From 3506edd85f07193ed4c2f4546c7cfc85576f35bc Mon Sep 17 00:00:00 2001
From: Timothy Warren <twarren@nabancard.com>
Date: Thu, 6 Jan 2022 15:37:22 -0500
Subject: [PATCH] Actually generate a map, completing part 3

---
 main.py    | 15 ++++++++--
 procgen.py | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 88 insertions(+), 8 deletions(-)

diff --git a/main.py b/main.py
index c3c3d0c..9671b48 100755
--- a/main.py
+++ b/main.py
@@ -12,7 +12,11 @@ def main() -> None:
     screen_height = 50
 
     map_width = 80
-    map_height = 50
+    map_height = 45
+
+    room_max_size = 10
+    room_min_size = 6
+    max_rooms = 30
 
     tileset = tcod.tileset.load_tilesheet(
         "dejavu10x10_gs_tc.png",
@@ -27,7 +31,14 @@ def main() -> None:
     npc = Entity(int(screen_width / 2 - 5), int(screen_height / 2), "@", (255, 255, 0))
     entities = {npc, player}
 
-    game_map = generate_dungeon(map_width, map_height)
+    game_map = generate_dungeon(
+        max_rooms,
+        room_min_size,
+        room_max_size,
+        map_width,
+        map_height,
+        player,
+    )
 
     engine = Engine(entities, event_handler, game_map, player)
 
diff --git a/procgen.py b/procgen.py
index 6e1d3d8..e042cd5 100644
--- a/procgen.py
+++ b/procgen.py
@@ -1,8 +1,16 @@
-from typing import Tuple
+from __future__ import annotations
+
+import random
+from typing import Iterator, List, Tuple, TYPE_CHECKING
+
+import tcod
 
 from game_map import GameMap
 import tile_types
 
+if TYPE_CHECKING:
+    from entity import Entity
+
 
 class RectangularRoom:
     def __init__(self, x: int, y: int, width: int, height: int):
@@ -23,14 +31,75 @@ class RectangularRoom:
         """Return the inner area of this room as a 2D array index."""
         return slice(self.x1 + 1, self.x2), slice(self.y1 + 1, self.y2)
 
+    def intersects(self, other: RectangularRoom) -> bool:
+        """Return True if this room overlaps with another RectangularRoom."""
+        return (
+                self.x1 <= other.x2
+                and self.x2 >= other.x1
+                and self.y1 <= other.y2
+                and self.y2 >= other.y1
+        )
 
-def generate_dungeon(map_width, map_height) -> GameMap:
+
+def tunnel_between(start: Tuple[int, int], end: Tuple[int, int]) -> Iterator[Tuple[int, int]]:
+    """Return an L-shaped tunnel between these two points."""
+    x1, y1 = start
+    x2, y2 = end
+    if random.random() < 0.5:  # 50% chance.
+        # Move horizontally, then vertically
+        corner_x, corner_y = x2, y1
+    else:
+        # Move vertically, then horizontally
+        corner_x, corner_y = x1, y2
+
+    # Generate the coordinates for this tunnel
+    for x, y in tcod.los.bresenham((x1, y1), (corner_x, corner_y)).tolist():
+        yield x, y
+
+    for x, y in tcod.los.bresenham((corner_x, corner_y), (x2, y2)).tolist():
+        yield x, y
+
+
+def generate_dungeon(
+        max_rooms: int,
+        room_min_size: int,
+        room_max_size: int,
+        map_width: int,
+        map_height: int,
+        player: Entity,
+) -> GameMap:
+    """Generate a new dungeon map."""
     dungeon = GameMap(map_width, map_height)
 
-    room_1 = RectangularRoom(x=20, y=15, width=10, height=15)
-    room_2 = RectangularRoom(x=35, y=15, width=10, height=15)
+    rooms: List[RectangularRoom] = []
 
-    dungeon.tiles[room_1.inner] = tile_types.floor
-    dungeon.tiles[room_2.inner] = tile_types.floor
+    for r in range(max_rooms):
+        room_width = random.randint(room_min_size, room_max_size)
+        room_height = random.randint(room_min_size, room_max_size)
+
+        x = random.randint(0, dungeon.width - room_width - 1)
+        y = random.randint(0, dungeon.height - room_height - 1)
+
+        # "RectangularRoom" class makes rectangles easier to work with
+        new_room = RectangularRoom(x, y, room_width, room_height)
+
+        # Run through the other rooms and see if they intersect with this one.
+        # If there are no intersections then the room is valid
+        if any(new_room.intersects(other_room) for other_room in rooms):
+            continue  # This room intersects, so go to the next attempt.
+
+        # Dig out this room's inner area.
+        dungeon.tiles[new_room.inner] = tile_types.floor
+
+        if len(rooms) == 0:
+            # The first room, where the player starts.
+            player.x, player.y = new_room.center
+        else:  # All rooms after the first.
+            # Dig out a tunnel between this room and the previous one
+            for x, y in tunnel_between(rooms[-1].center, new_room.center):
+                dungeon.tiles[x, y] = tile_types.floor
+
+        # Finally, append the new room to the list.
+        rooms.append(new_room)
 
     return dungeon