{-# LANGUAGE NegativeLiterals    #-}
{-# LANGUAGE ScopedTypeVariables #-}

module MetaBrush.Asset.Brushes
  ( ellipse, blob, rect )
  where

-- containers
import Data.Sequence
  ( Seq(..) )
import qualified Data.Sequence as Seq
  ( fromList )

-- MetaBrush
import Math.Bezier.Stroke
  ( StrokePoint(..) )
import Math.Vector2D
  ( Point2D(..) )

--------------------------------------------------------------------------------

ellipse :: forall d. Double -> Double -> d -> Seq ( StrokePoint d )
ellipse w h d = Seq.fromList
  [ pp ( Point2D   0    1  )
  , cp ( Point2D   a    1  )
  , cp ( Point2D   1    a  )
  , pp ( Point2D   1    0  )
  , cp ( Point2D   1  (-a) )
  , cp ( Point2D   a  (-1) )
  , pp ( Point2D   0  (-1) )
  , cp ( Point2D (-a) (-1) )
  , cp ( Point2D (-1) (-a) )
  , pp ( Point2D (-1)   0  )
  , cp ( Point2D (-1)   a  )
  , cp ( Point2D (-a)   1  )
  , pp ( Point2D   0    1  )
  ]
  where
    a :: Double
    a = 0.551915024494
    pp, cp :: Point2D Double -> StrokePoint d
    pp ( Point2D x y ) =    PathPoint ( Point2D ( w * x ) ( h * y ) ) d
    cp ( Point2D x y ) = ControlPoint ( Point2D ( w * x ) ( h * y ) ) d

blob :: forall d. Double -> Double -> d -> Seq ( StrokePoint d )
blob w h d = Seq.fromList
  [ pp ( Point2D  1  0 )
  , cp ( Point2D  1 -1 )
  , cp ( Point2D -1 -1 )
  , pp ( Point2D -1  0 )
  , cp ( Point2D -1  1 )
  , cp ( Point2D  1  1 )
  , pp ( Point2D  1  0 )
  ]
  where
    pp, cp :: Point2D Double -> StrokePoint d
    pp ( Point2D x y ) =    PathPoint ( Point2D ( w * x ) ( h * y ) ) d
    cp ( Point2D x y ) = ControlPoint ( Point2D ( w * x ) ( h * y ) ) d

rect :: forall d. Double -> Double -> d -> Seq ( StrokePoint d )
rect w h d = Seq.fromList
  [ pp ( Point2D  1  1 )
  , pp ( Point2D  1 -1 )
  , pp ( Point2D -1 -1 )
  , pp ( Point2D -1  1 )
  , pp ( Point2D  1  1 )
  ]
  where
    pp :: Point2D Double -> StrokePoint d
    pp ( Point2D x y ) = PathPoint ( Point2D ( w * x ) ( h * y ) ) d