Spear/Math/Triangle.hs


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module Spear.Math.Triangle
(
    Triangle(..)
)
where

import           Spear.Math.Algebra
import           Spear.Math.Vector

import           Foreign.C.Types
import           Foreign.Storable
import           Prelude            hiding ((*))


data Triangle = Triangle
    { p0 :: {-# UNPACK #-} !Vector3
    , p1 :: {-# UNPACK #-} !Vector3
    , p2 :: {-# UNPACK #-} !Vector3
    }


instance Storable Triangle where
    sizeOf _    = (3::Int) * sizeVector3
    alignment _ = alignment (undefined :: CFloat)

    peek ptr = do
        p0 <- peekByteOff ptr 0
        p1 <- peekByteOff ptr $ (1::Int) * sizeVector3
        p2 <- peekByteOff ptr $ (2::Int) * sizeVector3
        return $ Triangle p0 p1 p2

    poke ptr (Triangle p0 p1 p2) = do
        pokeByteOff ptr 0 p0
        pokeByteOff ptr ((1::Int) * sizeVector3) p1
        pokeByteOff ptr ((2::Int) * sizeVector3) p2