Add 'users/glittershark/xanthous/' from commit '53b56744f4'

git-subtree-dir: users/glittershark/xanthous
git-subtree-mainline: 91f53f02d8
git-subtree-split: 53b56744f4

users/glittershark/xanthous/src/Xanthous/Generators/LevelContents.hs

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+--------------------------------------------------------------------------------
+module Xanthous.Generators.LevelContents
+  ( chooseCharacterPosition
+  , randomItems
+  , randomCreatures
+  , randomDoors
+  , placeDownStaircase
+  , tutorialMessage
+  ) where
+--------------------------------------------------------------------------------
+import           Xanthous.Prelude hiding (any, toList)
+--------------------------------------------------------------------------------
+import           Control.Monad.Random
+import           Data.Array.IArray (amap, bounds, rangeSize, (!))
+import qualified Data.Array.IArray as Arr
+import           Data.Foldable (any, toList)
+--------------------------------------------------------------------------------
+import           Xanthous.Generators.Util
+import           Xanthous.Random
+import           Xanthous.Data ( Position, _Position, positionFromPair
+                               , rotations, arrayNeighbors, Neighbors(..)
+                               , neighborPositions
+                               )
+import           Xanthous.Data.EntityMap (EntityMap, _EntityMap)
+import           Xanthous.Entities.Raws (rawsWithType, RawType)
+import qualified Xanthous.Entities.Item as Item
+import           Xanthous.Entities.Item (Item)
+import qualified Xanthous.Entities.Creature as Creature
+import           Xanthous.Entities.Creature (Creature)
+import           Xanthous.Entities.Environment
+                 (GroundMessage(..), Door(..), unlockedDoor, Staircase(..))
+import           Xanthous.Messages (message_)
+import           Xanthous.Util.Graphics (circle)
+--------------------------------------------------------------------------------
+
+chooseCharacterPosition :: MonadRandom m => Cells -> m Position
+chooseCharacterPosition = randomPosition
+
+randomItems :: MonadRandom m => Cells -> m (EntityMap Item)
+randomItems = randomEntities Item.newWithType (0.0004, 0.001)
+
+placeDownStaircase :: MonadRandom m => Cells -> m (EntityMap Staircase)
+placeDownStaircase cells = do
+  pos <- randomPosition cells
+  pure $ _EntityMap # [(pos, DownStaircase)]
+
+randomDoors :: MonadRandom m => Cells -> m (EntityMap Door)
+randomDoors cells = do
+  doorRatio <- getRandomR subsetRange
+  let numDoors = floor $ doorRatio * fromIntegral (length candidateCells)
+      doorPositions =
+        removeAdjacent . fmap positionFromPair . take numDoors $ candidateCells
+      doors = zip doorPositions $ repeat unlockedDoor
+  pure $ _EntityMap # doors
+  where
+    removeAdjacent =
+      foldr (\pos acc ->
+               if pos `elem` (acc >>= toList . neighborPositions)
+               then acc
+               else pos : acc
+            ) []
+    candidateCells = filter doorable $ Arr.indices cells
+    subsetRange = (0.8 :: Double, 1.0)
+    doorable pos =
+      not (fromMaybe True $ cells ^? ix pos)
+      && any (teeish . fmap (fromMaybe True))
+        (rotations $ arrayNeighbors cells pos)
+    -- only generate doors at the *ends* of hallways, eg (where O is walkable,
+    -- X is a wall, and D is a door):
+    --
+    -- O O O
+    -- X D X
+    --   O
+    teeish (fmap not -> (Neighbors tl t tr l r _ b _ )) =
+      and [tl, t, tr, b] && (and . fmap not) [l, r]
+
+randomCreatures :: MonadRandom m => Cells -> m (EntityMap Creature)
+randomCreatures = randomEntities Creature.newWithType (0.0007, 0.002)
+
+tutorialMessage :: MonadRandom m
+  => Cells
+  -> Position -- ^ CharacterPosition
+  -> m (EntityMap GroundMessage)
+tutorialMessage cells characterPosition = do
+  let distance = 2
+  pos <- fmap (fromMaybe (error "No valid positions for tutorial message?"))
+        . choose . ChooseElement
+        $ accessiblePositionsWithin distance cells characterPosition
+  msg <- message_ ["tutorial", "message1"]
+  pure $ _EntityMap # [(pos, GroundMessage msg)]
+  where
+    accessiblePositionsWithin :: Int -> Cells -> Position -> [Position]
+    accessiblePositionsWithin dist valid pos =
+      review _Position
+      <$> filter (\(px, py) -> not $ valid ! (fromIntegral px, fromIntegral py))
+          (circle (pos ^. _Position) dist)
+
+randomEntities
+  :: forall entity raw m. (MonadRandom m, RawType raw)
+  => (raw -> entity)
+  -> (Float, Float)
+  -> Cells
+  -> m (EntityMap entity)
+randomEntities newWithType sizeRange cells =
+  case fromNullable $ rawsWithType @raw of
+    Nothing -> pure mempty
+    Just raws -> do
+      let len = rangeSize $ bounds cells
+      (numEntities :: Int) <-
+        floor . (* fromIntegral len) <$> getRandomR sizeRange
+      entities <- for [0..numEntities] $ const $ do
+        pos <- randomPosition cells
+        raw <- choose raws
+        let entity = newWithType raw
+        pure (pos, entity)
+      pure $ _EntityMap # entities
+
+randomPosition :: MonadRandom m => Cells -> m Position
+randomPosition = fmap positionFromPair . choose . impureNonNull . cellCandidates
+
+-- cellCandidates :: Cells -> Cells
+cellCandidates :: Cells -> Set (Word, Word)
+cellCandidates
+  -- find the largest contiguous region of cells in the cave.
+  = maximumBy (compare `on` length)
+  . fromMaybe (error "No regions generated! this should never happen.")
+  . fromNullable
+  . regions
+  -- cells ends up with true = wall, we want true = can put an item here
+  . amap not