feat(mapgen): add room-and-corridor and bsp generators

src/gen/rooms.lua

@@ -0,0 +1,51 @@
+-- Non-overlapping rectangular rooms joined by L-shaped corridors. Returns a
+-- carved Map with map.rooms populated; stair, door and trap placement is the
+-- dungeon layer's job, not the generator's.
+
+local Map = require("map")
+local Carve = require("gen.carve")
+
+local Rooms = {}
+
+local function overlaps(a, b)
+  return a.x <= b.x + b.w and a.x + a.w >= b.x
+     and a.y <= b.y + b.h and a.y + a.h >= b.y
+end
+
+function Rooms.generate(width, height, rng, options)
+  options = options or {}
+  local maxRooms = options.maxRooms or 14
+  local minSize = options.minRoomSize or 4
+  local maxSize = options.maxRoomSize or 9
+  local map = Map.new(width, height)
+
+  for _ = 1, maxRooms do
+    local w = rng:range(minSize, maxSize)
+    local h = rng:range(minSize, maxSize)
+    local room = {
+      x = rng:range(2, width - w - 1),
+      y = rng:range(2, height - h - 1),
+      w = w, h = h,
+    }
+    local fits = true
+    for _, other in ipairs(map.rooms) do
+      if overlaps(room, other) then
+        fits = false
+        break
+      end
+    end
+    if fits then
+      Carve.rect(map, room.x, room.y, room.w, room.h)
+      if #map.rooms > 0 then
+        local prevX, prevY = Carve.center(map.rooms[#map.rooms])
+        local newX, newY = Carve.center(room)
+        Carve.corridor(map, prevX, prevY, newX, newY, rng)
+      end
+      map.rooms[#map.rooms + 1] = room
+    end
+  end
+
+  return map
+end
+
+return Rooms