-- | Game state
module State where
import Graphics.Gloss
import World


-- | The game state.
data State
        = State
        { stateWorld            :: World
        , stateModeInterface    :: ModeInterface
        , stateModeDisplay      :: ModeDisplay
        , stateModeOverlay      :: ModeOverlay
        , stateViewPos          :: Point 
        , stateTargetPos        :: Maybe Point }


-- | What mode the interface interaction is in.
data ModeInterface
        -- | We're not doing anything inparticular.
        = ModeInterfaceIdle

        -- | We're moving the view position.
        | ModeInterfaceMove
        deriving (Show, Eq)


-- | What mode the display is in.
data ModeDisplay
        -- | Show the world in rectangular coordinates.
        = ModeDisplayWorld

        -- | Show the world normalised so the view position is at the origin.
        | ModeDisplayNormalised
        deriving (Show, Eq)


-- | What overlay to display.
data ModeOverlay
        -- | No overlay
        = ModeOverlayNone
        
        -- | Brute force, approximate visibility
        | ModeOverlayVisApprox
        deriving (Show, Eq)


-- | Initial game state.
initialState :: World -> State
initialState world
        = State
        { stateWorld            = world
        , stateModeInterface    = ModeInterfaceIdle
        , stateModeDisplay      = ModeDisplayWorld
        , stateModeOverlay      = ModeOverlayVisApprox
        , stateViewPos          = (0, 0) 
        , stateTargetPos        = Nothing }