diff options
Diffstat (limited to 'src/3rdparty/freetype/include/freetype/freetype.h')
| -rw-r--r-- | src/3rdparty/freetype/include/freetype/freetype.h | 1387 |
1 files changed, 920 insertions, 467 deletions
diff --git a/src/3rdparty/freetype/include/freetype/freetype.h b/src/3rdparty/freetype/include/freetype/freetype.h index b6247f510f..96644046e4 100644 --- a/src/3rdparty/freetype/include/freetype/freetype.h +++ b/src/3rdparty/freetype/include/freetype/freetype.h @@ -4,7 +4,7 @@ /* */ /* FreeType high-level API and common types (specification only). */ /* */ -/* Copyright 1996-2015 by */ +/* Copyright 1996-2018 by */ /* David Turner, Robert Wilhelm, and Werner Lemberg. */ /* */ /* This file is part of the FreeType project, and may only be used, */ @@ -16,8 +16,8 @@ /***************************************************************************/ -#ifndef __FREETYPE_H__ -#define __FREETYPE_H__ +#ifndef FREETYPE_H_ +#define FREETYPE_H_ #ifndef FT_FREETYPE_H @@ -138,24 +138,26 @@ FT_BEGIN_HEADER /* FT_FACE_FLAG_TRICKY */ /* FT_FACE_FLAG_KERNING */ /* FT_FACE_FLAG_MULTIPLE_MASTERS */ + /* FT_FACE_FLAG_VARIATION */ /* FT_FACE_FLAG_GLYPH_NAMES */ /* FT_FACE_FLAG_EXTERNAL_STREAM */ /* FT_FACE_FLAG_HINTER */ - /* FT_FACE_FLAG_TRICKY */ /* */ /* FT_HAS_HORIZONTAL */ /* FT_HAS_VERTICAL */ /* FT_HAS_KERNING */ /* FT_HAS_FIXED_SIZES */ /* FT_HAS_GLYPH_NAMES */ - /* FT_HAS_MULTIPLE_MASTERS */ /* FT_HAS_COLOR */ + /* FT_HAS_MULTIPLE_MASTERS */ /* */ /* FT_IS_SFNT */ /* FT_IS_SCALABLE */ /* FT_IS_FIXED_WIDTH */ /* FT_IS_CID_KEYED */ /* FT_IS_TRICKY */ + /* FT_IS_NAMED_INSTANCE */ + /* FT_IS_VARIATION */ /* */ /* FT_STYLE_FLAG_BOLD */ /* FT_STYLE_FLAG_ITALIC */ @@ -176,6 +178,7 @@ FT_BEGIN_HEADER /* FT_Done_Face */ /* FT_Reference_Face */ /* FT_New_Memory_Face */ + /* FT_Face_Properties */ /* FT_Open_Face */ /* FT_Open_Args */ /* FT_Parameter */ @@ -266,8 +269,8 @@ FT_BEGIN_HEADER /* FT_Glyph_Metrics */ /* */ /* <Description> */ - /* A structure used to model the metrics of a single glyph. The */ - /* values are expressed in 26.6 fractional pixel format; if the flag */ + /* A structure 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 has been used while loading the glyph, values */ /* are expressed in font units instead. */ /* */ @@ -306,6 +309,11 @@ FT_BEGIN_HEADER /* `horiAdvance' or `vertAdvance'; you have to manually adjust these */ /* values to account for the added width and height. */ /* */ + /* FreeType doesn't use the `VORG' table data for CFF fonts because */ + /* it doesn't have an interface to quickly retrieve the glyph height. */ + /* The y~coordinate of the vertical origin can be simply computed as */ + /* `vertBearingY + height' after loading a glyph. */ + /* */ typedef struct FT_Glyph_Metrics_ { FT_Pos width; @@ -350,10 +358,10 @@ FT_BEGIN_HEADER /* */ /* <Note> */ /* Windows FNT: */ - /* The nominal size given in a FNT font is not reliable. Thus when */ - /* the driver finds it incorrect, it sets `size' to some calculated */ - /* values and sets `x_ppem' and `y_ppem' to the pixel width and */ - /* height given in the font, respectively. */ + /* The nominal size given in a FNT font is not reliable. If the */ + /* driver finds it incorrect, it sets `size' to some calculated */ + /* values, and `x_ppem' and `y_ppem' to the pixel width and height */ + /* given in the font, respectively. */ /* */ /* TrueType embedded bitmaps: */ /* `size', `width', and `height' values are not contained in the */ @@ -422,9 +430,9 @@ FT_BEGIN_HEADER /* FT_Module */ /* */ /* <Description> */ - /* A handle to a given FreeType module object. Each module can be a */ + /* A handle to a given FreeType module object. A module can be a */ /* font driver, a renderer, or anything else that provides services */ - /* to the formers. */ + /* to the former. */ /* */ typedef struct FT_ModuleRec_* FT_Module; @@ -435,8 +443,8 @@ FT_BEGIN_HEADER /* FT_Driver */ /* */ /* <Description> */ - /* A handle to a given FreeType font driver object. Each font driver */ - /* is a special module capable of creating faces from font files. */ + /* A handle to a given FreeType font driver object. A font driver */ + /* is a module capable of creating faces from font files. */ /* */ typedef struct FT_DriverRec_* FT_Driver; @@ -447,10 +455,10 @@ FT_BEGIN_HEADER /* FT_Renderer */ /* */ /* <Description> */ - /* 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. */ + /* A handle to a given FreeType renderer. A renderer is a module in */ + /* charge of converting a glyph's outline image to a bitmap. It */ + /* supports a single glyph image format, and one or more target */ + /* surface depths. */ /* */ typedef struct FT_RendererRec_* FT_Renderer; @@ -468,15 +476,15 @@ FT_BEGIN_HEADER /* FT_Face */ /* */ /* <Description> */ - /* A handle to a given typographic face object. A face object models */ - /* a given typeface, in a given style. */ + /* A handle to a typographic face object. A face object models a */ + /* given typeface, in a given style. */ /* */ /* <Note> */ - /* Each face object also owns a single @FT_GlyphSlot object, as well */ + /* A face object also owns a single @FT_GlyphSlot object, as well */ /* as one or more @FT_Size objects. */ /* */ /* Use @FT_New_Face or @FT_Open_Face to create a new face object from */ - /* a given filepathname or a custom input stream. */ + /* a given filepath or a custom input stream. */ /* */ /* Use @FT_Done_Face to destroy it (along with its slot and sizes). */ /* */ @@ -501,11 +509,11 @@ FT_BEGIN_HEADER /* FT_Size */ /* */ /* <Description> */ - /* A handle to an object used to model a face scaled to a given */ + /* A handle to an object that models a face scaled to a given */ /* character size. */ /* */ /* <Note> */ - /* Each @FT_Face has an _active_ @FT_Size object that is used by */ + /* An @FT_Face has one _active_ @FT_Size object that is used by */ /* functions like @FT_Load_Glyph to determine the scaling */ /* transformation that in turn is used to load and hint glyphs and */ /* metrics. */ @@ -532,9 +540,8 @@ FT_BEGIN_HEADER /* FT_GlyphSlot */ /* */ /* <Description> */ - /* A handle to a given `glyph slot'. A slot is a container where it */ - /* is possible to load any of the glyphs contained in its parent */ - /* face. */ + /* A handle to a given `glyph slot'. A slot is a container that can */ + /* hold any of the glyphs contained in its parent face. */ /* */ /* In other words, each time you call @FT_Load_Glyph or */ /* @FT_Load_Char, the slot's content is erased by the new glyph data, */ @@ -553,13 +560,14 @@ FT_BEGIN_HEADER /* FT_CharMap */ /* */ /* <Description> */ - /* 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. */ + /* A handle to a character map (usually abbreviated to `charmap'). 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 @FT_Get_Char_Index or @FT_Load_Char. */ + /* can be `active', providing the data used by @FT_Get_Char_Index or */ + /* @FT_Load_Char. */ /* */ /* The list of available charmaps in a face is available through the */ /* `face->num_charmaps' and `face->charmaps' fields of @FT_FaceRec. */ @@ -570,7 +578,8 @@ FT_BEGIN_HEADER /* <Note> */ /* When a new face is created (either through @FT_New_Face or */ /* @FT_Open_Face), the library looks for a Unicode charmap within */ - /* the list and automatically activates it. */ + /* the list and automatically activates it. If there is no Unicode */ + /* charmap, FreeType doesn't set an `active' charmap. */ /* */ /* <Also> */ /* See @FT_CharMapRec for the publicly accessible fields of a given */ @@ -616,8 +625,8 @@ FT_BEGIN_HEADER /* FT_Encoding */ /* */ /* <Description> */ - /* An enumeration used to specify character sets supported by */ - /* charmaps. Used in the @FT_Select_Charmap API function. */ + /* An enumeration to specify character sets supported by charmaps. */ + /* Used in the @FT_Select_Charmap API function. */ /* */ /* <Note> */ /* Despite the name, this enumeration lists specific character */ @@ -631,19 +640,18 @@ FT_BEGIN_HEADER /* 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. */ + /* 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. */ /* */ /* For example, if you want to access Unicode value U+1F028 (and */ /* the font contains it), use value 0x1F028 as the input value for */ /* @FT_Get_Char_Index. */ /* */ /* FT_ENCODING_MS_SYMBOL :: */ - /* Corresponds to the Microsoft Symbol encoding, used to encode */ - /* mathematical symbols and wingdings. For more information, see */ - /* `http://www.microsoft.com/typography/otspec/recom.htm', */ + /* Microsoft Symbol encoding, used to encode mathematical symbols */ + /* and wingdings. For more information, see */ + /* `https://www.microsoft.com/typography/otspec/recom.htm', */ /* `http://www.kostis.net/charsets/symbol.htm', and */ /* `http://www.kostis.net/charsets/wingding.htm'. */ /* */ @@ -651,60 +659,60 @@ FT_BEGIN_HEADER /* Area) in the range U+F020-U+F0FF. */ /* */ /* FT_ENCODING_SJIS :: */ - /* Corresponds to Japanese SJIS encoding. More info at */ - /* at `http://en.wikipedia.org/wiki/Shift_JIS'. */ - /* See note on multi-byte encodings below. */ + /* Shift JIS encoding for Japanese. More info at */ + /* `https://en.wikipedia.org/wiki/Shift_JIS'. 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_PRC :: */ + /* Corresponds to encoding systems mainly for Simplified Chinese as */ + /* used in People's Republic of China (PRC). The encoding layout */ + /* is based on GB~2312 and its supersets GBK and GB~18030. */ /* */ /* 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. */ + /* Corresponds to the Korean encoding system known as Extended */ + /* Wansung (MS Windows code page 949). */ /* For more information see */ - /* `https://msdn.microsoft.com/en-US/goglobal/cc305154'. */ + /* `https://www.unicode.org/Public/MAPPINGS/VENDORS/MICSFT/WindowsBestFit/bestfit949.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. */ + /* includes all possible Hangul 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. */ + /* 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. */ + /* 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. */ + /* Apple roman encoding. Many TrueType and OpenType fonts contain */ + /* a charmap for this 8-bit 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 */ + /* This value is deprecated and was neither 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. */ + /* Same as FT_ENCODING_PRC. Deprecated. */ /* */ /* FT_ENCODING_MS_BIG5 :: */ /* Same as FT_ENCODING_BIG5. Deprecated. */ @@ -716,11 +724,12 @@ FT_BEGIN_HEADER /* Same as FT_ENCODING_JOHAB. Deprecated. */ /* */ /* <Note> */ - /* By default, FreeType automatically synthesizes a Unicode charmap */ - /* for PostScript fonts, using their glyph names dictionaries. */ - /* However, it also reports the encodings defined explicitly in the */ - /* font file, for the cases when they are needed, with the Adobe */ - /* values as well. */ + /* By default, FreeType enables a Unicode charmap and tags it with */ + /* FT_ENCODING_UNICODE when it is either provided or can be generated */ + /* from PostScript glyph name dictionaries in the font file. */ + /* All other encodings are considered legacy and tagged only if */ + /* explicitly defined in the font file. Otherwise, FT_ENCODING_NONE */ + /* is used. */ /* */ /* 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 */ @@ -737,21 +746,21 @@ FT_BEGIN_HEADER /* 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 */ + /* 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 that may */ /* be needed to be able to distinguish Apple encoding variants. See */ /* */ - /* http://www.unicode.org/Public/MAPPINGS/VENDORS/APPLE/Readme.txt */ + /* https://www.unicode.org/Public/MAPPINGS/VENDORS/APPLE/Readme.txt */ /* */ /* to get an idea how to do that. Basically, if the language ID */ /* is~0, don't 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_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 */ + /* `TT_MAC_ID_ARABIC' with `TT_MAC_LANGID_FARSI' means the Farsi */ /* variant the Arabic encoding. */ /* */ typedef enum FT_Encoding_ @@ -762,14 +771,15 @@ FT_BEGIN_HEADER FT_ENC_TAG( FT_ENCODING_UNICODE, 'u', 'n', 'i', 'c' ), FT_ENC_TAG( FT_ENCODING_SJIS, 's', 'j', 'i', 's' ), - FT_ENC_TAG( FT_ENCODING_GB2312, 'g', 'b', ' ', ' ' ), + FT_ENC_TAG( FT_ENCODING_PRC, 'g', 'b', ' ', ' ' ), FT_ENC_TAG( FT_ENCODING_BIG5, 'b', 'i', 'g', '5' ), FT_ENC_TAG( FT_ENCODING_WANSUNG, 'w', 'a', 'n', 's' ), FT_ENC_TAG( FT_ENCODING_JOHAB, 'j', 'o', 'h', 'a' ), - /* for backwards compatibility */ + /* for backward compatibility */ + FT_ENCODING_GB2312 = FT_ENCODING_PRC, FT_ENCODING_MS_SJIS = FT_ENCODING_SJIS, - FT_ENCODING_MS_GB2312 = FT_ENCODING_GB2312, + FT_ENCODING_MS_GB2312 = FT_ENCODING_PRC, FT_ENCODING_MS_BIG5 = FT_ENCODING_BIG5, FT_ENCODING_MS_WANSUNG = FT_ENCODING_WANSUNG, FT_ENCODING_MS_JOHAB = FT_ENCODING_JOHAB, @@ -794,7 +804,7 @@ FT_BEGIN_HEADER #define ft_encoding_latin_1 FT_ENCODING_ADOBE_LATIN_1 #define ft_encoding_latin_2 FT_ENCODING_OLD_LATIN_2 #define ft_encoding_sjis FT_ENCODING_SJIS -#define ft_encoding_gb2312 FT_ENCODING_GB2312 +#define ft_encoding_gb2312 FT_ENCODING_PRC #define ft_encoding_big5 FT_ENCODING_BIG5 #define ft_encoding_wansung FT_ENCODING_WANSUNG #define ft_encoding_johab FT_ENCODING_JOHAB @@ -821,11 +831,11 @@ FT_BEGIN_HEADER /* */ /* 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. */ + /* the TrueType specification and gets emulated for */ + /* other formats. */ /* */ /* encoding_id :: A platform specific encoding number. This also */ - /* comes from the TrueType specification and should be */ + /* comes from the TrueType specification and gets */ /* emulated similarly. */ /* */ typedef struct FT_CharMapRec_ @@ -853,8 +863,8 @@ FT_BEGIN_HEADER /* FT_Face_Internal */ /* */ /* <Description> */ - /* An opaque handle to an `FT_Face_InternalRec' structure, used to */ - /* model private data of a given @FT_Face object. */ + /* An opaque handle to an `FT_Face_InternalRec' structure that models */ + /* the private data of a given @FT_Face object. */ /* */ /* This structure might change between releases of FreeType~2 and is */ /* not generally available to client applications. */ @@ -874,7 +884,7 @@ FT_BEGIN_HEADER /* <Fields> */ /* num_faces :: The number of faces in the font file. Some */ /* font formats can have multiple faces in */ - /* a font file. */ + /* a single font file. */ /* */ /* face_index :: This field holds two different values. */ /* Bits 0-15 are the index of the face in the */ @@ -882,38 +892,50 @@ FT_BEGIN_HEADER /* are set to~0 if there is only one face in */ /* the font file. */ /* */ - /* Bits 16-30 are relevant to GX variation */ - /* fonts only, holding the named instance */ - /* index for the current face index (starting */ - /* with value~1; value~0 indicates font access */ - /* without GX variation data). For non-GX */ - /* fonts, bits 16-30 are ignored. If we have */ - /* the third named instance of face~4, say, */ - /* `face_index' is set to 0x00030004. */ + /* [Since 2.6.1] Bits 16-30 are relevant to GX */ + /* and OpenType variation fonts only, holding */ + /* the named instance index for the current */ + /* face index (starting with value~1; value~0 */ + /* indicates font access without a named */ + /* instance). For non-variation fonts, bits */ + /* 16-30 are ignored. If we have the third */ + /* named instance of face~4, say, `face_index' */ + /* is set to 0x00030004. */ /* */ /* Bit 31 is always zero (this is, */ /* `face_index' is always a positive value). */ /* */ + /* [Since 2.9] Changing the design coordinates */ + /* with @FT_Set_Var_Design_Coordinates or */ + /* @FT_Set_Var_Blend_Coordinates does not */ + /* influence the named instance index value */ + /* (only @FT_Set_Named_Instance does that). */ + /* */ /* face_flags :: A set of bit flags that give important */ /* information about the face; see */ /* @FT_FACE_FLAG_XXX for the details. */ /* */ /* style_flags :: The lower 16~bits contain a set of bit */ /* flags indicating the style of the face; see */ - /* @FT_STYLE_FLAG_XXX for the details. Bits */ - /* 16-30 hold the number of named instances */ - /* available for the current face if we have a */ - /* GX variation (sub)font. Bit 31 is always */ - /* zero (this is, `style_flags' is always a */ - /* positive value). */ + /* @FT_STYLE_FLAG_XXX for the details. */ + /* */ + /* [Since 2.6.1] Bits 16-30 hold the number */ + /* of named instances available for the */ + /* current face if we have a GX or OpenType */ + /* variation (sub)font. Bit 31 is always zero */ + /* (this is, `style_flags' is always a */ + /* positive value). Note that a variation */ + /* font has always at least one named */ + /* instance, namely the default instance. */ /* */ /* num_glyphs :: The number of glyphs in the face. If the */ /* face is scalable and has sbits (see */ /* `num_fixed_sizes'), it is set to the number */ /* of outline glyphs. */ /* */ - /* For CID-keyed fonts, this value gives the */ - /* highest CID used in the font. */ + /* For CID-keyed fonts (not in an SFNT */ + /* wrapper) this value gives the highest CID */ + /* used in the font. */ /* */ /* family_name :: The face's family name. This is an ASCII */ /* string, usually in English, that describes */ @@ -952,6 +974,10 @@ FT_BEGIN_HEADER /* strikes in the face. It is set to NULL if */ /* there is no bitmap strike. */ /* */ + /* Note that FreeType tries to sanitize the */ + /* strike data since they are sometimes sloppy */ + /* or incorrect, but this can easily fail. */ + /* */ /* num_charmaps :: The number of charmaps in the face. */ /* */ /* charmaps :: An array of the charmaps of the face. */ @@ -987,8 +1013,8 @@ FT_BEGIN_HEADER /* expressed in font units. For font formats */ /* not having this information, it is set to */ /* `bbox.yMin'. Note that this field is */ - /* usually negative. Only relevant for */ - /* scalable formats. */ + /* negative for values below the baseline. */ + /* Only relevant for scalable formats. */ /* */ /* height :: This value is the vertical distance */ /* between two consecutive baselines, */ @@ -1031,6 +1057,15 @@ FT_BEGIN_HEADER /* Fields may be changed after a call to @FT_Attach_File or */ /* @FT_Attach_Stream. */ /* */ + /* For an OpenType variation font, the values of the following fields */ + /* can change after a call to @FT_Set_Var_Design_Coordinates (and */ + /* friends) if the font contains an `MVAR' table: `ascender', */ + /* `descender', `height', `underline_position', and */ + /* `underline_thickness'. */ + /* */ + /* Especially for TrueType fonts see also the documentation for */ + /* @FT_Size_Metrics. */ + /* */ typedef struct FT_FaceRec_ { FT_Long num_faces; @@ -1102,49 +1137,51 @@ FT_BEGIN_HEADER /* */ /* <Values> */ /* FT_FACE_FLAG_SCALABLE :: */ - /* Indicates that the face contains outline glyphs. This doesn't */ - /* prevent bitmap strikes, i.e., a face can have both this and */ - /* and @FT_FACE_FLAG_FIXED_SIZES set. */ + /* The face contains outline glyphs. Note that a face can contain */ + /* bitmap strikes also, i.e., a face can have both this flag and */ + /* @FT_FACE_FLAG_FIXED_SIZES set. */ /* */ /* FT_FACE_FLAG_FIXED_SIZES :: */ - /* Indicates that the face contains bitmap strikes. See also the */ + /* The face contains bitmap strikes. See also the */ /* `num_fixed_sizes' and `available_sizes' fields of @FT_FaceRec. */ /* */ /* FT_FACE_FLAG_FIXED_WIDTH :: */ - /* Indicates that the face contains fixed-width characters (like */ - /* Courier, Lucido, MonoType, etc.). */ + /* The face contains fixed-width characters (like Courier, Lucida, */ + /* MonoType, etc.). */ /* */ /* FT_FACE_FLAG_SFNT :: */ - /* Indicates that the face uses the `sfnt' storage scheme. For */ - /* now, this means TrueType and OpenType. */ + /* 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. */ + /* 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. */ + /* 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 */ - /* @FT_Get_Kerning. Otherwise the function always return the */ - /* vector (0,0). Note that FreeType doesn't handle kerning data */ - /* from the `GPOS' table (as present in some OpenType fonts). */ + /* The face contains kerning information. If set, the kerning */ + /* distance can be retrieved using the function @FT_Get_Kerning. */ + /* Otherwise the function always return the vector (0,0). Note */ + /* that FreeType doesn't handle kerning data from the SFNT `GPOS' */ + /* table (as present in many OpenType fonts). */ /* */ /* 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. */ + /* The face contains multiple masters and is capable of */ + /* interpolating between them. Supported formats are Adobe MM, */ + /* TrueType GX, and OpenType variation fonts. */ + /* */ + /* See section @multiple_masters for API details. */ /* */ /* FT_FACE_FLAG_GLYPH_NAMES :: */ - /* Indicates that the font contains glyph names that can be */ - /* retrieved through @FT_Get_Glyph_Name. Note that some TrueType */ - /* fonts contain broken glyph name tables. Use the function */ + /* The face contains glyph names, which can be retrieved using */ + /* @FT_Get_Glyph_Name. Note that some TrueType fonts contain */ + /* broken glyph name tables. Use the function */ /* @FT_Has_PS_Glyph_Names when needed. */ /* */ /* FT_FACE_FLAG_EXTERNAL_STREAM :: */ @@ -1153,31 +1190,31 @@ FT_BEGIN_HEADER /* when @FT_Done_Face is called. Don't read or test this flag. */ /* */ /* FT_FACE_FLAG_HINTER :: */ - /* Set if the font driver has a hinting machine of its own. For */ - /* example, with TrueType fonts, it makes sense to use data from */ - /* the SFNT `gasp' table only if the native TrueType hinting engine */ - /* (with the bytecode interpreter) is available and active. */ + /* The font driver has a hinting machine of its own. For example, */ + /* with TrueType fonts, it makes sense to use data from the SFNT */ + /* `gasp' table only if the native TrueType hinting engine (with */ + /* the bytecode interpreter) is available and active. */ /* */ /* FT_FACE_FLAG_CID_KEYED :: */ - /* Set if the font is CID-keyed. In that case, the font is not */ - /* accessed by glyph indices but by CID values. For subsetted */ - /* CID-keyed fonts this has the consequence that not all index */ - /* values are a valid argument to FT_Load_Glyph. Only the CID */ - /* values for which corresponding glyphs in the subsetted font */ - /* exist make FT_Load_Glyph return successfully; in all other cases */ - /* you get an `FT_Err_Invalid_Argument' error. */ - /* */ - /* Note that CID-keyed fonts that are in an SFNT wrapper don't */ - /* have this flag set since the glyphs are accessed in the normal */ - /* way (using contiguous indices); the `CID-ness' isn't visible to */ - /* the application. */ + /* The face is CID-keyed. In that case, the face is not accessed */ + /* by glyph indices but by CID values. For subsetted CID-keyed */ + /* fonts this has the consequence that not all index values are a */ + /* valid argument to @FT_Load_Glyph. Only the CID values for which */ + /* corresponding glyphs in the subsetted font exist make */ + /* `FT_Load_Glyph' return successfully; in all other cases you get */ + /* an `FT_Err_Invalid_Argument' error. */ + /* */ + /* Note that CID-keyed fonts that are in an SFNT wrapper (this is, */ + /* all OpenType/CFF fonts) don't have this flag set since the */ + /* glyphs are accessed in the normal way (using contiguous */ + /* indices); the `CID-ness' isn't visible to the application. */ /* */ /* FT_FACE_FLAG_TRICKY :: */ - /* Set if the font is `tricky', this is, it always needs the */ - /* font format's native hinting engine to get a reasonable result. */ - /* A typical example is the Chinese font `mingli.ttf' that uses */ - /* TrueType bytecode instructions to move and scale all of its */ - /* subglyphs. */ + /* The face is `tricky', this is, it always needs the font format's */ + /* native hinting engine to get a reasonable result. A typical */ + /* example is the old Chinese font `mingli.ttf' (but not */ + /* `mingliu.ttc') that uses TrueType bytecode instructions to move */ + /* and scale all of its subglyphs. */ /* */ /* It is not possible to auto-hint such fonts using */ /* @FT_LOAD_FORCE_AUTOHINT; it will also ignore */ @@ -1189,8 +1226,15 @@ FT_BEGIN_HEADER /* tricky fonts; they are hard-coded in file `ttobjs.c'. */ /* */ /* FT_FACE_FLAG_COLOR :: */ - /* Set if the font has color glyph tables. To access color glyphs */ - /* use @FT_LOAD_COLOR. */ + /* [Since 2.5.1] The face has color glyph tables. To access color */ + /* glyphs use @FT_LOAD_COLOR. */ + /* */ + /* FT_FACE_FLAG_VARIATION :: */ + /* [Since 2.9] Set if the current face (or named instance) has been */ + /* altered with @FT_Set_MM_Design_Coordinates, */ + /* @FT_Set_Var_Design_Coordinates, or */ + /* @FT_Set_Var_Blend_Coordinates. This flag is unset by a call to */ + /* @FT_Set_Named_Instance. */ /* */ #define FT_FACE_FLAG_SCALABLE ( 1L << 0 ) #define FT_FACE_FLAG_FIXED_SIZES ( 1L << 1 ) @@ -1207,6 +1251,7 @@ FT_BEGIN_HEADER #define FT_FACE_FLAG_CID_KEYED ( 1L << 12 ) #define FT_FACE_FLAG_TRICKY ( 1L << 13 ) #define FT_FACE_FLAG_COLOR ( 1L << 14 ) +#define FT_FACE_FLAG_VARIATION ( 1L << 15 ) /************************************************************************* @@ -1223,7 +1268,7 @@ FT_BEGIN_HEADER * */ #define FT_HAS_HORIZONTAL( face ) \ - ( face->face_flags & FT_FACE_FLAG_HORIZONTAL ) + ( (face)->face_flags & FT_FACE_FLAG_HORIZONTAL ) /************************************************************************* @@ -1237,7 +1282,7 @@ FT_BEGIN_HEADER * */ #define FT_HAS_VERTICAL( face ) \ - ( face->face_flags & FT_FACE_FLAG_VERTICAL ) + ( (face)->face_flags & FT_FACE_FLAG_VERTICAL ) /************************************************************************* @@ -1251,7 +1296,7 @@ FT_BEGIN_HEADER * */ #define FT_HAS_KERNING( face ) \ - ( face->face_flags & FT_FACE_FLAG_KERNING ) + ( (face)->face_flags & FT_FACE_FLAG_KERNING ) /************************************************************************* @@ -1262,11 +1307,11 @@ FT_BEGIN_HEADER * @description: * A macro that returns true whenever a face object contains a scalable * font face (true for TrueType, Type~1, Type~42, CID, OpenType/CFF, - * and PFR font formats. + * and PFR font formats). * */ #define FT_IS_SCALABLE( face ) \ - ( face->face_flags & FT_FACE_FLAG_SCALABLE ) + ( (face)->face_flags & FT_FACE_FLAG_SCALABLE ) /************************************************************************* @@ -1285,7 +1330,7 @@ FT_BEGIN_HEADER * */ #define FT_IS_SFNT( face ) \ - ( face->face_flags & FT_FACE_FLAG_SFNT ) + ( (face)->face_flags & FT_FACE_FLAG_SFNT ) /************************************************************************* @@ -1300,7 +1345,7 @@ FT_BEGIN_HEADER * */ #define FT_IS_FIXED_WIDTH( face ) \ - ( face->face_flags & FT_FACE_FLAG_FIXED_WIDTH ) + ( (face)->face_flags & FT_FACE_FLAG_FIXED_WIDTH ) /************************************************************************* @@ -1315,7 +1360,7 @@ FT_BEGIN_HEADER * */ #define FT_HAS_FIXED_SIZES( face ) \ - ( face->face_flags & FT_FACE_FLAG_FIXED_SIZES ) + ( (face)->face_flags & FT_FACE_FLAG_FIXED_SIZES ) /************************************************************************* @@ -1341,7 +1386,7 @@ FT_BEGIN_HEADER * */ #define FT_HAS_GLYPH_NAMES( face ) \ - ( face->face_flags & FT_FACE_FLAG_GLYPH_NAMES ) + ( (face)->face_flags & FT_FACE_FLAG_GLYPH_NAMES ) /************************************************************************* @@ -1356,7 +1401,47 @@ FT_BEGIN_HEADER * */ #define FT_HAS_MULTIPLE_MASTERS( face ) \ - ( face->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS ) + ( (face)->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS ) + + + /************************************************************************* + * + * @macro: + * FT_IS_NAMED_INSTANCE( face ) + * + * @description: + * A macro that returns true whenever a face object is a named instance + * of a GX or OpenType variation font. + * + * [Since 2.9] Changing the design coordinates with + * @FT_Set_Var_Design_Coordinates or @FT_Set_Var_Blend_Coordinates does + * not influence the return value of this macro (only + * @FT_Set_Named_Instance does that). + * + * @since: + * 2.7 + * + */ +#define FT_IS_NAMED_INSTANCE( face ) \ + ( (face)->face_index & 0x7FFF0000L ) + + + /************************************************************************* + * + * @macro: + * FT_IS_VARIATION( face ) + * + * @description: + * A macro that returns true whenever a face object has been altered + * by @FT_Set_MM_Design_Coordinates, @FT_Set_Var_Design_Coordinates, or + * @FT_Set_Var_Blend_Coordinates. + * + * @since: + * 2.9 + * + */ +#define FT_IS_VARIATION( face ) \ + ( (face)->face_flags & FT_FACE_FLAG_VARIATION ) /************************************************************************* @@ -1374,7 +1459,7 @@ FT_BEGIN_HEADER * */ #define FT_IS_CID_KEYED( face ) \ - ( face->face_flags & FT_FACE_FLAG_CID_KEYED ) + ( (face)->face_flags & FT_FACE_FLAG_CID_KEYED ) /************************************************************************* @@ -1388,7 +1473,7 @@ FT_BEGIN_HEADER * */ #define FT_IS_TRICKY( face ) \ - ( face->face_flags & FT_FACE_FLAG_TRICKY ) + ( (face)->face_flags & FT_FACE_FLAG_TRICKY ) /************************************************************************* @@ -1400,9 +1485,12 @@ FT_BEGIN_HEADER * A macro that returns true whenever a face object contains * tables for color glyphs. * + * @since: + * 2.5.1 + * */ #define FT_HAS_COLOR( face ) \ - ( face->face_flags & FT_FACE_FLAG_COLOR ) + ( (face)->face_flags & FT_FACE_FLAG_COLOR ) /*************************************************************************/ @@ -1411,15 +1499,15 @@ FT_BEGIN_HEADER /* FT_STYLE_FLAG_XXX */ /* */ /* <Description> */ - /* A list of bit flags used to indicate the style of a given face. */ - /* These are used in the `style_flags' field of @FT_FaceRec. */ + /* A list of bit flags to indicate the style of a given face. These */ + /* are used in the `style_flags' field of @FT_FaceRec. */ /* */ /* <Values> */ /* FT_STYLE_FLAG_ITALIC :: */ - /* Indicates that a given face style is italic or oblique. */ + /* The face style is italic or oblique. */ /* */ /* FT_STYLE_FLAG_BOLD :: */ - /* Indicates that a given face is bold. */ + /* The face is bold. */ /* */ /* <Note> */ /* The style information as provided by FreeType is very basic. More */ @@ -1460,43 +1548,93 @@ FT_BEGIN_HEADER /* hence the term `ppem' (pixels per EM). It is also */ /* referred to as `nominal height'. */ /* */ - /* x_scale :: A 16.16 fractional scaling value used to convert */ + /* x_scale :: A 16.16 fractional scaling value to convert */ /* horizontal metrics from font units to 26.6 */ /* fractional pixels. Only relevant for scalable */ /* font formats. */ /* */ - /* y_scale :: A 16.16 fractional scaling value used to convert */ + /* y_scale :: A 16.16 fractional scaling value to convert */ /* vertical metrics from font units to 26.6 */ /* fractional pixels. Only relevant for scalable */ /* font formats. */ /* */ - /* ascender :: The ascender in 26.6 fractional pixels. See */ - /* @FT_FaceRec for the details. */ + /* ascender :: The ascender in 26.6 fractional pixels, rounded up */ + /* to an integer value. See @FT_FaceRec for the */ + /* details. */ /* */ - /* descender :: The descender in 26.6 fractional pixels. See */ - /* @FT_FaceRec for the details. */ + /* descender :: The descender in 26.6 fractional pixels, rounded */ + /* down to an integer value. See @FT_FaceRec for the */ + /* details. */ /* */ - /* height :: The height in 26.6 fractional pixels. See */ - /* @FT_FaceRec for the details. */ + /* height :: The height in 26.6 fractional pixels, rounded to */ + /* an integer value. See @FT_FaceRec for the */ + /* details. */ /* */ /* max_advance :: The maximum advance width in 26.6 fractional */ - /* pixels. See @FT_FaceRec for the details. */ + /* pixels, rounded to an integer value. See */ + /* @FT_FaceRec for the details. */ /* */ /* <Note> */ /* The scaling values, if relevant, are determined first during a */ /* size changing operation. The remaining fields are then set by the */ /* driver. For scalable formats, they are usually set to scaled */ - /* values of the corresponding fields in @FT_FaceRec. */ + /* values of the corresponding fields in @FT_FaceRec. Some values */ + /* like ascender or descender are rounded for historical reasons; */ + /* more precise values (for outline fonts) can be derived by scaling */ + /* the corresponding @FT_FaceRec values manually, with code similar */ + /* to the following. */ /* */ - /* Note that due to glyph hinting, these values might not be exact */ - /* for certain fonts. Thus they must be treated as unreliable */ - /* with an error margin of at least one pixel! */ + /* { */ + /* scaled_ascender = FT_MulFix( face->ascender, */ + /* size_metrics->y_scale ); */ + /* } */ + /* */ + /* Note that due to glyph hinting and the selected rendering mode */ + /* these values are usually not exact; consequently, they must be */ + /* treated as unreliable with an error margin of at least one pixel! */ /* */ /* Indeed, the only way to get the exact metrics is to render _all_ */ /* glyphs. As this would be a definite performance hit, it is up to */ /* client applications to perform such computations. */ /* */ - /* The FT_Size_Metrics structure is valid for bitmap fonts also. */ + /* The `FT_Size_Metrics' structure is valid for bitmap fonts also. */ + /* */ + /* */ + /* *TrueType* *fonts* *with* *native* *bytecode* *hinting* */ + /* */ + /* All applications that handle TrueType fonts with native hinting */ + /* must be aware that TTFs expect different rounding of vertical font */ + /* dimensions. The application has to cater for this, especially if */ + /* it wants to rely on a TTF's vertical data (for example, to */ + /* properly align box characters vertically). */ + /* */ + /* Only the application knows _in_ _advance_ that it is going to use */ + /* native hinting for TTFs! FreeType, on the other hand, selects the */ + /* hinting mode not at the time of creating an @FT_Size object but */ + /* much later, namely while calling @FT_Load_Glyph. */ + /* */ + /* Here is some pseudo code that illustrates a possible solution. */ + /* */ + /* { */ + /* font_format = FT_Get_Font_Format( face ); */ + /* */ + /* if ( !strcmp( font_format, "TrueType" ) && */ + /* do_native_bytecode_hinting ) */ + /* { */ + /* ascender = ROUND( FT_MulFix( face->ascender, */ + /* size_metrics->y_scale ) ); */ + /* descender = ROUND( FT_MulFix( face->descender, */ + /* size_metrics->y_scale ) ); */ + /* } */ + /* else */ + /* { */ + /* ascender = size_metrics->ascender; */ + /* descender = size_metrics->descender; */ + /* } */ + /* */ + /* height = size_metrics->height; */ + /* max_advance = size_metrics->max_advance; */ + /* } */ /* */ typedef struct FT_Size_Metrics_ { @@ -1636,32 +1774,27 @@ FT_BEGIN_HEADER /* contained in the glyph slot. Typically */ /* @FT_GLYPH_FORMAT_BITMAP, */ /* @FT_GLYPH_FORMAT_OUTLINE, or */ - /* @FT_GLYPH_FORMAT_COMPOSITE, but others are */ - /* possible. */ + /* @FT_GLYPH_FORMAT_COMPOSITE, but other values */ + /* 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 @FT_Load_Glyph and a */ - /* few other functions. */ + /* bitmap :: This field is used as a bitmap descriptor. */ + /* Note that the address and content of the */ + /* bitmap buffer can change between calls of */ + /* @FT_Load_Glyph and a few other functions. */ /* */ /* bitmap_left :: The bitmap's left bearing expressed in */ - /* integer pixels. Only valid if the format is */ - /* @FT_GLYPH_FORMAT_BITMAP, this is, if the */ - /* glyph slot contains a bitmap. */ + /* integer pixels. */ /* */ /* bitmap_top :: 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*. */ + /* pixels. 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. Once a glyph is */ /* loaded, `outline' can be transformed, */ - /* distorted, embolded, etc. However, it must */ + /* distorted, emboldened, etc. However, it must */ /* not be freed. */ /* */ /* num_subglyphs :: The number of subglyphs in a composite glyph. */ @@ -1677,15 +1810,13 @@ FT_BEGIN_HEADER /* 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. */ + /* This field is a pointer to such data; it is */ + /* currently internal to FreeType. */ /* */ /* control_len :: This is the length in bytes of the control */ - /* data. */ + /* data. Currently internal to FreeType. */ /* */ - /* other :: Really wicked formats can use this pointer to */ - /* present their own glyph image to client */ - /* applications. Note that the application */ - /* needs to know about the image format. */ + /* other :: Reserved. */ /* */ /* lsb_delta :: The difference between hinted and unhinted */ /* left side bearing while auto-hinting is */ @@ -1699,10 +1830,12 @@ FT_BEGIN_HEADER /* If @FT_Load_Glyph is called with default flags (see */ /* @FT_LOAD_DEFAULT) the glyph image is loaded in the glyph slot in */ /* its native format (e.g., an outline glyph for TrueType and Type~1 */ - /* formats). */ + /* formats). [Since 2.9] The prospective bitmap metrics are */ + /* calculated according to @FT_LOAD_TARGET_XXX and other flags even */ + /* for the outline glyph, even if @FT_LOAD_RENDER is not set. */ /* */ /* This image can later be converted into a bitmap by calling */ - /* @FT_Render_Glyph. This function finds the current renderer for */ + /* @FT_Render_Glyph. This function searches the current renderer for */ /* the native image's format, then invokes it. */ /* */ /* The renderer is in charge of transforming the native image through */ @@ -1714,34 +1847,65 @@ FT_BEGIN_HEADER /* position (e.g., coordinates (0,0) on the baseline). Of course, */ /* `slot->format' is also changed to @FT_GLYPH_FORMAT_BITMAP. */ /* */ - /* <Note> */ /* Here is a small pseudo code fragment that shows how to use */ - /* `lsb_delta' and `rsb_delta': */ + /* `lsb_delta' and `rsb_delta' to do fractional positioning of */ + /* glyphs: */ + /* */ + /* { */ + /* FT_GlyphSlot slot = face->glyph; */ + /* FT_Pos origin_x = 0; */ + /* */ + /* */ + /* for all glyphs do */ + /* <load glyph with `FT_Load_Glyph'> */ + /* */ + /* FT_Outline_Translate( slot->outline, origin_x & 63, 0 ); */ + /* */ + /* <save glyph image, or render glyph, or ...> */ + /* */ + /* <compute kern between current and next glyph */ + /* and add it to `origin_x'> */ + /* */ + /* origin_x += slot->advance.x; */ + /* origin_x += slot->rsb_delta - slot->lsb_delta; */ + /* endfor */ + /* } */ + /* */ + /* Here is another small pseudo code fragment that shows how to use */ + /* `lsb_delta' and `rsb_delta' to improve integer positioning of */ + /* glyphs: */ /* */ /* { */ - /* FT_Pos origin_x = 0; */ - /* FT_Pos prev_rsb_delta = 0; */ + /* FT_GlyphSlot slot = face->glyph; */ + /* 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'> */ + /* <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 ) */ + /* if ( prev_rsb_delta - slot->lsb_delta > 32 ) */ /* origin_x -= 64; */ - /* else if ( prev_rsb_delta - face->glyph->lsb_delta < -32 ) */ + /* else if ( prev_rsb_delta - slot->lsb_delta < -31 ) */ /* origin_x += 64; */ /* */ - /* prev_rsb_delta = face->glyph->rsb_delta; */ + /* prev_rsb_delta = slot->rsb_delta; */ /* */ /* <save glyph image, or render glyph, or ...> */ /* */ - /* origin_x += face->glyph->advance.x; */ + /* origin_x += slot->advance.x; */ /* endfor */ /* } */ /* */ + /* If you use strong auto-hinting, you *must* apply these delta */ + /* values! Otherwise you will experience far too large inter-glyph */ + /* spacing at small rendering sizes in most cases. Note that it */ + /* doesn't harm to use the above code for other hinting modes also, */ + /* since the delta values are zero then. */ + /* */ typedef struct FT_GlyphSlotRec_ { FT_Library library; @@ -1806,7 +1970,8 @@ FT_BEGIN_HEADER /* <Note> */ /* In case you want to provide your own memory allocating routines, */ /* use @FT_New_Library instead, followed by a call to */ - /* @FT_Add_Default_Modules (or a series of calls to @FT_Add_Module). */ + /* @FT_Add_Default_Modules (or a series of calls to @FT_Add_Module) */ + /* and @FT_Set_Default_Properties. */ /* */ /* See the documentation of @FT_Library and @FT_Face for */ /* multi-threading issues. */ @@ -1814,6 +1979,11 @@ FT_BEGIN_HEADER /* If you need reference-counting (cf. @FT_Reference_Library), use */ /* @FT_New_Library and @FT_Done_Library. */ /* */ + /* If compilation option FT_CONFIG_OPTION_ENVIRONMENT_PROPERTIES is */ + /* set, this function reads the `FREETYPE_PROPERTIES' environment */ + /* variable to control driver properties. See section @properties */ + /* for more. */ + /* */ FT_EXPORT( FT_Error ) FT_Init_FreeType( FT_Library *alibrary ); @@ -1884,8 +2054,8 @@ FT_BEGIN_HEADER /* FT_Parameter */ /* */ /* <Description> */ - /* A simple structure used to pass more or less generic parameters to */ - /* @FT_Open_Face. */ + /* A simple structure to pass more or less generic parameters to */ + /* @FT_Open_Face and @FT_Face_Properties. */ /* */ /* <Fields> */ /* tag :: A four-byte identification tag. */ @@ -1893,8 +2063,8 @@ FT_BEGIN_HEADER /* data :: A pointer to the parameter data. */ /* */ /* <Note> */ - /* The ID and function of parameters are driver-specific. See the */ - /* various FT_PARAM_TAG_XXX flags for more information. */ + /* The ID and function of parameters are driver-specific. See */ + /* section @parameter_tags for more information. */ /* */ typedef struct FT_Parameter_ { @@ -1910,9 +2080,9 @@ FT_BEGIN_HEADER /* FT_Open_Args */ /* */ /* <Description> */ - /* A structure used to indicate how to open a new font file or */ - /* stream. A pointer to such a structure can be used as a parameter */ - /* for the functions @FT_Open_Face and @FT_Attach_Stream. */ + /* A structure to indicate how to open a new font file or stream. A */ + /* pointer to such a structure can be used as a parameter for the */ + /* functions @FT_Open_Face and @FT_Attach_Stream. */ /* */ /* <Fields> */ /* flags :: A set of bit flags indicating how to use the */ @@ -1927,9 +2097,10 @@ FT_BEGIN_HEADER /* stream :: A handle to a source stream object. */ /* */ /* driver :: This field is exclusively used by @FT_Open_Face; */ - /* it simply specifies the font driver to use to open */ - /* the face. If set to~0, FreeType tries to load the */ - /* face with each one of the drivers in its list. */ + /* it simply specifies the font driver to use for */ + /* opening the face. If set to NULL, FreeType tries */ + /* to load the face with each one of the drivers in */ + /* its list. */ /* */ /* num_params :: The number of extra parameters. */ /* */ @@ -1942,7 +2113,7 @@ FT_BEGIN_HEADER /* */ /* If the @FT_OPEN_MEMORY bit is set, assume that this is a */ /* memory file of `memory_size' bytes, located at `memory_address'. */ - /* The data are are not copied, and the client is responsible for */ + /* The data are not copied, and the client is responsible for */ /* releasing and destroying them _after_ the corresponding call to */ /* @FT_Done_Face. */ /* */ @@ -1959,7 +2130,7 @@ FT_BEGIN_HEADER /* `num_params' and `params' is used. They are ignored otherwise. */ /* */ /* Ideally, both the `pathname' and `params' fields should be tagged */ - /* as `const'; this is missing for API backwards compatibility. In */ + /* as `const'; this is missing for API backward compatibility. In */ /* other words, applications should treat them as read-only. */ /* */ typedef struct FT_Open_Args_ @@ -1982,7 +2153,7 @@ FT_BEGIN_HEADER /* FT_New_Face */ /* */ /* <Description> */ - /* This function calls @FT_Open_Face to open a font by its pathname. */ + /* Call @FT_Open_Face to open a font by its pathname. */ /* */ /* <InOut> */ /* library :: A handle to the library resource. */ @@ -2017,8 +2188,8 @@ FT_BEGIN_HEADER /* FT_New_Memory_Face */ /* */ /* <Description> */ - /* This function calls @FT_Open_Face to open a font that has been */ - /* loaded into memory. */ + /* Call @FT_Open_Face to open a font that has been loaded into */ + /* memory. */ /* */ /* <InOut> */ /* library :: A handle to the library resource. */ @@ -2070,20 +2241,21 @@ FT_BEGIN_HEADER /* with value~0). Set it to~0 if there is only one */ /* face in the font file. */ /* */ - /* Bits 16-30 are relevant to GX variation fonts only, */ - /* specifying the named instance index for the current */ - /* face index (starting with value~1; value~0 makes */ - /* FreeType ignore named instances). For non-GX fonts, */ - /* bits 16-30 are ignored. Assuming that you want to */ - /* access the third named instance in face~4, */ - /* `face_index' should be set to 0x00030004. If you */ - /* want to access face~4 without GX variation handling, */ - /* simply set `face_index' to value~4. */ - /* */ - /* FT_Open_Face and its siblings can be used to quickly */ - /* check whether the font format of a given font */ - /* resource is supported by FreeType. In general, if */ - /* the `face_index' argument is negative, the */ + /* [Since 2.6.1] Bits 16-30 are relevant to GX and */ + /* OpenType variation fonts only, specifying the named */ + /* instance index for the current face index (starting */ + /* with value~1; value~0 makes FreeType ignore named */ + /* instances). For non-variation fonts, bits 16-30 are */ + /* ignored. Assuming that you want to access the third */ + /* named instance in face~4, `face_index' should be set */ + /* to 0x00030004. If you want to access face~4 without */ + /* variation handling, simply set `face_index' to */ + /* value~4. */ + /* */ + /* `FT_Open_Face' and its siblings can be used to */ + /* quickly check whether the font format of a given */ + /* font resource is supported by FreeType. In general, */ + /* if the `face_index' argument is negative, the */ /* function's return value is~0 if the font format is */ /* recognized, or non-zero otherwise. The function */ /* allocates a more or less empty face handle in */ @@ -2092,10 +2264,10 @@ FT_BEGIN_HEADER /* `face->num_faces' and `face->style_flags'. For any */ /* negative value of `face_index', `face->num_faces' */ /* gives the number of faces within the font file. For */ - /* the negative value `-(N+1)' (with `N' a 16-bit */ - /* value), bits 16-30 in `face->style_flags' give the */ - /* number of named instances in face `N' if we have a */ - /* GX variation font (or zero otherwise). After */ + /* the negative value `-(N+1)' (with `N' a non-negative */ + /* 16-bit value), bits 16-30 in `face->style_flags' */ + /* give the number of named instances in face `N' if we */ + /* have a variation font (or zero otherwise). After */ /* examination, the returned @FT_Face structure should */ /* be deallocated with a call to @FT_Done_Face. */ /* */ @@ -2202,7 +2374,7 @@ FT_BEGIN_HEADER /* FT_Attach_File */ /* */ /* <Description> */ - /* This function calls @FT_Attach_Stream to attach a file. */ + /* Call @FT_Attach_Stream to attach a file. */ /* */ /* <InOut> */ /* face :: The target face object. */ @@ -2246,7 +2418,7 @@ FT_BEGIN_HEADER /* */ /* Client applications are expected to know what they are doing */ /* when invoking this function. Most drivers simply do not implement */ - /* file attachments. */ + /* file or stream attachments. */ /* */ FT_EXPORT( FT_Error ) FT_Attach_Stream( FT_Face face, @@ -2309,7 +2481,10 @@ FT_BEGIN_HEADER /* FT_Select_Size */ /* */ /* <Description> */ - /* Select a bitmap strike. */ + /* Select a bitmap strike. To be more precise, this function sets */ + /* the scaling factors of the active @FT_Size object in a face so */ + /* that bitmaps from this particular strike are taken by */ + /* @FT_Load_Glyph and friends. */ /* */ /* <InOut> */ /* face :: A handle to a target face object. */ @@ -2321,6 +2496,20 @@ FT_BEGIN_HEADER /* <Return> */ /* FreeType error code. 0~means success. */ /* */ + /* <Note> */ + /* For bitmaps embedded in outline fonts it is common that only a */ + /* subset of the available glyphs at a given ppem value is available. */ + /* FreeType silently uses outlines if there is no bitmap for a given */ + /* glyph index. */ + /* */ + /* For GX and OpenType variation fonts, a bitmap strike makes sense */ + /* only if the default instance is active (this is, no glyph */ + /* variation takes place); otherwise, FreeType simply ignores bitmap */ + /* strikes. The same is true for all named instances that are */ + /* different from the default instance. */ + /* */ + /* Don't use this function if you are using the FreeType cache API. */ + /* */ FT_EXPORT( FT_Error ) FT_Select_Size( FT_Face face, FT_Int strike_index ); @@ -2332,17 +2521,26 @@ FT_BEGIN_HEADER /* FT_Size_Request_Type */ /* */ /* <Description> */ - /* An enumeration type that lists the supported size request types. */ + /* An enumeration type that lists the supported size request types, */ + /* i.e., what input size (in font units) maps to the requested output */ + /* size (in pixels, as computed from the arguments of */ + /* @FT_Size_Request). */ /* */ /* <Values> */ /* FT_SIZE_REQUEST_TYPE_NOMINAL :: */ /* The nominal size. The `units_per_EM' field of @FT_FaceRec is */ /* used to determine both scaling values. */ /* */ + /* This is the standard scaling found in most applications. In */ + /* particular, use this size request type for TrueType fonts if */ + /* they provide optical scaling or something similar. Note, */ + /* however, that `units_per_EM' is a rather abstract value which */ + /* bears no relation to the actual size of the glyphs in a font. */ + /* */ /* FT_SIZE_REQUEST_TYPE_REAL_DIM :: */ - /* The real dimension. The sum of the the `ascender' and (minus */ - /* of) the `descender' fields of @FT_FaceRec are used to determine */ - /* both scaling values. */ + /* The real dimension. The sum of the `ascender' and (minus of) */ + /* the `descender' fields of @FT_FaceRec is used to determine both */ + /* scaling values. */ /* */ /* FT_SIZE_REQUEST_TYPE_BBOX :: */ /* The font bounding box. The width and height of the `bbox' field */ @@ -2387,27 +2585,36 @@ FT_BEGIN_HEADER /* FT_Size_RequestRec */ /* */ /* <Description> */ - /* A structure used to model a size request. */ + /* A structure to model a size request. */ /* */ /* <Fields> */ /* type :: See @FT_Size_Request_Type. */ /* */ - /* width :: The desired width. */ + /* width :: The desired width, given as a 26.6 fractional */ + /* point value (with 72pt = 1in). */ /* */ - /* height :: The desired height. */ + /* height :: The desired height, given as a 26.6 fractional */ + /* point value (with 72pt = 1in). */ /* */ - /* horiResolution :: The horizontal resolution. If set to zero, */ - /* `width' is treated as a 26.6 fractional pixel */ - /* value. */ + /* horiResolution :: The horizontal resolution (dpi, i.e., pixels per */ + /* inch). If set to zero, `width' is treated as a */ + /* 26.6 fractional *pixel* value, which gets */ + /* internally rounded to an integer. */ /* */ - /* vertResolution :: The vertical resolution. If set to zero, */ - /* `height' is treated as a 26.6 fractional pixel */ - /* value. */ + /* vertResolution :: The vertical resolution (dpi, i.e., pixels per */ + /* inch). If set to zero, `height' is treated as a */ + /* 26.6 fractional *pixel* value, which gets */ + /* internally rounded to an integer. */ /* */ /* <Note> */ - /* If `width' is zero, then the horizontal scaling value is set equal */ + /* If `width' is zero, the horizontal scaling value is set equal */ /* to the vertical scaling value, and vice versa. */ /* */ + /* If `type' is FT_SIZE_REQUEST_TYPE_SCALES, `width' and `height' are */ + /* interpreted directly as 16.16 fractional scaling values, without */ + /* any further modification, and both `horiResolution' and */ + /* `vertResolution' are ignored. */ + /* */ typedef struct FT_Size_RequestRec_ { FT_Size_Request_Type type; @@ -2457,7 +2664,11 @@ FT_BEGIN_HEADER /* size is dependent entirely on how the size is defined in the */ /* source face. The font designer chooses the final size of each */ /* glyph relative to this size. For more information refer to */ - /* `http://www.freetype.org/freetype2/docs/glyphs/glyphs-2.html' */ + /* `https://www.freetype.org/freetype2/docs/glyphs/glyphs-2.html'. */ + /* */ + /* Contrary to @FT_Set_Char_Size, this function doesn't have special */ + /* code to normalize zero-valued widths, heights, or resolutions */ + /* (which lead to errors in most cases). */ /* */ /* Don't use this function if you are using the FreeType cache API. */ /* */ @@ -2472,8 +2683,7 @@ FT_BEGIN_HEADER /* FT_Set_Char_Size */ /* */ /* <Description> */ - /* This function calls @FT_Request_Size to request the nominal size */ - /* (in points). */ + /* Call @FT_Request_Size to request the nominal size (in points). */ /* */ /* <InOut> */ /* face :: A handle to a target face object. */ @@ -2491,6 +2701,10 @@ FT_BEGIN_HEADER /* FreeType error code. 0~means success. */ /* */ /* <Note> */ + /* While this function allows fractional points as input values, the */ + /* resulting ppem value for the given resolution is always rounded to */ + /* the nearest integer. */ + /* */ /* If either the character width or height is zero, it is set equal */ /* to the other value. */ /* */ @@ -2516,8 +2730,7 @@ FT_BEGIN_HEADER /* FT_Set_Pixel_Sizes */ /* */ /* <Description> */ - /* This function calls @FT_Request_Size to request the nominal size */ - /* (in pixels). */ + /* Call @FT_Request_Size to request the nominal size (in pixels). */ /* */ /* <InOut> */ /* face :: A handle to the target face object. */ @@ -2531,8 +2744,8 @@ FT_BEGIN_HEADER /* FreeType error code. 0~means success. */ /* */ /* <Note> */ - /* You should not rely on the resulting glyphs matching, or being */ - /* constrained, to this pixel size. Refer to @FT_Request_Size to */ + /* You should not rely on the resulting glyphs matching or being */ + /* constrained to this pixel size. Refer to @FT_Request_Size to */ /* understand how requested sizes relate to actual sizes. */ /* */ /* Don't use this function if you are using the FreeType cache API. */ @@ -2549,8 +2762,7 @@ FT_BEGIN_HEADER /* FT_Load_Glyph */ /* */ /* <Description> */ - /* A function used to load a single glyph into the glyph slot of a */ - /* face object. */ + /* Load a glyph into the glyph slot of a face object. */ /* */ /* <InOut> */ /* face :: A handle to the target face object where the glyph */ @@ -2579,6 +2791,10 @@ FT_BEGIN_HEADER /* don't have a corresponding glyph in the font). See the discussion */ /* of the @FT_FACE_FLAG_CID_KEYED flag for more details. */ /* */ + /* If you receive `FT_Err_Glyph_Too_Big', try getting the glyph */ + /* outline at EM size, then scale it manually and fill it as a */ + /* graphics operation. */ + /* */ FT_EXPORT( FT_Error ) FT_Load_Glyph( FT_Face face, FT_UInt glyph_index, @@ -2591,8 +2807,8 @@ FT_BEGIN_HEADER /* FT_Load_Char */ /* */ /* <Description> */ - /* A function used to load a single glyph into the glyph slot of a */ - /* face object, according to its character code. */ + /* Load a glyph into the glyph slot of a face object, accessed by its */ + /* character code. */ /* */ /* <InOut> */ /* face :: A handle to a target face object where the glyph */ @@ -2614,6 +2830,14 @@ FT_BEGIN_HEADER /* <Note> */ /* This function simply calls @FT_Get_Char_Index and @FT_Load_Glyph. */ /* */ + /* Many fonts contain glyphs that can't be loaded by this function */ + /* since its glyph indices are not listed in any of the font's */ + /* charmaps. */ + /* */ + /* If no active cmap is set up (i.e., `face->charmap' is zero), the */ + /* call to @FT_Get_Char_Index is omitted, and the function behaves */ + /* identically to @FT_Load_Glyph. */ + /* */ FT_EXPORT( FT_Error ) FT_Load_Char( FT_Face face, FT_ULong char_code, @@ -2626,8 +2850,8 @@ FT_BEGIN_HEADER * FT_LOAD_XXX * * @description: - * A list of bit field constants used with @FT_Load_Glyph to indicate - * what kind of operations to perform during glyph loading. + * A list of bit field constants for @FT_Load_Glyph to indicate what + * kind of operations to perform during glyph loading. * * @values: * FT_LOAD_DEFAULT :: @@ -2639,13 +2863,13 @@ FT_BEGIN_HEADER * 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). + * 2. If no embedded bitmap is searched for 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 + * 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. * @@ -2692,13 +2916,13 @@ FT_BEGIN_HEADER * various font formats. * * FT_LOAD_FORCE_AUTOHINT :: - * Indicates that the auto-hinter is preferred over the font's native - * hinter. See also the note below. + * Prefer the auto-hinter over the font's native hinter. See also + * the note below. * * FT_LOAD_PEDANTIC :: - * Indicates that the font driver should perform pedantic verifications - * during glyph loading. This is mostly used to detect broken glyphs - * in fonts. By default, FreeType tries to handle broken fonts also. + * Make the font driver perform pedantic verifications during glyph + * loading. This is mostly used to detect broken glyphs in fonts. + * By default, FreeType tries to handle broken fonts also. * * In particular, errors from the TrueType bytecode engine are not * passed to the application if this flag is not set; this might @@ -2706,17 +2930,16 @@ FT_BEGIN_HEADER * bytecode is buggy. * * FT_LOAD_NO_RECURSE :: - * Indicate that the font driver 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 @FT_GLYPH_FORMAT_COMPOSITE. The description of - * subglyphs can then be accessed with @FT_Get_SubGlyph_Info. + * Don't load composite glyphs recursively. Instead, the font + * driver should set the `num_subglyph' and `subglyphs' values of + * the glyph slot accordingly, and set `glyph->format' to + * @FT_GLYPH_FORMAT_COMPOSITE. The description of subglyphs can + * then be accessed with @FT_Get_SubGlyph_Info. * * This flag implies @FT_LOAD_NO_SCALE and @FT_LOAD_IGNORE_TRANSFORM. * * FT_LOAD_IGNORE_TRANSFORM :: - * Indicates that the transform matrix set by @FT_Set_Transform should - * be ignored. + * Ignore the transform matrix set by @FT_Set_Transform. * * FT_LOAD_MONOCHROME :: * This flag is used with @FT_LOAD_RENDER to indicate that you want to @@ -2728,31 +2951,37 @@ FT_BEGIN_HEADER * monochrome-optimized hinting algorithm is used. * * FT_LOAD_LINEAR_DESIGN :: - * Indicates that the `linearHoriAdvance' and `linearVertAdvance' - * fields of @FT_GlyphSlotRec should be kept in font units. See - * @FT_GlyphSlotRec for details. + * Keep `linearHoriAdvance' and `linearVertAdvance' fields of + * @FT_GlyphSlotRec in font units. See @FT_GlyphSlotRec for + * details. * * FT_LOAD_NO_AUTOHINT :: - * Disable auto-hinter. See also the note below. + * Disable the auto-hinter. See also the note below. * * FT_LOAD_COLOR :: - * This flag is used to request loading of color embedded-bitmap - * images. The resulting color bitmaps, if available, will have the - * @FT_PIXEL_MODE_BGRA format. When the flag is not used and color - * bitmaps are found, they will be converted to 256-level gray - * bitmaps transparently. Those bitmaps will be in the + * [Since 2.5] Load embedded color bitmap images. The resulting color + * bitmaps, if available, will have the @FT_PIXEL_MODE_BGRA format. + * If the flag is not set and color bitmaps are found, they are + * converted to 256-level gray bitmaps transparently, using the * @FT_PIXEL_MODE_GRAY format. * * FT_LOAD_COMPUTE_METRICS :: - * This flag sets computing glyph metrics without the use of bundled - * metrics tables (for example, the `hdmx' table in TrueType fonts). - * Well-behaving fonts have optimized bundled metrics and these should - * be used. This flag is mainly used by font validating or font - * editing applications, which need to ignore, verify, or edit those - * tables. + * [Since 2.6.1] Compute glyph metrics from the glyph data, without + * the use of bundled metrics tables (for example, the `hdmx' table in + * TrueType fonts). This flag is mainly used by font validating or + * font editing applications, which need to ignore, verify, or edit + * those tables. * * Currently, this flag is only implemented for TrueType fonts. * + * FT_LOAD_BITMAP_METRICS_ONLY :: + * [Since 2.7.1] Request loading of the metrics and bitmap image + * information of a (possibly embedded) bitmap glyph without + * allocating or copying the bitmap image data itself. No effect if + * the target glyph is not a bitmap image. + * + * This flag unsets @FT_LOAD_RENDER. + * * FT_LOAD_CROP_BITMAP :: * Ignored. Deprecated. * @@ -2796,13 +3025,14 @@ FT_BEGIN_HEADER #define FT_LOAD_MONOCHROME ( 1L << 12 ) #define FT_LOAD_LINEAR_DESIGN ( 1L << 13 ) #define FT_LOAD_NO_AUTOHINT ( 1L << 15 ) - /* Bits 16..19 are used by `FT_LOAD_TARGET_' */ + /* Bits 16-19 are used by `FT_LOAD_TARGET_' */ #define FT_LOAD_COLOR ( 1L << 20 ) #define FT_LOAD_COMPUTE_METRICS ( 1L << 21 ) +#define FT_LOAD_BITMAP_METRICS_ONLY ( 1L << 22 ) /* */ - /* used internally only by certain font drivers! */ + /* used internally only by certain font drivers */ #define FT_LOAD_ADVANCE_ONLY ( 1L << 8 ) #define FT_LOAD_SBITS_ONLY ( 1L << 14 ) @@ -2813,29 +3043,40 @@ FT_BEGIN_HEADER * FT_LOAD_TARGET_XXX * * @description: - * A list of values that are used to select a specific hinting algorithm - * to use by the hinter. You should OR one of these values to your - * `load_flags' when calling @FT_Load_Glyph. - * - * Note that font's native hinters may ignore the hinting algorithm you - * have specified (e.g., the TrueType bytecode interpreter). You can set - * @FT_LOAD_FORCE_AUTOHINT to ensure that the auto-hinter is used. + * A list of values to select a specific hinting algorithm for the + * hinter. You should OR one of these values to your `load_flags' + * when calling @FT_Load_Glyph. * - * Also note that @FT_LOAD_TARGET_LIGHT is an exception, in that it - * always implies @FT_LOAD_FORCE_AUTOHINT. + * Note that a font's native hinters may ignore the hinting algorithm + * you have specified (e.g., the TrueType bytecode interpreter). You + * can set @FT_LOAD_FORCE_AUTOHINT to ensure that the auto-hinter is + * used. * * @values: * FT_LOAD_TARGET_NORMAL :: - * This corresponds to the default hinting algorithm, optimized for - * standard gray-level rendering. For monochrome output, use - * @FT_LOAD_TARGET_MONO instead. + * The default hinting algorithm, optimized for standard gray-level + * rendering. For monochrome output, use @FT_LOAD_TARGET_MONO + * instead. * * FT_LOAD_TARGET_LIGHT :: - * A lighter hinting algorithm for non-monochrome modes. Many - * generated glyphs are more fuzzy but better resemble its original - * shape. A bit like rendering on Mac OS~X. + * A lighter hinting algorithm for gray-level modes. Many generated + * glyphs are fuzzier but better resemble their original shape. This + * is achieved by snapping glyphs to the pixel grid only vertically + * (Y-axis), as is done by FreeType's new CFF engine or Microsoft's + * ClearType font renderer. This preserves inter-glyph spacing in + * horizontal text. The snapping is done either by the native font + * driver, if the driver itself and the font support it, or by the + * auto-hinter. * - * As a special exception, this target implies @FT_LOAD_FORCE_AUTOHINT. + * Advance widths are rounded to integer values; however, using the + * `lsb_delta' and `rsb_delta' fields of @FT_GlyphSlotRec, it is + * possible to get fractional advance widths for subpixel positioning + * (which is recommended to use). + * + * If configuration option AF_CONFIG_OPTION_TT_SIZE_METRICS is active, + * TrueType-like metrics are used to make this mode behave similarly + * as in unpatched FreeType versions between 2.4.6 and 2.7.1 + * (inclusive). * * FT_LOAD_TARGET_MONO :: * Strong hinting algorithm that should only be used for monochrome @@ -2843,7 +3084,7 @@ FT_BEGIN_HEADER * in non-monochrome modes. * * FT_LOAD_TARGET_LCD :: - * A variant of @FT_LOAD_TARGET_NORMAL optimized for horizontally + * A variant of @FT_LOAD_TARGET_LIGHT optimized for horizontally * decimated LCD displays. * * FT_LOAD_TARGET_LCD_V :: @@ -2856,7 +3097,7 @@ FT_BEGIN_HEADER * * If @FT_LOAD_RENDER is also set, the glyph is rendered in the * corresponding mode (i.e., the mode that matches the used algorithm - * best). An exeption is FT_LOAD_TARGET_MONO since it implies + * best). An exception is FT_LOAD_TARGET_MONO since it implies * @FT_LOAD_MONOCHROME. * * You can use a hinting algorithm that doesn't correspond to the same @@ -2871,6 +3112,13 @@ FT_BEGIN_HEADER * FT_Render_Glyph( face->glyph, FT_RENDER_MODE_LCD ); * } * + * In general, you should stick with one rendering mode. For example, + * switching between @FT_LOAD_TARGET_NORMAL and @FT_LOAD_TARGET_MONO + * enforces a lot of recomputation for TrueType fonts, which is slow. + * Another reason is caching: Selecting a different mode usually causes + * changes in both the outlines and the rasterized bitmaps; it is thus + * necessary to empty the cache after a mode switch to avoid false hits. + * */ #define FT_LOAD_TARGET_( x ) ( (FT_Int32)( (x) & 15 ) << 16 ) @@ -2900,18 +3148,17 @@ FT_BEGIN_HEADER /* FT_Set_Transform */ /* */ /* <Description> */ - /* A function used to set the transformation that is applied to glyph */ - /* images when they are loaded into a glyph slot through */ - /* @FT_Load_Glyph. */ + /* Set the transformation that is applied to glyph images when they */ + /* are loaded into a glyph slot through @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. */ + /* matrix :: A pointer to the transformation's 2x2 matrix. Use NULL */ + /* for the identity matrix. */ + /* delta :: A pointer to the translation vector. Use NULL for the */ + /* null vector. */ /* */ /* <Note> */ /* The transformation is only applied to scalable image formats after */ @@ -2934,20 +3181,22 @@ FT_BEGIN_HEADER /* FT_Render_Mode */ /* */ /* <Description> */ - /* 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. */ + /* Render modes supported by FreeType~2. Each mode corresponds to a */ + /* specific type of scanline conversion performed on the outline. */ /* */ /* For bitmap fonts and embedded bitmaps the `bitmap->pixel_mode' */ /* field in the @FT_GlyphSlotRec structure gives the format of the */ /* returned bitmap. */ /* */ - /* All modes except @FT_RENDER_MODE_MONO use 256 levels of opacity. */ + /* All modes except @FT_RENDER_MODE_MONO use 256 levels of opacity, */ + /* indicating pixel coverage. Use linear alpha blending and gamma */ + /* correction to correctly render non-monochrome glyph bitmaps onto a */ + /* surface; see @FT_Render_Glyph. */ /* */ /* <Values> */ /* FT_RENDER_MODE_NORMAL :: */ - /* This is the default render mode; it corresponds to 8-bit */ - /* anti-aliased bitmaps. */ + /* Default render mode; it corresponds to 8-bit anti-aliased */ + /* bitmaps. */ /* */ /* FT_RENDER_MODE_LIGHT :: */ /* This is equivalent to @FT_RENDER_MODE_NORMAL. It is only */ @@ -2960,23 +3209,25 @@ FT_BEGIN_HEADER /* opacity). */ /* */ /* FT_RENDER_MODE_LCD :: */ - /* This mode corresponds to horizontal RGB and BGR sub-pixel */ + /* This mode corresponds to horizontal RGB and BGR subpixel */ /* 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 @FT_PIXEL_MODE_LCD mode. */ /* */ /* FT_RENDER_MODE_LCD_V :: */ - /* This mode corresponds to vertical RGB and BGR sub-pixel displays */ + /* This mode corresponds to vertical RGB and BGR subpixel 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 @FT_PIXEL_MODE_LCD_V mode. */ /* */ /* <Note> */ - /* The LCD-optimized glyph bitmaps produced by FT_Render_Glyph can be */ - /* filtered to reduce color-fringes by using @FT_Library_SetLcdFilter */ - /* (not active in the default builds). It is up to the caller to */ - /* either call @FT_Library_SetLcdFilter (if available) or do the */ - /* filtering itself. */ + /* Should you define FT_CONFIG_OPTION_SUBPIXEL_RENDERING in your */ + /* `ftoption.h', which enables patented ClearType-style rendering, */ + /* the LCD-optimized glyph bitmaps should be filtered to reduce color */ + /* fringes inherent to this technology. You can either set up LCD */ + /* filtering with @FT_Library_SetLcdFilter or @FT_Face_Properties, */ + /* or do the filtering yourself. The default FreeType LCD rendering */ + /* technology does not require filtering. */ /* */ /* The selected render mode only affects vector glyphs of a font. */ /* Embedded bitmaps often have a different pixel mode like */ @@ -3017,16 +3268,93 @@ FT_BEGIN_HEADER /* 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. */ + /* render_mode :: 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. */ /* */ /* <Note> */ /* To get meaningful results, font scaling values must be set with */ - /* functions like @FT_Set_Char_Size before calling FT_Render_Glyph. */ + /* functions like @FT_Set_Char_Size before calling `FT_Render_Glyph'. */ + /* */ + /* When FreeType outputs a bitmap of a glyph, it really outputs an */ + /* alpha coverage map. If a pixel is completely covered by a */ + /* filled-in outline, the bitmap contains 0xFF at that pixel, meaning */ + /* that 0xFF/0xFF fraction of that pixel is covered, meaning the */ + /* pixel is 100% black (or 0% bright). If a pixel is only 50% */ + /* covered (value 0x80), the pixel is made 50% black (50% bright or a */ + /* middle shade of grey). 0% covered means 0% black (100% bright or */ + /* white). */ + /* */ + /* On high-DPI screens like on smartphones and tablets, the pixels */ + /* are so small that their chance of being completely covered and */ + /* therefore completely black are fairly good. On the low-DPI */ + /* screens, however, the situation is different. The pixels are too */ + /* large for most of the details of a glyph and shades of gray are */ + /* the norm rather than the exception. */ + /* */ + /* This is relevant because all our screens have a second problem: */ + /* they are not linear. 1~+~1 is not~2. Twice the value does not */ + /* result in twice the brightness. When a pixel is only 50% covered, */ + /* the coverage map says 50% black, and this translates to a pixel */ + /* value of 128 when you use 8~bits per channel (0-255). However, */ + /* this does not translate to 50% brightness for that pixel on our */ + /* sRGB and gamma~2.2 screens. Due to their non-linearity, they */ + /* dwell longer in the darks and only a pixel value of about 186 */ + /* results in 50% brightness -- 128 ends up too dark on both bright */ + /* and dark backgrounds. The net result is that dark text looks */ + /* burnt-out, pixely and blotchy on bright background, bright text */ + /* too frail on dark backgrounds, and colored text on colored */ + /* background (for example, red on green) seems to have dark halos or */ + /* `dirt' around it. The situation is especially ugly for diagonal */ + /* stems like in `w' glyph shapes where the quality of FreeType's */ + /* anti-aliasing depends on the correct display of grays. On */ + /* high-DPI screens where smaller, fully black pixels reign supreme, */ + /* this doesn't matter, but on our low-DPI screens with all the gray */ + /* shades, it does. 0% and 100% brightness are the same things in */ + /* linear and non-linear space, just all the shades in-between */ + /* aren't. */ + /* */ + /* The blending function for placing text over a background is */ + /* */ + /* { */ + /* dst = alpha * src + (1 - alpha) * dst , */ + /* } */ + /* */ + /* which is known as the OVER operator. */ + /* */ + /* To correctly composite an antialiased pixel of a glyph onto a */ + /* surface, */ + /* */ + /* 1. take the foreground and background colors (e.g., in sRGB space) */ + /* and apply gamma to get them in a linear space, */ + /* */ + /* 2. use OVER to blend the two linear colors using the glyph pixel */ + /* as the alpha value (remember, the glyph bitmap is an alpha */ + /* coverage bitmap), and */ + /* */ + /* 3. apply inverse gamma to the blended pixel and write it back to */ + /* the image. */ + /* */ + /* Internal testing at Adobe found that a target inverse gamma of~1.8 */ + /* for step~3 gives good results across a wide range of displays with */ + /* an sRGB gamma curve or a similar one. */ + /* */ + /* This process can cost performance. There is an approximation that */ + /* does not need to know about the background color; see */ + /* https://bel.fi/alankila/lcd/ and */ + /* https://bel.fi/alankila/lcd/alpcor.html for details. */ + /* */ + /* *ATTENTION*: Linear blending is even more important when dealing */ + /* with subpixel-rendered glyphs to prevent color-fringing! A */ + /* subpixel-rendered glyph must first be filtered with a filter that */ + /* gives equal weight to the three color primaries and does not */ + /* exceed a sum of 0x100, see section @lcd_filtering. Then the */ + /* only difference to gray linear blending is that subpixel-rendered */ + /* linear blending is done 3~times per pixel: red foreground subpixel */ + /* to red background subpixel and so on for green and blue. */ /* */ FT_EXPORT( FT_Error ) FT_Render_Glyph( FT_GlyphSlot slot, @@ -3039,17 +3367,15 @@ FT_BEGIN_HEADER /* FT_Kerning_Mode */ /* */ /* <Description> */ - /* An enumeration used to specify which kerning values to return in */ + /* An enumeration to specify the format of kerning values returned by */ /* @FT_Get_Kerning. */ /* */ /* <Values> */ /* FT_KERNING_DEFAULT :: Return grid-fitted kerning distances in */ - /* pixels (value is~0). Whether they are */ - /* scaled depends on @FT_LOAD_NO_SCALE. */ + /* 26.6 fractional pixels. */ /* */ /* FT_KERNING_UNFITTED :: Return un-grid-fitted kerning distances in */ - /* 26.6 fractional pixels. Whether they are */ - /* scaled depends on @FT_LOAD_NO_SCALE. */ + /* 26.6 fractional pixels. */ /* */ /* FT_KERNING_UNSCALED :: Return the kerning vector in original font */ /* units. */ @@ -3059,9 +3385,13 @@ FT_BEGIN_HEADER /* FreeType heuristically scale down kerning distances at small ppem */ /* values so that they don't become too big. */ /* */ + /* Both FT_KERNING_DEFAULT and FT_KERNING_UNFITTED use the current */ + /* horizontal scaling factor (as set e.g. with @FT_Set_Char_Size) to */ + /* convert font units to pixels. */ + /* */ typedef enum FT_Kerning_Mode_ { - FT_KERNING_DEFAULT = 0, + FT_KERNING_DEFAULT = 0, FT_KERNING_UNFITTED, FT_KERNING_UNSCALED @@ -3081,7 +3411,7 @@ FT_BEGIN_HEADER /* FT_Get_Kerning */ /* */ /* <Description> */ - /* Return the kerning vector between two glyphs of a same face. */ + /* Return the kerning vector between two glyphs of the same face. */ /* */ /* <Input> */ /* face :: A handle to a source face object. */ @@ -3109,6 +3439,10 @@ FT_BEGIN_HEADER /* kernings, are out of the scope of this API function -- they can be */ /* implemented through format-specific interfaces. */ /* */ + /* Kerning for OpenType fonts implemented in a `GPOS' table is not */ + /* supported; use @FT_HAS_KERNING to find out whether a font has data */ + /* that can be extracted with `FT_Get_Kerning'. */ + /* */ FT_EXPORT( FT_Error ) FT_Get_Kerning( FT_Face face, FT_UInt left_glyph, @@ -3148,7 +3482,7 @@ FT_BEGIN_HEADER /* @FT_Attach_Stream). */ /* */ /* Only very few AFM files come with track kerning data; please refer */ - /* to the Adobe's AFM specification for more details. */ + /* to Adobe's AFM specification for more details. */ /* */ FT_EXPORT( FT_Error ) FT_Get_Track_Kerning( FT_Face face, @@ -3194,7 +3528,7 @@ FT_BEGIN_HEADER /* `.notdef'). */ /* */ /* This function always returns an error if the config macro */ - /* `FT_CONFIG_OPTION_NO_GLYPH_NAMES' is not defined in `ftoptions.h'. */ + /* `FT_CONFIG_OPTION_NO_GLYPH_NAMES' is not defined in `ftoption.h'. */ /* */ FT_EXPORT( FT_Error ) FT_Get_Glyph_Name( FT_Face face, @@ -3210,7 +3544,7 @@ FT_BEGIN_HEADER /* */ /* <Description> */ /* Retrieve the ASCII PostScript name of a given face, if available. */ - /* This only works with PostScript and TrueType fonts. */ + /* This only works with PostScript, TrueType, and OpenType fonts. */ /* */ /* <Input> */ /* face :: A handle to the source face object. */ @@ -3222,6 +3556,20 @@ FT_BEGIN_HEADER /* The returned pointer is owned by the face and is destroyed with */ /* it. */ /* */ + /* For variation fonts, this string changes if you select a different */ + /* instance, and you have to call `FT_Get_PostScript_Name' again to */ + /* retrieve it. FreeType follows Adobe TechNote #5902, `Generating */ + /* PostScript Names for Fonts Using OpenType Font Variations'. */ + /* */ + /* https://download.macromedia.com/pub/developer/opentype/tech-notes/5902.AdobePSNameGeneration.html */ + /* */ + /* [Since 2.9] Special PostScript names for named instances are only */ + /* returned if the named instance is set with @FT_Set_Named_Instance */ + /* (and the font has corresponding entries in its `fvar' table). If */ + /* @FT_IS_VARIATION returns true, the algorithmically derived */ + /* PostScript name is provided, not looking up special entries for */ + /* named instances. */ + /* */ FT_EXPORT( const char* ) FT_Get_Postscript_Name( FT_Face face ); @@ -3281,7 +3629,8 @@ FT_BEGIN_HEADER /* the face (i.e., if it is not listed in the `face->charmaps' */ /* table). */ /* */ - /* It also fails if a type~14 charmap is selected. */ + /* It also fails if an OpenType type~14 charmap is selected (which */ + /* doesn't map character codes to glyph indices at all). */ /* */ FT_EXPORT( FT_Error ) FT_Set_Charmap( FT_Face face, @@ -3316,7 +3665,7 @@ FT_BEGIN_HEADER /* */ /* <Description> */ /* Return the glyph index of a given character code. This function */ - /* uses a charmap object to do the mapping. */ + /* uses the currently selected charmap to do the mapping. */ /* */ /* <Input> */ /* face :: A handle to the source face object. */ @@ -3350,9 +3699,8 @@ FT_BEGIN_HEADER /* FT_Get_First_Char */ /* */ /* <Description> */ - /* This function is used to return the first character code in the */ - /* current charmap of a given face. It also returns the */ - /* corresponding glyph index. */ + /* Return the first character code in the current charmap of a given */ + /* face, together with its corresponding glyph index. */ /* */ /* <Input> */ /* face :: A handle to the source face object. */ @@ -3365,7 +3713,7 @@ FT_BEGIN_HEADER /* The charmap's first character code. */ /* */ /* <Note> */ - /* You should use this function with @FT_Get_Next_Char to be able to */ + /* You should use this function together with @FT_Get_Next_Char to */ /* parse all character codes available in a given charmap. The code */ /* should look like this: */ /* */ @@ -3405,12 +3753,13 @@ FT_BEGIN_HEADER /* FT_Get_Next_Char */ /* */ /* <Description> */ - /* 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. */ + /* 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> */ @@ -3423,7 +3772,7 @@ FT_BEGIN_HEADER /* <Note> */ /* You should use this function with @FT_Get_First_Char to walk */ /* over all character codes available in a given charmap. See the */ - /* note for this function for a simple code example. */ + /* note for that function for a simple code example. */ /* */ /* Note that `*agindex' is set to~0 when there are no more codes in */ /* the charmap. */ @@ -3434,14 +3783,112 @@ FT_BEGIN_HEADER FT_UInt *agindex ); + /************************************************************************* + * + * @function: + * FT_Face_Properties + * + * @description: + * Set or override certain (library or module-wide) properties on a + * face-by-face basis. Useful for finer-grained control and avoiding + * locks on shared structures (threads can modify their own faces as + * they see fit). + * + * Contrary to @FT_Property_Set, this function uses @FT_Parameter so + * that you can pass multiple properties to the target face in one call. + * Note that only a subset of the available properties can be + * controlled. + * + * * @FT_PARAM_TAG_STEM_DARKENING (stem darkening, corresponding to the + * property `no-stem-darkening' provided by the `autofit', `cff', + * `type1', and `t1cid' modules; see @no-stem-darkening). + * + * * @FT_PARAM_TAG_LCD_FILTER_WEIGHTS (LCD filter weights, corresponding + * to function @FT_Library_SetLcdFilterWeights). + * + * * @FT_PARAM_TAG_RANDOM_SEED (seed value for the CFF, Type~1, and CID + * `random' operator, corresponding to the `random-seed' property + * provided by the `cff', `type1', and `t1cid' modules; see + * @random-seed). + * + * Pass NULL as `data' in @FT_Parameter for a given tag to reset the + * option and use the library or module default again. + * + * @input: + * face :: + * A handle to the source face object. + * + * num_properties :: + * The number of properties that follow. + * + * properties :: + * A handle to an @FT_Parameter array with `num_properties' elements. + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * Here an example that sets three properties. You must define + * FT_CONFIG_OPTION_SUBPIXEL_RENDERING to make the LCD filter examples + * work. + * + * { + * FT_Parameter property1; + * FT_Bool darken_stems = 1; + * + * FT_Parameter property2; + * FT_LcdFiveTapFilter custom_weight = + * { 0x11, 0x44, 0x56, 0x44, 0x11 }; + * + * FT_Parameter property3; + * FT_Int32 random_seed = 314159265; + * + * FT_Parameter properties[3] = { property1, + * property2, + * property3 }; + * + * + * property1.tag = FT_PARAM_TAG_STEM_DARKENING; + * property1.data = &darken_stems; + * + * property2.tag = FT_PARAM_TAG_LCD_FILTER_WEIGHTS; + * property2.data = custom_weight; + * + * property3.tag = FT_PARAM_TAG_RANDOM_SEED; + * property3.data = &random_seed; + * + * FT_Face_Properties( face, 3, properties ); + * } + * + * The next example resets a single property to its default value. + * + * { + * FT_Parameter property; + * + * + * property.tag = FT_PARAM_TAG_LCD_FILTER_WEIGHTS; + * property.data = NULL; + * + * FT_Face_Properties( face, 1, &property ); + * } + * + * @since: + * 2.8 + * + */ + FT_EXPORT( FT_Error ) + FT_Face_Properties( FT_Face face, + FT_UInt num_properties, + FT_Parameter* properties ); + + /*************************************************************************/ /* */ /* <Function> */ /* FT_Get_Name_Index */ /* */ /* <Description> */ - /* Return the glyph index of a given glyph name. This function uses */ - /* driver specific objects to do the translation. */ + /* Return the glyph index of a given glyph name. */ /* */ /* <Input> */ /* face :: A handle to the source face object. */ @@ -3462,8 +3909,10 @@ FT_BEGIN_HEADER * FT_SUBGLYPH_FLAG_XXX * * @description: - * A list of constants used to describe subglyphs. Please refer to the - * TrueType specification for the meaning of the various flags. + * A list of constants describing subglyphs. Please refer to the + * `glyf' table description in the OpenType specification for the + * meaning of the various flags (which get synthesized for + * non-OpenType subglyphs). * * @values: * FT_SUBGLYPH_FLAG_ARGS_ARE_WORDS :: @@ -3524,7 +3973,7 @@ FT_BEGIN_HEADER * @note: * The values of `*p_arg1', `*p_arg2', and `*p_transform' must be * interpreted depending on the flags returned in `*p_flags'. See the - * TrueType specification for details. + * OpenType specification for details. * */ FT_EXPORT( FT_Error ) @@ -3550,7 +3999,7 @@ FT_BEGIN_HEADER /* and subsetting restrictions associated with a font. */ /* */ /* See */ - /* http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/FontPolicies.pdf */ + /* https://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/FontPolicies.pdf */ /* for more details. */ /* */ /* <Values> */ @@ -3564,33 +4013,31 @@ FT_BEGIN_HEADER /* the font software copyright owner. */ /* */ /* FT_FSTYPE_PREVIEW_AND_PRINT_EMBEDDING :: */ - /* If this bit is set, the font may be embedded and temporarily */ - /* loaded on the remote system. Documents containing Preview & */ - /* Print fonts must be opened `read-only'; no edits can be applied */ - /* to the document. */ + /* The font may be embedded and temporarily loaded on the remote */ + /* system. Documents containing Preview & Print fonts must be */ + /* opened `read-only'; no edits can be applied to the document. */ /* */ /* FT_FSTYPE_EDITABLE_EMBEDDING :: */ - /* If this bit is set, the font may be embedded but must only be */ - /* installed temporarily on other systems. In contrast to Preview */ - /* & Print fonts, documents containing editable fonts may be opened */ - /* for reading, editing is permitted, and changes may be saved. */ + /* The font may be embedded but must only be installed temporarily */ + /* on other systems. In contrast to Preview & Print fonts, */ + /* documents containing editable fonts may be opened for reading, */ + /* editing is permitted, and changes may be saved. */ /* */ /* FT_FSTYPE_NO_SUBSETTING :: */ - /* If this bit is set, the font may not be subsetted prior to */ - /* embedding. */ + /* The font may not be subsetted prior to embedding. */ /* */ /* FT_FSTYPE_BITMAP_EMBEDDING_ONLY :: */ - /* If this bit is set, only bitmaps contained in the font may be */ - /* embedded; no outline data may be embedded. If there are no */ - /* bitmaps available in the font, then the font is unembeddable. */ + /* Only bitmaps contained in the font may be embedded; no outline */ + /* data may be embedded. If there are no bitmaps available in the */ + /* font, then the font is unembeddable. */ /* */ /* <Note> */ /* The flags are ORed together, thus more than a single value can be */ /* returned. */ /* */ - /* While the fsType flags can indicate that a font may be embedded, a */ - /* license with the font vendor may be separately required to use the */ - /* font in this way. */ + /* While the `fsType' flags can indicate that a font may be embedded, */ + /* a license with the font vendor may be separately required to use */ + /* the font in this way. */ /* */ #define FT_FSTYPE_INSTALLABLE_EMBEDDING 0x0000 #define FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING 0x0002 @@ -3606,13 +4053,13 @@ FT_BEGIN_HEADER /* FT_Get_FSType_Flags */ /* */ /* <Description> */ - /* Return the fsType flags for a font. */ + /* Return the `fsType' flags for a font. */ /* */ /* <Input> */ /* face :: A handle to the source face object. */ /* */ /* <Return> */ - /* The fsType flags, @FT_FSTYPE_XXX. */ + /* The `fsType' flags, see @FT_FSTYPE_XXX. */ /* */ /* <Note> */ /* Use this function rather than directly reading the `fs_type' field */ @@ -3632,39 +4079,51 @@ FT_BEGIN_HEADER /* glyph_variants */ /* */ /* <Title> */ - /* Glyph Variants */ + /* Unicode Variation Sequences */ /* */ /* <Abstract> */ - /* The FreeType~2 interface to Unicode Ideographic Variation */ - /* Sequences (IVS), using the SFNT cmap format~14. */ + /* The FreeType~2 interface to Unicode Variation Sequences (UVS), */ + /* using the SFNT cmap format~14. */ /* */ /* <Description> */ - /* Many CJK characters have variant forms. They are a sort of grey */ - /* area somewhere between being totally irrelevant and semantically */ - /* distinct; for this reason, the Unicode consortium decided to */ - /* introduce Ideographic Variation Sequences (IVS), consisting of a */ - /* Unicode base character and one of 240 variant selectors */ - /* (U+E0100-U+E01EF), instead of further extending the already huge */ - /* code range for CJK characters. */ - /* */ - /* An IVS is registered and unique; for further details please refer */ - /* to Unicode Technical Standard #37, the Ideographic Variation */ - /* Database: */ - /* */ - /* http://www.unicode.org/reports/tr37/ */ - /* */ - /* To date (November 2014), the character with the most variants is */ - /* U+9089, having 32 such IVS. */ - /* */ - /* Adobe and MS decided to support IVS with a new cmap subtable */ - /* (format~14). It is an odd subtable because it is not a mapping of */ - /* input code points to glyphs, but contains lists of all variants */ - /* supported by the font. */ - /* */ - /* A variant may be either `default' or `non-default'. A default */ - /* variant is the one you will get for that code point if you look it */ - /* up in the standard Unicode cmap. A non-default variant is a */ - /* different glyph. */ + /* Many characters, especially for CJK scripts, have variant forms. */ + /* They are a sort of grey area somewhere between being totally */ + /* irrelevant and semantically distinct; for this reason, the Unicode */ + /* consortium decided to introduce Variation Sequences (VS), */ + /* consisting of a Unicode base character and a variation selector */ + /* instead of further extending the already huge number of */ + /* characters. */ + /* */ + /* Unicode maintains two different sets, namely `Standardized */ + /* Variation Sequences' and registered `Ideographic Variation */ + /* Sequences' (IVS), collected in the `Ideographic Variation */ + /* Database' (IVD). */ + /* */ + /* https://unicode.org/Public/UCD/latest/ucd/StandardizedVariants.txt */ + /* https://unicode.org/reports/tr37/ */ + /* https://unicode.org/ivd/ */ + /* */ + /* To date (January 2017), the character with the most ideographic */ + /* variations is U+9089, having 32 such IVS. */ + /* */ + /* Three Mongolian Variation Selectors have the values U+180B-U+180D; */ + /* 256 generic Variation Selectors are encoded in the ranges */ + /* U+FE00-U+FE0F and U+E0100-U+E01EF. IVS currently use Variation */ + /* Selectors from the range U+E0100-U+E01EF only. */ + /* */ + /* A VS consists of the base character value followed by a single */ + /* Variation Selector. For example, to get the first variation of */ + /* U+9089, you have to write the character sequence `U+9089 U+E0100'. */ + /* */ + /* Adobe and MS decided to support both standardized and ideographic */ + /* VS with a new cmap subtable (format~14). It is an odd subtable */ + /* because it is not a mapping of input code points to glyphs, but */ + /* contains lists of all variations supported by the font. */ + /* */ + /* A variation may be either `default' or `non-default' for a given */ + /* font. A default variation is the one you will get for that code */ + /* point if you look it up in the standard Unicode cmap. A */ + /* non-default variation is a different glyph. */ /* */ /*************************************************************************/ @@ -3720,8 +4179,8 @@ FT_BEGIN_HEADER /* FT_Face_GetCharVariantIsDefault */ /* */ /* <Description> */ - /* Check whether this variant of this Unicode character is the one to */ - /* be found in the `cmap'. */ + /* Check whether this variation of this Unicode character is the one */ + /* to be found in the `cmap'. */ /* */ /* <Input> */ /* face :: */ @@ -3735,7 +4194,7 @@ FT_BEGIN_HEADER /* */ /* <Return> */ /* 1~if found in the standard (Unicode) cmap, 0~if found in the */ - /* variation selector cmap, or -1 if it is not a variant. */ + /* variation selector cmap, or -1 if it is not a variation. */ /* */ /* <Note> */ /* This function is only meaningful if the font has a variation */ @@ -3756,7 +4215,7 @@ FT_BEGIN_HEADER /* FT_Face_GetVariantSelectors */ /* */ /* <Description> */ - /* Return a zero-terminated list of Unicode variant selectors found */ + /* Return a zero-terminated list of Unicode variation selectors found */ /* in the font. */ /* */ /* <Input> */ @@ -3765,7 +4224,7 @@ FT_BEGIN_HEADER /* */ /* <Return> */ /* A pointer to an array of selector code points, or NULL if there is */ - /* no valid variant selector cmap subtable. */ + /* no valid variation selector cmap subtable. */ /* */ /* <Note> */ /* The last item in the array is~0; the array is owned by the */ @@ -3785,7 +4244,7 @@ FT_BEGIN_HEADER /* FT_Face_GetVariantsOfChar */ /* */ /* <Description> */ - /* Return a zero-terminated list of Unicode variant selectors found */ + /* Return a zero-terminated list of Unicode variation selectors found */ /* for the specified character code. */ /* */ /* <Input> */ @@ -3796,7 +4255,7 @@ FT_BEGIN_HEADER /* The character codepoint in Unicode. */ /* */ /* <Return> */ - /* A pointer to an array of variant selector code points that are */ + /* A pointer to an array of variation selector code points that are */ /* active for the given character, or NULL if the corresponding list */ /* is empty. */ /* */ @@ -3820,19 +4279,19 @@ FT_BEGIN_HEADER /* */ /* <Description> */ /* Return a zero-terminated list of Unicode character codes found for */ - /* the specified variant selector. */ + /* the specified variation selector. */ /* */ /* <Input> */ /* face :: */ /* A handle to the source face object. */ /* */ /* variantSelector :: */ - /* The variant selector code point in Unicode. */ + /* The variation selector code point in Unicode. */ /* */ /* <Return> */ /* A list of all the code points that are specified by this selector */ /* (both default and non-default codes are returned) or NULL if there */ - /* is no valid cmap or the variant selector is invalid. */ + /* is no valid cmap or the variation selector is invalid. */ /* */ /* <Note> */ /* The last item in the array is~0; the array is owned by the */ @@ -3882,16 +4341,17 @@ FT_BEGIN_HEADER /* FT_MulDiv */ /* */ /* <Description> */ - /* A very simple function used to perform the computation `(a*b)/c' */ - /* with maximum accuracy (it uses a 64-bit intermediate integer */ - /* whenever necessary). */ + /* Compute `(a*b)/c' with maximum accuracy, using a 64-bit */ + /* intermediate integer whenever necessary. */ /* */ /* This function isn't necessarily as fast as some processor specific */ /* operations, but is at least completely portable. */ /* */ /* <Input> */ /* a :: The first multiplier. */ + /* */ /* b :: The second multiplier. */ + /* */ /* c :: The divisor. */ /* */ /* <Return> */ @@ -3911,12 +4371,12 @@ FT_BEGIN_HEADER /* FT_MulFix */ /* */ /* <Description> */ - /* A very simple function used to perform the computation */ - /* `(a*b)/0x10000' with maximum accuracy. Most of the time this is */ - /* used to multiply a given value by a 16.16 fixed-point factor. */ + /* Compute `(a*b)/0x10000' with maximum accuracy. Its main use is to */ + /* multiply a given value by a 16.16 fixed-point factor. */ /* */ /* <Input> */ /* a :: The first multiplier. */ + /* */ /* b :: The second multiplier. Use a 16.16 factor here whenever */ /* possible (see note below). */ /* */ @@ -3945,12 +4405,12 @@ FT_BEGIN_HEADER /* FT_DivFix */ /* */ /* <Description> */ - /* A very simple function used to perform the computation */ - /* `(a*0x10000)/b' with maximum accuracy. Most of the time, this is */ - /* used to divide a given value by a 16.16 fixed-point factor. */ + /* Compute `(a*0x10000)/b' with maximum accuracy. Its main use is to */ + /* divide a given value by a 16.16 fixed-point factor. */ /* */ /* <Input> */ /* a :: The numerator. */ + /* */ /* b :: The denominator. Use a 16.16 factor here. */ /* */ /* <Return> */ @@ -3967,15 +4427,18 @@ FT_BEGIN_HEADER /* FT_RoundFix */ /* */ /* <Description> */ - /* A very simple function used to round a 16.16 fixed number. */ + /* Round a 16.16 fixed number. */ /* */ /* <Input> */ /* a :: The number to be rounded. */ /* */ /* <Return> */ - /* `a' rounded to nearest 16.16 fixed integer, halfway cases away */ + /* `a' rounded to the nearest 16.16 fixed integer, halfway cases away */ /* from zero. */ /* */ + /* <Note> */ + /* The function uses wrap-around arithmetic. */ + /* */ FT_EXPORT( FT_Fixed ) FT_RoundFix( FT_Fixed a ); @@ -3986,8 +4449,7 @@ FT_BEGIN_HEADER /* FT_CeilFix */ /* */ /* <Description> */ - /* A very simple function used to compute the ceiling function of a */ - /* 16.16 fixed number. */ + /* Compute the smallest following integer of a 16.16 fixed number. */ /* */ /* <Input> */ /* a :: The number for which the ceiling function is to be computed. */ @@ -3995,6 +4457,9 @@ FT_BEGIN_HEADER /* <Return> */ /* `a' rounded towards plus infinity. */ /* */ + /* <Note> */ + /* The function uses wrap-around arithmetic. */ + /* */ FT_EXPORT( FT_Fixed ) FT_CeilFix( FT_Fixed a ); @@ -4005,8 +4470,7 @@ FT_BEGIN_HEADER /* FT_FloorFix */ /* */ /* <Description> */ - /* A very simple function used to compute the floor function of a */ - /* 16.16 fixed number. */ + /* Compute the largest previous integer of a 16.16 fixed number. */ /* */ /* <Input> */ /* a :: The number for which the floor function is to be computed. */ @@ -4092,7 +4556,7 @@ FT_BEGIN_HEADER * */ #define FREETYPE_MAJOR 2 -#define FREETYPE_MINOR 6 +#define FREETYPE_MINOR 9 #define FREETYPE_PATCH 1 @@ -4138,20 +4602,13 @@ FT_BEGIN_HEADER /* FT_Face_CheckTrueTypePatents */ /* */ /* <Description> */ - /* Parse all bytecode instructions of a TrueType font file to check */ - /* whether any of the patented opcodes are used. This is only useful */ - /* if you want to be able to use the unpatented hinter with */ - /* fonts that do *not* use these opcodes. */ - /* */ - /* Note that this function parses *all* glyph instructions in the */ - /* font file, which may be slow. */ + /* Deprecated, does nothing. */ /* */ /* <Input> */ /* face :: A face handle. */ /* */ /* <Return> */ - /* 1~if this is a TrueType font that uses one of the patented */ - /* opcodes, 0~otherwise. */ + /* Always returns false. */ /* */ /* <Note> */ /* Since May 2010, TrueType hinting is no longer patented. */ @@ -4169,9 +4626,7 @@ FT_BEGIN_HEADER /* FT_Face_SetUnpatentedHinting */ /* */ /* <Description> */ - /* Enable or disable the unpatented hinter for a given face. */ - /* Only enable it if you have determined that the face doesn't */ - /* use any patented opcodes (see @FT_Face_CheckTrueTypePatents). */ + /* Deprecated, does nothing. */ /* */ /* <Input> */ /* face :: A face handle. */ @@ -4179,9 +4634,7 @@ FT_BEGIN_HEADER /* value :: New boolean setting. */ /* */ /* <Return> */ - /* The old setting value. This will always be false if this is not */ - /* an SFNT font, or if the unpatented hinter is not compiled in this */ - /* instance of the library. */ + /* Always returns false. */ /* */ /* <Note> */ /* Since May 2010, TrueType hinting is no longer patented. */ @@ -4198,7 +4651,7 @@ FT_BEGIN_HEADER FT_END_HEADER -#endif /* __FREETYPE_H__ */ +#endif /* FREETYPE_H_ */ /* END */ |