Safe Haskell	None
Language	Haskell2010

Graphics.Text.TrueType

Contents

Functions
Font cache
Types

Description

Module in charge of loading fonts.

Synopsis

decodeFont :: ByteString -> Either String Font
loadFontFile :: FilePath -> IO (Either String Font)
getStringCurveAtPoint :: Dpi -> (Float, Float) -> [(Font, PointSize, String)] -> [[Vector (Float, Float)]]
unitsPerEm :: Font -> Word16
isPlaceholder :: Font -> Char -> Bool
getCharacterGlyphsAndMetrics :: Font -> Char -> (Float, Vector RawGlyph)
getGlyphForStrings :: Dpi -> [(Font, PointSize, String)] -> [[Vector (Float, Float)]]
stringBoundingBox :: Font -> Dpi -> PointSize -> String -> BoundingBox
findFontOfFamily :: String -> FontStyle -> IO (Maybe FilePath)
pointInPixelAtDpi :: PointSize -> Dpi -> Float
pixelSizeInPointAtDpi :: Float -> Dpi -> PointSize
data FontCache
data FontDescriptor = FontDescriptor {
- _descriptorFamilyName :: !Text
- _descriptorStyle :: !FontStyle
}
emptyFontCache :: FontCache
findFontInCache :: FontCache -> FontDescriptor -> Maybe FilePath
buildCache :: IO FontCache
enumerateFonts :: FontCache -> [FontDescriptor]
descriptorOf :: Font -> Maybe FontDescriptor
data Font
data FontStyle = FontStyle {
- _fontStyleBold :: !Bool
- _fontStyleItalic :: !Bool
}
data RawGlyph = RawGlyph {
- _rawGlyphCompositionScale :: ![CompositeScaling]
- _rawGlyphIndex :: !Int
- _rawGlyphContour :: ![Vector (Int16, Int16)]
}
type Dpi = Int
newtype PointSize = PointSize {
- getPointSize :: Float
}
data CompositeScaling = CompositeScaling {
- _a :: !Int16
- _b :: !Int16
- _c :: !Int16
- _d :: !Int16
}
data BoundingBox = BoundingBox {
- _xMin :: !Float
- _yMin :: !Float
- _xMax :: !Float
- _yMax :: !Float
- _baselineHeight :: !Float
}

Functions

decodeFont :: ByteString -> Either String Font #

Decode a in-memory true type file.

loadFontFile :: FilePath -> IO (Either String Font) #

Load a font file, the file path must be pointing to the true type file (.ttf)

getStringCurveAtPoint #

Arguments

:: Dpi	Dot per inch of the output.
-> (Float, Float)	Initial position of the baseline.
-> [(Font, PointSize, String)]	Text to draw
-> [[Vector (Float, Float)]]	List of contours for each char

Extract a list of outlines for every char in the string. The given curves are in an image like coordinate system, with the origin point in the upper left corner.

unitsPerEm :: Font -> Word16 #

Return the number of pixels relative to the point size.

isPlaceholder :: Font -> Char -> Bool #

True if the character is not present in the font, therefore it will appear as a placeholder in renderings.

getCharacterGlyphsAndMetrics #

Arguments

:: Font
-> Char
-> (Float, Vector RawGlyph)	Advance and glyph information.

Retrive the glyph contours and associated transformations. The coordinate system is assumed to be the TTF one (y upward). No transformation is performed.

getGlyphForStrings :: Dpi -> [(Font, PointSize, String)] -> [[Vector (Float, Float)]] #

This function return the list of all contour for all char with the given font in a string. All glyph are at the same position, they are not placed like with getStringCurveAtPoint. It is a function helpful to extract the glyph geometry for further external manipulation.

stringBoundingBox :: Font -> Dpi -> PointSize -> String -> BoundingBox #

Compute the bounding box of a string displayed with a font at a given size. The resulting coordinate represent the width and the height in pixels.

findFontOfFamily :: String -> FontStyle -> IO (Maybe FilePath) #

This function will scan the system's font folder to find a font with the desired properties. Favor using a FontCache to speed up the lookup process.

pointInPixelAtDpi :: PointSize -> Dpi -> Float #

pixelSizeInPointAtDpi :: Float -> Dpi -> PointSize #

Font cache

data FontCache #

A font cache is a cache listing all the found fonts on the system, allowing faster font lookup once created

FontCache is an instance of binary, to get okish performance you should save it in a file somewhere instead of rebuilding it everytime!

The font cache is dependent on the version of rasterific, you must rebuild it for every version.

Instances

Show FontCache #
Instance details Defined in Graphics.Text.TrueType.FontFolders Methods showsPrec :: Int -> FontCache -> ShowS # show :: FontCache -> String # showList :: [FontCache] -> ShowS #
Binary FontCache #
Instance details Defined in Graphics.Text.TrueType.FontFolders Methods put :: FontCache -> Put # get :: Get FontCache # putList :: [FontCache] -> Put #

data FontDescriptor #

A font descriptor is a key used to find a font in a font cache.

Constructors

FontDescriptor
Fields _descriptorFamilyName :: !Text The family name of the font _descriptorStyle :: !FontStyle The desired style

Instances

Eq FontDescriptor #
Instance details Defined in Graphics.Text.TrueType.FontFolders Methods (==) :: FontDescriptor -> FontDescriptor -> Bool # (/=) :: FontDescriptor -> FontDescriptor -> Bool #
Ord FontDescriptor #
Instance details Defined in Graphics.Text.TrueType.FontFolders Methods compare :: FontDescriptor -> FontDescriptor -> Ordering # (<) :: FontDescriptor -> FontDescriptor -> Bool # (<=) :: FontDescriptor -> FontDescriptor -> Bool # (>) :: FontDescriptor -> FontDescriptor -> Bool # (>=) :: FontDescriptor -> FontDescriptor -> Bool # max :: FontDescriptor -> FontDescriptor -> FontDescriptor # min :: FontDescriptor -> FontDescriptor -> FontDescriptor #
Show FontDescriptor #
Instance details Defined in Graphics.Text.TrueType.FontFolders Methods showsPrec :: Int -> FontDescriptor -> ShowS # show :: FontDescriptor -> String # showList :: [FontDescriptor] -> ShowS #
Binary FontDescriptor #
Instance details Defined in Graphics.Text.TrueType.FontFolders Methods put :: FontDescriptor -> Put # get :: Get FontDescriptor # putList :: [FontDescriptor] -> Put #

emptyFontCache :: FontCache #

Font cache with no pre-existing fonts in it.

findFontInCache :: FontCache -> FontDescriptor -> Maybe FilePath #

Try to find a font with the given properties in the font cache.

buildCache :: IO FontCache #

This function will search in the system for truetype files and index them in a cache for further fast search.

enumerateFonts :: FontCache -> [FontDescriptor] #

Returns a list of descriptors of fonts stored in the given cache.

descriptorOf :: Font -> Maybe FontDescriptor #

If possible, returns a descriptor of the Font.

Types

data Font #

Type representing a font.

Instances

Show Font #
Instance details Defined in Graphics.Text.TrueType.FontType Methods showsPrec :: Int -> Font -> ShowS # show :: Font -> String # showList :: [Font] -> ShowS #
NFData Font #
Instance details Defined in Graphics.Text.TrueType.FontType Methods rnf :: Font -> () #

data FontStyle #

Describe the basic stylistic properties of a font.

Constructors

FontStyle
Fields _fontStyleBold :: !Bool If the font is bold. _fontStyleItalic :: !Bool If the font is italic.

Instances

Eq FontStyle #
Instance details Defined in Graphics.Text.TrueType.Header Methods (==) :: FontStyle -> FontStyle -> Bool # (/=) :: FontStyle -> FontStyle -> Bool #
Ord FontStyle #
Instance details Defined in Graphics.Text.TrueType.Header Methods compare :: FontStyle -> FontStyle -> Ordering # (<) :: FontStyle -> FontStyle -> Bool # (<=) :: FontStyle -> FontStyle -> Bool # (>) :: FontStyle -> FontStyle -> Bool # (>=) :: FontStyle -> FontStyle -> Bool # max :: FontStyle -> FontStyle -> FontStyle # min :: FontStyle -> FontStyle -> FontStyle #
Show FontStyle #
Instance details Defined in Graphics.Text.TrueType.Header Methods showsPrec :: Int -> FontStyle -> ShowS # show :: FontStyle -> String # showList :: [FontStyle] -> ShowS #
Binary FontStyle #
Instance details Defined in Graphics.Text.TrueType.Header Methods put :: FontStyle -> Put # get :: Get FontStyle # putList :: [FontStyle] -> Put #

data RawGlyph #

This type represent unscaled glyph information, everything is still in its raw form.

Constructors

RawGlyph
Fields _rawGlyphCompositionScale :: ![CompositeScaling] List of transformations to apply to the contour in order to get their correct placement. _rawGlyphIndex :: !Int Glyph index in the current font. _rawGlyphContour :: ![Vector (Int16, Int16)] Real Geometry of glyph, each vector contain one contour.

type Dpi = Int #

Express device resolution in dot per inch.

newtype PointSize #

Font size expressed in points. You must convert size expressed in pixels to point using the DPI information. See pixelSizeInPointAtDpi

Constructors

PointSize
Fields getPointSize :: Float

Instances

Eq PointSize #
Instance details Defined in Graphics.Text.TrueType Methods (==) :: PointSize -> PointSize -> Bool # (/=) :: PointSize -> PointSize -> Bool #
Show PointSize #
Instance details Defined in Graphics.Text.TrueType Methods showsPrec :: Int -> PointSize -> ShowS # show :: PointSize -> String # showList :: [PointSize] -> ShowS #

data CompositeScaling #

Transformation matrix used to transform composite glyph

  | a b |
  | c d |

Constructors

CompositeScaling
Fields _a :: !Int16 a coeff. _b :: !Int16 b coeff. _c :: !Int16 c coeff. _d :: !Int16 d coeff.

Instances

Eq CompositeScaling #
Instance details Defined in Graphics.Text.TrueType.Glyph Methods (==) :: CompositeScaling -> CompositeScaling -> Bool # (/=) :: CompositeScaling -> CompositeScaling -> Bool #
Show CompositeScaling #
Instance details Defined in Graphics.Text.TrueType.Glyph Methods showsPrec :: Int -> CompositeScaling -> ShowS # show :: CompositeScaling -> String # showList :: [CompositeScaling] -> ShowS #

data BoundingBox #

String bounding box. with value for min/max.

Constructors

BoundingBox
Fields _xMin :: !Float _yMin :: !Float _xMax :: !Float _yMax :: !Float _baselineHeight :: !Float Should be 0 most of the times.

Instances

Eq BoundingBox #
Instance details Defined in Graphics.Text.TrueType Methods (==) :: BoundingBox -> BoundingBox -> Bool # (/=) :: BoundingBox -> BoundingBox -> Bool #