1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
{- This Source Code Form is subject to the terms of the Mozilla Public License,
v. 2.0. If a copy of the MPL was not distributed with this file, You can
obtain one at https://mozilla.org/MPL/2.0/. -}
-- | Generic font types.
module Graphics.Fountainhead.Type
( F2Dot14(..)
, Fixed32(..)
, FWord
, UFWord
, fixed2Double
, succIntegral
, ttfEpoch
) where
import Data.Bits ((.>>.), (.&.))
import Data.Int (Int16, Int32)
import Data.Word (Word16, Word32)
import Data.Time (Day(..))
import Data.Time.Calendar.OrdinalDate (fromOrdinalDate)
import Data.Fixed (HasResolution(..))
newtype Fixed32 = Fixed32 Word32
deriving (Eq, Show)
instance Num Fixed32
where
(Fixed32 x) + (Fixed32 y) = Fixed32 $ x + y
(Fixed32 x) - (Fixed32 y) = Fixed32 $ x - y
(Fixed32 x) * (Fixed32 y) = Fixed32 $ div (x * y) 65536
abs (Fixed32 x) = Fixed32 $ fromIntegral $ abs (fromIntegral x :: Int32)
signum (Fixed32 x)
| x == 0 = Fixed32 0
| (fromIntegral x :: Int32) < 0 = Fixed32 0xffff0000
| otherwise = Fixed32 0x10000
fromInteger x = Fixed32 $ fromInteger $ x * 65536
instance Ord Fixed32
where
compare (Fixed32 x) (Fixed32 y) =
compare (fromIntegral x :: Int32) (fromIntegral y)
instance Real Fixed32
where
toRational (Fixed32 x) = toRational (fromIntegral x :: Int32) / 65536.0
instance HasResolution Fixed32
where
resolution = const 65536
newtype F2Dot14 = F2Dot14 Int16
deriving (Eq, Show)
type FWord = Int16
type UFWord = Word16
ttfEpoch :: Day
ttfEpoch = fromOrdinalDate 1904 1
succIntegral :: Integral a => a -> Int
succIntegral = succ . fromIntegral
fixed2Double :: F2Dot14 -> Double
fixed2Double (F2Dot14 fixed) =
let mantissa = realToFrac (fixed .>>. 14)
fraction = realToFrac (fixed .&. 0x3fff) / 16384.0
in mantissa + fraction
|
