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1{-# LANGUAGE MagicHash, UnboxedTuples #-}
2-- | FFI and hmatrix helpers.
3--
4-- Sample usage, to upload a perspective matrix to a shader.
5--
6-- @ glUniformMatrix4fv 0 1 (fromIntegral gl_TRUE) \`appMatrix\` perspective 0.01 100 (pi\/2) (4\/3)
7-- @
8--
9module Data.Packed.Foreign
10 ( app
11 , appVector, appVectorLen
12 , appMatrix, appMatrixLen, appMatrixRaw, appMatrixRawLen
13 , unsafeMatrixToVector, unsafeMatrixToForeignPtr
14 ) where
15import Data.Packed.Internal
16import qualified Data.Vector.Storable as S
17import Foreign (Ptr, ForeignPtr, Storable)
18import Foreign.C.Types (CInt)
19import GHC.Base (IO(..), realWorld#)
20
21{-# INLINE unsafeInlinePerformIO #-}
22-- | If we use unsafePerformIO, it may not get inlined, so in a function that returns IO (which are all safe uses of app* in this module), there would be
23-- unecessary calls to unsafePerformIO or its internals.
24unsafeInlinePerformIO :: IO a -> a
25unsafeInlinePerformIO (IO f) = case f realWorld# of
26 (# _, x #) -> x
27
28{-# INLINE app #-}
29-- | Only useful since it is left associated with a precedence of 1, unlike 'Prelude.$', which is right associative.
30-- e.g.
31--
32-- @
33-- someFunction
34-- \`appMatrixLen\` m
35-- \`appVectorLen\` v
36-- \`app\` other
37-- \`app\` arguments
38-- \`app\` go here
39-- @
40--
41-- One could also write:
42--
43-- @
44-- (someFunction
45-- \`appMatrixLen\` m
46-- \`appVectorLen\` v)
47-- other
48-- arguments
49-- (go here)
50-- @
51--
52app :: (a -> b) -> a -> b
53app f = f
54
55{-# INLINE appVector #-}
56appVector :: Storable a => (Ptr a -> b) -> Vector a -> b
57appVector f x = unsafeInlinePerformIO (S.unsafeWith x (return . f))
58
59{-# INLINE appVectorLen #-}
60appVectorLen :: Storable a => (CInt -> Ptr a -> b) -> Vector a -> b
61appVectorLen f x = unsafeInlinePerformIO (S.unsafeWith x (return . f (fromIntegral (S.length x))))
62
63{-# INLINE appMatrix #-}
64appMatrix :: Element a => (Ptr a -> b) -> Matrix a -> b
65appMatrix f x = unsafeInlinePerformIO (S.unsafeWith (flatten x) (return . f))
66
67{-# INLINE appMatrixLen #-}
68appMatrixLen :: Element a => (CInt -> CInt -> Ptr a -> b) -> Matrix a -> b
69appMatrixLen f x = unsafeInlinePerformIO (S.unsafeWith (flatten x) (return . f r c))
70 where
71 r = fromIntegral (rows x)
72 c = fromIntegral (cols x)
73
74{-# INLINE appMatrixRaw #-}
75appMatrixRaw :: Storable a => (Ptr a -> b) -> Matrix a -> b
76appMatrixRaw f x = unsafeInlinePerformIO (S.unsafeWith (xdat x) (return . f))
77
78{-# INLINE appMatrixRawLen #-}
79appMatrixRawLen :: Element a => (CInt -> CInt -> Ptr a -> b) -> Matrix a -> b
80appMatrixRawLen f x = unsafeInlinePerformIO (S.unsafeWith (xdat x) (return . f r c))
81 where
82 r = fromIntegral (rows x)
83 c = fromIntegral (cols x)
84
85infixl 1 `app`
86infixl 1 `appVector`
87infixl 1 `appMatrix`
88infixl 1 `appMatrixRaw`
89
90{-# INLINE unsafeMatrixToVector #-}
91-- | This will disregard the order of the matrix, and simply return it as-is.
92-- If the order of the matrix is RowMajor, this function is identical to 'flatten'.
93unsafeMatrixToVector :: Matrix a -> Vector a
94unsafeMatrixToVector = xdat
95
96{-# INLINE unsafeMatrixToForeignPtr #-}
97unsafeMatrixToForeignPtr :: Storable a => Matrix a -> (ForeignPtr a, Int)
98unsafeMatrixToForeignPtr m = S.unsafeToForeignPtr0 (xdat m)
99