| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Graphics.Text.TrueType
Contents
Description
Module in charge of loading fonts.
- 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 -> (Float, Float)
- findFontOfFamily :: String -> FontStyle -> IO (Maybe FilePath)
- data FontCache
- data FontDescriptor = FontDescriptor {}
- emptyFontCache :: FontCache
- findFontInCache :: FontCache -> FontDescriptor -> Maybe FilePath
- buildCache :: IO FontCache
- enumerateFonts :: FontCache -> [FontDescriptor]
- data Font
- data FontStyle = FontStyle {
- _fontStyleBold :: !Bool
- _fontStyleItalic :: !Bool
- data RawGlyph = RawGlyph {
- _rawGlyphCompositionScale :: ![CompositeScaling]
- _rawGlyphIndex :: !Int
- _rawGlyphContour :: ![Vector (Int16, Int16)]
- type Dpi = Int
- type PointSize = Int
- data CompositeScaling = CompositeScaling {}
Functions
decodeFont :: ByteString -> Either String Font Source
Decode a in-memory true type file.
loadFontFile :: FilePath -> IO (Either String Font) Source
Load a font file, the file path must be pointing to the true type file (.ttf)
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 Source
Return the number of pixels relative to the point size.
isPlaceholder :: Font -> Char -> Bool Source
True if the character is not present in the font, therefore it will appear as a placeholder in renderings.
getCharacterGlyphsAndMetrics Source
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)]] Source
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 -> (Float, Float) Source
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) Source
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.
Font cache
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.
data FontDescriptor Source
A font descriptor is a key used to find a font in a font cache.
Constructors
| FontDescriptor | |
Fields
| |
emptyFontCache :: FontCache Source
Font cache with no pre-existing fonts in it.
findFontInCache :: FontCache -> FontDescriptor -> Maybe FilePath Source
Try to find a font with the given properties in the font cache.
buildCache :: IO FontCache Source
This function will search in the system for truetype files and index them in a cache for further fast search.
enumerateFonts :: FontCache -> [FontDescriptor] Source
Returns a list of descriptors of fonts stored in the given cache.
Types
Describe the basic stylistic properties of a font.
Constructors
| FontStyle | |
Fields
| |
This type represent unscaled glyph information, everything is still in its raw form.
Constructors
| RawGlyph | |
Fields
| |
data CompositeScaling Source
Transformation matrix used to transform composite glyph
| a b c | | d e f |
Constructors
| CompositeScaling | |
Instances