FreeType-2.1.10 API Reference
Base Interface
Synopsis
#FT_Library
FT_Library
#FT_HAS_FIXED_SIZES
FT_HAS_FIXED_SIZES
#FT_Set_Char_Size
FT_Set_Char_Size
#FT_Face
FT_Face
#FT_HAS_FAST_GLYPHS
FT_HAS_FAST_GLYPHS
#FT_Set_Pixel_Sizes
FT_Set_Pixel_Sizes
#FT_Size
FT_Size
#FT_HAS_GLYPH_NAMES
FT_HAS_GLYPH_NAMES
#FT_Load_Glyph
FT_Load_Glyph
#FT_GlyphSlot
FT_GlyphSlot
#FT_HAS_MULTIPLE_MASTERS
FT_HAS_MULTIPLE_MASTERS
#FT_Load_Char
FT_Load_Char
#FT_CharMap
FT_CharMap
#FT_STYLE_FLAG_XXX
FT_STYLE_FLAG_XXX
#FT_LOAD_XXX
FT_LOAD_XXX
#FT_Encoding
FT_Encoding
#FT_Size_Internal
FT_Size_Internal
#FT_Set_Transform
FT_Set_Transform
#FT_Glyph_Metrics
FT_Glyph_Metrics
#FT_Size_Metrics
FT_Size_Metrics
#FT_Render_Mode
FT_Render_Mode
#FT_Bitmap_Size
FT_Bitmap_Size
#FT_SizeRec
FT_SizeRec
#ft_render_mode_xxx
ft_render_mode_xxx
#FT_Module
FT_Module
#FT_SubGlyph
FT_SubGlyph
#FT_Render_Glyph
FT_Render_Glyph
#FT_Driver
FT_Driver
#FT_Slot_Internal
FT_Slot_Internal
#FT_Kerning_Mode
FT_Kerning_Mode
#FT_Renderer
FT_Renderer
#FT_GlyphSlotRec
FT_GlyphSlotRec
#ft_kerning_default
ft_kerning_default
#FT_ENC_TAG
FT_ENC_TAG
#FT_Init_FreeType
FT_Init_FreeType
#ft_kerning_unfitted
ft_kerning_unfitted
#ft_encoding_xxx
ft_encoding_xxx
#FT_Library_Version
FT_Library_Version
#ft_kerning_unscaled
ft_kerning_unscaled
#FT_CharMapRec
FT_CharMapRec
#FT_Done_FreeType
FT_Done_FreeType
#FT_Get_Kerning
FT_Get_Kerning
#FT_Face_Internal
FT_Face_Internal
#FT_OPEN_XXX
FT_OPEN_XXX
#FT_Get_Glyph_Name
FT_Get_Glyph_Name
#FT_FaceRec
FT_FaceRec
#FT_Parameter
FT_Parameter
#FT_Get_Postscript_Name
FT_Get_Postscript_Name
#FT_FACE_FLAG_XXX
FT_FACE_FLAG_XXX
#FT_Open_Args
FT_Open_Args
#FT_Select_Charmap
FT_Select_Charmap
#FT_HAS_HORIZONTAL
FT_HAS_HORIZONTAL
#FT_New_Face
FT_New_Face
#FT_Set_Charmap
FT_Set_Charmap
#FT_HAS_VERTICAL
FT_HAS_VERTICAL
#FT_New_Memory_Face
FT_New_Memory_Face
#FT_Get_Charmap_Index
FT_Get_Charmap_Index
#FT_HAS_KERNING
FT_HAS_KERNING
#FT_Open_Face
FT_Open_Face
#FT_Get_Char_Index
FT_Get_Char_Index
#FT_IS_SCALABLE
FT_IS_SCALABLE
#FT_Attach_File
FT_Attach_File
#FT_Get_First_Char
FT_Get_First_Char
#FT_IS_SFNT
FT_IS_SFNT
#FT_Attach_Stream
FT_Attach_Stream
#FT_Get_Next_Char
FT_Get_Next_Char
#FT_IS_FIXED_WIDTH
FT_IS_FIXED_WIDTH
#FT_Done_Face
FT_Done_Face
#FT_Get_Name_Index
FT_Get_Name_Index
This section describes the public high-level API of FreeType 2.
FT_Library
typedef
struct
FT_LibraryRec_  *
FT_Library
;
A handle to a FreeType library instance. Each `library' is completely independent from the others; it is the `root' of a set of objects like fonts, faces, sizes, etc.
It also embeds a memory manager (see
ft2-system_interface.html#FT_Memory
FT_Memory
), as well as a scan-line converter object (see
ft2-raster.html#FT_Raster
FT_Raster
).
note
Library objects are normally created by
ft2-base_interface.html#FT_Init_FreeType
FT_Init_FreeType
, and destroyed with
ft2-base_interface.html#FT_Done_FreeType
FT_Done_FreeType
.
FT_Face
typedef
struct
FT_FaceRec_*
FT_Face
;
A handle to a given typographic face object. A face object models a given typeface, in a given style.
note
Each face object also owns a single
ft2-base_interface.html#FT_GlyphSlot
FT_GlyphSlot
object, as well as one or more
ft2-base_interface.html#FT_Size
FT_Size
objects.
Use
ft2-base_interface.html#FT_New_Face
FT_New_Face
or
ft2-base_interface.html#FT_Open_Face
FT_Open_Face
to create a new face object from a given filepathname or a custom input stream.
Use
ft2-base_interface.html#FT_Done_Face
FT_Done_Face
to destroy it (along with its slot and sizes).
also
The
ft2-base_interface.html#FT_FaceRec
FT_FaceRec
details the publicly accessible fields of a given face object.
FT_Size
typedef
struct
FT_SizeRec_*
FT_Size
;
A handle to a given size object. Such an object models the data that depends on the current
resolution
and _character size_ in a given
ft2-base_interface.html#FT_Face
FT_Face
.
note
Each face object owns one or more sizes. There is however a single
active
size for the face at any time that will be used by functions like
ft2-base_interface.html#FT_Load_Glyph
FT_Load_Glyph
,
ft2-base_interface.html#FT_Get_Kerning
FT_Get_Kerning
, etc.
You can use the
ft2-sizes_management.html#FT_Activate_Size
FT_Activate_Size
API to change the current active size of any given face.
also
The
ft2-base_interface.html#FT_SizeRec
FT_SizeRec
structure details the publicly accessible fields of a given face object.
FT_GlyphSlot
typedef
struct
FT_GlyphSlotRec_*
FT_GlyphSlot
;
A handle to a given `glyph slot'. A slot is a container where it is possible to load any one of the glyphs contained in its parent face.
In other words, each time you call
ft2-base_interface.html#FT_Load_Glyph
FT_Load_Glyph
or
ft2-base_interface.html#FT_Load_Char
FT_Load_Char
, the slot's content is erased by the new glyph data, i.e. the glyph's metrics, its image (bitmap or outline), and other control information.
also
ft2-base_interface.html#FT_GlyphSlotRec
FT_GlyphSlotRec
details the publicly accessible glyph fields.
FT_CharMap
typedef
struct
FT_CharMapRec_*
FT_CharMap
;
A handle to a given character map. A charmap is used to translate character codes in a given encoding into glyph indexes for its parent's face. Some font formats may provide several charmaps per font.
Each face object owns zero or more charmaps, but only one of them can be "active" and used by
ft2-base_interface.html#FT_Get_Char_Index
FT_Get_Char_Index
or
ft2-base_interface.html#FT_Load_Char
FT_Load_Char
.
The list of available charmaps in a face is available through the "face->num_charmaps" and "face->charmaps" fields of
ft2-base_interface.html#FT_FaceRec
FT_FaceRec
.
The currently active charmap is available as "face->charmap". You should call
ft2-base_interface.html#FT_Set_Charmap
FT_Set_Charmap
to change it.
note
When a new face is created (either through
ft2-base_interface.html#FT_New_Face
FT_New_Face
or
ft2-base_interface.html#FT_Open_Face
FT_Open_Face
), the library looks for a Unicode charmap within the list and automatically activates it.
also
The
ft2-base_interface.html#FT_CharMapRec
FT_CharMapRec
details the publicly accessible fields of a given character map.
FT_Encoding
typedef
enum
FT_Encoding_
{
ft2-base_interface.html#FT_ENC_TAG
FT_ENC_TAG
(
ft2-base_interface.html#FT_Encoding
FT_ENCODING_NONE
, 0, 0, 0, 0 ),
ft2-base_interface.html#FT_ENC_TAG
FT_ENC_TAG
(
ft2-base_interface.html#FT_Encoding
FT_ENCODING_MS_SYMBOL
,  's', 'y', 'm', 'b' ),
ft2-base_interface.html#FT_ENC_TAG
FT_ENC_TAG
(
ft2-base_interface.html#FT_Encoding
FT_ENCODING_UNICODE
,    'u', 'n', 'i', 'c' ),
ft2-base_interface.html#FT_ENC_TAG
FT_ENC_TAG
(
ft2-base_interface.html#FT_Encoding
FT_ENCODING_SJIS
,    's', 'j', 'i', 's' ),
ft2-base_interface.html#FT_ENC_TAG
FT_ENC_TAG
(
ft2-base_interface.html#FT_Encoding
FT_ENCODING_GB2312
,  'g', 'b', ' ', ' ' ),
ft2-base_interface.html#FT_ENC_TAG
FT_ENC_TAG
(
ft2-base_interface.html#FT_Encoding
FT_ENCODING_BIG5
,    'b', 'i', 'g', '5' ),
ft2-base_interface.html#FT_ENC_TAG
FT_ENC_TAG
(
ft2-base_interface.html#FT_Encoding
FT_ENCODING_WANSUNG
, 'w', 'a', 'n', 's' ),
ft2-base_interface.html#FT_ENC_TAG
FT_ENC_TAG
(
ft2-base_interface.html#FT_Encoding
FT_ENCODING_JOHAB
,   'j', 'o', 'h', 'a' ),
/* for backwards compatibility */
ft2-base_interface.html#FT_Encoding
FT_ENCODING_MS_SJIS
=
ft2-base_interface.html#FT_Encoding
FT_ENCODING_SJIS
,
ft2-base_interface.html#FT_Encoding
FT_ENCODING_MS_GB2312
=
ft2-base_interface.html#FT_Encoding
FT_ENCODING_GB2312
,
ft2-base_interface.html#FT_Encoding
FT_ENCODING_MS_BIG5
=
ft2-base_interface.html#FT_Encoding
FT_ENCODING_BIG5
,
ft2-base_interface.html#FT_Encoding
FT_ENCODING_MS_WANSUNG
=
ft2-base_interface.html#FT_Encoding
FT_ENCODING_WANSUNG
,
ft2-base_interface.html#FT_Encoding
FT_ENCODING_MS_JOHAB
=
ft2-base_interface.html#FT_Encoding
FT_ENCODING_JOHAB
,
ft2-base_interface.html#FT_ENC_TAG
FT_ENC_TAG
(
ft2-base_interface.html#FT_Encoding
FT_ENCODING_ADOBE_STANDARD
, 'A', 'D', 'O', 'B' ),
ft2-base_interface.html#FT_ENC_TAG
FT_ENC_TAG
(
ft2-base_interface.html#FT_Encoding
FT_ENCODING_ADOBE_EXPERT
,   'A', 'D', 'B', 'E' ),
ft2-base_interface.html#FT_ENC_TAG
FT_ENC_TAG
(
ft2-base_interface.html#FT_Encoding
FT_ENCODING_ADOBE_CUSTOM
,   'A', 'D', 'B', 'C' ),
ft2-base_interface.html#FT_ENC_TAG
FT_ENC_TAG
(
ft2-base_interface.html#FT_Encoding
FT_ENCODING_ADOBE_LATIN_1
,  'l', 'a', 't', '1' ),
ft2-base_interface.html#FT_ENC_TAG
FT_ENC_TAG
(
ft2-base_interface.html#FT_Encoding
FT_ENCODING_OLD_LATIN_2
, 'l', 'a', 't', '2' ),
ft2-base_interface.html#FT_ENC_TAG
FT_ENC_TAG
(
ft2-base_interface.html#FT_Encoding
FT_ENCODING_APPLE_ROMAN
, 'a', 'r', 'm', 'n' )
}
FT_Encoding
;
An enumeration used to specify encodings supported by charmaps. Used in the
ft2-base_interface.html#FT_Select_Charmap
FT_Select_Charmap
API function.
note
Because of 32-bit charcodes defined in Unicode (i.e., surrogates), all character codes must be expressed as FT_Longs.
The values of this type correspond to specific character repertories (i.e. charsets), and not to text encoding methods (like UTF-8, UTF-16, GB2312_EUC, etc.).
Other encodings might be defined in the future.
values
FT_ENCODING_NONE
The encoding value 0 is reserved.
FT_ENCODING_UNICODE
Corresponds to the Unicode character set. This value covers all versions of the Unicode repertoire, including ASCII and Latin-1. Most fonts include a Unicode charmap, but not all of them.
FT_ENCODING_MS_SYMBOL
Corresponds to the Microsoft Symbol encoding, used to encode mathematical symbols in the 32..255 character code range. For more information, see `http://www.ceviz.net/symbol.htm'.
FT_ENCODING_SJIS
Corresponds to Japanese SJIS encoding. More info at at `http://langsupport.japanreference.com/encoding.shtml'. See note on multi-byte encodings below.
FT_ENCODING_GB2312
Corresponds to an encoding system for Simplified Chinese as used used in mainland China.
FT_ENCODING_BIG5
Corresponds to an encoding system for Traditional Chinese as used in Taiwan and Hong Kong.
FT_ENCODING_WANSUNG
Corresponds to the Korean encoding system known as Wansung. For more information see `http://www.microsoft.com/typography/unicode/949.txt'.
FT_ENCODING_JOHAB
The Korean standard character set (KS C-5601-1992), which corresponds to MS Windows code page 1361. This character set includes all possible Hangeul character combinations.
FT_ENCODING_ADOBE_LATIN_1
Corresponds to a Latin-1 encoding as defined in a Type 1 Postscript font. It is limited to 256 character codes.
FT_ENCODING_ADOBE_STANDARD
Corresponds to the Adobe Standard encoding, as found in Type 1, CFF, and OpenType/CFF fonts. It is limited to 256 character codes.
FT_ENCODING_ADOBE_EXPERT
Corresponds to the Adobe Expert encoding, as found in Type 1, CFF, and OpenType/CFF fonts. It is limited to 256 character codes.
FT_ENCODING_ADOBE_CUSTOM
Corresponds to a custom encoding, as found in Type 1, CFF, and OpenType/CFF fonts. It is limited to 256 character codes.
FT_ENCODING_APPLE_ROMAN
Corresponds to the 8-bit Apple roman encoding. Many TrueType and OpenType fonts contain a charmap for this encoding, since older versions of Mac OS are able to use it.
FT_ENCODING_OLD_LATIN_2
This value is deprecated and was never used nor reported by FreeType. Don't use or test for it.
FT_ENCODING_MS_SJIS
Same as FT_ENCODING_SJIS. Deprecated.
FT_ENCODING_MS_GB2312
Same as FT_ENCODING_GB2312. Deprecated.
FT_ENCODING_MS_BIG5
Same as FT_ENCODING_BIG5. Deprecated.
FT_ENCODING_MS_WANSUNG
Same as FT_ENCODING_WANSUNG. Deprecated.
FT_ENCODING_MS_JOHAB
Same as FT_ENCODING_JOHAB. Deprecated.
note
By default, FreeType automatically synthetizes a Unicode charmap for Postscript fonts, using their glyph names dictionaries. However, it will also report the encodings defined explicitly in the font file, for the cases when they are needed, with the Adobe values as well.
FT_ENCODING_NONE is set by the BDF and PCF drivers if the charmap is neither Unicode nor ISO-8859-1 (otherwise it is set to FT_ENCODING_UNICODE). Use `FT_Get_BDF_Charset_ID' to find out which encoding is really present. If, for example, the `cs_registry' field is `KOI8' and the `cs_encoding' field is `R', the font is encoded in KOI8-R.
FT_ENCODING_NONE is always set (with a single exception) by the winfonts driver. Use `FT_Get_WinFNT_Header' and examine the `charset' field of the `FT_WinFNT_HeaderRec' structure to find out which encoding is really present. For example, FT_WinFNT_ID_CP1251 (204) means Windows code page 1251 (for Russian).
FT_ENCODING_NONE is set if `platform_id' is `TT_PLATFORM_MACINTOSH' and `encoding_id' is not `TT_MAC_ID_ROMAN' (otherwise it is set to FT_ENCODING_APPLE_ROMAN).
If `platform_id' is `TT_PLATFORM_MACINTOSH', use the function `FT_Get_CMap_Language_ID' to query the Mac language ID which may be needed to be able to distinguish Apple encoding variants. See
http://www.unicode.org/Public/MAPPINGS/VENDORS/APPLE/README.TXT
to get an idea how to do that. Basically, if the language ID is 0, dont use it, otherwise subtract 1 from the language ID. Then examine `encoding_id'. If, for example, `encoding_id' is `TT_MAC_ID_ROMAN' and the language ID (minus 1) is `TT_MAC_LANGID_GREEK', it is the Greek encoding, not Roman. `TT_MAC_ID_ARABIC' with `TT_MAC_LANGID_FARSI' means the Farsi variant the Arabic encoding.
FT_Glyph_Metrics
typedef
struct
FT_Glyph_Metrics_
{
ft2-basic_types.html#FT_Pos
FT_Pos
width;
ft2-basic_types.html#FT_Pos
FT_Pos
height;
ft2-basic_types.html#FT_Pos
FT_Pos
horiBearingX;
ft2-basic_types.html#FT_Pos
FT_Pos
horiBearingY;
ft2-basic_types.html#FT_Pos
FT_Pos
horiAdvance;
ft2-basic_types.html#FT_Pos
FT_Pos
vertBearingX;
ft2-basic_types.html#FT_Pos
FT_Pos
vertBearingY;
ft2-basic_types.html#FT_Pos
FT_Pos
vertAdvance;
}
FT_Glyph_Metrics
;
A structure used to model the metrics of a single glyph. The values are expressed in 26.6 fractional pixel format; if the flag FT_LOAD_NO_SCALE is used, values are returned in font units instead.
fields
width
The glyph's width.
height
The glyph's height.
horiBearingX
Left side bearing for horizontal layout.
horiBearingY
Top side bearing for horizontal layout.
horiAdvance
Advance width for horizontal layout.
vertBearingX
Left side bearing for vertical layout.
vertBearingY
Top side bearing for vertical layout.
vertAdvance
Advance height for vertical layout.
FT_Bitmap_Size
typedef
struct
FT_Bitmap_Size_
{
ft2-basic_types.html#FT_Short
FT_Short
height;
ft2-basic_types.html#FT_Short
FT_Short
width;
ft2-basic_types.html#FT_Pos
FT_Pos
size;
ft2-basic_types.html#FT_Pos
FT_Pos
x_ppem;
ft2-basic_types.html#FT_Pos
FT_Pos
y_ppem;
}
FT_Bitmap_Size
;
This structure models the size of a bitmap strike (i.e., a bitmap instance of the font for a given resolution) in a fixed-size font face. It is used for the `available_sizes' field of the
ft2-base_interface.html#FT_FaceRec
FT_FaceRec
structure.
fields
height
The (vertical) baseline-to-baseline distance in pixels. It makes most sense to define the height of a bitmap font in this way.
width
The average width of the font (in pixels). Since the algorithms to compute this value are different for the various bitmap formats, it can only give an additional hint if the `height' value isn't sufficient to select the proper font. For monospaced fonts the average width is the same as the maximum width.
size
The point size in 26.6 fractional format this font shall represent (for a given vertical resolution).
x_ppem
The horizontal ppem value (in 26.6 fractional format).
y_ppem
The vertical ppem value (in 26.6 fractional format). Usually, this is the `nominal' pixel height of the font.
note
The values in this structure are taken from the bitmap font. If the font doesn't provide a parameter it is set to zero to indicate that the information is not available.
The following formula converts from dpi to ppem:
ppem = size * dpi / 72
where `size' is in points.
Windows FNT: The `size' parameter is not reliable: There exist fonts (e.g., app850.fon) which have a wrong size for some subfonts; x_ppem and y_ppem are thus set equal to pixel width and height given in in the Windows FNT header.
TrueType embedded bitmaps: `size', `width', and `height' values are not contained in the bitmap strike itself. They are computed from the global font parameters.
FT_Module
typedef
struct
FT_ModuleRec_*
FT_Module
;
A handle to a given FreeType module object. Each module can be a font driver, a renderer, or anything else that provides services to the formers.
FT_Driver
typedef
struct
FT_DriverRec_*
FT_Driver
;
A handle to a given FreeType font driver object. Each font driver is a special module capable of creating faces from font files.
FT_Renderer
typedef
struct
FT_RendererRec_*
FT_Renderer
;
A handle to a given FreeType renderer. A renderer is a special module in charge of converting a glyph image to a bitmap, when necessary. Each renderer supports a given glyph image format, and one or more target surface depths.
FT_ENC_TAG
#ifndef
FT_ENC_TAG
#define
FT_ENC_TAG
( value, a, b, c, d )         \
value = ( ( (FT_UInt32)(a) << 24 ) |  \
( (FT_UInt32)(b) << 16 ) |  \
( (FT_UInt32)(c) <<  8 ) |  \
(FT_UInt32)(d)         )
#endif /*
FT_ENC_TAG
*/
This macro converts four letter tags into an unsigned long. It is used to define "encoding" identifiers (see
ft2-base_interface.html#FT_Encoding
FT_Encoding
).
note
Since many 16bit compilers don't like 32bit enumerations, you should redefine this macro in case of problems to something like this:
#define FT_ENC_TAG( value, a, b, c, d ) value
to get a simple enumeration without assigning special numbers.
ft_encoding_xxx
#define
ft2-base_interface.html#ft_encoding_xxx
ft_encoding_none
ft2-base_interface.html#FT_Encoding
FT_ENCODING_NONE
#define
ft2-base_interface.html#ft_encoding_xxx
ft_encoding_unicode
ft2-base_interface.html#FT_Encoding
FT_ENCODING_UNICODE
#define
ft2-base_interface.html#ft_encoding_xxx
ft_encoding_symbol
ft2-base_interface.html#FT_Encoding
FT_ENCODING_MS_SYMBOL
#define
ft2-base_interface.html#ft_encoding_xxx
ft_encoding_latin_1
ft2-base_interface.html#FT_Encoding
FT_ENCODING_ADOBE_LATIN_1
#define
ft2-base_interface.html#ft_encoding_xxx
ft_encoding_latin_2
ft2-base_interface.html#FT_Encoding
FT_ENCODING_OLD_LATIN_2
#define
ft2-base_interface.html#ft_encoding_xxx
ft_encoding_sjis
ft2-base_interface.html#FT_Encoding
FT_ENCODING_SJIS
#define
ft2-base_interface.html#ft_encoding_xxx
ft_encoding_gb2312
ft2-base_interface.html#FT_Encoding
FT_ENCODING_GB2312
#define
ft2-base_interface.html#ft_encoding_xxx
ft_encoding_big5
ft2-base_interface.html#FT_Encoding
FT_ENCODING_BIG5
#define
ft2-base_interface.html#ft_encoding_xxx
ft_encoding_wansung
ft2-base_interface.html#FT_Encoding
FT_ENCODING_WANSUNG
#define
ft2-base_interface.html#ft_encoding_xxx
ft_encoding_johab
ft2-base_interface.html#FT_Encoding
FT_ENCODING_JOHAB
#define
ft2-base_interface.html#ft_encoding_xxx
ft_encoding_adobe_standard
ft2-base_interface.html#FT_Encoding
FT_ENCODING_ADOBE_STANDARD
#define
ft2-base_interface.html#ft_encoding_xxx
ft_encoding_adobe_expert
ft2-base_interface.html#FT_Encoding
FT_ENCODING_ADOBE_EXPERT
#define
ft2-base_interface.html#ft_encoding_xxx
ft_encoding_adobe_custom
ft2-base_interface.html#FT_Encoding
FT_ENCODING_ADOBE_CUSTOM
#define
ft2-base_interface.html#ft_encoding_xxx
ft_encoding_apple_roman
ft2-base_interface.html#FT_Encoding
FT_ENCODING_APPLE_ROMAN
These constants are deprecated; use the corresponding
ft2-base_interface.html#FT_Encoding
FT_Encoding
values instead.
values
ft_encoding_none
see
ft2-base_interface.html#FT_Encoding
FT_ENCODING_NONE
ft_encoding_unicode
see
ft2-base_interface.html#FT_Encoding
FT_ENCODING_UNICODE
ft_encoding_latin_2
see
ft2-base_interface.html#FT_Encoding
FT_ENCODING_OLD_LATIN_2
ft_encoding_symbol
see
ft2-base_interface.html#FT_Encoding
FT_ENCODING_MS_SYMBOL
ft_encoding_sjis
see
ft2-base_interface.html#FT_Encoding
FT_ENCODING_SJIS
ft_encoding_gb2312
see
ft2-base_interface.html#FT_Encoding
FT_ENCODING_GB2312
ft_encoding_big5
see
ft2-base_interface.html#FT_Encoding
FT_ENCODING_BIG5
ft_encoding_wansung
see
ft2-base_interface.html#FT_Encoding
FT_ENCODING_WANSUNG
ft_encoding_johab
see
ft2-base_interface.html#FT_Encoding
FT_ENCODING_JOHAB
ft_encoding_adobe_standard
see
ft2-base_interface.html#FT_Encoding
FT_ENCODING_ADOBE_STANDARD
ft_encoding_adobe_expert
see
ft2-base_interface.html#FT_Encoding
FT_ENCODING_ADOBE_EXPERT
ft_encoding_adobe_custom
see
ft2-base_interface.html#FT_Encoding
FT_ENCODING_ADOBE_CUSTOM
ft_encoding_latin_1
see
ft2-base_interface.html#FT_Encoding
FT_ENCODING_ADOBE_LATIN_1
ft_encoding_apple_roman
see
ft2-base_interface.html#FT_Encoding
FT_ENCODING_APPLE_ROMAN
FT_CharMapRec
typedef
struct
FT_CharMapRec_
{
ft2-base_interface.html#FT_Face
FT_Face
face;
ft2-base_interface.html#FT_Encoding
FT_Encoding
encoding;
ft2-basic_types.html#FT_UShort
FT_UShort
platform_id;
ft2-basic_types.html#FT_UShort
FT_UShort
encoding_id;
}
FT_CharMapRec
;
The base charmap structure.
fields
face
A handle to the parent face object.
encoding
An
ft2-base_interface.html#FT_Encoding
FT_Encoding
tag identifying the charmap. Use this with
ft2-base_interface.html#FT_Select_Charmap
FT_Select_Charmap
.
platform_id
An ID number describing the platform for the following encoding ID. This comes directly from the TrueType specification and should be emulated for other formats.
encoding_id
A platform specific encoding number. This also comes from the TrueType specification and should be emulated similarly.
FT_Face_Internal
typedef
struct
FT_Face_InternalRec_*
FT_Face_Internal
;
An opaque handle to an FT_Face_InternalRec structure, used to model private data of a given
ft2-base_interface.html#FT_Face
FT_Face
object.
This structure might change between releases of FreeType 2 and is not generally available to client applications.
FT_FaceRec
typedef
struct
FT_FaceRec_
{
ft2-basic_types.html#FT_Long
FT_Long
num_faces;
ft2-basic_types.html#FT_Long
FT_Long
face_index;
ft2-basic_types.html#FT_Long
FT_Long
face_flags;
ft2-basic_types.html#FT_Long
FT_Long
style_flags;
ft2-basic_types.html#FT_Long
FT_Long
num_glyphs;
ft2-basic_types.html#FT_String
FT_String
*        family_name;
ft2-basic_types.html#FT_String
FT_String
*        style_name;
ft2-basic_types.html#FT_Int
FT_Int
num_fixed_sizes;
ft2-base_interface.html#FT_Bitmap_Size
FT_Bitmap_Size
*   available_sizes;
ft2-basic_types.html#FT_Int
FT_Int
num_charmaps;
ft2-base_interface.html#FT_CharMap
FT_CharMap
*
charmaps
;
ft2-basic_types.html#FT_Generic
FT_Generic
generic;
/*# the following are only relevant to scalable outlines */
ft2-basic_types.html#FT_BBox
FT_BBox
bbox;
ft2-basic_types.html#FT_UShort
FT_UShort
units_per_EM;
ft2-basic_types.html#FT_Short
FT_Short
ascender;
ft2-basic_types.html#FT_Short
FT_Short
descender;
ft2-basic_types.html#FT_Short
FT_Short
height;
ft2-basic_types.html#FT_Short
FT_Short
max_advance_width;
ft2-basic_types.html#FT_Short
FT_Short
max_advance_height;
ft2-basic_types.html#FT_Short
FT_Short
underline_position;
ft2-basic_types.html#FT_Short
FT_Short
underline_thickness;
ft2-base_interface.html#FT_GlyphSlot
FT_GlyphSlot
glyph;
ft2-base_interface.html#FT_Size
FT_Size
size;
ft2-base_interface.html#FT_CharMap
FT_CharMap
charmap
;
/*@private begin */
ft2-base_interface.html#FT_Driver
FT_Driver
driver;
ft2-system_interface.html#FT_Memory
FT_Memory
memory;
ft2-system_interface.html#FT_Stream
FT_Stream
stream;
ft2-list_processing.html#FT_ListRec
FT_ListRec
sizes_list;
ft2-basic_types.html#FT_Generic
FT_Generic
autohint;
void
*             extensions;
ft2-base_interface.html#FT_Face_Internal
FT_Face_Internal
internal
;
/*@private end */
}
FT_FaceRec
;
FreeType root face class structure. A face object models the resolution and point-size independent data found in a font file.
fields
num_faces
In the case where the face is located in a collection (i.e., a file which embeds several faces), this is the total number of faces found in the resource. 1 by default. Accessing non-existent face indices causes an error.
face_index
The index of the face in its font file. Usually, this is 0 for all normal font formats. It can be > 0 in the case of collections (which embed several fonts in a single resource/file).
face_flags
A set of bit flags that give important information about the face; see the
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_XXX
constants for details.
style_flags
A set of bit flags indicating the style of the face (i.e., italic, bold, underline, etc). See the
ft2-base_interface.html#FT_STYLE_FLAG_XXX
FT_STYLE_FLAG_XXX
constants.
num_glyphs
The total number of glyphs in the face.
family_name
The face's family name. This is an ASCII string, usually in English, which describes the typeface's family (like `Times New Roman', `Bodoni', `Garamond', etc). This is a least common denominator used to list fonts. Some formats (TrueType & OpenType) provide localized and Unicode versions of this string. Applications should use the format specific interface to access them.
style_name
The face's style name. This is an ASCII string, usually in English, which describes the typeface's style (like `Italic', `Bold', `Condensed', etc). Not all font formats provide a style name, so this field is optional, and can be set to NULL. As for `family_name', some formats provide localized/Unicode versions of this string. Applications should use the format specific interface to access them.
num_fixed_sizes
The number of fixed sizes available in this face. This should be set to 0 for scalable fonts, unless its face includes a set of glyphs (called a `strike') for the specified sizes.
available_sizes
An array of sizes specifying the available bitmap/graymap sizes that are contained in in the font face. Should be set to NULL if the field `num_fixed_sizes' is set to 0.
num_charmaps
The total number of character maps in the face.
charmaps
A table of pointers to the face's charmaps. Used to scan the list of available charmaps -- this table might change after a call to
ft2-base_interface.html#FT_Attach_File
FT_Attach_File
or
ft2-base_interface.html#FT_Attach_Stream
FT_Attach_Stream
(e.g. if used to hook an additional encoding or CMap to the face object).
generic
A field reserved for client uses. See the
ft2-basic_types.html#FT_Generic
FT_Generic
type description.
bbox
The font bounding box. Coordinates are expressed in font units (see units_per_EM). The box is large enough to contain any glyph from the font. Thus, bbox.yMax can be seen as the `maximal ascender', bbox.yMin as the `minimal descender', and the maximal glyph width is given by `bbox.xMax-bbox.xMin' (not to be confused with the maximal
advance_width
Only relevant for scalable formats.
units_per_EM
The number of font units per EM square for this face. This is typically 2048 for TrueType fonts, 1000 for Type1 fonts, and should be set to the (unrealistic) value 1 for fixed-sizes fonts. Only relevant for scalable formats.
ascender
The face's ascender is the vertical distance from the baseline to the topmost point of any glyph in the face. This field's value is positive, expressed in font units. Some font designs use a value different from `bbox.yMax'. Only relevant for scalable formats.
descender
The face's descender is the vertical distance from the baseline to the bottommost point of any glyph in the face. This field's value is
negative
for values below the baseline. It is expressed in font units. Some font designs use a value different from `bbox.yMin'. Only relevant for scalable formats.
height
The face's height is the vertical distance from one baseline to the next when writing several lines of text. Its value is always positive, expressed in font units. The value can be computed as `ascender+descender+line_gap' where the value of `line_gap' is also called `external leading'. Only relevant for scalable formats.
max_advance_width
The maximal advance width, in font units, for all glyphs in this face. This can be used to make word wrapping computations faster. Only relevant for scalable formats.
max_advance_height
The maximal advance height, in font units, for all glyphs in this face. This is only relevant for vertical layouts, and should be set to the `height' for fonts that do not provide vertical metrics. Only relevant for scalable formats.
underline_position
The position, in font units, of the underline line for this face. It's the center of the underlining stem. Only relevant for scalable formats.
underline_thickness
The thickness, in font units, of the underline for this face. Only relevant for scalable formats.
glyph
The face's associated glyph slot(s). This object is created automatically with a new face object. However, certain kinds of applications (mainly tools like converters) can need more than one slot to ease their task.
size
The current active size for this face.
charmap
The current active charmap for this face.
FT_FACE_FLAG_XXX
#define
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_SCALABLE
( 1L <<  0 )
#define
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_FIXED_SIZES
( 1L <<  1 )
#define
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_FIXED_WIDTH
( 1L <<  2 )
#define
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_SFNT
( 1L <<  3 )
#define
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_HORIZONTAL
( 1L <<  4 )
#define
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_VERTICAL
( 1L <<  5 )
#define
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_KERNING
( 1L <<  6 )
#define
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_FAST_GLYPHS
( 1L <<  7 )
#define
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_MULTIPLE_MASTERS
( 1L <<  8 )
#define
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_GLYPH_NAMES
( 1L <<  9 )
#define
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_EXTERNAL_STREAM
( 1L << 10 )
A list of bit flags used in the `face_flags' field of the
ft2-base_interface.html#FT_FaceRec
FT_FaceRec
structure. They inform client applications of properties of the corresponding face.
values
FT_FACE_FLAG_SCALABLE
Indicates that the face provides vectorial outlines. This doesn't prevent embedded bitmaps, i.e., a face can have both this bit and
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_FIXED_SIZES
set.
FT_FACE_FLAG_FIXED_SIZES
Indicates that the face contains `fixed sizes', i.e., bitmap strikes for some given pixel sizes. See the `num_fixed_sizes' and `available_sizes' fields of
ft2-base_interface.html#FT_FaceRec
FT_FaceRec
.
FT_FACE_FLAG_FIXED_WIDTH
Indicates that the face contains fixed-width characters (like Courier, Lucido, MonoType, etc.).
FT_FACE_FLAG_SFNT
Indicates that the face uses the `sfnt' storage scheme. For now, this means TrueType and OpenType.
FT_FACE_FLAG_HORIZONTAL
Indicates that the face contains horizontal glyph metrics. This should be set for all common formats.
FT_FACE_FLAG_VERTICAL
Indicates that the face contains vertical glyph metrics. This is only available in some formats, not all of them.
FT_FACE_FLAG_KERNING
Indicates that the face contains kerning information. If set, the kerning distance can be retrieved through the function
ft2-base_interface.html#FT_Get_Kerning
FT_Get_Kerning
. Note that if unset, this function will always return the vector (0,0).
FT_FACE_FLAG_FAST_GLYPHS
THIS FLAG IS DEPRECATED. DO NOT USE OR TEST IT.
FT_FACE_FLAG_MULTIPLE_MASTERS
Indicates that the font contains multiple masters and is capable of interpolating between them. See the multiple-masters specific API for details.
FT_FACE_FLAG_GLYPH_NAMES
Indicates that the font contains glyph names that can be retrieved through
ft2-base_interface.html#FT_Get_Glyph_Name
FT_Get_Glyph_Name
. Note that some TrueType fonts contain broken glyph name tables. Use the function
ft2-type1_tables.html#FT_Has_PS_Glyph_Names
FT_Has_PS_Glyph_Names
when needed.
FT_FACE_FLAG_EXTERNAL_STREAM
Used internally by FreeType to indicate that a face's stream was provided by the client application and should not be destroyed when
ft2-base_interface.html#FT_Done_Face
FT_Done_Face
is called. Don't read or test this flag.
FT_HAS_HORIZONTAL
#define
FT_HAS_HORIZONTAL
( face ) \
( face->face_flags &
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_HORIZONTAL
)
A macro that returns true whenever a face object contains horizontal metrics (this is true for all font formats though).
also
ft2-base_interface.html#FT_HAS_VERTICAL
FT_HAS_VERTICAL
can be used to check for vertical metrics.
FT_HAS_VERTICAL
#define
FT_HAS_VERTICAL
( face ) \
( face->face_flags &
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_VERTICAL
)
A macro that returns true whenever a face object contains vertical metrics.
FT_HAS_KERNING
#define
FT_HAS_KERNING
( face ) \
( face->face_flags &
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_KERNING
)
A macro that returns true whenever a face object contains kerning data that can be accessed with
ft2-base_interface.html#FT_Get_Kerning
FT_Get_Kerning
.
FT_IS_SCALABLE
#define
FT_IS_SCALABLE
( face ) \
( face->face_flags &
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_SCALABLE
)
A macro that returns true whenever a face object contains a scalable font face (true for TrueType, Type 1, CID, and OpenType/CFF font formats.
FT_IS_SFNT
#define
FT_IS_SFNT
( face ) \
( face->face_flags &
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_SFNT
)
A macro that returns true whenever a face object contains a font whose format is based on the SFNT storage scheme. This usually means: TrueType fonts, OpenType fonts, as well as SFNT-based embedded bitmap fonts.
If this macro is true, all functions defined in
ft2-header_file_macros.html#FT_SFNT_NAMES_H
FT_SFNT_NAMES_H
and
ft2-header_file_macros.html#FT_TRUETYPE_TABLES_H
FT_TRUETYPE_TABLES_H
are available.
FT_IS_FIXED_WIDTH
#define
FT_IS_FIXED_WIDTH
( face ) \
( face->face_flags &
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_FIXED_WIDTH
)
A macro that returns true whenever a face object contains a font face that contains fixed-width (or "monospace", "fixed-pitch", etc.) glyphs.
FT_HAS_FIXED_SIZES
#define
FT_HAS_FIXED_SIZES
( face ) \
( face->face_flags &
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_FIXED_SIZES
)
A macro that returns true whenever a face object contains some embedded bitmaps. See the `available_sizes' field of the
ft2-base_interface.html#FT_FaceRec
FT_FaceRec
structure.
FT_HAS_FAST_GLYPHS
#define
FT_HAS_FAST_GLYPHS
( face ) \
( face->face_flags &
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_FAST_GLYPHS
)
Deprecated; indicates that the face contains so-called "fast" glyph bitmaps.
FT_HAS_GLYPH_NAMES
#define
FT_HAS_GLYPH_NAMES
( face ) \
( face->face_flags &
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_GLYPH_NAMES
)
A macro that returns true whenever a face object contains some glyph names that can be accessed through
ft2-base_interface.html#FT_Get_Glyph_Name
FT_Get_Glyph_Name
.
FT_HAS_MULTIPLE_MASTERS
#define
FT_HAS_MULTIPLE_MASTERS
( face ) \
( face->face_flags &
ft2-base_interface.html#FT_FACE_FLAG_XXX
FT_FACE_FLAG_MULTIPLE_MASTERS
)
A macro that returns true whenever a face object contains some multiple masters. The functions provided by
ft2-header_file_macros.html#FT_MULTIPLE_MASTERS_H
FT_MULTIPLE_MASTERS_H
are then available to choose the exact design you want.
FT_STYLE_FLAG_XXX
#define
ft2-base_interface.html#FT_STYLE_FLAG_XXX
FT_STYLE_FLAG_ITALIC
( 1 << 0 )
#define
ft2-base_interface.html#FT_STYLE_FLAG_XXX
FT_STYLE_FLAG_BOLD
( 1 << 1 )
A list of bit-flags used to indicate the style of a given face. These are used in the `style_flags' field of
ft2-base_interface.html#FT_FaceRec
FT_FaceRec
.
values
FT_STYLE_FLAG_ITALIC
Indicates that a given face is italicized.
FT_STYLE_FLAG_BOLD
Indicates that a given face is bold.
FT_Size_Internal
typedef
struct
FT_Size_InternalRec_*
FT_Size_Internal
;
An opaque handle to an FT_Size_InternalRec structure, used to model private data of a given FT_Size object.
FT_Size_Metrics
typedef
struct
FT_Size_Metrics_
{
ft2-basic_types.html#FT_UShort
FT_UShort
x_ppem;      /* horizontal pixels per EM               */
ft2-basic_types.html#FT_UShort
FT_UShort
y_ppem;      /* vertical pixels per EM                 */
ft2-basic_types.html#FT_Fixed
FT_Fixed
x_scale;     /* two scales used to convert font units  */
ft2-basic_types.html#FT_Fixed
FT_Fixed
y_scale;     /* to 26.6 frac. pixel coordinates        */
ft2-basic_types.html#FT_Pos
FT_Pos
ascender;    /* ascender in 26.6 frac. pixels          */
ft2-basic_types.html#FT_Pos
FT_Pos
descender;   /* descender in 26.6 frac. pixels         */
ft2-basic_types.html#FT_Pos
FT_Pos
height;      /* text height in 26.6 frac. pixels       */
ft2-basic_types.html#FT_Pos
FT_Pos
max_advance; /* max horizontal advance, in 26.6 pixels */
}
FT_Size_Metrics
;
The size metrics structure returned scaled important distances for a given size object.
fields
x_ppem
The character width, expressed in integer pixels. This is the width of the EM square expressed in pixels, hence the term `ppem' (pixels per EM).
y_ppem
The character height, expressed in integer pixels. This is the height of the EM square expressed in pixels, hence the term `ppem' (pixels per EM).
x_scale
A simple 16.16 fixed point format coefficient used to scale horizontal distances expressed in font units to fractional (26.6) pixel coordinates.
y_scale
A simple 16.16 fixed point format coefficient used to scale vertical distances expressed in font units to fractional (26.6) pixel coordinates.
ascender
The ascender, expressed in 26.6 fixed point pixels. Positive for ascenders above the baseline.
descender
The descender, expressed in 26.6 fixed point pixels. Negative for descenders below the baseline.
height
The text height, expressed in 26.6 fixed point pixels. Always positive.
max_advance
Maximum horizontal advance, expressed in 26.6 fixed point pixels. Always positive.
note
For scalable fonts, the values of `ascender', `descender', and `height' are scaled versions of `face->ascender', `face->descender', and `face->height', respectively.
Unfortunately, due to glyph hinting, these values might not be exact for certain fonts. They thus must be treated as unreliable with an error margin of at least one pixel!
Indeed, the only way to get the exact pixel ascender and descender is to render
all
glyphs. As this would be a definite performance hit, it is up to client applications to perform such computations.
FT_SizeRec
typedef
struct
FT_SizeRec_
{
ft2-base_interface.html#FT_Face
FT_Face
face;      /* parent face object              */
ft2-basic_types.html#FT_Generic
FT_Generic
generic;   /* generic pointer for client uses */
ft2-base_interface.html#FT_Size_Metrics
FT_Size_Metrics
metrics;   /* size metrics                    */
ft2-base_interface.html#FT_Size_Internal
FT_Size_Internal
internal
;
}
FT_SizeRec
;
FreeType root size class structure. A size object models the resolution and pointsize dependent data of a given face.
fields
face
Handle to the parent face object.
generic
A typeless pointer, which is unused by the FreeType library or any of its drivers. It can be used by client applications to link their own data to each size object.
metrics
Metrics for this size object. This field is read-only.
FT_SubGlyph
typedef
struct
FT_SubGlyphRec_*
FT_SubGlyph
;
The subglyph structure is an internal object used to describe subglyphs (for example, in the case of composites).
note
The subglyph implementation is not part of the high-level API, hence the forward structure declaration.
FT_Slot_Internal
typedef
struct
FT_Slot_InternalRec_*
FT_Slot_Internal
;
An opaque handle to an FT_Slot_InternalRec structure, used to model private data of a given FT_GlyphSlot object.
FT_GlyphSlotRec
typedef
struct
FT_GlyphSlotRec_
{
ft2-base_interface.html#FT_Library
FT_Library
library;
ft2-base_interface.html#FT_Face
FT_Face
face;
ft2-base_interface.html#FT_GlyphSlot
FT_GlyphSlot
next;
ft2-basic_types.html#FT_UInt
FT_UInt
reserved;       /* retained for binary compatibility */
ft2-basic_types.html#FT_Generic
FT_Generic
generic;
ft2-base_interface.html#FT_Glyph_Metrics
FT_Glyph_Metrics
metrics;
ft2-basic_types.html#FT_Fixed
FT_Fixed
linearHoriAdvance;
ft2-basic_types.html#FT_Fixed
FT_Fixed
linearVertAdvance;
ft2-basic_types.html#FT_Vector
FT_Vector
advance;
ft2-basic_types.html#FT_Glyph_Format
FT_Glyph_Format
format;
ft2-basic_types.html#FT_Bitmap
FT_Bitmap
bitmap;
ft2-basic_types.html#FT_Int
FT_Int
bitmap_left;
ft2-basic_types.html#FT_Int
FT_Int
bitmap_top;
ft2-outline_processing.html#FT_Outline
FT_Outline
outline;
ft2-basic_types.html#FT_UInt
FT_UInt
num_subglyphs;
ft2-base_interface.html#FT_SubGlyph
FT_SubGlyph
subglyphs;
void
*             control_data;
long
control_len;
ft2-basic_types.html#FT_Pos
FT_Pos
lsb_delta;
ft2-basic_types.html#FT_Pos
FT_Pos
rsb_delta;
void
*             other;
ft2-base_interface.html#FT_Slot_Internal
FT_Slot_Internal
internal
;
}
FT_GlyphSlotRec
;
FreeType root glyph slot class structure. A glyph slot is a container where individual glyphs can be loaded, be they vectorial or bitmap/graymaps.
fields
library
A handle to the FreeType library instance this slot belongs to.
face
A handle to the parent face object.
next
In some cases (like some font tools), several glyph slots per face object can be a good thing. As this is rare, the glyph slots are listed through a direct, single-linked list using its `next' field.
generic
A typeless pointer which is unused by the FreeType library or any of its drivers. It can be used by client applications to link their own data to each glyph slot object.
metrics
The metrics of the last loaded glyph in the slot. The returned values depend on the last load flags (see the
ft2-base_interface.html#FT_Load_Glyph
FT_Load_Glyph
API function) and can be expressed either in 26.6 fractional pixels or font units.
Note that even when the glyph image is transformed, the metrics are not.
linearHoriAdvance
For scalable formats only, this field holds the linearly scaled horizontal advance width for the glyph (i.e. the scaled and unhinted value of the hori advance). This can be important to perform correct WYSIWYG layout.
Note that this value is expressed by default in 16.16 pixels. However, when the glyph is loaded with the FT_LOAD_LINEAR_DESIGN flag, this field contains simply the value of the advance in original font units.
linearVertAdvance
For scalable formats only, this field holds the linearly scaled vertical advance height for the glyph. See linearHoriAdvance for comments.
advance
This is the transformed advance width for the glyph.
format
This field indicates the format of the image contained in the glyph slot. Typically FT_GLYPH_FORMAT_BITMAP, FT_GLYPH_FORMAT_OUTLINE, and FT_GLYPH_FORMAT_COMPOSITE, but others are possible.
bitmap
This field is used as a bitmap descriptor when the slot format is FT_GLYPH_FORMAT_BITMAP. Note that the address and content of the bitmap buffer can change between calls of
ft2-base_interface.html#FT_Load_Glyph
FT_Load_Glyph
and a few other functions.
bitmap_left
This is the bitmap's left bearing expressed in integer pixels. Of course, this is only valid if the format is FT_GLYPH_FORMAT_BITMAP.
bitmap_top
This is the bitmap's top bearing expressed in integer pixels. Remember that this is the distance from the baseline to the top-most glyph scanline, upwards y-coordinates being
positive
outline
The outline descriptor for the current glyph image if its format is FT_GLYPH_FORMAT_OUTLINE.
num_subglyphs
The number of subglyphs in a composite glyph. This field is only valid for the composite glyph format that should normally only be loaded with the
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_NO_RECURSE
flag. For now this is internal to FreeType.
subglyphs
An array of subglyph descriptors for composite glyphs. There are `num_subglyphs' elements in there. Currently internal to FreeType.
control_data
Certain font drivers can also return the control data for a given glyph image (e.g. TrueType bytecode, Type 1 charstrings, etc.). This field is a pointer to such data.
control_len
This is the length in bytes of the control data.
other
Really wicked formats can use this pointer to present their own glyph image to client apps. Note that the app will need to know about the image format.
lsb_delta
The difference between hinted and unhinted left side bearing while autohinting is active. Zero otherwise.
rsb_delta
The difference between hinted and unhinted right side bearing while autohinting is active. Zero otherwise.
note
If
ft2-base_interface.html#FT_Load_Glyph
FT_Load_Glyph
is called with default flags (see
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_DEFAULT
) the glyph image is loaded in the glyph slot in its native format (e.g. a vectorial outline for TrueType and Type 1 formats).
This image can later be converted into a bitmap by calling
ft2-base_interface.html#FT_Render_Glyph
FT_Render_Glyph
. This function finds the current renderer for the native image's format then invokes it.
The renderer is in charge of transforming the native image through the slot's face transformation fields, then convert it into a bitmap that is returned in `slot->bitmap'.
Note that `slot->bitmap_left' and `slot->bitmap_top' are also used to specify the position of the bitmap relative to the current pen position (e.g. coordinates [0,0] on the baseline). Of course, `slot->format' is also changed to `FT_GLYPH_FORMAT_BITMAP' .
note
Here a small pseudo code fragment which shows how to use `lsb_delta' and `rsb_delta':
FT_Pos  origin_x       = 0;
FT_Pos  prev_rsb_delta = 0;
for all glyphs do
<compute kern between current and previous glyph and add it to
`origin_x'>
<load glyph with `FT_Load_Glyph'>
if ( prev_rsb_delta - face->glyph->lsb_delta >= 32 )
origin_x -= 64;
else if ( prev_rsb_delta - face->glyph->lsb_delta < -32 )
origin_x += 64;
prev_rsb_delta = face->glyph->rsb_delta;
<save glyph image, or render glyph, or ...>
origin_x += face->glyph->advance.x;
endfor
FT_Init_FreeType
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_Init_FreeType
(
ft2-base_interface.html#FT_Library
FT_Library
*alibrary );
Initializes a new FreeType library object. The set of modules that are registered by this function is determined at build time.
output
alibrary
A handle to a new library object.
return
FreeType error code. 0 means success.
FT_Library_Version
FT_EXPORT(
void
)
FT_Library_Version
(
ft2-base_interface.html#FT_Library
FT_Library
library,
ft2-basic_types.html#FT_Int
FT_Int
*amajor,
ft2-basic_types.html#FT_Int
FT_Int
*aminor,
ft2-basic_types.html#FT_Int
FT_Int
*apatch );
Return the version of the FreeType library being used. This is useful when dynamically linking to the library, since one cannot use the macros FT_FREETYPE_MAJOR, FT_FREETYPE_MINOR, and FT_FREETYPE_PATCH.
input
library
A source library handle.
output
amajor
The major version number.
aminor
The minor version number.
apatch
The patch version number.
note
The reason why this function takes a 'library' argument is because certain programs implement library initialization in a custom way that doesn't use `FT_Init_FreeType'.
In such cases, the library version might not be available before the library object has been created.
FT_Done_FreeType
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_Done_FreeType
(
ft2-base_interface.html#FT_Library
FT_Library
library );
Destroys a given FreeType library object and all of its childs, including resources, drivers, faces, sizes, etc.
input
library
A handle to the target library object.
return
FreeType error code. 0 means success.
FT_OPEN_XXX
#define
ft2-base_interface.html#FT_OPEN_XXX
FT_OPEN_MEMORY
0x1
#define
ft2-base_interface.html#FT_OPEN_XXX
FT_OPEN_STREAM
0x2
#define
ft2-base_interface.html#FT_OPEN_XXX
FT_OPEN_PATHNAME
0x4
#define
ft2-base_interface.html#FT_OPEN_XXX
FT_OPEN_DRIVER
0x8
#define
ft2-base_interface.html#FT_OPEN_XXX
FT_OPEN_PARAMS
0x10
#define
ft2-base_interface.html#FT_OPEN_XXX
ft_open_memory
ft2-base_interface.html#FT_OPEN_XXX
FT_OPEN_MEMORY
/* deprecated */
#define
ft2-base_interface.html#FT_OPEN_XXX
ft_open_stream
ft2-base_interface.html#FT_OPEN_XXX
FT_OPEN_STREAM
/* deprecated */
#define
ft2-base_interface.html#FT_OPEN_XXX
ft_open_pathname
ft2-base_interface.html#FT_OPEN_XXX
FT_OPEN_PATHNAME
/* deprecated */
#define
ft2-base_interface.html#FT_OPEN_XXX
ft_open_driver
ft2-base_interface.html#FT_OPEN_XXX
FT_OPEN_DRIVER
/* deprecated */
#define
ft2-base_interface.html#FT_OPEN_XXX
ft_open_params
ft2-base_interface.html#FT_OPEN_XXX
FT_OPEN_PARAMS
/* deprecated */
A list of bit-field constants used within the `flags' field of the
ft2-base_interface.html#FT_Open_Args
FT_Open_Args
structure.
values
FT_OPEN_MEMORY
This is a memory-based stream.
FT_OPEN_STREAM
Copy the stream from the `stream' field.
FT_OPEN_PATHNAME
Create a new input stream from a C path name.
FT_OPEN_DRIVER
Use the `driver' field.
FT_OPEN_PARAMS
Use the `num_params' & `params' field.
ft_open_memory
Deprecated; use
ft2-base_interface.html#FT_OPEN_XXX
FT_OPEN_MEMORY
instead.
ft_open_stream
Deprecated; use
ft2-base_interface.html#FT_OPEN_XXX
FT_OPEN_STREAM
instead.
ft_open_pathname
Deprecated; use
ft2-base_interface.html#FT_OPEN_XXX
FT_OPEN_PATHNAME
instead.
ft_open_driver
Deprecated; use
ft2-base_interface.html#FT_OPEN_XXX
FT_OPEN_DRIVER
instead.
ft_open_params
Deprecated; use
ft2-base_interface.html#FT_OPEN_XXX
FT_OPEN_PARAMS
instead.
note
The `FT_OPEN_MEMORY', `FT_OPEN_STREAM', and `FT_OPEN_PATHNAME' flags are mutually exclusive.
FT_Parameter
typedef
struct
FT_Parameter_
{
ft2-basic_types.html#FT_ULong
FT_ULong
tag;
ft2-basic_types.html#FT_Pointer
FT_Pointer
data;
}
FT_Parameter
;
A simple structure used to pass more or less generic parameters to
ft2-base_interface.html#FT_Open_Face
FT_Open_Face
.
fields
tag
A 4-byte identification tag.
data
A pointer to the parameter data.
note
The id and function of parameters are driver-specific.
FT_Open_Args
typedef
struct
FT_Open_Args_
{
ft2-basic_types.html#FT_UInt
FT_UInt
flags;
const
ft2-basic_types.html#FT_Byte
FT_Byte
*  memory_base;
ft2-basic_types.html#FT_Long
FT_Long
memory_size;
ft2-basic_types.html#FT_String
FT_String
*      pathname;
ft2-system_interface.html#FT_Stream
FT_Stream
stream;
ft2-base_interface.html#FT_Module
FT_Module
driver;
ft2-basic_types.html#FT_Int
FT_Int
num_params;
ft2-base_interface.html#FT_Parameter
FT_Parameter
*   params;
}
FT_Open_Args
;
A structure used to indicate how to open a new font file/stream. A pointer to such a structure can be used as a parameter for the functions
ft2-base_interface.html#FT_Open_Face
FT_Open_Face
and
ft2-base_interface.html#FT_Attach_Stream
FT_Attach_Stream
.
fields
flags
A set of bit flags indicating how to use the structure.
memory_base
The first byte of the file in memory.
memory_size
The size in bytes of the file in memory.
pathname
A pointer to an 8-bit file pathname.
stream
A handle to a source stream object.
driver
This field is exclusively used by
ft2-base_interface.html#FT_Open_Face
FT_Open_Face
; it simply specifies the font driver to use to open the face. If set to 0, FreeType will try to load the face with each one of the drivers in its list.
num_params
The number of extra parameters.
params
Extra parameters passed to the font driver when opening a new face.
note
The stream type is determined by the contents of `flags' which are tested in the following order by
ft2-base_interface.html#FT_Open_Face
FT_Open_Face
:
If the `FT_OPEN_MEMORY' bit is set, assume that this is a memory file of `memory_size' bytes,located at `memory_address'.
Otherwise, if the `FT_OPEN_STREAM' bit is set, assume that a custom input stream `stream' is used.
Otherwise, if the `FT_OPEN_PATHNAME' bit is set, assume that this is a normal file and use `pathname' to open it.
If the `FT_OPEN_DRIVER' bit is set,
ft2-base_interface.html#FT_Open_Face
FT_Open_Face
will only try to open the file with the driver whose handler is in `driver'.
If the `FT_OPEN_PARAMS' bit is set, the parameters given by `num_params' and `params' will be used. They are ignored otherwise.
FT_New_Face
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_New_Face
(
ft2-base_interface.html#FT_Library
FT_Library
library,
const
char
*  filepathname,
ft2-basic_types.html#FT_Long
FT_Long
face_index,
ft2-base_interface.html#FT_Face
FT_Face
*aface );
Creates a new face object from a given resource and typeface index using a pathname to the font file.
inout
library
A handle to the library resource.
input
pathname
A path to the font file.
face_index
The index of the face within the resource. The first face has index 0.
output
aface
A handle to a new face object.
return
FreeType error code. 0 means success.
note
Unlike FreeType 1.x, this function automatically creates a glyph slot for the face object which can be accessed directly through `face->glyph'.
ft2-base_interface.html#FT_New_Face
FT_New_Face
can be used to determine and/or check the font format of a given font resource. If the `face_index' field is negative, the function will
not
return any face handle in `aface'; the return value is 0 if the font format is recognized, or non-zero otherwise.
Each new face object created with this function also owns a default
ft2-base_interface.html#FT_Size
FT_Size
object, accessible as `face->size'.
FT_New_Memory_Face
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_New_Memory_Face
(
ft2-base_interface.html#FT_Library
FT_Library
library,
const
ft2-basic_types.html#FT_Byte
FT_Byte
*  file_base,
ft2-basic_types.html#FT_Long
FT_Long
file_size,
ft2-basic_types.html#FT_Long
FT_Long
face_index,
ft2-base_interface.html#FT_Face
FT_Face
*aface );
Creates a new face object from a given resource and typeface index using a font file already loaded into memory.
inout
library
A handle to the library resource.
input
file_base
A pointer to the beginning of the font data.
file_size
The size of the memory chunk used by the font data.
face_index
The index of the face within the resource. The first face has index 0.
output
aface
A handle to a new face object.
return
FreeType error code. 0 means success.
note
The font data bytes are used
directly
by the
ft2-base_interface.html#FT_Face
FT_Face
object. This means that they are not copied, and that the client is responsible for releasing/destroying them
after
the corresponding call to
ft2-base_interface.html#FT_Done_Face
FT_Done_Face
.
Unlike FreeType 1.x, this function automatically creates a glyph slot for the face object which can be accessed directly through `face->glyph'.
ft2-base_interface.html#FT_New_Memory_Face
FT_New_Memory_Face
can be used to determine and/or check the font format of a given font resource. If the `face_index' field is negative, the function will
not
return any face handle in `aface'; the return value is 0 if the font format is recognized, or non-zero otherwise.
FT_Open_Face
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_Open_Face
(
ft2-base_interface.html#FT_Library
FT_Library
library,
const
ft2-base_interface.html#FT_Open_Args
FT_Open_Args
*  args,
ft2-basic_types.html#FT_Long
FT_Long
face_index,
ft2-base_interface.html#FT_Face
FT_Face
*aface );
Opens a face object from a given resource and typeface index using an `FT_Open_Args' structure. If the face object doesn't exist, it will be created.
inout
library
A handle to the library resource.
input
args
A pointer to an `FT_Open_Args' structure which must be filled by the caller.
face_index
The index of the face within the resource. The first face has index 0.
output
aface
A handle to a new face object.
return
FreeType error code. 0 means success.
note
Unlike FreeType 1.x, this function automatically creates a glyph slot for the face object which can be accessed directly through `face->glyph'.
ft2-base_interface.html#FT_Open_Face
FT_Open_Face
can be used to determine and/or check the font format of a given font resource. If the `face_index' field is negative, the function will
not
return any face handle in `*aface'; the function's return value is 0 if the font format is recognized, or non-zero otherwise.
FT_Attach_File
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_Attach_File
(
ft2-base_interface.html#FT_Face
FT_Face
face,
const
char
*  filepathname );
`Attaches' a given font file to an existing face. This is usually to read additional information for a single face object. For example, it is used to read the AFM files that come with Type 1 fonts in order to add kerning data and other metrics.
inout
face
The target face object.
input
filepathname
An 8-bit pathname naming the `metrics' file.
return
FreeType error code. 0 means success.
note
If your font file is in memory, or if you want to provide your own input stream object, use
ft2-base_interface.html#FT_Attach_Stream
FT_Attach_Stream
.
The meaning of the `attach' action (i.e., what really happens when the new file is read) is not fixed by FreeType itself. It really depends on the font format (and thus the font driver).
Client applications are expected to know what they are doing when invoking this function. Most drivers simply do not implement file attachments.
FT_Attach_Stream
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_Attach_Stream
(
ft2-base_interface.html#FT_Face
FT_Face
face,
ft2-base_interface.html#FT_Open_Args
FT_Open_Args
*  parameters );
This function is similar to
ft2-base_interface.html#FT_Attach_File
FT_Attach_File
with the exception that it reads the attachment from an arbitrary stream.
inout
face
The target face object.
input
parameters
A pointer to an FT_Open_Args structure used to describe the input stream to FreeType.
return
FreeType error code. 0 means success.
note
The meaning of the `attach' (i.e. what really happens when the new file is read) is not fixed by FreeType itself. It really depends on the font format (and thus the font driver).
Client applications are expected to know what they are doing when invoking this function. Most drivers simply do not implement file attachments.
FT_Done_Face
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_Done_Face
(
ft2-base_interface.html#FT_Face
FT_Face
face );
Discards a given face object, as well as all of its child slots and sizes.
input
face
A handle to a target face object.
return
FreeType error code. 0 means success.
FT_Set_Char_Size
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_Set_Char_Size
(
ft2-base_interface.html#FT_Face
FT_Face
face,
ft2-basic_types.html#FT_F26Dot6
FT_F26Dot6
char_width
,
ft2-basic_types.html#FT_F26Dot6
FT_F26Dot6
char_height
,
ft2-basic_types.html#FT_UInt
FT_UInt
horz_resolution,
ft2-basic_types.html#FT_UInt
FT_UInt
vert_resolution );
Sets the character dimensions of a given face object. The `char_width' and `char_height' values are used for the width and height, respectively, expressed in 26.6 fractional points.
If the horizontal or vertical resolution values are zero, a default value of 72dpi is used. Similarly, if one of the character dimensions is zero, its value is set equal to the other.
inout
face
A handle to a target face object.
input
char_width
The character width, in 26.6 fractional points.
char_height
The character height, in 26.6 fractional points.
horz_resolution
The horizontal resolution.
vert_resolution
The vertical resolution.
return
FreeType error code. 0 means success.
note
For BDF and PCF formats, this function uses the `PIXEL_SIZE' property of the bitmap font; the `char_width' parameter is ignored.
FT_Set_Pixel_Sizes
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_Set_Pixel_Sizes
(
ft2-base_interface.html#FT_Face
FT_Face
face,
ft2-basic_types.html#FT_UInt
FT_UInt
pixel_width,
ft2-basic_types.html#FT_UInt
FT_UInt
pixel_height );
Sets the character dimensions of a given face object. The width and height are expressed in integer pixels.
If one of the character dimensions is zero, its value is set equal to the other.
inout
face
A handle to the target face object.
input
pixel_width
The character width, in integer pixels.
pixel_height
The character height, in integer pixels.
return
FreeType error code. 0 means success.
note
The values of `pixel_width' and `pixel_height' correspond to the pixel values of the
typographic
character size, which are NOT necessarily the same as the dimensions of the glyph `bitmap cells'.
The `character size' is really the size of an abstract square called the `EM', used to design the font. However, depending on the font design, glyphs will be smaller or greater than the EM.
This means that setting the pixel size to, say, 8x8 doesn't guarantee in any way that you will get glyph bitmaps that all fit within an 8x8 cell (sometimes even far from it).
For bitmap fonts, `pixel_height' usually is a reliable value for the height of the bitmap cell. Drivers for bitmap font formats which contain a single bitmap strike only (BDF, PCF, FNT) ignore `pixel_width'.
For BDF and PCF formats, this function uses the sum of the `FONT_ASCENT' and `FONT_DESCENT' properties of the bitmap font.
FT_Load_Glyph
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_Load_Glyph
(
ft2-base_interface.html#FT_Face
FT_Face
face,
ft2-basic_types.html#FT_UInt
FT_UInt
glyph_index,
FT_Int32  load_flags );
A function used to load a single glyph within a given glyph slot, for a given size.
inout
face
A handle to the target face object where the glyph will be loaded.
input
glyph_index
The index of the glyph in the font file. For CID-keyed fonts (either in PS or in CFF format) this argument specifies the CID value.
load_flags
A flag indicating what to load for this glyph. The
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_XXX
constants can be used to control the glyph loading process (e.g., whether the outline should be scaled, whether to load bitmaps or not, whether to hint the outline, etc).
return
FreeType error code. 0 means success.
note
If the glyph image is not a bitmap, and if the bit flag FT_LOAD_IGNORE_TRANSFORM is unset, the glyph image will be transformed with the information passed to a previous call to
ft2-base_interface.html#FT_Set_Transform
FT_Set_Transform
.
Note that this also transforms the `face.glyph.advance' field, but
not
the values in `face.glyph.metrics'.
FT_Load_Char
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_Load_Char
(
ft2-base_interface.html#FT_Face
FT_Face
face,
ft2-basic_types.html#FT_ULong
FT_ULong
char_code
,
FT_Int32  load_flags );
A function used to load a single glyph within a given glyph slot, for a given size, according to its character code.
inout
face
A handle to a target face object where the glyph will be loaded.
input
char_code
The glyph's character code, according to the current charmap used in the face.
load_flags
A flag indicating what to load for this glyph. The
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_XXX
constants can be used to control the glyph loading process (e.g., whether the outline should be scaled, whether to load bitmaps or not, whether to hint the outline, etc).
return
FreeType error code. 0 means success.
note
If the face has no current charmap, or if the character code is not defined in the charmap, this function will return an error.
If the glyph image is not a bitmap, and if the bit flag FT_LOAD_IGNORE_TRANSFORM is unset, the glyph image will be transformed with the information passed to a previous call to
ft2-base_interface.html#FT_Set_Transform
FT_Set_Transform
.
Note that this also transforms the `face.glyph.advance' field, but
not
the values in `face.glyph.metrics'.
FT_LOAD_XXX
#define
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_DEFAULT
0x0
#define
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_NO_SCALE
0x1
#define
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_NO_HINTING
0x2
#define
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_RENDER
0x4
#define
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_NO_BITMAP
0x8
#define
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_VERTICAL_LAYOUT
0x10
#define
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_FORCE_AUTOHINT
0x20
#define
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_CROP_BITMAP
0x40
#define
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_PEDANTIC
0x80
#define
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH
0x200
#define
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_NO_RECURSE
0x400
#define
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_IGNORE_TRANSFORM
0x800
#define
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_MONOCHROME
0x1000
#define
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_LINEAR_DESIGN
0x2000
/* temporary hack! */
#define FT_LOAD_SBITS_ONLY                   0x4000
#define
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_NO_AUTOHINT
0x8000U
A list of bit-field constants, used with
ft2-base_interface.html#FT_Load_Glyph
FT_Load_Glyph
to indicate what kind of operations to perform during glyph loading.
values
FT_LOAD_DEFAULT
Corresponding to 0, this value is used a default glyph load. In this case, the following will happen:
1. FreeType looks for a bitmap for the glyph corresponding to the face's current size. If one is found, the function returns. The bitmap data can be accessed from the glyph slot (see note below).
2. If no embedded bitmap is searched or found, FreeType looks for a scalable outline. If one is found, it is loaded from the font file, scaled to device pixels, then "hinted" to the pixel grid in order to optimize it. The outline data can be accessed from the glyph slot (see note below).
Note that by default, the glyph loader doesn't render outlines into bitmaps. The following flags are used to modify this default behaviour to more specific and useful cases.
FT_LOAD_NO_SCALE
Don't scale the vector outline being loaded to 26.6 fractional pixels, but kept in font units. Note that this also disables hinting and the loading of embedded bitmaps. You should only use it when you want to retrieve the original glyph outlines in font units.
FT_LOAD_NO_HINTING
Don't hint glyph outlines after their scaling to device pixels. This generally generates "blurrier" glyphs in anti-aliased modes.
This flag is ignored if
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_NO_SCALE
is set.
FT_LOAD_RENDER
Render the glyph outline immediately into a bitmap before the glyph loader returns. By default, the glyph is rendered for the
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_NORMAL
mode, which corresponds to 8-bit anti-aliased bitmaps using 256 opacity levels. You can use either
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_TARGET_MONO
or
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_MONOCHROME
to render 1-bit monochrome bitmaps.
This flag is ignored if
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_NO_SCALE
is set.
FT_LOAD_NO_BITMAP
Don't look for bitmaps when loading the glyph. Only scalable outlines will be loaded when available, and scaled, hinted, or rendered depending on other bit flags.
This does not prevent you from rendering outlines to bitmaps with
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_RENDER
, however.
FT_LOAD_VERTICAL_LAYOUT
Prepare the glyph image for vertical text layout. This basically means that `face.glyph.advance' will correspond to the vertical advance height (instead of the default horizontal advance width), and that the glyph image will be translated to match the vertical bearings positions.
FT_LOAD_FORCE_AUTOHINT
Force the use of the FreeType auto-hinter when a glyph outline is loaded. You shouldn't need this in a typical application, since it is mostly used to experiment with its algorithm.
FT_LOAD_CROP_BITMAP
Indicates that the glyph loader should try to crop the bitmap (i.e., remove all space around its black bits) when loading it. This is only useful when loading embedded bitmaps in certain fonts, since bitmaps rendered with
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_RENDER
are always cropped by default.
FT_LOAD_PEDANTIC
Indicates that the glyph loader should perform pedantic verifications during glyph loading, rejecting invalid fonts. This is mostly used to detect broken glyphs in fonts. By default, FreeType tries to handle broken fonts also.
FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH
Indicates that the glyph loader should ignore the global advance width defined in the font. For historical reasons (to support buggy CJK fonts), FreeType uses the value of the `advanceWidthMax' field in the `htmx' table for all glyphs if the font is monospaced. Activating this flags makes FreeType use the metric values given in the `htmx' table.
FT_LOAD_NO_RECURSE
This flag is only used internally. It merely indicates that the glyph loader should not load composite glyphs recursively. Instead, it should set the `num_subglyph' and `subglyphs' values of the glyph slot accordingly, and set "glyph->format" to
ft2-basic_types.html#FT_Glyph_Format
FT_GLYPH_FORMAT_COMPOSITE
.
The description of sub-glyphs is not available to client applications for now.
FT_LOAD_IGNORE_TRANSFORM
Indicates that the glyph loader should not try to transform the loaded glyph image. This doesn't prevent scaling, hinting, or rendering.
FT_LOAD_MONOCHROME
This flag is used with
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_RENDER
to indicate that you want to render a 1-bit monochrome glyph bitmap from a vectorial outline.
Note that this has no effect on the hinting algorithm used by the glyph loader. You should better use
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_TARGET_MONO
if you want to render monochrome-optimized glyph images instead.
FT_LOAD_LINEAR_DESIGN
Return the linearly scaled metrics expressed in original font units instead of the default 16.16 pixel values.
FT_LOAD_NO_AUTOHINT
Indicates that the auto-hinter should never be used to hint glyph outlines. This doesn't prevent native format-specific hinters from being used. This can be important for certain fonts where unhinted output is better than auto-hinted one.
FT_LOAD_TARGET_NORMAL
Use hinting for
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_NORMAL
.
FT_LOAD_TARGET_LIGHT
Use hinting for
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_LIGHT
.
FT_LOAD_TARGET_MONO
Use hinting for
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_MONO
.
FT_LOAD_TARGET_LCD
Use hinting for
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_LCD
.
FT_LOAD_TARGET_LCD_V
Use hinting for
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_LCD_V
.
FT_Set_Transform
FT_EXPORT(
void
)
FT_Set_Transform
(
ft2-base_interface.html#FT_Face
FT_Face
face,
ft2-basic_types.html#FT_Matrix
FT_Matrix
*  matrix,
ft2-basic_types.html#FT_Vector
FT_Vector
*  delta );
A function used to set the transformation that is applied to glyph images when they are loaded into a glyph slot through
ft2-base_interface.html#FT_Load_Glyph
FT_Load_Glyph
.
inout
face
A handle to the source face object.
input
matrix
A pointer to the transformation's 2x2 matrix. Use 0 for the identity matrix.
delta
A pointer to the translation vector. Use 0 for the null vector.
note
The transformation is only applied to scalable image formats after the glyph has been loaded. It means that hinting is unaltered by the transformation and is performed on the character size given in the last call to
ft2-base_interface.html#FT_Set_Char_Size
FT_Set_Char_Size
or
ft2-base_interface.html#FT_Set_Pixel_Sizes
FT_Set_Pixel_Sizes
.
FT_Render_Mode
typedef
enum
FT_Render_Mode_
{
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_NORMAL
= 0,
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_LIGHT
,
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_MONO
,
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_LCD
,
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_LCD_V
,
FT_RENDER_MODE_MAX
}
FT_Render_Mode
;
An enumeration type that lists the render modes supported by FreeType 2. Each mode corresponds to a specific type of scanline conversion performed on the outline, as well as specific hinting optimizations.
For bitmap fonts the `bitmap->pixel_mode' field in the
ft2-base_interface.html#FT_GlyphSlotRec
FT_GlyphSlotRec
structure gives the format of the returned bitmap.
values
FT_RENDER_MODE_NORMAL
This is the default render mode; it corresponds to 8-bit anti-aliased bitmaps, using 256 levels of opacity.
FT_RENDER_MODE_LIGHT
This is similar to
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_NORMAL
-- you have to use
ft2-base_interface.html#FT_LOAD_XXX
FT_LOAD_TARGET_LIGHT
in calls to
ft2-base_interface.html#FT_Load_Glyph
FT_Load_Glyph
to get any effect since the rendering process no longer influences the positioning of glyph outlines.
The resulting glyph shapes are more similar to the original, while being a bit more fuzzy (`better shapes' instead of `better contrast', so to say.
FT_RENDER_MODE_MONO
This mode corresponds to 1-bit bitmaps.
FT_RENDER_MODE_LCD
This mode corresponds to horizontal RGB/BGR sub-pixel displays, like LCD-screens. It produces 8-bit bitmaps that are 3 times the width of the original glyph outline in pixels, and which use the
ft2-basic_types.html#FT_Pixel_Mode
FT_PIXEL_MODE_LCD
mode.
FT_RENDER_MODE_LCD_V
This mode corresponds to vertical RGB/BGR sub-pixel displays (like PDA screens, rotated LCD displays, etc.). It produces 8-bit bitmaps that are 3 times the height of the original glyph outline in pixels and use the
ft2-basic_types.html#FT_Pixel_Mode
FT_PIXEL_MODE_LCD_V
mode.
note
The LCD-optimized glyph bitmaps produced by FT_Render_Glyph are _not filtered_ to reduce color-fringes. It is up to the caller to perform this pass.
ft_render_mode_xxx
#define
ft2-base_interface.html#ft_render_mode_xxx
ft_render_mode_normal
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_NORMAL
#define
ft2-base_interface.html#ft_render_mode_xxx
ft_render_mode_mono
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_MONO
These constats are deprecated. Use the corresponding
ft2-base_interface.html#FT_Render_Mode
FT_Render_Mode
values instead.
values
ft_render_mode_normal
see
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_NORMAL
ft_render_mode_mono
see
ft2-base_interface.html#FT_Render_Mode
FT_RENDER_MODE_MONO
FT_Render_Glyph
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_Render_Glyph
(
ft2-base_interface.html#FT_GlyphSlot
FT_GlyphSlot
slot,
ft2-base_interface.html#FT_Render_Mode
FT_Render_Mode
render_mode );
Converts a given glyph image to a bitmap. It does so by inspecting the glyph image format, find the relevant renderer, and invoke it.
inout
slot
A handle to the glyph slot containing the image to convert.
input
render_mode
This is the render mode used to render the glyph image into a bitmap. See FT_Render_Mode for a list of possible values.
return
FreeType error code. 0 means success.
FT_Kerning_Mode
typedef
enum
FT_Kerning_Mode_
{
ft2-base_interface.html#FT_Kerning_Mode
FT_KERNING_DEFAULT
= 0,
ft2-base_interface.html#FT_Kerning_Mode
FT_KERNING_UNFITTED
,
ft2-base_interface.html#FT_Kerning_Mode
FT_KERNING_UNSCALED
}
FT_Kerning_Mode
;
An enumeration used to specify which kerning values to return in
ft2-base_interface.html#FT_Get_Kerning
FT_Get_Kerning
.
values
FT_KERNING_DEFAULT
Return scaled and grid-fitted kerning distances (value is 0).
FT_KERNING_UNFITTED
Return scaled but un-grid-fitted kerning distances.
FT_KERNING_UNSCALED
Return the kerning vector in original font units.
ft_kerning_default
#define
ft_kerning_default
ft2-base_interface.html#FT_Kerning_Mode
FT_KERNING_DEFAULT
This constant is deprecated. Please use
ft2-base_interface.html#FT_Kerning_Mode
FT_KERNING_DEFAULT
instead.
ft_kerning_unfitted
#define
ft_kerning_unfitted
ft2-base_interface.html#FT_Kerning_Mode
FT_KERNING_UNFITTED
This constant is deprecated. Please use
ft2-base_interface.html#FT_Kerning_Mode
FT_KERNING_UNFITTED
instead.
ft_kerning_unscaled
#define
ft_kerning_unscaled
ft2-base_interface.html#FT_Kerning_Mode
FT_KERNING_UNSCALED
This constant is deprecated. Please use
ft2-base_interface.html#FT_Kerning_Mode
FT_KERNING_UNSCALED
instead.
FT_Get_Kerning
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_Get_Kerning
(
ft2-base_interface.html#FT_Face
FT_Face
face,
ft2-basic_types.html#FT_UInt
FT_UInt
left_glyph,
ft2-basic_types.html#FT_UInt
FT_UInt
right_glyph,
ft2-basic_types.html#FT_UInt
FT_UInt
kern_mode,
ft2-basic_types.html#FT_Vector
FT_Vector
*akerning );
Returns the kerning vector between two glyphs of a same face.
input
face
A handle to a source face object.
left_glyph
The index of the left glyph in the kern pair.
right_glyph
The index of the right glyph in the kern pair.
kern_mode
See
ft2-base_interface.html#FT_Kerning_Mode
FT_Kerning_Mode
for more information. Determines the scale/dimension of the returned kerning vector.
output
akerning
The kerning vector. This is either in font units or in pixels (26.6 format) for scalable formats, and in pixels for fixed-sizes formats.
return
FreeType error code. 0 means success.
note
Only horizontal layouts (left-to-right & right-to-left) are supported by this method. Other layouts, or more sophisticated kernings, are out of the scope of this API function -- they can be implemented through format-specific interfaces.
FT_Get_Glyph_Name
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_Get_Glyph_Name
(
ft2-base_interface.html#FT_Face
FT_Face
face,
ft2-basic_types.html#FT_UInt
FT_UInt
glyph_index,
ft2-basic_types.html#FT_Pointer
FT_Pointer
buffer,
ft2-basic_types.html#FT_UInt
FT_UInt
buffer_max );
Retrieves the ASCII name of a given glyph in a face. This only works for those faces where FT_HAS_GLYPH_NAME(face) returns true.
input
face
A handle to a source face object.
glyph_index
The glyph index.
buffer_max
The maximal number of bytes available in the buffer.
output
buffer
A pointer to a target buffer where the name will be copied to.
return
FreeType error code. 0 means success.
note
An error is returned if the face doesn't provide glyph names or if the glyph index is invalid. In all cases of failure, the first byte of `buffer' will be set to 0 to indicate an empty name.
The glyph name is truncated to fit within the buffer if it is too long. The returned string is always zero-terminated.
This function is not compiled within the library if the config macro FT_CONFIG_OPTION_NO_GLYPH_NAMES is defined in `include/freetype/config/ftoptions.h'
FT_Get_Postscript_Name
FT_EXPORT(
const
char
* )
FT_Get_Postscript_Name
(
ft2-base_interface.html#FT_Face
FT_Face
face );
Retrieves the ASCII Postscript name of a given face, if available. This only works with Postscript and TrueType fonts.
input
face
A handle to the source face object.
return
A pointer to the face's Postscript name. NULL if unavailable.
note
The returned pointer is owned by the face and will be destroyed with it.
FT_Select_Charmap
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_Select_Charmap
(
ft2-base_interface.html#FT_Face
FT_Face
face,
ft2-base_interface.html#FT_Encoding
FT_Encoding
encoding );
Selects a given charmap by its encoding tag (as listed in `freetype.h').
inout
face
A handle to the source face object.
input
encoding
A handle to the selected charmap.
return
FreeType error code. 0 means success.
note
This function will return an error if no charmap in the face corresponds to the encoding queried here.
FT_Set_Charmap
FT_EXPORT(
ft2-basic_types.html#FT_Error
FT_Error
)
FT_Set_Charmap
(
ft2-base_interface.html#FT_Face
FT_Face
face,
ft2-base_interface.html#FT_CharMap
FT_CharMap
charmap
);
Selects a given charmap for character code to glyph index decoding.
inout
face
A handle to the source face object.
input
charmap
A handle to the selected charmap.
return
FreeType error code. 0 means success.
note
This function will return an error if the charmap is not part of the face (i.e., if it is not listed in the face->charmaps[] table).
FT_Get_Charmap_Index
FT_EXPORT(
ft2-basic_types.html#FT_Int
FT_Int
)
FT_Get_Charmap_Index
(
ft2-base_interface.html#FT_CharMap
FT_CharMap
charmap
);
Retrieve index of a given charmap.
input
charmap
A handle to a charmap.
return
The index into the array of character maps within the face to which `charmap' belongs.
FT_Get_Char_Index
FT_EXPORT(
ft2-basic_types.html#FT_UInt
FT_UInt
)
FT_Get_Char_Index
(
ft2-base_interface.html#FT_Face
FT_Face
face,
ft2-basic_types.html#FT_ULong
FT_ULong
charcode
);
Returns the glyph index of a given character code. This function uses a charmap object to do the translation.
input
face
A handle to the source face object.
charcode
The character code.
return
The glyph index. 0 means `undefined character code'.
note
FreeType computes its own glyph indices which are not necessarily the same as used in the font in case the font is based on glyph indices. Reason for this behaviour is to assure that index 0 is never used, representing the missing glyph.
FT_Get_First_Char
FT_EXPORT(
ft2-basic_types.html#FT_ULong
FT_ULong
)
FT_Get_First_Char
(
ft2-base_interface.html#FT_Face
FT_Face
face,
ft2-basic_types.html#FT_UInt
FT_UInt
*agindex );
This function is used to return the first character code in the current charmap of a given face. It will also return the corresponding glyph index.
input
face
A handle to the source face object.
output
agindex
Glyph index of first character code. 0 if charmap is empty.
return
The charmap's first character code.
note
You should use this function with
ft2-base_interface.html#FT_Get_Next_Char
FT_Get_Next_Char
to be able to parse all character codes available in a given charmap. The code should look like this:
FT_ULong  charcode;
FT_UInt   gindex;
charcode = FT_Get_First_Char( face, &gindex );
while ( gindex != 0 )
{
... do something with (charcode,gindex) pair ...
charcode = FT_Get_Next_Char( face, charcode, &gindex );
}
Note that `*agindex' will be set to 0 if the charmap is empty. The result itself can be 0 in two cases: if the charmap is empty or when the value 0 is the first valid character code.
FT_Get_Next_Char
FT_EXPORT(
ft2-basic_types.html#FT_ULong
FT_ULong
)
FT_Get_Next_Char
(
ft2-base_interface.html#FT_Face
FT_Face
face,
ft2-basic_types.html#FT_ULong
FT_ULong
char_code
,
ft2-basic_types.html#FT_UInt
FT_UInt
*agindex );
This function is used to return the next character code in the current charmap of a given face following the value 'char_code', as well as the corresponding glyph index.
input
face
A handle to the source face object.
char_code
The starting character code.
output
agindex
Glyph index of first character code. 0 if charmap is empty.
return
The charmap's next character code.
note
You should use this function with
ft2-base_interface.html#FT_Get_First_Char
FT_Get_First_Char
to walk through all character codes available in a given charmap. See the note for this function for a simple code example.
Note that `*agindex' will be set to 0 when there are no more codes in the charmap.
FT_Get_Name_Index
FT_EXPORT(
ft2-basic_types.html#FT_UInt
FT_UInt
)
FT_Get_Name_Index
(
ft2-base_interface.html#FT_Face
FT_Face
face,
ft2-basic_types.html#FT_String
FT_String
*  glyph_name );
Returns the glyph index of a given glyph name. This function uses driver specific objects to do the translation.
input
face
A handle to the source face object.
glyph_name
The glyph name.
return
The glyph index. 0 means `undefined character code'.
