Safe Haskell	None
Language	GHC2021

KB.Text.Shape.Font

Contents

Distillation
Loading
Using
Querying
- Font metrics
Loading internals

Synopsis

extractBlob :: ByteString -> Int -> IO ByteString
data FontData = FontData {
- fontData :: ForeignPtr Word8
- fontResources :: [ByteString]
}
createFont :: ByteString -> Int -> IO FontData
destroyFont :: FontData -> IO ()
withFontData :: FontData -> (Font -> IO r) -> IO r
data Font
getFontInfo :: Font -> IO Info
data Info = Info {
- strings :: [(FontInfoStringId, Text)]
- styleFlags :: FontStyleFlags
- weight :: FontWeight
- width :: FontWidth
}
emToCaps :: Fractional a => Font -> a
capHeight :: Num a => Font -> a
unitsPerEm :: Num a => Font -> a
withLoader :: (FontData -> Ptr LoadFontState -> IO a) -> IO a
loadFont :: ByteString -> Int -> FontData -> Ptr LoadFontState -> IO (Either LoadFontError LoadFontResult)
data LoadFontResult
- = LoadFontReady
- | LoadFontNeedsBlob {
  - scratchSize :: Int
  - outputSize :: Int
  }
placeBlob :: FontData -> Ptr LoadFontState -> Int -> Int -> IO ByteString

Distillation

extractBlob Source #

Arguments

:: ByteString	TTF font data
-> Int	Font index (use 0 for the first/only font)
-> IO ByteString	KBTS blob data

Extract and pre-process font data needed for shaping.

Loading

data FontData Source #

Haskell-owned font data

Constructors

FontData
Fields fontData :: ForeignPtr Word8 fontResources :: [ByteString]

Instances

Instances details

Show FontData Source #
Instance details Defined in KB.Text.Shape.Font Methods showsPrec :: Int -> FontData -> ShowS # show :: FontData -> String # showList :: [FontData] -> ShowS #
Eq FontData Source #
Instance details Defined in KB.Text.Shape.Font Methods (==) :: FontData -> FontData -> Bool # (/=) :: FontData -> FontData -> Bool #

createFont :: ByteString -> Int -> IO FontData Source #

destroyFont :: FontData -> IO () Source #

Using

withFontData :: FontData -> (Font -> IO r) -> IO r Source #

Use the font handle from a loaded font

data Font Source #

An opaque handle to the font data.

Instances

Instances details

Storable Font Source #
Instance details Defined in KB.Text.Shape.FFI.Handles Methods sizeOf :: Font -> Int # alignment :: Font -> Int # peekElemOff :: Ptr Font -> Int -> IO Font # pokeElemOff :: Ptr Font -> Int -> Font -> IO () # peekByteOff :: Ptr b -> Int -> IO Font # pokeByteOff :: Ptr b -> Int -> Font -> IO () # peek :: Ptr Font -> IO Font # poke :: Ptr Font -> Font -> IO () #
Show Font Source #
Instance details Defined in KB.Text.Shape.FFI.Handles Methods showsPrec :: Int -> Font -> ShowS # show :: Font -> String # showList :: [Font] -> ShowS #
Eq Font Source #
Instance details Defined in KB.Text.Shape.FFI.Handles Methods (==) :: Font -> Font -> Bool # (/=) :: Font -> Font -> Bool #
Ord Font Source #
Instance details Defined in KB.Text.Shape.FFI.Handles Methods compare :: Font -> Font -> Ordering # (<) :: Font -> Font -> Bool # (<=) :: Font -> Font -> Bool # (>) :: Font -> Font -> Bool # (>=) :: Font -> Font -> Bool # max :: Font -> Font -> Font # min :: Font -> Font -> Font #

Querying

getFontInfo :: Font -> IO Info Source #

data Info Source #

Constructors

Info
Fields strings :: [(FontInfoStringId, Text)] styleFlags :: FontStyleFlags weight :: FontWeight width :: FontWidth

Instances

Instances details

Show Info Source #
Instance details Defined in KB.Text.Shape.Font Methods showsPrec :: Int -> Info -> ShowS # show :: Info -> String # showList :: [Info] -> ShowS #
Eq Info Source #
Instance details Defined in KB.Text.Shape.Font Methods (==) :: Info -> Info -> Bool # (/=) :: Info -> Info -> Bool #

Font metrics

emToCaps :: Fractional a => Font -> a Source #

Scaling factor to go from font-specific Em units to a cap-height normalized units.

This results in more consistent font sizing when using multiple fonts. You may even have a chance to align something vertically!

capHeight :: Num a => Font -> a Source #

Get the height of font's capital letters, in the font's logical units.

unitsPerEm :: Num a => Font -> a Source #

Get the font's "Em square" size, in the font's logical units.

Loading internals

withLoader :: (FontData -> Ptr LoadFontState -> IO a) -> IO a Source #

loadFont :: ByteString -> Int -> FontData -> Ptr LoadFontState -> IO (Either LoadFontError LoadFontResult) Source #

data LoadFontResult Source #

Constructors

LoadFontReady
LoadFontNeedsBlob
Fields scratchSize :: Int outputSize :: Int

placeBlob :: FontData -> Ptr LoadFontState -> Int -> Int -> IO ByteString Source #