Cleaner implementation of tile switching that detects if the switch is

allowed

src/level.nim

@@ -1,5 +1,4 @@
 import
-  sequtils,
   strformat,
   strutils,
   sugar,
@@ -45,19 +44,17 @@ proc init*(level: Level, number: Positive) =
         for ch in line:
           tilesByName[ch]
   level.passable = @[AirTile, PlayerTile, SecretTileOpen, Button0TileUnpressed, Button0TilePressed, Door0TileOpen]
-  level.onlyReachableColliders = true
   level.initCollider()
 
 proc switchSecretTiles*(level: Level) =
-  level.map.apply((row: var seq[int]) => row.apply(tile => (
+  for row in level.map.mitems:
+    for tile in row.mitems:
       case tile
       of SecretTileClosed:
-        SecretTileOpen
+        tile = SecretTileOpen
       of SecretTileOpen:
-        SecretTileClosed
-      else:
-        tile
-    )))
+        tile = SecretTileClosed
+      else: discard
   level.initCollider
 
 proc newLevel*(number: Positive): Level =

src/main.nim

@@ -60,3 +60,5 @@ method update*(scene: MainScene, elapsed: float) =
     scene.player.left(elapsed)
   if ScanCodeSpace.pressed:
     scene.level.switchSecretTiles
+    if scene.level.collider.collide(scene.player.collider):
+      scene.level.switchSecretTiles