     public static SpriteFont DebugFont;
     public static SpriteFont BannerFont;

Shared/World.cs

@@ -6,7 +6,7 @@ using System.Linq;
 
 namespace SemiColinGames {
 
-  class Terrain {
+  public class Terrain {
 
     public static Terrain FromSymbol(char symbol) {
       if (mapping.ContainsKey(symbol)) {
@@ -18,6 +18,7 @@ namespace SemiColinGames {
 
     private readonly static Dictionary<char, Terrain> mapping = new Dictionary<char, Terrain>();
 
+    public static Terrain Empty = new Terrain('\0', false, Textures.Grassland, 0, 0);
     public static Terrain Grass = new Terrain('=', true, Textures.Grassland, 3, 0);
     public static Terrain GrassL = new Terrain('<', true, Textures.Grassland, 2, 0);
     public static Terrain GrassR = new Terrain('>', true, Textures.Grassland, 4, 0);
@@ -49,6 +50,7 @@ namespace SemiColinGames {
     public static Terrain Mushroom = new Terrain('t', false, Textures.Grassland, 17, 2);
 
     public bool IsObstacle { get; private set; }
+    public bool IsHarmful { get; private set; } = false;
     public TextureRef Texture { get; private set; }
     public Rectangle TextureSource { get; private set; }
 
@@ -58,6 +60,10 @@ namespace SemiColinGames {
       }
       mapping[symbol] = this;
       IsObstacle = isObstacle;
+      // TODO: don't hard-code just the one spike.
+      if (symbol == '^') {
+        IsHarmful = true;
+      }
       Texture = texture;
       int size = World.TileSize;
       TextureSource = new Rectangle(x * size, y * size, size, size);
@@ -138,7 +144,7 @@ namespace SemiColinGames {
       for (int i = 0; i < tiles.Length; i++) {
         Vector2 center = new Vector2(
           tiles[i].Position.Left + halfSize.X, tiles[i].Position.Top + halfSize.Y);
-        CollisionTargets[i + 1] = new AABB(center, halfSize);
+        CollisionTargets[i + 1] = new AABB(center, halfSize, tiles[i].Terrain);
       }
 
       // Add a final synthetic collisionTarget on the right side of the world.