diff options
Diffstat (limited to 'users/aspen/xanthous/src/Xanthous/Generators/Level/Util.hs')
| -rw-r--r-- | users/aspen/xanthous/src/Xanthous/Generators/Level/Util.hs | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/users/aspen/xanthous/src/Xanthous/Generators/Level/Util.hs b/users/aspen/xanthous/src/Xanthous/Generators/Level/Util.hs new file mode 100644 index 0000000000..0008eb965c --- /dev/null +++ b/users/aspen/xanthous/src/Xanthous/Generators/Level/Util.hs @@ -0,0 +1,236 @@ +{-# LANGUAGE QuantifiedConstraints #-} +{-# LANGUAGE AllowAmbiguousTypes #-} +-------------------------------------------------------------------------------- +module Xanthous.Generators.Level.Util + ( MCells + , Cells + , CellM + , randInitialize + , initializeEmpty + , numAliveNeighborsM + , numAliveNeighbors + , fillOuterEdgesM + , cloneMArray + , floodFill + , regions + , fillAll + , fillAllM + , fromPoints + , fromPointsM + ) where +-------------------------------------------------------------------------------- +import Xanthous.Prelude hiding (Foldable, toList, for_) +-------------------------------------------------------------------------------- +import Data.Array.ST +import Data.Array.Unboxed +import Control.Monad.ST +import Control.Monad.Random +import Data.Monoid +import Data.Foldable (Foldable, toList, for_) +import qualified Data.Set as Set +import Data.Semigroup.Foldable +import Linear.V2 +-------------------------------------------------------------------------------- +import Xanthous.Util (foldlMapM', maximum1, minimum1) +import Xanthous.Data (Dimensions, width, height) +-------------------------------------------------------------------------------- + +type MCells s = STUArray s (V2 Word) Bool +type Cells = UArray (V2 Word) Bool +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 <- initializeEmpty dims + for_ [0..dims ^. width] $ \i -> + for_ [0..dims ^. height] $ \j -> do + val <- (>= aliveChance) <$> getRandomR (0, 1) + lift $ writeArray res (V2 i j) val + pure res + +initializeEmpty :: RandomGen g => Dimensions -> CellM g s (MCells s) +initializeEmpty dims = + lift $ newArray (0, V2 (dims ^. width) (dims ^. height)) False + +-- | Returns the number of neighbors of the given point in the given array that +-- are True. +-- +-- Behavior if point is out-of-bounds for the array is undefined, but will not +-- error +numAliveNeighborsM + :: forall a i m + . (MArray a Bool m, Ix i, Integral i) + => a (V2 i) Bool + -> V2 i + -> m Word +numAliveNeighborsM cells pt@(V2 x y) = do + cellBounds <- getBounds cells + getSum <$> foldlMapM' + (fmap (Sum . fromIntegral . fromEnum) . boundedGet cellBounds) + neighborPositions + + where + boundedGet :: (V2 i, V2 i) -> (Int, Int) -> m Bool + boundedGet bnds _ + | not (inRange bnds pt) + = pure True + boundedGet (V2 minX minY, V2 maxX maxY) (i, j) + | (x <= minX && i < 0) + || (y <= minY && j < 0) + || (x >= maxX && i > 0) + || (y >= maxY && j > 0) + = pure True + | otherwise = + let nx = fromIntegral $ fromIntegral x + i + ny = fromIntegral $ fromIntegral y + j + in readArray cells $ V2 nx ny + +-- | Returns the number of neighbors of the given point in the given array that +-- are True. +-- +-- Behavior if point is out-of-bounds for the array is undefined, but will not +-- error +numAliveNeighbors + :: forall a i + . (IArray a Bool, Ix i, Integral i) + => a (V2 i) Bool + -> V2 i + -> Word +numAliveNeighbors cells pt@(V2 x y) = + let cellBounds = bounds cells + in getSum $ foldMap + (Sum . fromIntegral . fromEnum . boundedGet cellBounds) + neighborPositions + + where + boundedGet :: (V2 i, V2 i) -> (Int, Int) -> Bool + boundedGet bnds _ + | not (inRange bnds pt) + = True + boundedGet (V2 minX minY, V2 maxX maxY) (i, j) + | (x <= minX && i < 0) + || (y <= minY && j < 0) + || (x >= maxX && i > 0) + || (y >= maxY && j > 0) + = True + | otherwise = + let nx = fromIntegral $ fromIntegral x + i + ny = fromIntegral $ fromIntegral y + j + in cells ! V2 nx ny + +neighborPositions :: [(Int, Int)] +neighborPositions = [(i, j) | i <- [-1..1], j <- [-1..1], (i, j) /= (0, 0)] + +fillOuterEdgesM :: (MArray a Bool m, Ix i) => a (V2 i) Bool -> m () +fillOuterEdgesM arr = do + (V2 minX minY, V2 maxX maxY) <- getBounds arr + for_ (range (minX, maxX)) $ \x -> do + writeArray arr (V2 x minY) True + writeArray arr (V2 x maxY) True + for_ (range (minY, maxY)) $ \y -> do + writeArray arr (V2 minX y) True + writeArray arr (V2 maxX y) True + +cloneMArray + :: forall a a' i e m. + ( Ix i + , MArray a e m + , MArray a' e m + , IArray UArray e + ) + => a i e + -> m (a' i e) +cloneMArray = thaw @_ @UArray <=< freeze + +-------------------------------------------------------------------------------- + +-- | Flood fill a cell array starting at a point, returning a list of all the +-- (true) cell locations reachable from that point +floodFill :: forall a i. + ( IArray a Bool + , Ix i + , Enum i + , Bounded i + , Eq i + ) + => a (V2 i) Bool -- ^ array + -> (V2 i) -- ^ position + -> Set (V2 i) +floodFill = go mempty + where + go :: Set (V2 i) -> a (V2 i) Bool -> (V2 i) -> Set (V2 i) + go res arr@(bounds -> arrBounds) idx@(V2 x y) + | not (inRange arrBounds idx) = res + | not (arr ! idx) = res + | otherwise = + let neighbors + = filter (inRange arrBounds) + . filter (/= idx) + . filter (`notMember` res) + $ V2 + <$> [(if x == minBound then x else pred x) + .. + (if x == maxBound then x else succ x)] + <*> [(if y == minBound then y else pred y) + .. + (if y == maxBound then y else succ y)] + in foldl' (\r idx' -> + if arr ! idx' + then r <> (let r' = r & contains idx' .~ True + in r' `seq` go r' arr idx') + else r) + (res & contains idx .~ True) neighbors +{-# SPECIALIZE floodFill :: UArray (V2 Word) Bool -> (V2 Word) -> Set (V2 Word) #-} + +-- | Gives a list of all the disconnected regions in a cell array, represented +-- each as lists of points +regions :: forall a i. + ( IArray a Bool + , Ix i + , Enum i + , Bounded i + , Eq i + ) + => a (V2 i) Bool + -> [Set (V2 i)] +regions arr + | Just firstPoint <- findFirstPoint arr = + let region = floodFill arr firstPoint + arr' = fillAll region arr + in region : regions arr' + | otherwise = [] + where + findFirstPoint :: a (V2 i) Bool -> Maybe (V2 i) + findFirstPoint = fmap fst . headMay . filter snd . assocs +{-# SPECIALIZE regions :: UArray (V2 Word) Bool -> [Set (V2 Word)] #-} + +fillAll :: (IArray a Bool, Ix i, Foldable f) => f i -> a i Bool -> a i Bool +fillAll ixes a = accum (const fst) a $ (, (False, ())) <$> toList ixes + +fillAllM :: (MArray a Bool m, Ix i, Foldable f) => f i -> a i Bool -> m () +fillAllM ixes a = for_ ixes $ \i -> writeArray a i False + +fromPoints + :: forall a f i. + ( IArray a Bool + , Ix i + , Functor f + , Foldable1 f + ) + => f (i, i) + -> a (i, i) Bool +fromPoints points = + let pts = Set.fromList $ toList points + dims = ( (minimum1 $ fst <$> points, minimum1 $ snd <$> points) + , (maximum1 $ fst <$> points, maximum1 $ snd <$> points) + ) + in array dims $ range dims <&> \i -> (i, i `member` pts) + +fromPointsM + :: (MArray a Bool m, Ix i, Element f ~ i, MonoFoldable f) + => NonNull f + -> m (a i Bool) +fromPointsM points = do + arr <- newArray (minimum points, maximum points) False + fillAllM (otoList points) arr + pure arr |