fix bug

src/level.rs

@@ -74,7 +74,7 @@ impl Level {
                 break;
             }
         }
-        for y_r in y..=min(y + 2, LEVEL_WIDTH - 1) {
+        for y_r in y..=min(y + 2, LEVEL_HEIGHT - 1) {
             self.discovered[x][y_r] = true;
             if self.structure[x][y_r] == LevelElement::Wall {
                 break;