Convert generated levels to walls

Add support for converting generated levels to walls, and merge one into
the entity map at the beginning of the game.

There's nothing here that guarantees the character ends up *inside* the
level though (they almost always don't) so that'll have to be slotted
into the level generation process.

1 files changed, 29 insertions, 0 deletions

diff --git a/src/Xanthous/Generators/Util.hs b/src/Xanthous/Generators/Util.hs
index 3f0d691b7fac..260c41ac6002 100644
--- a/src/Xanthous/Generators/Util.hs
+++ b/src/Xanthous/Generators/Util.hs
@@ -5,6 +5,7 @@ module Xanthous.Generators.Util
   , CellM
   , randInitialize
   , numAliveNeighborsM
+  , numAliveNeighbors
   , cloneMArray
   ) where
 
@@ -58,6 +59,34 @@ numAliveNeighborsM cells (x, y) = do
     neighborPositions :: [(Int, Int)]
     neighborPositions = [(i, j) | i <- [-1..1], j <- [-1..1], (i, j) /= (0, 0)]
 
+numAliveNeighbors
+  :: forall a i j
+  . (IArray a Bool, Ix (i, j), Integral i, Integral j)
+  => a (i, j) Bool
+  -> (i, j)
+  -> Word
+numAliveNeighbors cells (x, y) =
+  let cellBounds = bounds cells
+  in getSum $ foldMap
+      (Sum . fromIntegral . fromEnum . boundedGet cellBounds)
+      neighborPositions
+
+  where
+    boundedGet :: ((i, j), (i, j)) -> (Int, Int) -> Bool
+    boundedGet ((minX, minY), (maxX, maxY)) (i, j)
+      | x <= minX
+        || y <= minY
+        || x >= maxX
+        || y >= maxY
+      = True
+      | otherwise =
+        let nx = fromIntegral $ fromIntegral x + i
+            ny = fromIntegral $ fromIntegral y + j
+        in cells ! (nx, ny)
+
+    neighborPositions :: [(Int, Int)]
+    neighborPositions = [(i, j) | i <- [-1..1], j <- [-1..1], (i, j) /= (0, 0)]
+
 cloneMArray
   :: forall a a' i e m.
   ( Ix i