{-# LANGUAGE ScopedTypeVariables #-}
module Codec.FFmpeg.Internal.Linear where
import Control.Applicative
import Foreign.C.Types
import Foreign.Ptr (castPtr)
import Foreign.Storable
data V2 a = V2 !a !a
data V3 a = V3 !a !a !a
instance Functor V3 where
fmap f (V3 x y z) = V3 (f x) (f y) (f z)
instance Storable a => Storable (V3 a) where
sizeOf _ = 3 * sizeOf (undefined::a)
alignment _ = alignment (undefined::a)
peek ptr = let ptr' = castPtr ptr
in V3 <$> peek ptr' <*> peekElemOff ptr' 1 <*> peekElemOff ptr' 2
poke ptr (V3 x y z) = let ptr' = castPtr ptr
in do poke ptr' x
pokeElemOff ptr' 1 y
pokeElemOff ptr' 2 z
qd :: V3 CInt -> V3 CInt -> CInt
qd (V3 x1 y1 z1) (V3 x2 y2 z2) = let dx = x2 - x1
dy = y2 - y1
dz = z2 - z1
in dx * dx + dy * dy + dz * dz
data V4 a = V4 !a !a !a !a
instance Functor V4 where
fmap f (V4 x y z w) = V4 (f x) (f y) (f z) (f w)
instance Storable a => Storable (V4 a) where
sizeOf _ = 4 * sizeOf (undefined::a)
alignment _ = alignment (undefined::a)
peek ptr = let ptr' = castPtr ptr
in V4 <$> peek ptr' <*> peekElemOff ptr' 1
<*> peekElemOff ptr' 2 <*> peekElemOff ptr' 3
poke ptr (V4 x y z w) = let ptr' = castPtr ptr
in do poke ptr' x
pokeElemOff ptr' 1 y
pokeElemOff ptr' 2 z
pokeElemOff ptr' 3 w