Add dungeon level generation

Add a dungeon level generator, which:

1. generates an infinite sequence of rectangular rooms within the
   dimensions of the level
2. removes any duplicates from that sequence
3. Generates a graph from the delaunay triangulation of the centerpoints
   of those rooms
4. Generates the minimum-spanning-tree of that delaunay triangulation,
   with weights given by line length in points
5. Adds back a subset (default 10-15%) of edges from the delaunay
   triangulation to the graph
6. Uses the resulting graph to draw corridors between the rooms, using a
   random point on the near edge of each room to pick the points of the
   corridors

1 files changed, 6 insertions, 1 deletions

diff --git a/src/Xanthous/Generators/Util.hs b/src/Xanthous/Generators/Util.hs
index 2c041149d900..13f248a045d8 100644
--- a/src/Xanthous/Generators/Util.hs
+++ b/src/Xanthous/Generators/Util.hs
@@ -7,6 +7,7 @@ module Xanthous.Generators.Util
   , Cells
   , CellM
   , randInitialize
+  , initializeEmpty
   , numAliveNeighborsM
   , numAliveNeighbors
   , fillOuterEdgesM
@@ -39,13 +40,17 @@ type CellM g s a = RandT g (ST s) a
 
 randInitialize :: RandomGen g => Dimensions -> Double -> CellM g s (MCells s)
 randInitialize dims aliveChance = do
-  res <- lift $ newArray ((0, 0), (dims ^. width, dims ^. height)) False
+  res <- initializeEmpty dims
   for_ [0..dims ^. width] $ \i ->
     for_ [0..dims ^. height] $ \j -> do
       val <- (>= aliveChance) <$> getRandomR (0, 1)
       lift $ writeArray res (i, j) val
   pure res
 
+initializeEmpty :: RandomGen g => Dimensions -> CellM g s (MCells s)
+initializeEmpty dims =
+  lift $ newArray ((0, 0), (dims ^. width, dims ^. height)) False
+
 numAliveNeighborsM
   :: forall a i j m
   . (MArray a Bool m, Ix (i, j), Integral i, Integral j)