From ba26fa4eb37e78b6dc47cb7f4e96733375e022fc Mon Sep 17 00:00:00 2001
From: alf9310 <alf9310@rit.edu>
Date: Sun, 9 Nov 2025 17:12:15 -0500
Subject: dungeon_generation: added stair generation and fixed room center vs
 rabdom point recursion

---
 dungeon/src/bsp.rs         | 41 ++++++++++++++++++++++++++++++-----------
 dungeon/tests/bsp_tests.rs | 14 ++++++++++++++
 2 files changed, 44 insertions(+), 11 deletions(-)

(limited to 'dungeon')

diff --git a/dungeon/src/bsp.rs b/dungeon/src/bsp.rs
index f996405..9b288a2 100644
--- a/dungeon/src/bsp.rs
+++ b/dungeon/src/bsp.rs
@@ -17,7 +17,7 @@ const MAX_ROOM_SIZE: u16 = 12;
 
 /// The `Rect` type represents a rectangle inside the map (x,y,width,height).
 /// (x,y) is the top-left corner.
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 struct Rect {
 	x: u16,
 	y: u16,
@@ -34,13 +34,20 @@ impl Rect {
 	fn center(&self) -> Pos {
 		let cx = self.x + self.w / 2;
 		let cy = self.y + self.h / 2;
-		Pos::new(cx as u16, cy as u16).unwrap_or(const_pos!(1, 1))
+		Pos::new(cx, cy).unwrap_or(const_pos!(1, 1))
+	}
+
+	/// Returns a random point in this rectangle.
+	fn random_point<R: Rng>(&self, rng: &mut R) -> Pos {
+		let rx = rng.random_range(self.x..(self.x + self.w));
+		let ry = rng.random_range(self.y..(self.y + self.h));
+		Pos::new(rx, ry).unwrap_or(self.center())
 	}
 }
 
 /// The `Node` type represents a node in the BSP tree.
 /// Has optional left and right children, and an optional room rectangle.
-#[derive(Debug)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 struct Node {
 	rect: Rect,               // Area this node covers
 	left: Option<Box<Node>>,  // Left child (if not leaf)
@@ -207,19 +214,24 @@ impl Node {
 			return right.room_center();
 		}
 		// Fallback (should not happen)
-		const_pos!(1, 1)
+		panic!("No room found in subtree");
 	}
 
-	/// Return a point (x,y) on the border of the room in this node.
+	/// Return a random point for a room in this subtree:
+	/// if node has a room, return a randiom point in it, else try left then right.
 	fn random_point_in_room<R: Rng>(&self, rng: &mut R) -> Pos {
+		// Base case: if this node has a room, return a random point in it
 		if let Some(room) = &self.room {
-			let rx = rng.random_range(room.x..(room.x + room.w));
-			let ry = rng.random_range(room.y..(room.y + room.h));
-			Pos::new(rx, ry).unwrap_or(self.rect.center())
-		} else {
-			// No room: return center of rect
-			self.rect.center()
+			return room.random_point(rng);
+		}
+		if let Some(left) = &self.left {
+			return left.random_point_in_room(rng);
 		}
+		if let Some(right) = &self.right {
+			return right.random_point_in_room(rng);
+		}
+		// Fallback (should not happen)
+		panic!("No room found in subtree");
 	}
 
 	/// Connect rooms of child nodes recursively and collect corridors to carve.
@@ -377,6 +389,13 @@ pub fn generate(seed: u64) -> (Box<[Tile; TILE_COUNT]>, Pos) {
 	let player_start = player_room.room_center();
 
 	// Set one tile to Stairs (exit) in a random room different from player start
+	let mut exit_room = player_room;
+	while exit_room == player_room {
+		exit_room = leaves.choose(&mut rng).unwrap_or(&leaves[0]);
+	}
+	let exit_pos = exit_room.room_center();
+	let exit_idx = exit_pos.xy().0 + exit_pos.xy().1 * MAP_SIZE;
+	tiles_box[exit_idx as usize] = Tile::Stairs;
 
 	// Return tiles and player_start
 	(tiles_box, player_start)
diff --git a/dungeon/tests/bsp_tests.rs b/dungeon/tests/bsp_tests.rs
index 2e3a781..6bd0153 100644
--- a/dungeon/tests/bsp_tests.rs
+++ b/dungeon/tests/bsp_tests.rs
@@ -3,6 +3,7 @@
 mod tests {
 	use dungeon::*;
 
+	/// Basic integration test for BSP generation
 	#[test]
 	fn test_bsp_integration() {
 		let seed = 12345u64;
@@ -12,4 +13,17 @@ mod tests {
 		assert!(player_start.x() < map::MAP_SIZE);
 		assert!(player_start.y() < map::MAP_SIZE);
 	}
+
+	/// Test that BSP-generated floors have a valid player start
+	#[test]
+	fn test_bsp_player_start() {
+		let seed = 12345u64;
+		let (tiles, player_start) = bsp::generate(seed);
+		// Ensure player start is within bounds
+		assert!(player_start.x() < map::MAP_SIZE);
+		assert!(player_start.y() < map::MAP_SIZE);
+		// Ensure player start is an air tile
+		let idx = player_start.idx();
+		assert_eq!(tiles[idx], map::Tile::Air);
+	}
 }
-- 
cgit v1.2.3-freya