add floor transition: Space on exit descends to next depth

2 files changed, 32 insertions, 5 deletions

diff --git a/src/game.rs b/src/game.rs
index 992023e..1c13dd4 100644
--- a/src/game.rs
+++ b/src/game.rs
@@ -1585,10 +1585,32 @@ impl Game {
 
     // ---- misc -------------------------------------------------------------
 
-    pub fn check_win(&self) -> bool {
+    /// True when the player is standing on the exit staircase.
+    pub fn on_exit(&self) -> bool {
         self.maze.is_exit(self.player.x, self.player.y)
     }
 
+    /// Descend to the next dungeon depth.  Generates a new maze, places the
+    /// player in a starting room facing east.  All stats, inventory, and
+    /// weapon carry over.
+    pub fn descend(&mut self) {
+        self.depth += 1;
+        let mut rng = rand::rng();
+        let (maze, (start_x, start_y)) = Maze::generate(self.depth, &mut rng);
+        self.maze = maze;
+        self.player = Player::new(start_x, start_y, 0.0); // facing east
+        self.wall_texture = crate::texture::generate_wall_texture(&mut rng);
+        self.floor_texture = crate::texture::generate_floor_texture(&mut rng);
+        self.exit_texture = crate::texture::generate_exit_texture(&mut rng);
+        self.state = GameState::WaitingForInput;
+        self.moving = false;
+        self.turning = false;
+        self.attacking = false;
+        self.enemy_moves.clear();
+        self.acted_this_turn.clear();
+        self.set_message(&format!("You descend to depth {}...", self.depth));
+    }
+
     /// Whole heartbeats elapsed (displayed in HUD).
     pub fn heartbeats(&self) -> usize {
         self.heartbeat_count as usize
diff --git a/src/main.rs b/src/main.rs
index e82d939..694773d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -110,7 +110,11 @@ fn main() {
             } else if cur_e && !prev_e {
                 game.turn_right();
             } else if cur_space && !prev_space {
-                game.attack();
+                if game.on_exit() {
+                    game.descend();
+                } else {
+                    game.attack();
+                }
             } else if cur_z && !prev_z {
                 game.use_item();
             } else if cur_x && !prev_x {
@@ -156,9 +160,10 @@ fn main() {
             }
         }
 
-        // ---- win check (placeholder — becomes staircase in Phase 1) ----
-        if game.check_win() {
-            std::process::exit(0);
+        // ---- descend prompt ----
+        // Show the prompt persistently while the player stands on the exit.
+        if game.on_exit() && game.state == GameState::WaitingForInput {
+            game.set_message("Press Space to descend...");
         }
 
         // ---- render ----