Data.Text.Glyphize

HarfBuzz is a text shaping library. Using the HarfBuzz library allows programs to convert a sequence of Unicode input into properly formatted and positioned glyph output — for any writing system and language. See shape for the central function all other datatypes serves to support.

Documentation

shape :: Font -> Buffer -> [Feature] -> [(GlyphInfo, GlyphPos)]

Shapes the text in the given Buffer according to the given Font yielding glyphs and their positions. If any Features are given they will be applied during shaping. If two Features have the same tag but overlapping ranges the value of the Feature with the higher index takes precedance.

version :: (Int, Int, Int)

Returns the library version as 3 integer components.

versionAtLeast :: Int -> Int -> Int -> Bool

Tests the library version against a minimum value, as 3 integer components.

versionString :: String

Returns library version as a string with 3 integer components.

data Buffer

Text to be shaped or the resulting glyphs, for which languagescriptdirection/etc.

Constructors

Buffer

Fields

• text :: Text

  The Unicode text, in visual order, for HarfBuzz to convert into glyphs. See https://hackage.haskell.org/package/text-2.0.1/docs/Data-Text-Internal-Lazy.html#t:Text for details.

• contentType :: Maybe ContentType

  What the bytes of the ByteString contents represents, namely unicode characters (before shaping) or glyphs (result of shaping). Typically callers should leave this as `Just ContentTypeUnicode`.

• direction :: Maybe Direction

  The text flow direction of the buffer. No shaping can happen without setting buffer direction, and it controls the visual direction for the output glyphs; for RTL direction the glyphs will be reversed. Many layout features depend on the proper setting of the direction, for example, reversing RTL text before shaping, then shaping with LTR direction is not the same as keeping the text in logical order and shaping with RTL direction.

• script :: Maybe String

  Script is crucial for choosing the proper shaping behaviour for scripts that require it (e.g. Arabic) and the which OpenType features defined in the font to be applied.

• language :: Maybe String

  Languages are crucial for selecting which OpenType feature to apply to the buffer which can result in applying language-specific behaviour. Languages are orthogonal to the scripts, and though they are related, they are different concepts and should not be confused with each other.

• beginsText :: Bool

  special handling of the beginning of text paragraph can be applied to this buffer. Should usually be set, unless you are passing to the buffer only part of the text without the full context.

• endsText :: Bool

  special handling of the end of text paragraph can be applied to this buffer.

• preserveDefaultIgnorables :: Bool

  character with Default_Ignorable Unicode property should use the corresponding glyph from the font, instead of hiding them (done by replacing them with the space glyph and zeroing the advance width.) Takes precedance over removeDefaultIgnorables.

• removeDefaultIgnorables :: Bool

  character with Default_Ignorable Unicode property should be removed from glyph string instead of hiding them (done by replacing them with the space glyph and zeroing the advance width.)

• don'tInsertDottedCircle :: Bool

  a dotted circle should not be inserted in the rendering of incorrect character sequences (such as 093E).

• clusterLevel :: ClusterLevel

  dictates one aspect of how HarfBuzz will treat non-base characters during shaping.

• invisibleGlyph :: Char

  The glyph number that replaces invisible characters in the shaping result. If set to zero (default), the glyph for the U+0020 SPACE character is used. Otherwise, this value is used verbatim.

• replacementCodepoint :: Char

  the glyph number that replaces invalid entries for a given encoding when adding text to buffer.

• notFoundGlyph :: Char

  the glyph number that replaces replaces characters not found in the font.

Instances

Eq Buffer

Defined in Data.Text.Glyphize.Buffer

Methods

(==) :: Buffer -> Buffer -> Bool

(/=) :: Buffer -> Buffer -> Bool

Ord Buffer

Defined in Data.Text.Glyphize.Buffer

Methods

compare :: Buffer -> Buffer -> Ordering

(<) :: Buffer -> Buffer -> Bool

(<=) :: Buffer -> Buffer -> Bool

(>) :: Buffer -> Buffer -> Bool

(>=) :: Buffer -> Buffer -> Bool

max :: Buffer -> Buffer -> Buffer

min :: Buffer -> Buffer -> Buffer

Read Buffer

Defined in Data.Text.Glyphize.Buffer

Methods

readsPrec :: Int -> ReadS Buffer

readList :: ReadS [Buffer]

readPrec :: ReadPrec Buffer

readListPrec :: ReadPrec [Buffer]

Show Buffer

Defined in Data.Text.Glyphize.Buffer

Methods

showsPrec :: Int -> Buffer -> ShowS

show :: Buffer -> String

showList :: [Buffer] -> ShowS

data ContentType

Whether the given text is Unicode or font-specific "glyphs".

Constructors

ContentTypeUnicode

ContentTypeGlyphs

Instances

Eq ContentType

Defined in Data.Text.Glyphize.Buffer

Methods

(==) :: ContentType -> ContentType -> Bool

(/=) :: ContentType -> ContentType -> Bool

Ord ContentType

Defined in Data.Text.Glyphize.Buffer

Methods

compare :: ContentType -> ContentType -> Ordering

(<) :: ContentType -> ContentType -> Bool

(<=) :: ContentType -> ContentType -> Bool

(>) :: ContentType -> ContentType -> Bool

(>=) :: ContentType -> ContentType -> Bool

max :: ContentType -> ContentType -> ContentType

min :: ContentType -> ContentType -> ContentType

Read ContentType

Defined in Data.Text.Glyphize.Buffer

Methods

readsPrec :: Int -> ReadS ContentType

readList :: ReadS [ContentType]

readPrec :: ReadPrec ContentType

readListPrec :: ReadPrec [ContentType]

Show ContentType

Defined in Data.Text.Glyphize.Buffer

Methods

showsPrec :: Int -> ContentType -> ShowS

show :: ContentType -> String

showList :: [ContentType] -> ShowS

data ClusterLevel

Defines how fine the groupings represented by GlyphInfo's cluster property are.`

Constructors

ClusterMonotoneGraphemes

ClusterMonotoneChars

ClusterChars

Instances

Eq ClusterLevel

Defined in Data.Text.Glyphize.Buffer

Methods

(==) :: ClusterLevel -> ClusterLevel -> Bool

(/=) :: ClusterLevel -> ClusterLevel -> Bool

Ord ClusterLevel

Defined in Data.Text.Glyphize.Buffer

Methods

compare :: ClusterLevel -> ClusterLevel -> Ordering

(<) :: ClusterLevel -> ClusterLevel -> Bool

(<=) :: ClusterLevel -> ClusterLevel -> Bool

(>) :: ClusterLevel -> ClusterLevel -> Bool

(>=) :: ClusterLevel -> ClusterLevel -> Bool

max :: ClusterLevel -> ClusterLevel -> ClusterLevel

min :: ClusterLevel -> ClusterLevel -> ClusterLevel

Read ClusterLevel

Defined in Data.Text.Glyphize.Buffer

Methods

readsPrec :: Int -> ReadS ClusterLevel

readList :: ReadS [ClusterLevel]

readPrec :: ReadPrec ClusterLevel

readListPrec :: ReadPrec [ClusterLevel]

Show ClusterLevel

Defined in Data.Text.Glyphize.Buffer

Methods

showsPrec :: Int -> ClusterLevel -> ShowS

show :: ClusterLevel -> String

showList :: [ClusterLevel] -> ShowS

data Direction

The direction of a text segment or buffer.

Constructors

DirLTR

DirRTL

DirTTB

DirBTT

Instances

Eq Direction

Defined in Data.Text.Glyphize.Buffer

Methods

(==) :: Direction -> Direction -> Bool

(/=) :: Direction -> Direction -> Bool

Ord Direction

Defined in Data.Text.Glyphize.Buffer

Methods

compare :: Direction -> Direction -> Ordering

(<) :: Direction -> Direction -> Bool

(<=) :: Direction -> Direction -> Bool

(>) :: Direction -> Direction -> Bool

(>=) :: Direction -> Direction -> Bool

max :: Direction -> Direction -> Direction

min :: Direction -> Direction -> Direction

Read Direction

Defined in Data.Text.Glyphize.Buffer

Methods

readsPrec :: Int -> ReadS Direction

readList :: ReadS [Direction]

readPrec :: ReadPrec Direction

readListPrec :: ReadPrec [Direction]

Show Direction

Defined in Data.Text.Glyphize.Buffer

Methods

showsPrec :: Int -> Direction -> ShowS

show :: Direction -> String

showList :: [Direction] -> ShowS

defaultBuffer :: Buffer

An empty buffer with sensible default properties.

dirFromStr :: [Char] -> Maybe Direction

Converts a string to an Direction. Matching is loose and applies only to the first letter. For examples, LTR and "left-to-right" will both return HB_DIRECTION_LTR.

dirToStr :: Direction -> [Char]

Converts an Direction to a string.

dirReverse :: Direction -> Direction

Reverses a text direction.

dirBackward :: Direction -> Bool

Tests whether a text direction moves backward (from right to left, or from bottom to top).

dirForward :: Direction -> Bool

Tests whether a text direction moves forward (from left to right, or from top to bottom).

dirHorizontal :: Direction -> Bool

Tests whether a text direction is horizontal.

dirVertical :: Direction -> Bool

Tests whether a text direction is vertical.

scriptHorizontalDir :: String -> Maybe Direction

Fetches the Direction of a script when it is set horizontally. All right-to-left scripts will return DirRTL. All left-to-right scripts will return DirLTR. Scripts that can be written either horizontally or vertically will return Nothing. Unknown scripts will return DirLTR.

languageDefault :: IO String

Fetch the default language from current locale. NOTE that the first time this function is called, it calls (C code) "setlocale (LC_CTYPE, nullptr)" to fetch current locale. The underlying setlocale function is, in many implementations, NOT threadsafe. To avoid problems, call this function once before multiple threads can call it. This function may be used to fill in missing fields on a Buffer.

tag_from_string :: String -> Word32

Converts a String into a "tag" Word32. Valid tags are 4 Chars. Shorter input Strings will be padded with spaces. Longer input strings will be truncated.

tag_to_string :: Word32 -> String

Converts a "tag" Word32 into a 4 Char String.

guessSegmentProperties :: Buffer -> Buffer

Fills in unset segment properties based on buffer unicode contents. If buffer is not empty it must have ContentType ContentTypeUnicode. If buffer script is not set it will be set to the Unicode script of the first character in the buffer that has a script other than "common", "inherited", or "unknown". Next if the buffer direction is not set it will be set to the natural horizontal direction of the buffer script as returned by scriptHorizontalDir. If scriptHorizontalDir returns Nothing, then DirLTR is used. Finally if buffer language is not set, it will be set to the process's default language as returned by languageDefault. This may change in the future by taking buffer script into consideration when choosting a language. Note that languageDefault is not thread-safe the first time it is called. See documentation for that function for details.

data GlyphInfo

Holds information about the glyphs & their relation to input text.

Constructors

GlyphInfo

Fields

• codepoint :: Word32

  Glyph index (or unicode codepoint)

• cluster :: Word32

  The index of the character in the original text that corresponds to this GlyphInfo. More than one GlyphInfo may have the same cluster value if they resulted from the same character, & when more than one character gets merged into the same glyph GlyphInfo will have the smallest cluster value of them. By default some characters are merged into the same cluster even when they are seperate glyphs, Buffer's clusterLevel property allows selecting more fine grained cluster handling.

• unsafeToBreak :: Bool

  Indicates that if input text is broken at the beginning of the cluster this glyph is part of, then both sides need to be re-shaped, as the result might be different. On the flip side, it means that when this flag is not present, then it is safe to break the glyph-run at the beginning of this cluster, and the two sides will represent the exact same result one would get if breaking input text at the beginning of this cluster and shaping the two sides separately. This can be used to optimize paragraph layout, by avoiding re-shaping of each line after line-breaking.

• unsafeToConcat :: Bool

  Indicates that if input text is changed on one side of the beginning of the cluster this glyph is part of, then the shaping results for the other side might change. Note that the absence of this flag will NOT by itself mean that it IS safe to concat text. Only two pieces of text both of which clear of this flag can be concatenated safely. See https://harfbuzz.github.io/harfbuzz-hb-buffer.html#HB_GLYPH_FLAG_UNSAFE_TO_CONCAT for more details.

• safeToInsertTatweel :: Bool

  In scripts that use elongation (Arabic, Mongolian, Syriac, etc.), this flag signifies that it is safe to insert a U+0640 TATWEEL character before this cluster for elongation. This flag does not determine the script-specific elongation places, but only when it is safe to do the elongation without interrupting text shaping.

Instances

Eq GlyphInfo

Defined in Data.Text.Glyphize.Buffer

Methods

(==) :: GlyphInfo -> GlyphInfo -> Bool

(/=) :: GlyphInfo -> GlyphInfo -> Bool

Read GlyphInfo

Defined in Data.Text.Glyphize.Buffer

Methods

readsPrec :: Int -> ReadS GlyphInfo

readList :: ReadS [GlyphInfo]

readPrec :: ReadPrec GlyphInfo

readListPrec :: ReadPrec [GlyphInfo]

Show GlyphInfo

Defined in Data.Text.Glyphize.Buffer

Methods

showsPrec :: Int -> GlyphInfo -> ShowS

show :: GlyphInfo -> String

showList :: [GlyphInfo] -> ShowS

Storable GlyphInfo

Defined in Data.Text.Glyphize.Buffer

Methods

sizeOf :: GlyphInfo -> Int

alignment :: GlyphInfo -> Int

peekElemOff :: Ptr GlyphInfo -> Int -> IO GlyphInfo

pokeElemOff :: Ptr GlyphInfo -> Int -> GlyphInfo -> IO ()

peekByteOff :: Ptr b -> Int -> IO GlyphInfo

pokeByteOff :: Ptr b -> Int -> GlyphInfo -> IO ()

peek :: Ptr GlyphInfo -> IO GlyphInfo

poke :: Ptr GlyphInfo -> GlyphInfo -> IO ()

data GlyphPos

Holds positions of the glyph in both horizontal & vertical directions. All positions are relative to current point.

Constructors

GlyphPos

Fields

• x_advance :: Int32

  How much the line advances after drawing this glyph when setting text in horizontal direction.

• y_advance :: Int32

  How much the line advances after drawing this glyph when setting text in vertical direction.

• x_offset :: Int32

  How much the glyph moves on the X-axis before drawing it, this should not effect how much the line advances.

• y_offset :: Int32

  How much the glyph moves on the Y-axis before drawing it, this should not effect how much the line advances.

Instances

Eq GlyphPos

Defined in Data.Text.Glyphize.Buffer

Methods

(==) :: GlyphPos -> GlyphPos -> Bool

(/=) :: GlyphPos -> GlyphPos -> Bool

Read GlyphPos

Defined in Data.Text.Glyphize.Buffer

Methods

readsPrec :: Int -> ReadS GlyphPos

readList :: ReadS [GlyphPos]

readPrec :: ReadPrec GlyphPos

readListPrec :: ReadPrec [GlyphPos]

Show GlyphPos

Defined in Data.Text.Glyphize.Buffer

Methods

showsPrec :: Int -> GlyphPos -> ShowS

show :: GlyphPos -> String

showList :: [GlyphPos] -> ShowS

Generic GlyphPos

Defined in Data.Text.Glyphize.Buffer

Associated Types

type Rep GlyphPos :: Type -> Type

Methods

from :: GlyphPos -> Rep GlyphPos x

to :: Rep GlyphPos x -> GlyphPos

Storable GlyphPos

Defined in Data.Text.Glyphize.Buffer

Methods

sizeOf :: GlyphPos -> Int

alignment :: GlyphPos -> Int

peekElemOff :: Ptr GlyphPos -> Int -> IO GlyphPos

pokeElemOff :: Ptr GlyphPos -> Int -> GlyphPos -> IO ()

peekByteOff :: Ptr b -> Int -> IO GlyphPos

pokeByteOff :: Ptr b -> Int -> GlyphPos -> IO ()

peek :: Ptr GlyphPos -> IO GlyphPos

poke :: Ptr GlyphPos -> GlyphPos -> IO ()

type Rep GlyphPos

Defined in Data.Text.Glyphize.Buffer

type Rep GlyphPos = D1 (MetaData "GlyphPos" "Data.Text.Glyphize.Buffer" "harfbuzz-pure-1.0.1.0-inplace" False) (C1 (MetaCons "GlyphPos" PrefixI True) ((S1 (MetaSel (Just "x_advance") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Int32) :*: S1 (MetaSel (Just "y_advance") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Int32)) :*: (S1 (MetaSel (Just "x_offset") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Int32) :*: S1 (MetaSel (Just "y_offset") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Int32))))

data Feature

The structure that holds information about requested feature application. The feature will be applied with the given value to all glyphs which are in clusters between start (inclusive) and end (exclusive). Setting start to HB_FEATURE_GLOBAL_START and end to HB_FEATURE_GLOBAL_END specifies that the feature always applies to the entire buffer.

Constructors

Feature

Fields

• featTag' :: Word32

  Tag of the feature. Use featTag to decode as an ASCII string.

• featValue :: Word32

  The value of the feature. 0 disables the feature, non-zero (usually 1) enables the feature. For features implemented as lookup type 3 (like "salt") the value is a one based index into the alternates.

• featStart :: Word

  The cluster to start applying this feature setting (inclusive).

• featEnd :: Word

  The cluster to end applying this feature setting (exclusive).

Instances

Read Feature

Defined in Data.Text.Glyphize.Font

Methods

readsPrec :: Int -> ReadS Feature

readList :: ReadS [Feature]

readPrec :: ReadPrec Feature

readListPrec :: ReadPrec [Feature]

Show Feature

Defined in Data.Text.Glyphize.Font

Methods

showsPrec :: Int -> Feature -> ShowS

show :: Feature -> String

showList :: [Feature] -> ShowS

Generic Feature

Defined in Data.Text.Glyphize.Font

Associated Types

type Rep Feature :: Type -> Type

Methods

from :: Feature -> Rep Feature x

to :: Rep Feature x -> Feature

GStorable Feature

Defined in Data.Text.Glyphize.Font

Methods

gsizeOf :: Feature -> Int

galignment :: Feature -> Int

gpeekByteOff :: Ptr b -> Int -> IO Feature

gpokeByteOff :: Ptr b -> Int -> Feature -> IO ()

type Rep Feature

Defined in Data.Text.Glyphize.Font

type Rep Feature = D1 (MetaData "Feature" "Data.Text.Glyphize.Font" "harfbuzz-pure-1.0.1.0-inplace" False) (C1 (MetaCons "Feature" PrefixI True) ((S1 (MetaSel (Just "featTag'") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Word32) :*: S1 (MetaSel (Just "featValue") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Word32)) :*: (S1 (MetaSel (Just "featStart") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Word) :*: S1 (MetaSel (Just "featEnd") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Word))))

featTag :: Feature -> String

Tag of the feature.

data Variation

Data type for holding variation data. Registered OpenType variation-axis tags are listed in OpenType Axis Tag Registry.

Constructors

Variation

Fields

• varTag' :: Word32

  Tag of the variation-axis name. Use varTag to decode as an ASCII string.

• varValue :: Float

  Value of the variation axis.

Instances

Read Variation

Defined in Data.Text.Glyphize.Font

Methods

readsPrec :: Int -> ReadS Variation

readList :: ReadS [Variation]

readPrec :: ReadPrec Variation

readListPrec :: ReadPrec [Variation]

Show Variation

Defined in Data.Text.Glyphize.Font

Methods

showsPrec :: Int -> Variation -> ShowS

show :: Variation -> String

showList :: [Variation] -> ShowS

Generic Variation

Defined in Data.Text.Glyphize.Font

Associated Types

type Rep Variation :: Type -> Type

Methods

from :: Variation -> Rep Variation x

to :: Rep Variation x -> Variation

GStorable Variation

Defined in Data.Text.Glyphize.Font

Methods

gsizeOf :: Variation -> Int

galignment :: Variation -> Int

gpeekByteOff :: Ptr b -> Int -> IO Variation

gpokeByteOff :: Ptr b -> Int -> Variation -> IO ()

type Rep Variation

Defined in Data.Text.Glyphize.Font

type Rep Variation = D1 (MetaData "Variation" "Data.Text.Glyphize.Font" "harfbuzz-pure-1.0.1.0-inplace" False) (C1 (MetaCons "Variation" PrefixI True) (S1 (MetaSel (Just "varTag'") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Word32) :*: S1 (MetaSel (Just "varValue") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Float)))

varTag :: Variation -> String

Tag of the variation-axis.

parseFeature :: String -> Maybe Feature

Parses a string into a hb_feature_t. The format for specifying feature strings follows. All valid CSS font-feature-settings values other than "normal" and the global values are also accepted. CSS string escapes are not supported. See https://harfbuzz.github.io/harfbuzz-hb-common.html#hb-feature-from-string for additional details. The range indices refer to the positions between Unicode characters. The position before the first character is always 0.

unparseFeature :: Feature -> String

Converts a Feature into a String in the format understood by parseFeature.

parseVariation :: String -> Maybe Variation

Parses a string into a hb_variation_t. The format for specifying variation settings follows. All valid CSS font-variation-settings values other than "normal" and "inherited" are also accepted, though, not documented below. The format is a tag, optionally followed by an equals sign, followed by a number. For example wght=500, or slnt=-7.5.

unparseVariation :: Variation -> String

Converts a Variation into a String in the format understood by parseVariation.

globalStart :: Word

Special setting for featStart to apply the feature from the start of the buffer.

globalEnd :: Word

Special setting for featEnd to apply the feature to the end of the buffer.

countFace :: ByteString -> Word

Fetches the number of Faces in a ByteString.

type Face = ForeignPtr Face'

A Font face.

createFace :: ByteString -> Word -> Face

Constructs a new face object from the specified blob and a face index into that blob. The face index is used for blobs of file formats such as TTC and and DFont that can contain more than one face. Face indices within such collections are zero-based. Note: If the blob font format is not a collection, index is ignored. Otherwise, only the lower 16-bits of index are used. The unmodified index can be accessed via faceIndex. Note: The high 16-bits of index, if non-zero, are used by createFont to load named-instances in variable fonts. See createFont for details.

ftCreateFace :: FT_Face -> IO Face

Creates aFace object from the specified FT_Face. Not thread-safe due to FreeType dependency.

emptyFace :: Face

Fetches the singleton empty Face object.

faceTableTags :: Face -> Word -> Word -> (Word, [String])

Fetches a list of all table tags for a face, if possible. The list returned will begin at the offset provided

faceGlyphCount :: Face -> Word

Fetches the glyph-count value of the specified face object.

faceCollectUnicodes :: Face -> [Word32]

Collects all of the Unicode characters covered by Face into a list of unique values.

faceCollectVarSels :: Face -> [Word32]

Collects all Unicode "Variation Selector" characters covered by Face into a list of unique values.

faceCollectVarUnicodes :: Face -> Word32 -> [Word32]

Collects all Unicode characters for variation_selector covered by Face into a list of unique values.

faceIndex :: Face -> Word

Fetches the face-index corresponding to the given Face.

faceUpem :: Face -> Word

Fetches the units-per-em (upem) value of the specified Face object.

faceBlob :: Face -> ByteString

Fetches the binary blob that contains the specified Face. Returns an empty ByteString if referencing face data is not possible.

faceTable :: Face -> String -> ByteString

Fetches the specified table within the specified face.

type Font = ForeignPtr Font'

Data type for holding fonts

createFont :: Face -> Font

Constructs a new Font object from the specified Face. Note: If face's index value (as passed to createFace has non-zero top 16-bits, those bits minus one are passed to hb_font_set_var_named_instance(), effectively loading a named-instance of a variable font, instead of the default-instance. This allows specifying which named-instance to load by default when creating the face.

ftCreateFont :: FT_Face -> IO Font

Creates an Font object from the specified FT_Face. Note: You must set the face size on ft_face before calling ftCreateFont on it. HarfBuzz assumes size is always set and will access frSize` member of FT_Face unconditionally.

emptyFont :: Font

Fetches the empty Font object.

fontFace :: Font -> Face

Fetches the Face associated with the specified Font object.

fontGlyph :: Font -> Char -> Maybe Char -> Maybe Word32

Fetches the glyph ID for a Unicode codepoint in the specified Font, with an optional variation selector.

fontGlyphAdvance :: Font -> Word32 -> Maybe Direction -> (Int32, Int32)

Fetches the advance for a glyph ID from the specified font, in a text segment of the specified direction. Calls the appropriate direction-specific variant (horizontal or vertical) depending on the value of direction .

fontGlyphContourPoint :: Font -> Word32 -> Int -> Maybe (Int32, Int32)

Fetches the (x,y) coordinates of a specified contour-point index in the specified glyph, within the specified font.

fontGlyphContourPointForOrigin :: Font -> Word32 -> Int -> Maybe Direction -> Maybe (Int32, Int32)

Fetches the (X,Y) coordinates of a specified contour-point index in the specified glyph ID in the specified font, with respect to the origin in a text segment in the specified direction. Calls the appropriate direction-specific variant (horizontal or vertical) depending on the value of direction .

fontGlyphFromName :: Font -> String -> Maybe Word32

Fetches the glyph ID that corresponds to a name string in the specified Font.

fontGlyphHAdvance :: Font -> Word32 -> Int32

Fetches the advance for a glyph ID in the specified Font, for horizontal text segments.

fontGlyphVAdvance :: Font -> Word32 -> Int32

Fetches the advance for a glyph ID in the specified Font, for vertical text segments.

fontGlyphHKerning :: Font -> Word32 -> Word32 -> Int32

Fetches the kerning-adjustment value for a glyph-pair in the specified Font, for horizontal text segments.

fontGlyphHOrigin :: Font -> Word32 -> Maybe (Int32, Int32)

Fetches the (X,Y) coordinate of the origin for a glyph ID in the specified Font, for horizontal text segments.

fontGlyphVOrigin :: Font -> Word32 -> Maybe (Int32, Int32)

Fetches the (X,Y) coordinates of the origin for a glyph ID in the specified Font, for vertical text segments.

fontGlyphKerningForDir :: Font -> Word32 -> Word32 -> Maybe Direction -> (Int32, Int32)

Fetches the kerning-adjustment value for a glyph-pair in the specified Font. Calls the appropriate direction-specific variant (horizontal or vertical) depending on the value of given Direction.

fontGlyphName :: Font -> Word32 -> Maybe String

Fetches the glyph-name string for a glyph ID in the specified Font.

fontGlyphName_ :: Font -> Word32 -> Int -> Maybe String

Variant of fontGlyphName which lets you specify the maximum of the return value. Defaults to 32.

fontGlyphOriginForDir :: Font -> Word32 -> Maybe Direction -> (Int32, Int32)

Fetches the (X,Y) coordinates of the origin for a glyph in the specified Font. Calls the appropriate direction-specific variant (horizontal or vertical) depending on the value of given Direction.

fontNominalGlyph :: Font -> Char -> Maybe Word32

Fetches the nominal glyph ID for a Unicode codepoint in the specified font. This version of the function should not be used to fetch glyph IDs for codepoints modified by variation selectors. For variation-selector support use fontVarGlyph or use fontGlyph.

fontPPEm :: Font -> (Word32, Word32)

Fetches the horizontal & vertical points-per-em (ppem) of a Font.

fontPtEm :: Font -> Float

Fetches the "point size" of a Font. Used in CoreText to implement optical sizing.

fontScale :: Font -> (Int, Int)

Fetches the horizontal and vertical scale of a Font.

fontVarGlyph :: Font -> Word32 -> Word32 -> Maybe Word32

Fetches the glyph ID for a Unicode codepoint when followed by the specified variation-selector codepoint, in the specified Font.

fontSyntheticSlant :: Font -> Float

Fetches the "synthetic slant" of a font.

fontVarCoordsNormalized :: Font -> [Int]

Fetches the list of normalized variation coordinates currently set on a font. Note that this returned list may only contain values for some (or none) of the axes; ommitted axes effectively have default values.

fontTxt2Glyph :: Font -> String -> Maybe Word32

Fetches the glyph ID from given Font that matches the specified string. Strings of the format gidDDD or uniUUUU are parsed automatically.

fontGlyph2Str :: Font -> Word32 -> Int -> String

Fetches the name of the specified glyph ID in given Font as a string. If the glyph ID has no name in the Font, a string of the form gidDDD is generated with DDD being the glyph ID.

fontVarCoordsDesign :: Font -> [Float]

Fetches the list of variation coordinates (in design-space units) currently set on a Font. Note that this returned list may only contain values for some (or none) of the axes; ommitted axes effectively have their default values.

data GlyphExtents

Glyph extent values, measured in font units. Note that height is negative, in coordinate systems that grow up.

Constructors

GlyphExtents

Fields

• xBearing :: Word32

  Distance from the x-origin to the left extremum of the glyph.

• yBearing :: Word32

  Distance from the top extremum of the glyph to the y-origin.

• width :: Word32

  Distance from the left extremum of the glyph to the right extremum.

• height :: Word32

  Distance from the top extremum of the glyph to the right extremum.

Instances

Generic GlyphExtents

Defined in Data.Text.Glyphize.Font

Associated Types

type Rep GlyphExtents :: Type -> Type

Methods

from :: GlyphExtents -> Rep GlyphExtents x

to :: Rep GlyphExtents x -> GlyphExtents

GStorable GlyphExtents

Defined in Data.Text.Glyphize.Font

Methods

gsizeOf :: GlyphExtents -> Int

galignment :: GlyphExtents -> Int

gpeekByteOff :: Ptr b -> Int -> IO GlyphExtents

gpokeByteOff :: Ptr b -> Int -> GlyphExtents -> IO ()

type Rep GlyphExtents

Defined in Data.Text.Glyphize.Font

type Rep GlyphExtents = D1 (MetaData "GlyphExtents" "Data.Text.Glyphize.Font" "harfbuzz-pure-1.0.1.0-inplace" False) (C1 (MetaCons "GlyphExtents" PrefixI True) ((S1 (MetaSel (Just "xBearing") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Word32) :*: S1 (MetaSel (Just "yBearing") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Word32)) :*: (S1 (MetaSel (Just "width") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Word32) :*: S1 (MetaSel (Just "height") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Word32))))

fontGlyphExtents :: Font -> Word32 -> Maybe GlyphExtents

Fetches the GlyphExtents data for a glyph ID in the specified Font.

fontGlyphExtentsForOrigin :: Font -> Word32 -> Maybe Direction -> Maybe GlyphExtents

Fetches the GlyphExtents data for a glyph ID in the specified Font, with respect to the origin in a text segment in the specified direction. Calls the appropriate direction-specific variant (horizontal or vertical) depending on the value of given Direction.

data FontExtents

Font-wide extent values, measured in font units. Note that typically ascender is positive and descender is negative, in coordinate systems that grow up. Note: Due to presence of 9 additional private fields, arrays of font extents will not decode correctly. So far this doesn't matter.

Constructors

FontExtents

Fields

• ascender :: Int32

  The height of typographic ascenders.

• descender :: Int32

  The depth of typographic descenders.

• lineGap :: Int32

  The suggested line-spacing gap.

Instances

Generic FontExtents

Defined in Data.Text.Glyphize.Font

Associated Types

type Rep FontExtents :: Type -> Type

Methods

from :: FontExtents -> Rep FontExtents x

to :: Rep FontExtents x -> FontExtents

GStorable FontExtents

Defined in Data.Text.Glyphize.Font

Methods

gsizeOf :: FontExtents -> Int

galignment :: FontExtents -> Int

gpeekByteOff :: Ptr b -> Int -> IO FontExtents

gpokeByteOff :: Ptr b -> Int -> FontExtents -> IO ()

type Rep FontExtents

Defined in Data.Text.Glyphize.Font

type Rep FontExtents = D1 (MetaData "FontExtents" "Data.Text.Glyphize.Font" "harfbuzz-pure-1.0.1.0-inplace" False) (C1 (MetaCons "FontExtents" PrefixI True) (S1 (MetaSel (Just "ascender") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Int32) :*: (S1 (MetaSel (Just "descender") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Int32) :*: S1 (MetaSel (Just "lineGap") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Int32))))

fontExtentsForDir :: Font -> Maybe Direction -> FontExtents

Fetches the extents for a font in a text segment of the specified direction. Calls the appropriate direction-specific variant (horizontal or vertical) depending on the value of direction .

fontHExtents :: ForeignPtr Font' -> Maybe FontExtents

Fetches the extents for a specified font, for horizontal text segments.

fontVExtents :: ForeignPtr Font' -> Maybe FontExtents

Fetches the extents for a specified font, for vertical text segments.

data FontOptions

Allows configuring properties on a Font when creating it.

Constructors

FontOptions

Fields

• optionPPEm :: Maybe (Word, Word)

  Sets the horizontal and vertical pixels-per-em (ppem) of the newly-created Font.

• optionPtEm :: Maybe Float

  Sets the "point size" of a newly-created Font. Used in CoreText to implement optical sizing. Note: There are 72 points in an inch.

• optionScale :: Maybe (Int, Int)

  Sets the horizontal and vertical scale of a newly-created Font.

• optionFace :: Maybe Face

  Sets the font-face value of the newly-created Font.

• optionParent :: Maybe Font

  Sets the parent Font of the newly-created Font.

• optionSynthSlant :: Maybe Float

  Sets the "synthetic slant" of a newly-created Font. By default is zero. Synthetic slant is the graphical skew applied to the font at rendering time. Harfbuzz needs to know this value to adjust shaping results, metrics, and style valuesto match the slanted rendering. Note: The slant value is a ratio. For example, a 20% slant would be represented as a 0.2 value.

• optionVariations :: [Variation]

  Applies a list of font-variation settings to a font. Axes not included will be effectively set to their default values.

• optionVarCoordsDesign :: [Float]

  Applies a list of variation coordinates (in design-space units) to a newly-created Font. Axes not included in coords will be effectively set to their default values.

• optionVarCoordsNormalized :: [Int]

  Applies a list of variation coordinates (in normalized units) to a newly-created Font. Axes not included in coords will be effectively set to their default values.

• optionVarNamedInstance :: Maybe Word

  Sets design coords of a font from a named instance index.

defaultFontOptions :: FontOptions

FontOptions which has no effect on the newly-created Font.

createFontWithOptions :: FontOptions -> Face -> Font

Variant of createFont which applies the given FontOptions.

ftCreateFontWithOptions :: FontOptions -> FT_Face -> Font

Variant of ftCreateFont which applies the given FontOptions.