44 lines
No EOL
1.6 KiB
Haskell
44 lines
No EOL
1.6 KiB
Haskell
module RPGEngine.Input.Player
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( spawnPlayer
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, movePlayer
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) where
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import RPGEngine.Data (Game(..), Direction(..), Player(..), X, Y, Physical (..), Level(..))
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import RPGEngine.Input.Level (whatIsAt, findFirst)
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import Data.Maybe (fromJust, isNothing)
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----------------------------- Constants ------------------------------
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diffs :: Direction -> (X, Y)
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diffs North = ( 0, 1)
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diffs East = ( 1, 0)
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diffs South = ( 0, -1)
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diffs West = (-1, 0)
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diffs Center = ( 0, 0)
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----------------------------------------------------------------------
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-- Set the initial position of the player in a given level.
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spawnPlayer :: Level -> Player -> Player
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spawnPlayer l@Level{ layout = lay } p@Player{ position = prevPos } = p{ position = newPos }
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where try = findFirst l Entrance
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newPos | isNothing try = prevPos
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| otherwise = fromJust try
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-- Move a player in a direction if possible.
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movePlayer :: Direction -> Game -> Game
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movePlayer dir g@Game{ player = p@Player{ position = (x, y) }} = newGame
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where newGame = g{ player = newPlayer }
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newPlayer = p{ position = newCoord }
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newCoord | isLegalMove dir g = (x + xD, y + yD)
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| otherwise = (x, y)
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(xD, yD) = diffs dir
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-- Check if a move is legal by checking what is located at the new position.
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isLegalMove :: Direction -> Game -> Bool
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isLegalMove dir g@Game{ playing = lvl, player = p@Player{ position = (x, y) }} = legality
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where legality = physical `elem` [Walkable, Entrance, Exit]
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physical = whatIsAt newPos lvl
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newPos = (x + xD, y + yD)
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(xD, yD) = diffs dir |