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diff --git a/modules/freetype2/include/freetype/freetype.h b/modules/freetype2/include/freetype/freetype.h new file mode 100644 index 0000000000..efff74fe39 --- /dev/null +++ b/modules/freetype2/include/freetype/freetype.h @@ -0,0 +1,5058 @@ +/**************************************************************************** + * + * freetype.h + * + * FreeType high-level API and common types (specification only). + * + * Copyright (C) 1996-2023 by + * David Turner, Robert Wilhelm, and Werner Lemberg. + * + * This file is part of the FreeType project, and may only be used, + * modified, and distributed under the terms of the FreeType project + * license, LICENSE.TXT. By continuing to use, modify, or distribute + * this file you indicate that you have read the license and + * understand and accept it fully. + * + */ + + +#ifndef FREETYPE_H_ +#define FREETYPE_H_ + + +#include <ft2build.h> +#include FT_CONFIG_CONFIG_H +#include <freetype/fttypes.h> +#include <freetype/fterrors.h> + + +FT_BEGIN_HEADER + + + + /************************************************************************** + * + * @section: + * preamble + * + * @title: + * Preamble + * + * @abstract: + * What FreeType is and isn't + * + * @description: + * FreeType is a library that provides access to glyphs in font files. It + * scales the glyph images and their metrics to a requested size, and it + * rasterizes the glyph images to produce pixel or subpixel alpha coverage + * bitmaps. + * + * Note that FreeType is _not_ a text layout engine. You have to use + * higher-level libraries like HarfBuzz, Pango, or ICU for that. + * + * Note also that FreeType does _not_ perform alpha blending or + * compositing the resulting bitmaps or pixmaps by itself. Use your + * favourite graphics library (for example, Cairo or Skia) to further + * process FreeType's output. + * + */ + + + /************************************************************************** + * + * @section: + * header_inclusion + * + * @title: + * FreeType's header inclusion scheme + * + * @abstract: + * How client applications should include FreeType header files. + * + * @description: + * To be as flexible as possible (and for historical reasons), you must + * load file `ft2build.h` first before other header files, for example + * + * ``` + * #include <ft2build.h> + * + * #include <freetype/freetype.h> + * #include <freetype/ftoutln.h> + * ``` + */ + + + /************************************************************************** + * + * @section: + * user_allocation + * + * @title: + * User allocation + * + * @abstract: + * How client applications should allocate FreeType data structures. + * + * @description: + * FreeType assumes that structures allocated by the user and passed as + * arguments are zeroed out except for the actual data. In other words, + * it is recommended to use `calloc` (or variants of it) instead of + * `malloc` for allocation. + * + */ + + + + /*************************************************************************/ + /*************************************************************************/ + /* */ + /* B A S I C T Y P E S */ + /* */ + /*************************************************************************/ + /*************************************************************************/ + + + /************************************************************************** + * + * @section: + * base_interface + * + * @title: + * Base Interface + * + * @abstract: + * The FreeType~2 base font interface. + * + * @description: + * This section describes the most important public high-level API + * functions of FreeType~2. + * + * @order: + * FT_Library + * FT_Face + * FT_Size + * FT_GlyphSlot + * FT_CharMap + * FT_Encoding + * FT_ENC_TAG + * + * FT_FaceRec + * + * FT_FACE_FLAG_SCALABLE + * FT_FACE_FLAG_FIXED_SIZES + * FT_FACE_FLAG_FIXED_WIDTH + * FT_FACE_FLAG_HORIZONTAL + * FT_FACE_FLAG_VERTICAL + * FT_FACE_FLAG_COLOR + * FT_FACE_FLAG_SFNT + * FT_FACE_FLAG_CID_KEYED + * 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_SVG + * FT_FACE_FLAG_SBIX + * FT_FACE_FLAG_SBIX_OVERLAY + * + * FT_HAS_HORIZONTAL + * FT_HAS_VERTICAL + * FT_HAS_KERNING + * FT_HAS_FIXED_SIZES + * FT_HAS_GLYPH_NAMES + * FT_HAS_COLOR + * FT_HAS_MULTIPLE_MASTERS + * FT_HAS_SVG + * FT_HAS_SBIX + * FT_HAS_SBIX_OVERLAY + * + * 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 + * + * FT_SizeRec + * FT_Size_Metrics + * + * FT_GlyphSlotRec + * FT_Glyph_Metrics + * FT_SubGlyph + * + * FT_Bitmap_Size + * + * FT_Init_FreeType + * FT_Done_FreeType + * + * FT_New_Face + * FT_Done_Face + * FT_Reference_Face + * FT_New_Memory_Face + * FT_Face_Properties + * FT_Open_Face + * FT_Open_Args + * FT_Parameter + * FT_Attach_File + * FT_Attach_Stream + * + * FT_Set_Char_Size + * FT_Set_Pixel_Sizes + * FT_Request_Size + * FT_Select_Size + * FT_Size_Request_Type + * FT_Size_RequestRec + * FT_Size_Request + * FT_Set_Transform + * FT_Get_Transform + * FT_Load_Glyph + * FT_Get_Char_Index + * FT_Get_First_Char + * FT_Get_Next_Char + * FT_Load_Char + * + * FT_OPEN_MEMORY + * FT_OPEN_STREAM + * FT_OPEN_PATHNAME + * FT_OPEN_DRIVER + * FT_OPEN_PARAMS + * + * FT_LOAD_DEFAULT + * FT_LOAD_RENDER + * FT_LOAD_MONOCHROME + * FT_LOAD_LINEAR_DESIGN + * FT_LOAD_NO_SCALE + * FT_LOAD_NO_HINTING + * FT_LOAD_NO_BITMAP + * FT_LOAD_SBITS_ONLY + * FT_LOAD_NO_AUTOHINT + * FT_LOAD_COLOR + * + * FT_LOAD_VERTICAL_LAYOUT + * FT_LOAD_IGNORE_TRANSFORM + * FT_LOAD_FORCE_AUTOHINT + * FT_LOAD_NO_RECURSE + * FT_LOAD_PEDANTIC + * + * FT_LOAD_TARGET_NORMAL + * FT_LOAD_TARGET_LIGHT + * FT_LOAD_TARGET_MONO + * FT_LOAD_TARGET_LCD + * FT_LOAD_TARGET_LCD_V + * + * FT_LOAD_TARGET_MODE + * + * FT_Render_Glyph + * FT_Render_Mode + * FT_Get_Kerning + * FT_Kerning_Mode + * FT_Get_Track_Kerning + * + * FT_CharMapRec + * FT_Select_Charmap + * FT_Set_Charmap + * FT_Get_Charmap_Index + * + * FT_Get_Name_Index + * FT_Get_Glyph_Name + * FT_Get_Postscript_Name + * FT_Get_FSType_Flags + * FT_Get_SubGlyph_Info + * + * FT_Face_Internal + * FT_Size_Internal + * FT_Slot_Internal + * + * FT_FACE_FLAG_XXX + * FT_STYLE_FLAG_XXX + * FT_OPEN_XXX + * FT_LOAD_XXX + * FT_LOAD_TARGET_XXX + * FT_SUBGLYPH_FLAG_XXX + * FT_FSTYPE_XXX + * + * FT_HAS_FAST_GLYPHS + * + */ + + + /************************************************************************** + * + * @struct: + * FT_Glyph_Metrics + * + * @description: + * 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. + * + * @fields: + * width :: + * The glyph's width. + * + * height :: + * The glyph's height. + * + * horiBearingX :: + * Left side bearing for horizontal layout. + * + * horiBearingY :: + * Top side bearing for horizontal layout. + * + * horiAdvance :: + * Advance width for horizontal layout. + * + * vertBearingX :: + * Left side bearing for vertical layout. + * + * vertBearingY :: + * Top side bearing for vertical layout. Larger positive values mean + * further below the vertical glyph origin. + * + * vertAdvance :: + * Advance height for vertical layout. Positive values mean the glyph + * has a positive advance downward. + * + * @note: + * If not disabled with @FT_LOAD_NO_HINTING, the values represent + * dimensions of the hinted glyph (in case hinting is applicable). + * + * Stroking a glyph with an outside border does not increase + * `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; + FT_Pos height; + + FT_Pos horiBearingX; + FT_Pos horiBearingY; + FT_Pos horiAdvance; + + FT_Pos vertBearingX; + FT_Pos vertBearingY; + FT_Pos vertAdvance; + + } FT_Glyph_Metrics; + + + /************************************************************************** + * + * @struct: + * FT_Bitmap_Size + * + * @description: + * This structure models the metrics of a bitmap strike (i.e., a set of + * glyphs for a given point size and resolution) in a bitmap font. It is + * used for the `available_sizes` field of @FT_Face. + * + * @fields: + * height :: + * The vertical distance, in pixels, between two consecutive baselines. + * It is always positive. + * + * width :: + * The average width, in pixels, of all glyphs in the strike. + * + * size :: + * The nominal size of the strike in 26.6 fractional points. This + * field is not very useful. + * + * x_ppem :: + * The horizontal ppem (nominal width) in 26.6 fractional pixels. + * + * y_ppem :: + * The vertical ppem (nominal height) in 26.6 fractional pixels. + * + * @note: + * Windows FNT: + * 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 bitmap + * strike itself. They are computed from the global font parameters. + */ + typedef struct FT_Bitmap_Size_ + { + FT_Short height; + FT_Short width; + + FT_Pos size; + + FT_Pos x_ppem; + FT_Pos y_ppem; + + } FT_Bitmap_Size; + + + /*************************************************************************/ + /*************************************************************************/ + /* */ + /* O B J E C T C L A S S E S */ + /* */ + /*************************************************************************/ + /*************************************************************************/ + + /************************************************************************** + * + * @type: + * FT_Library + * + * @description: + * A handle to a FreeType library instance. Each 'library' is completely + * independent from the others; it is the 'root' of a set of objects like + * fonts, faces, sizes, etc. + * + * It also embeds a memory manager (see @FT_Memory), as well as a + * scan-line converter object (see @FT_Raster). + * + * [Since 2.5.6] In multi-threaded applications it is easiest to use one + * `FT_Library` object per thread. In case this is too cumbersome, a + * single `FT_Library` object across threads is possible also, as long as + * a mutex lock is used around @FT_New_Face and @FT_Done_Face. + * + * @note: + * Library objects are normally created by @FT_Init_FreeType, and + * destroyed with @FT_Done_FreeType. If you need reference-counting + * (cf. @FT_Reference_Library), use @FT_New_Library and @FT_Done_Library. + */ + typedef struct FT_LibraryRec_ *FT_Library; + + + /************************************************************************** + * + * @section: + * module_management + * + */ + + /************************************************************************** + * + * @type: + * FT_Module + * + * @description: + * 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 + * former. + */ + typedef struct FT_ModuleRec_* FT_Module; + + + /************************************************************************** + * + * @type: + * FT_Driver + * + * @description: + * 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; + + + /************************************************************************** + * + * @type: + * FT_Renderer + * + * @description: + * 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; + + + /************************************************************************** + * + * @section: + * base_interface + * + */ + + /************************************************************************** + * + * @type: + * FT_Face + * + * @description: + * A handle to a typographic face object. A face object models a given + * typeface, in a given style. + * + * @note: + * 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 filepath or a custom input stream. + * + * Use @FT_Done_Face to destroy it (along with its slot and sizes). + * + * An `FT_Face` object can only be safely used from one thread at a time. + * Similarly, creation and destruction of `FT_Face` with the same + * @FT_Library object can only be done from one thread at a time. On the + * other hand, functions like @FT_Load_Glyph and its siblings are + * thread-safe and do not need the lock to be held as long as the same + * `FT_Face` object is not used from multiple threads at the same time. + * + * @also: + * See @FT_FaceRec for the publicly accessible fields of a given face + * object. + */ + typedef struct FT_FaceRec_* FT_Face; + + + /************************************************************************** + * + * @type: + * FT_Size + * + * @description: + * A handle to an object that models a face scaled to a given character + * size. + * + * @note: + * 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. + * + * A newly created `FT_Size` object contains only meaningless zero values. + * You must use @FT_Set_Char_Size, @FT_Set_Pixel_Sizes, @FT_Request_Size + * or even @FT_Select_Size to change the content (i.e., the scaling + * values) of the active `FT_Size`. Otherwise, the scaling and hinting + * will not be performed. + * + * You can use @FT_New_Size to create additional size objects for a given + * @FT_Face, but they won't be used by other functions until you activate + * it through @FT_Activate_Size. Only one size can be activated at any + * given time per face. + * + * @also: + * See @FT_SizeRec for the publicly accessible fields of a given size + * object. + */ + typedef struct FT_SizeRec_* FT_Size; + + + /************************************************************************** + * + * @type: + * FT_GlyphSlot + * + * @description: + * 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, i.e., the glyph's + * metrics, its image (bitmap or outline), and other control information. + * + * @also: + * See @FT_GlyphSlotRec for the publicly accessible glyph fields. + */ + typedef struct FT_GlyphSlotRec_* FT_GlyphSlot; + + + /************************************************************************** + * + * @type: + * FT_CharMap + * + * @description: + * 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', 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. + * + * The currently active charmap is available as `face->charmap`. You + * should call @FT_Set_Charmap to change it. + * + * @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. 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 + * character map. + */ + typedef struct FT_CharMapRec_* FT_CharMap; + + + /************************************************************************** + * + * @macro: + * FT_ENC_TAG + * + * @description: + * This macro converts four-letter tags into an unsigned long. It is + * used to define 'encoding' identifiers (see @FT_Encoding). + * + * @note: + * Since many 16-bit compilers don't like 32-bit enumerations, you should + * redefine this macro in case of problems to something like this: + * + * ``` + * #define FT_ENC_TAG( value, a, b, c, d ) value + * ``` + * + * to get a simple enumeration without assigning special numbers. + */ + +#ifndef FT_ENC_TAG + +#define FT_ENC_TAG( value, a, b, c, d ) \ + value = ( ( FT_STATIC_BYTE_CAST( FT_UInt32, a ) << 24 ) | \ + ( FT_STATIC_BYTE_CAST( FT_UInt32, b ) << 16 ) | \ + ( FT_STATIC_BYTE_CAST( FT_UInt32, c ) << 8 ) | \ + FT_STATIC_BYTE_CAST( FT_UInt32, d ) ) + +#endif /* FT_ENC_TAG */ + + + /************************************************************************** + * + * @enum: + * FT_Encoding + * + * @description: + * 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 + * repertoires (i.e., charsets), and not text encoding methods (e.g., + * UTF-8, UTF-16, etc.). + * + * Other encodings might be defined in the future. + * + * @values: + * FT_ENCODING_NONE :: + * The encoding value~0 is reserved for all formats except BDF, PCF, + * and Windows FNT; see below for more information. + * + * FT_ENCODING_UNICODE :: + * 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 :: + * Microsoft Symbol encoding, used to encode mathematical symbols and + * wingdings. For more information, see + * 'https://www.microsoft.com/typography/otspec/recom.htm#non-standard-symbol-fonts', + * 'http://www.kostis.net/charsets/symbol.htm', and + * 'http://www.kostis.net/charsets/wingding.htm'. + * + * This encoding uses character codes from the PUA (Private Unicode + * Area) in the range U+F020-U+F0FF. + * + * FT_ENCODING_SJIS :: + * Shift JIS encoding for Japanese. More info at + * 'https://en.wikipedia.org/wiki/Shift_JIS'. See note on multi-byte + * encodings below. + * + * 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 Extended Wansung + * (MS Windows code page 949). For more information see + * '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 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 :: + * Adobe Standard encoding, as found in Type~1, CFF, and OpenType/CFF + * fonts. It is limited to 256 character codes. + * + * FT_ENCODING_ADOBE_EXPERT :: + * 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 :: + * 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 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_PRC. Deprecated. + * + * FT_ENCODING_MS_BIG5 :: + * Same as FT_ENCODING_BIG5. Deprecated. + * + * FT_ENCODING_MS_WANSUNG :: + * Same as FT_ENCODING_WANSUNG. Deprecated. + * + * FT_ENCODING_MS_JOHAB :: + * Same as FT_ENCODING_JOHAB. Deprecated. + * + * @note: + * When loading a font, FreeType makes a Unicode charmap active if + * possible (either if the font provides such a charmap, or if FreeType + * can synthesize one from PostScript glyph name dictionaries; in either + * case, the charmap is tagged with `FT_ENCODING_UNICODE`). If such a + * charmap is synthesized, it is placed at the first position of the + * charmap array. + * + * 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 + * `FT_ENCODING_UNICODE`). Use @FT_Get_BDF_Charset_ID to find out which + * encoding is really present. If, for example, the `cs_registry` field + * is 'KOI8' and the `cs_encoding` field is 'R', the font is encoded in + * KOI8-R. + * + * `FT_ENCODING_NONE` is always set (with a single exception) by the + * winfonts driver. Use @FT_Get_WinFNT_Header and examine the `charset` + * field of the @FT_WinFNT_HeaderRec structure to find out which encoding + * is really present. For example, @FT_WinFNT_ID_CP1251 (204) means + * Windows code page 1251 (for Russian). + * + * `FT_ENCODING_NONE` is set if `platform_id` is @TT_PLATFORM_MACINTOSH + * and `encoding_id` is not `TT_MAC_ID_ROMAN` (otherwise it is set to + * `FT_ENCODING_APPLE_ROMAN`). + * + * If `platform_id` is @TT_PLATFORM_MACINTOSH, use the function + * @FT_Get_CMap_Language_ID to query the Mac language ID that may be + * needed to be able to distinguish Apple encoding variants. See + * + * 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_LANGID_GREEK`, it is the + * Greek encoding, not Roman. `TT_MAC_ID_ARABIC` with + * `TT_MAC_LANGID_FARSI` means the Farsi variant of the Arabic encoding. + */ + typedef enum FT_Encoding_ + { + FT_ENC_TAG( FT_ENCODING_NONE, 0, 0, 0, 0 ), + + FT_ENC_TAG( FT_ENCODING_MS_SYMBOL, 's', 'y', 'm', 'b' ), + 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_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 backward compatibility */ + FT_ENCODING_GB2312 = FT_ENCODING_PRC, + FT_ENCODING_MS_SJIS = FT_ENCODING_SJIS, + 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, + + FT_ENC_TAG( FT_ENCODING_ADOBE_STANDARD, 'A', 'D', 'O', 'B' ), + FT_ENC_TAG( FT_ENCODING_ADOBE_EXPERT, 'A', 'D', 'B', 'E' ), + FT_ENC_TAG( FT_ENCODING_ADOBE_CUSTOM, 'A', 'D', 'B', 'C' ), + FT_ENC_TAG( FT_ENCODING_ADOBE_LATIN_1, 'l', 'a', 't', '1' ), + + FT_ENC_TAG( FT_ENCODING_OLD_LATIN_2, 'l', 'a', 't', '2' ), + + FT_ENC_TAG( FT_ENCODING_APPLE_ROMAN, 'a', 'r', 'm', 'n' ) + + } FT_Encoding; + + + /* these constants are deprecated; use the corresponding `FT_Encoding` */ + /* values instead */ +#define ft_encoding_none FT_ENCODING_NONE +#define ft_encoding_unicode FT_ENCODING_UNICODE +#define ft_encoding_symbol FT_ENCODING_MS_SYMBOL +#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_PRC +#define ft_encoding_big5 FT_ENCODING_BIG5 +#define ft_encoding_wansung FT_ENCODING_WANSUNG +#define ft_encoding_johab FT_ENCODING_JOHAB + +#define ft_encoding_adobe_standard FT_ENCODING_ADOBE_STANDARD +#define ft_encoding_adobe_expert FT_ENCODING_ADOBE_EXPERT +#define ft_encoding_adobe_custom FT_ENCODING_ADOBE_CUSTOM +#define ft_encoding_apple_roman FT_ENCODING_APPLE_ROMAN + + + /************************************************************************** + * + * @struct: + * FT_CharMapRec + * + * @description: + * The base charmap structure. + * + * @fields: + * face :: + * A handle to the parent face object. + * + * encoding :: + * An @FT_Encoding tag identifying the charmap. Use this with + * @FT_Select_Charmap. + * + * platform_id :: + * An ID number describing the platform for the following encoding ID. + * This comes directly from the TrueType specification and gets + * emulated for other formats. + * + * encoding_id :: + * A platform-specific encoding number. This also comes from the + * TrueType specification and gets emulated similarly. + */ + typedef struct FT_CharMapRec_ + { + FT_Face face; + FT_Encoding encoding; + FT_UShort platform_id; + FT_UShort encoding_id; + + } FT_CharMapRec; + + + /*************************************************************************/ + /*************************************************************************/ + /* */ + /* B A S E O B J E C T C L A S S E S */ + /* */ + /*************************************************************************/ + /*************************************************************************/ + + + /************************************************************************** + * + * @type: + * FT_Face_Internal + * + * @description: + * 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. + */ + typedef struct FT_Face_InternalRec_* FT_Face_Internal; + + + /************************************************************************** + * + * @struct: + * FT_FaceRec + * + * @description: + * FreeType root face class structure. A face object models a typeface + * in a font file. + * + * @fields: + * num_faces :: + * The number of faces in the font file. Some font formats can have + * multiple faces in a single font file. + * + * face_index :: + * This field holds two different values. Bits 0-15 are the index of + * the face in the font file (starting with value~0). They are set + * to~0 if there is only one face in the font file. + * + * [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. + * + * [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 (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 the typeface's family (like 'Times New + * Roman', 'Bodoni', 'Garamond', etc). This is a least common + * denominator used to list fonts. Some formats (TrueType & OpenType) + * provide localized and Unicode versions of this string. Applications + * should use the format-specific interface to access them. Can be + * `NULL` (e.g., in fonts embedded in a PDF file). + * + * In case the font doesn't provide a specific family name entry, + * FreeType tries to synthesize one, deriving it from other name + * entries. + * + * style_name :: + * The face's style name. This is an ASCII string, usually in English, + * that describes the typeface's style (like 'Italic', 'Bold', + * 'Condensed', etc). Not all font formats provide a style name, so + * this field is optional, and can be set to `NULL`. As for + * `family_name`, some formats provide localized and Unicode versions + * of this string. Applications should use the format-specific + * interface to access them. + * + * num_fixed_sizes :: + * The number of bitmap strikes in the face. Even if the face is + * scalable, there might still be bitmap strikes, which are called + * 'sbits' in that case. + * + * available_sizes :: + * An array of @FT_Bitmap_Size for all bitmap 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. + * + * generic :: + * A field reserved for client uses. See the @FT_Generic type + * description. + * + * bbox :: + * The font bounding box. Coordinates are expressed in font units (see + * `units_per_EM`). The box is large enough to contain any glyph from + * the font. Thus, `bbox.yMax` can be seen as the 'maximum ascender', + * and `bbox.yMin` as the 'minimum descender'. Only relevant for + * scalable formats. + * + * Note that the bounding box might be off by (at least) one pixel for + * hinted fonts. See @FT_Size_Metrics for further discussion. + * + * Note that the bounding box does not vary in OpenType variable fonts + * and should only be used in relation to the default instance. + * + * units_per_EM :: + * The number of font units per EM square for this face. This is + * typically 2048 for TrueType fonts, and 1000 for Type~1 fonts. Only + * relevant for scalable formats. + * + * ascender :: + * The typographic ascender of the face, expressed in font units. For + * font formats not having this information, it is set to `bbox.yMax`. + * Only relevant for scalable formats. + * + * descender :: + * The typographic descender of the face, expressed in font units. For + * font formats not having this information, it is set to `bbox.yMin`. + * Note that this field is negative for values below the baseline. + * Only relevant for scalable formats. + * + * height :: + * This value is the vertical distance between two consecutive + * baselines, expressed in font units. It is always positive. Only + * relevant for scalable formats. + * + * If you want the global glyph height, use `ascender - descender`. + * + * max_advance_width :: + * The maximum advance width, in font units, for all glyphs in this + * face. This can be used to make word wrapping computations faster. + * Only relevant for scalable formats. + * + * max_advance_height :: + * The maximum advance height, in font units, for all glyphs in this + * face. This is only relevant for vertical layouts, and is set to + * `height` for fonts that do not provide vertical metrics. Only + * relevant for scalable formats. + * + * underline_position :: + * The position, in font units, of the underline line for this face. + * It is the center of the underlining stem. Only relevant for + * scalable formats. + * + * underline_thickness :: + * The thickness, in font units, of the underline for this face. Only + * relevant for scalable formats. + * + * glyph :: + * The face's associated glyph slot(s). + * + * size :: + * The current active size for this face. + * + * charmap :: + * The current active charmap for this face. + * + * @note: + * 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; + FT_Long face_index; + + FT_Long face_flags; + FT_Long style_flags; + + FT_Long num_glyphs; + + FT_String* family_name; + FT_String* style_name; + + FT_Int num_fixed_sizes; + FT_Bitmap_Size* available_sizes; + + FT_Int num_charmaps; + FT_CharMap* charmaps; + + FT_Generic generic; + + /*# The following member variables (down to `underline_thickness`) */ + /*# are only relevant to scalable outlines; cf. @FT_Bitmap_Size */ + /*# for bitmap fonts. */ + FT_BBox bbox; + + FT_UShort units_per_EM; + FT_Short ascender; + FT_Short descender; + FT_Short height; + + FT_Short max_advance_width; + FT_Short max_advance_height; + + FT_Short underline_position; + FT_Short underline_thickness; + + FT_GlyphSlot glyph; + FT_Size size; + FT_CharMap charmap; + + /*@private begin */ + + FT_Driver driver; + FT_Memory memory; + FT_Stream stream; + + FT_ListRec sizes_list; + + FT_Generic autohint; /* face-specific auto-hinter data */ + void* extensions; /* unused */ + + FT_Face_Internal internal; + + /*@private end */ + + } FT_FaceRec; + + + /************************************************************************** + * + * @enum: + * FT_FACE_FLAG_XXX + * + * @description: + * A list of bit flags used in the `face_flags` field of the @FT_FaceRec + * structure. They inform client applications of properties of the + * corresponding face. + * + * @values: + * FT_FACE_FLAG_SCALABLE :: + * 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 :: + * The face contains bitmap strikes. See also the `num_fixed_sizes` + * and `available_sizes` fields of @FT_FaceRec. + * + * FT_FACE_FLAG_FIXED_WIDTH :: + * The face contains fixed-width characters (like Courier, Lucida, + * MonoType, etc.). + * + * FT_FACE_FLAG_SFNT :: + * The face uses the SFNT storage scheme. For now, this means TrueType + * and OpenType. + * + * FT_FACE_FLAG_HORIZONTAL :: + * The face contains horizontal glyph metrics. This should be set for + * all common formats. + * + * FT_FACE_FLAG_VERTICAL :: + * The face contains vertical glyph metrics. This is only available in + * some formats, not all of them. + * + * FT_FACE_FLAG_KERNING :: + * The face contains kerning information. If set, the kerning distance + * can be retrieved using the function @FT_Get_Kerning. Otherwise the + * function always returns 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 :: + * 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 :: + * 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 :: + * Used internally by FreeType to indicate that a face's stream was + * provided by the client application and should not be destroyed when + * @FT_Done_Face is called. Don't read or test this flag. + * + * FT_FACE_FLAG_HINTER :: + * 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 :: + * 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 :: + * 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 @FT_LOAD_NO_HINTING. + * You have to set both @FT_LOAD_NO_HINTING and @FT_LOAD_NO_AUTOHINT to + * really disable hinting; however, you probably never want this except + * for demonstration purposes. + * + * Currently, there are about a dozen TrueType fonts in the list of + * tricky fonts; they are hard-coded in file `ttobjs.c`. + * + * FT_FACE_FLAG_COLOR :: + * [Since 2.5.1] The face has color glyph tables. See @FT_LOAD_COLOR + * for more information. + * + * 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. + * + * FT_FACE_FLAG_SVG :: + * [Since 2.12] The face has an 'SVG~' OpenType table. + * + * FT_FACE_FLAG_SBIX :: + * [Since 2.12] The face has an 'sbix' OpenType table *and* outlines. + * For such fonts, @FT_FACE_FLAG_SCALABLE is not set by default to + * retain backward compatibility. + * + * FT_FACE_FLAG_SBIX_OVERLAY :: + * [Since 2.12] The face has an 'sbix' OpenType table where outlines + * should be drawn on top of bitmap strikes. + * + */ +#define FT_FACE_FLAG_SCALABLE ( 1L << 0 ) +#define FT_FACE_FLAG_FIXED_SIZES ( 1L << 1 ) +#define FT_FACE_FLAG_FIXED_WIDTH ( 1L << 2 ) +#define FT_FACE_FLAG_SFNT ( 1L << 3 ) +#define FT_FACE_FLAG_HORIZONTAL ( 1L << 4 ) +#define FT_FACE_FLAG_VERTICAL ( 1L << 5 ) +#define FT_FACE_FLAG_KERNING ( 1L << 6 ) +#define FT_FACE_FLAG_FAST_GLYPHS ( 1L << 7 ) +#define FT_FACE_FLAG_MULTIPLE_MASTERS ( 1L << 8 ) +#define FT_FACE_FLAG_GLYPH_NAMES ( 1L << 9 ) +#define FT_FACE_FLAG_EXTERNAL_STREAM ( 1L << 10 ) +#define FT_FACE_FLAG_HINTER ( 1L << 11 ) +#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 ) +#define FT_FACE_FLAG_SVG ( 1L << 16 ) +#define FT_FACE_FLAG_SBIX ( 1L << 17 ) +#define FT_FACE_FLAG_SBIX_OVERLAY ( 1L << 18 ) + + + /************************************************************************** + * + * @macro: + * FT_HAS_HORIZONTAL + * + * @description: + * A macro that returns true whenever a face object contains horizontal + * metrics (this is true for all font formats though). + * + * @also: + * @FT_HAS_VERTICAL can be used to check for vertical metrics. + * + */ +#define FT_HAS_HORIZONTAL( face ) \ + ( !!( (face)->face_flags & FT_FACE_FLAG_HORIZONTAL ) ) + + + /************************************************************************** + * + * @macro: + * FT_HAS_VERTICAL + * + * @description: + * A macro that returns true whenever a face object contains real + * vertical metrics (and not only synthesized ones). + * + */ +#define FT_HAS_VERTICAL( face ) \ + ( !!( (face)->face_flags & FT_FACE_FLAG_VERTICAL ) ) + + + /************************************************************************** + * + * @macro: + * FT_HAS_KERNING + * + * @description: + * A macro that returns true whenever a face object contains kerning data + * that can be accessed with @FT_Get_Kerning. + * + */ +#define FT_HAS_KERNING( face ) \ + ( !!( (face)->face_flags & FT_FACE_FLAG_KERNING ) ) + + + /************************************************************************** + * + * @macro: + * FT_IS_SCALABLE + * + * @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). + * + */ +#define FT_IS_SCALABLE( face ) \ + ( !!( (face)->face_flags & FT_FACE_FLAG_SCALABLE ) ) + + + /************************************************************************** + * + * @macro: + * FT_IS_SFNT + * + * @description: + * A macro that returns true whenever a face object contains a font whose + * format is based on the SFNT storage scheme. This usually means: + * TrueType fonts, OpenType fonts, as well as SFNT-based embedded bitmap + * fonts. + * + * If this macro is true, all functions defined in @FT_SFNT_NAMES_H and + * @FT_TRUETYPE_TABLES_H are available. + * + */ +#define FT_IS_SFNT( face ) \ + ( !!( (face)->face_flags & FT_FACE_FLAG_SFNT ) ) + + + /************************************************************************** + * + * @macro: + * FT_IS_FIXED_WIDTH + * + * @description: + * A macro that returns true whenever a face object contains a font face + * that contains fixed-width (or 'monospace', 'fixed-pitch', etc.) + * glyphs. + * + */ +#define FT_IS_FIXED_WIDTH( face ) \ + ( !!( (face)->face_flags & FT_FACE_FLAG_FIXED_WIDTH ) ) + + + /************************************************************************** + * + * @macro: + * FT_HAS_FIXED_SIZES + * + * @description: + * A macro that returns true whenever a face object contains some + * embedded bitmaps. See the `available_sizes` field of the @FT_FaceRec + * structure. + * + */ +#define FT_HAS_FIXED_SIZES( face ) \ + ( !!( (face)->face_flags & FT_FACE_FLAG_FIXED_SIZES ) ) + + + /************************************************************************** + * + * @macro: + * FT_HAS_FAST_GLYPHS + * + * @description: + * Deprecated. + * + */ +#define FT_HAS_FAST_GLYPHS( face ) 0 + + + /************************************************************************** + * + * @macro: + * FT_HAS_GLYPH_NAMES + * + * @description: + * A macro that returns true whenever a face object contains some glyph + * names that can be accessed through @FT_Get_Glyph_Name. + * + */ +#define FT_HAS_GLYPH_NAMES( face ) \ + ( !!( (face)->face_flags & FT_FACE_FLAG_GLYPH_NAMES ) ) + + + /************************************************************************** + * + * @macro: + * FT_HAS_MULTIPLE_MASTERS + * + * @description: + * A macro that returns true whenever a face object contains some + * multiple masters. The functions provided by @FT_MULTIPLE_MASTERS_H + * are then available to choose the exact design you want. + * + */ +#define FT_HAS_MULTIPLE_MASTERS( face ) \ + ( !!( (face)->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS ) ) + + + /************************************************************************** + * + * @macro: + * FT_IS_NAMED_INSTANCE + * + * @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 + * + * @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 ) ) + + + /************************************************************************** + * + * @macro: + * FT_IS_CID_KEYED + * + * @description: + * A macro that returns true whenever a face object contains a CID-keyed + * font. See the discussion of @FT_FACE_FLAG_CID_KEYED for more details. + * + * If this macro is true, all functions defined in @FT_CID_H are + * available. + * + */ +#define FT_IS_CID_KEYED( face ) \ + ( !!( (face)->face_flags & FT_FACE_FLAG_CID_KEYED ) ) + + + /************************************************************************** + * + * @macro: + * FT_IS_TRICKY + * + * @description: + * A macro that returns true whenever a face represents a 'tricky' font. + * See the discussion of @FT_FACE_FLAG_TRICKY for more details. + * + */ +#define FT_IS_TRICKY( face ) \ + ( !!( (face)->face_flags & FT_FACE_FLAG_TRICKY ) ) + + + /************************************************************************** + * + * @macro: + * FT_HAS_COLOR + * + * @description: + * 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 ) ) + + + /************************************************************************** + * + * @macro: + * FT_HAS_SVG + * + * @description: + * A macro that returns true whenever a face object contains an 'SVG~' + * OpenType table. + * + * @since: + * 2.12 + */ +#define FT_HAS_SVG( face ) \ + ( !!( (face)->face_flags & FT_FACE_FLAG_SVG ) ) + + + /************************************************************************** + * + * @macro: + * FT_HAS_SBIX + * + * @description: + * A macro that returns true whenever a face object contains an 'sbix' + * OpenType table *and* outline glyphs. + * + * Currently, FreeType only supports bitmap glyphs in PNG format for this + * table (i.e., JPEG and TIFF formats are unsupported, as are + * Apple-specific formats not part of the OpenType specification). + * + * @note: + * For backward compatibility, a font with an 'sbix' table is treated as + * a bitmap-only face. Using @FT_Open_Face with + * @FT_PARAM_TAG_IGNORE_SBIX, an application can switch off 'sbix' + * handling so that the face is treated as an ordinary outline font with + * scalable outlines. + * + * Here is some pseudo code that roughly illustrates how to implement + * 'sbix' handling according to the OpenType specification. + * + * ``` + * if ( FT_HAS_SBIX( face ) ) + * { + * // open font as a scalable one without sbix handling + * FT_Face face2; + * FT_Parameter param = { FT_PARAM_TAG_IGNORE_SBIX, NULL }; + * FT_Open_Args args = { FT_OPEN_PARAMS | ..., + * ..., + * 1, ¶m }; + * + * + * FT_Open_Face( library, &args, 0, &face2 ); + * + * <sort `face->available_size` as necessary into + * `preferred_sizes`[*]> + * + * for ( i = 0; i < face->num_fixed_sizes; i++ ) + * { + * size = preferred_sizes[i].size; + * + * error = FT_Set_Pixel_Sizes( face, size, size ); + * <error handling omitted> + * + * // check whether we have a glyph in a bitmap strike + * error = FT_Load_Glyph( face, + * glyph_index, + * FT_LOAD_SBITS_ONLY | + * FT_LOAD_BITMAP_METRICS_ONLY ); + * if ( error == FT_Err_Invalid_Argument ) + * continue; + * else if ( error ) + * <other error handling omitted> + * else + * break; + * } + * + * if ( i != face->num_fixed_sizes ) + * <load embedded bitmap with `FT_Load_Glyph`, + * scale it, display it, etc.> + * + * if ( i == face->num_fixed_sizes || + * FT_HAS_SBIX_OVERLAY( face ) ) + * <use `face2` to load outline glyph with `FT_Load_Glyph`, + * scale it, display it on top of the bitmap, etc.> + * } + * ``` + * + * [*] Assuming a target value of 400dpi and available strike sizes 100, + * 200, 300, and 400dpi, a possible order might be [400, 200, 300, 100]: + * scaling 200dpi to 400dpi usually gives better results than scaling + * 300dpi to 400dpi; it is also much faster. However, scaling 100dpi to + * 400dpi can yield a too pixelated result, thus the preference might be + * 300dpi over 100dpi. + * + * @since: + * 2.12 + */ +#define FT_HAS_SBIX( face ) \ + ( !!( (face)->face_flags & FT_FACE_FLAG_SBIX ) ) + + + /************************************************************************** + * + * @macro: + * FT_HAS_SBIX_OVERLAY + * + * @description: + * A macro that returns true whenever a face object contains an 'sbix' + * OpenType table with bit~1 in its `flags` field set, instructing the + * application to overlay the bitmap strike with the corresponding + * outline glyph. See @FT_HAS_SBIX for pseudo code how to use it. + * + * @since: + * 2.12 + */ +#define FT_HAS_SBIX_OVERLAY( face ) \ + ( !!( (face)->face_flags & FT_FACE_FLAG_SBIX_OVERLAY ) ) + + + /************************************************************************** + * + * @enum: + * FT_STYLE_FLAG_XXX + * + * @description: + * 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 :: + * The face style is italic or oblique. + * + * FT_STYLE_FLAG_BOLD :: + * The face is bold. + * + * @note: + * The style information as provided by FreeType is very basic. More + * details are beyond the scope and should be done on a higher level (for + * example, by analyzing various fields of the 'OS/2' table in SFNT based + * fonts). + */ +#define FT_STYLE_FLAG_ITALIC ( 1 << 0 ) +#define FT_STYLE_FLAG_BOLD ( 1 << 1 ) + + + /************************************************************************** + * + * @type: + * FT_Size_Internal + * + * @description: + * An opaque handle to an `FT_Size_InternalRec` structure, used to model + * private data of a given @FT_Size object. + */ + typedef struct FT_Size_InternalRec_* FT_Size_Internal; + + + /************************************************************************** + * + * @struct: + * FT_Size_Metrics + * + * @description: + * The size metrics structure gives the metrics of a size object. + * + * @fields: + * x_ppem :: + * The width of the scaled EM square in pixels, hence the term 'ppem' + * (pixels per EM). It is also referred to as 'nominal width'. + * + * y_ppem :: + * The height of the scaled EM square in pixels, hence the term 'ppem' + * (pixels per EM). It is also referred to as 'nominal height'. + * + * 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 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, rounded up to an integer + * value. 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, rounded to an integer value. + * See @FT_FaceRec for the details. + * + * max_advance :: + * The maximum advance width in 26.6 fractional 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. 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. + * + * ``` + * 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. + * + * + * **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_ + { + FT_UShort x_ppem; /* horizontal pixels per EM */ + FT_UShort y_ppem; /* vertical pixels per EM */ + + FT_Fixed x_scale; /* scaling values used to convert font */ + FT_Fixed y_scale; /* units to 26.6 fractional pixels */ + + FT_Pos ascender; /* ascender in 26.6 frac. pixels */ + FT_Pos descender; /* descender in 26.6 frac. pixels */ + FT_Pos height; /* text height in 26.6 frac. pixels */ + FT_Pos max_advance; /* max horizontal advance, in 26.6 pixels */ + + } FT_Size_Metrics; + + + /************************************************************************** + * + * @struct: + * FT_SizeRec + * + * @description: + * FreeType root size class structure. A size object models a face + * object at a given size. + * + * @fields: + * face :: + * Handle to the parent face object. + * + * generic :: + * A typeless pointer, unused by the FreeType library or any of its + * drivers. It can be used by client applications to link their own + * data to each size object. + * + * metrics :: + * Metrics for this size object. This field is read-only. + */ + typedef struct FT_SizeRec_ + { + FT_Face face; /* parent face object */ + FT_Generic generic; /* generic pointer for client uses */ + FT_Size_Metrics metrics; /* size metrics */ + FT_Size_Internal internal; + + } FT_SizeRec; + + + /************************************************************************** + * + * @struct: + * FT_SubGlyph + * + * @description: + * The subglyph structure is an internal object used to describe + * subglyphs (for example, in the case of composites). + * + * @note: + * The subglyph implementation is not part of the high-level API, hence + * the forward structure declaration. + * + * You can however retrieve subglyph information with + * @FT_Get_SubGlyph_Info. + */ + typedef struct FT_SubGlyphRec_* FT_SubGlyph; + + + /************************************************************************** + * + * @type: + * FT_Slot_Internal + * + * @description: + * An opaque handle to an `FT_Slot_InternalRec` structure, used to model + * private data of a given @FT_GlyphSlot object. + */ + typedef struct FT_Slot_InternalRec_* FT_Slot_Internal; + + + /************************************************************************** + * + * @struct: + * FT_GlyphSlotRec + * + * @description: + * FreeType root glyph slot class structure. A glyph slot is a container + * where individual glyphs can be loaded, be they in outline or bitmap + * format. + * + * @fields: + * library :: + * A handle to the FreeType library instance this slot belongs to. + * + * face :: + * A handle to the parent face object. + * + * next :: + * In some cases (like some font tools), several glyph slots per face + * object can be a good thing. As this is rare, the glyph slots are + * listed through a direct, single-linked list using its `next` field. + * + * glyph_index :: + * [Since 2.10] The glyph index passed as an argument to @FT_Load_Glyph + * while initializing the glyph slot. + * + * generic :: + * A typeless pointer unused by the FreeType library or any of its + * drivers. It can be used by client applications to link their own + * data to each glyph slot object. + * + * metrics :: + * The metrics of the last loaded glyph in the slot. The returned + * values depend on the last load flags (see the @FT_Load_Glyph API + * function) and can be expressed either in 26.6 fractional pixels or + * font units. + * + * Note that even when the glyph image is transformed, the metrics are + * not. + * + * linearHoriAdvance :: + * The advance width of the unhinted glyph. Its value is expressed in + * 16.16 fractional pixels, unless @FT_LOAD_LINEAR_DESIGN is set when + * loading the glyph. This field can be important to perform correct + * WYSIWYG layout. Only relevant for scalable glyphs. + * + * linearVertAdvance :: + * The advance height of the unhinted glyph. Its value is expressed in + * 16.16 fractional pixels, unless @FT_LOAD_LINEAR_DESIGN is set when + * loading the glyph. This field can be important to perform correct + * WYSIWYG layout. Only relevant for scalable glyphs. + * + * advance :: + * This shorthand is, depending on @FT_LOAD_IGNORE_TRANSFORM, the + * transformed (hinted) advance width for the glyph, in 26.6 fractional + * pixel format. As specified with @FT_LOAD_VERTICAL_LAYOUT, it uses + * either the `horiAdvance` or the `vertAdvance` value of `metrics` + * field. + * + * format :: + * This field indicates the format of the image contained in the glyph + * slot. Typically @FT_GLYPH_FORMAT_BITMAP, @FT_GLYPH_FORMAT_OUTLINE, + * or @FT_GLYPH_FORMAT_COMPOSITE, but other values are possible. + * + * 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. + * + * bitmap_top :: + * The bitmap's top bearing expressed in integer 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, emboldened, etc. However, it must not be + * freed. + * + * [Since 2.10.1] If @FT_LOAD_NO_SCALE is set, outline coordinates of + * OpenType variation fonts for a selected instance are internally + * handled as 26.6 fractional font units but returned as (rounded) + * integers, as expected. To get unrounded font units, don't use + * @FT_LOAD_NO_SCALE but load the glyph with @FT_LOAD_NO_HINTING and + * scale it, using the font's `units_per_EM` value as the ppem. + * + * num_subglyphs :: + * The number of subglyphs in a composite glyph. This field is only + * valid for the composite glyph format that should normally only be + * loaded with the @FT_LOAD_NO_RECURSE flag. + * + * subglyphs :: + * An array of subglyph descriptors for composite glyphs. There are + * `num_subglyphs` elements in there. Currently internal to FreeType. + * + * control_data :: + * Certain font drivers can also return the control data for a given + * glyph image (e.g. TrueType bytecode, Type~1 charstrings, etc.). + * This field is a pointer to such data; it is currently internal to + * FreeType. + * + * control_len :: + * This is the length in bytes of the control data. Currently internal + * to FreeType. + * + * other :: + * Reserved. + * + * lsb_delta :: + * The difference between hinted and unhinted left side bearing while + * auto-hinting is active. Zero otherwise. + * + * rsb_delta :: + * The difference between hinted and unhinted right side bearing while + * auto-hinting is active. Zero otherwise. + * + * @note: + * 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). [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 searches the current renderer for the + * native image's format, then invokes it. + * + * The renderer is in charge of transforming the native image through the + * slot's face transformation fields, then converting it into a bitmap + * that is returned in `slot->bitmap`. + * + * Note that `slot->bitmap_left` and `slot->bitmap_top` are also used to + * specify the position of the bitmap relative to the current pen + * position (e.g., coordinates (0,0) on the baseline). Of course, + * `slot->format` is also changed to @FT_GLYPH_FORMAT_BITMAP. + * + * Here is a small pseudo code fragment that shows how to use `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->lsb_delta - slot->rsb_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_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'> + * + * <load glyph with `FT_Load_Glyph'> + * + * if ( prev_rsb_delta - slot->lsb_delta > 32 ) + * origin_x -= 64; + * else if ( prev_rsb_delta - slot->lsb_delta < -31 ) + * origin_x += 64; + * + * prev_rsb_delta = slot->rsb_delta; + * + * <save glyph image, or render glyph, or ...> + * + * 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; + FT_Face face; + FT_GlyphSlot next; + FT_UInt glyph_index; /* new in 2.10; was reserved previously */ + FT_Generic generic; + + FT_Glyph_Metrics metrics; + FT_Fixed linearHoriAdvance; + FT_Fixed linearVertAdvance; + FT_Vector advance; + + FT_Glyph_Format format; + + FT_Bitmap bitmap; + FT_Int bitmap_left; + FT_Int bitmap_top; + + FT_Outline outline; + + FT_UInt num_subglyphs; + FT_SubGlyph subglyphs; + + void* control_data; + long control_len; + + FT_Pos lsb_delta; + FT_Pos rsb_delta; + + void* other; + + FT_Slot_Internal internal; + + } FT_GlyphSlotRec; + + + /*************************************************************************/ + /*************************************************************************/ + /* */ + /* F U N C T I O N S */ + /* */ + /*************************************************************************/ + /*************************************************************************/ + + + /************************************************************************** + * + * @function: + * FT_Init_FreeType + * + * @description: + * Initialize a new FreeType library object. The set of modules that are + * registered by this function is determined at build time. + * + * @output: + * alibrary :: + * A handle to a new library object. + * + * @return: + * FreeType error code. 0~means success. + * + * @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) and + * @FT_Set_Default_Properties. + * + * See the documentation of @FT_Library and @FT_Face for multi-threading + * issues. + * + * 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 ); + + + /************************************************************************** + * + * @function: + * FT_Done_FreeType + * + * @description: + * Destroy a given FreeType library object and all of its children, + * including resources, drivers, faces, sizes, etc. + * + * @input: + * library :: + * A handle to the target library object. + * + * @return: + * FreeType error code. 0~means success. + */ + FT_EXPORT( FT_Error ) + FT_Done_FreeType( FT_Library library ); + + + /************************************************************************** + * + * @enum: + * FT_OPEN_XXX + * + * @description: + * A list of bit field constants used within the `flags` field of the + * @FT_Open_Args structure. + * + * @values: + * FT_OPEN_MEMORY :: + * This is a memory-based stream. + * + * FT_OPEN_STREAM :: + * Copy the stream from the `stream` field. + * + * FT_OPEN_PATHNAME :: + * Create a new input stream from a C~path name. + * + * FT_OPEN_DRIVER :: + * Use the `driver` field. + * + * FT_OPEN_PARAMS :: + * Use the `num_params` and `params` fields. + * + * @note: + * The `FT_OPEN_MEMORY`, `FT_OPEN_STREAM`, and `FT_OPEN_PATHNAME` flags + * are mutually exclusive. + */ +#define FT_OPEN_MEMORY 0x1 +#define FT_OPEN_STREAM 0x2 +#define FT_OPEN_PATHNAME 0x4 +#define FT_OPEN_DRIVER 0x8 +#define FT_OPEN_PARAMS 0x10 + + + /* these constants are deprecated; use the corresponding `FT_OPEN_XXX` */ + /* values instead */ +#define ft_open_memory FT_OPEN_MEMORY +#define ft_open_stream FT_OPEN_STREAM +#define ft_open_pathname FT_OPEN_PATHNAME +#define ft_open_driver FT_OPEN_DRIVER +#define ft_open_params FT_OPEN_PARAMS + + + /************************************************************************** + * + * @struct: + * FT_Parameter + * + * @description: + * 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. + * + * data :: + * A pointer to the parameter data. + * + * @note: + * The ID and function of parameters are driver-specific. See section + * @parameter_tags for more information. + */ + typedef struct FT_Parameter_ + { + FT_ULong tag; + FT_Pointer data; + + } FT_Parameter; + + + /************************************************************************** + * + * @struct: + * FT_Open_Args + * + * @description: + * 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 structure. + * + * memory_base :: + * The first byte of the file in memory. + * + * memory_size :: + * The size in bytes of the file in memory. + * + * pathname :: + * A pointer to an 8-bit file pathname, which must be a C~string (i.e., + * no null bytes except at the very end). The pointer is not owned by + * FreeType. + * + * 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 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. + * + * params :: + * Extra parameters passed to the font driver when opening a new face. + * + * @note: + * The stream type is determined by the contents of `flags`: + * + * 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 not + * copied, and the client is responsible for releasing and destroying + * them _after_ the corresponding call to @FT_Done_Face. + * + * Otherwise, if the @FT_OPEN_STREAM bit is set, assume that a custom + * input stream `stream` is used. + * + * Otherwise, if the @FT_OPEN_PATHNAME bit is set, assume that this is a + * normal file and use `pathname` to open it. + * + * If none of the above bits are set or if multiple are set at the same + * time, the flags are invalid and @FT_Open_Face fails. + * + * If the @FT_OPEN_DRIVER bit is set, @FT_Open_Face only tries to open + * the file with the driver whose handler is in `driver`. + * + * If the @FT_OPEN_PARAMS bit is set, the parameters given by + * `num_params` and `params` is used. They are ignored otherwise. + * + * Ideally, both the `pathname` and `params` fields should be tagged as + * 'const'; this is missing for API backward compatibility. In other + * words, applications should treat them as read-only. + */ + typedef struct FT_Open_Args_ + { + FT_UInt flags; + const FT_Byte* memory_base; + FT_Long memory_size; + FT_String* pathname; + FT_Stream stream; + FT_Module driver; + FT_Int num_params; + FT_Parameter* params; + + } FT_Open_Args; + + + /************************************************************************** + * + * @function: + * FT_New_Face + * + * @description: + * Call @FT_Open_Face to open a font by its pathname. + * + * @inout: + * library :: + * A handle to the library resource. + * + * @input: + * pathname :: + * A path to the font file. + * + * face_index :: + * See @FT_Open_Face for a detailed description of this parameter. + * + * @output: + * aface :: + * A handle to a new face object. If `face_index` is greater than or + * equal to zero, it must be non-`NULL`. + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * The `pathname` string should be recognizable as such by a standard + * `fopen` call on your system; in particular, this means that `pathname` + * must not contain null bytes. If that is not sufficient to address all + * file name possibilities (for example, to handle wide character file + * names on Windows in UTF-16 encoding) you might use @FT_Open_Face to + * pass a memory array or a stream object instead. + * + * Use @FT_Done_Face to destroy the created @FT_Face object (along with + * its slot and sizes). + */ + FT_EXPORT( FT_Error ) + FT_New_Face( FT_Library library, + const char* filepathname, + FT_Long face_index, + FT_Face *aface ); + + + /************************************************************************** + * + * @function: + * FT_New_Memory_Face + * + * @description: + * Call @FT_Open_Face to open a font that has been loaded into memory. + * + * @inout: + * library :: + * A handle to the library resource. + * + * @input: + * file_base :: + * A pointer to the beginning of the font data. + * + * file_size :: + * The size of the memory chunk used by the font data. + * + * face_index :: + * See @FT_Open_Face for a detailed description of this parameter. + * + * @output: + * aface :: + * A handle to a new face object. If `face_index` is greater than or + * equal to zero, it must be non-`NULL`. + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * You must not deallocate the memory before calling @FT_Done_Face. + */ + FT_EXPORT( FT_Error ) + FT_New_Memory_Face( FT_Library library, + const FT_Byte* file_base, + FT_Long file_size, + FT_Long face_index, + FT_Face *aface ); + + + /************************************************************************** + * + * @function: + * FT_Open_Face + * + * @description: + * Create a face object from a given resource described by @FT_Open_Args. + * + * @inout: + * library :: + * A handle to the library resource. + * + * @input: + * args :: + * A pointer to an `FT_Open_Args` structure that must be filled by the + * caller. + * + * face_index :: + * This field holds two different values. Bits 0-15 are the index of + * the face in the font file (starting with value~0). Set it to~0 if + * there is only one face in the font file. + * + * [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 `*aface` (if `aface` isn't `NULL`); the only two useful fields in + * this special case are `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 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. + * + * @output: + * aface :: + * A handle to a new face object. If `face_index` is greater than or + * equal to zero, it must be non-`NULL`. + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * Unlike FreeType 1.x, this function automatically creates a glyph slot + * for the face object that can be accessed directly through + * `face->glyph`. + * + * Each new face object created with this function also owns a default + * @FT_Size object, accessible as `face->size`. + * + * One @FT_Library instance can have multiple face objects, this is, + * @FT_Open_Face and its siblings can be called multiple times using the + * same `library` argument. + * + * See the discussion of reference counters in the description of + * @FT_Reference_Face. + * + * If `FT_OPEN_STREAM` is set in `args->flags`, the stream in + * `args->stream` is automatically closed before this function returns + * any error (including `FT_Err_Invalid_Argument`). + * + * @example: + * To loop over all faces, use code similar to the following snippet + * (omitting the error handling). + * + * ``` + * ... + * FT_Face face; + * FT_Long i, num_faces; + * + * + * error = FT_Open_Face( library, args, -1, &face ); + * if ( error ) { ... } + * + * num_faces = face->num_faces; + * FT_Done_Face( face ); + * + * for ( i = 0; i < num_faces; i++ ) + * { + * ... + * error = FT_Open_Face( library, args, i, &face ); + * ... + * FT_Done_Face( face ); + * ... + * } + * ``` + * + * To loop over all valid values for `face_index`, use something similar + * to the following snippet, again without error handling. The code + * accesses all faces immediately (thus only a single call of + * `FT_Open_Face` within the do-loop), with and without named instances. + * + * ``` + * ... + * FT_Face face; + * + * FT_Long num_faces = 0; + * FT_Long num_instances = 0; + * + * FT_Long face_idx = 0; + * FT_Long instance_idx = 0; + * + * + * do + * { + * FT_Long id = ( instance_idx << 16 ) + face_idx; + * + * + * error = FT_Open_Face( library, args, id, &face ); + * if ( error ) { ... } + * + * num_faces = face->num_faces; + * num_instances = face->style_flags >> 16; + * + * ... + * + * FT_Done_Face( face ); + * + * if ( instance_idx < num_instances ) + * instance_idx++; + * else + * { + * face_idx++; + * instance_idx = 0; + * } + * + * } while ( face_idx < num_faces ) + * ``` + */ + FT_EXPORT( FT_Error ) + FT_Open_Face( FT_Library library, + const FT_Open_Args* args, + FT_Long face_index, + FT_Face *aface ); + + + /************************************************************************** + * + * @function: + * FT_Attach_File + * + * @description: + * Call @FT_Attach_Stream to attach a file. + * + * @inout: + * face :: + * The target face object. + * + * @input: + * filepathname :: + * The pathname. + * + * @return: + * FreeType error code. 0~means success. + */ + FT_EXPORT( FT_Error ) + FT_Attach_File( FT_Face face, + const char* filepathname ); + + + /************************************************************************** + * + * @function: + * FT_Attach_Stream + * + * @description: + * 'Attach' data to a face object. Normally, this is used to read + * additional information for the face object. For example, you can + * attach an AFM file that comes with a Type~1 font to get the kerning + * values and other metrics. + * + * @inout: + * face :: + * The target face object. + * + * @input: + * parameters :: + * A pointer to @FT_Open_Args that must be filled by the caller. + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * The meaning of the 'attach' (i.e., what really happens when the new + * file is read) is not fixed by FreeType itself. It really depends on + * the font format (and thus the font driver). + * + * Client applications are expected to know what they are doing when + * invoking this function. Most drivers simply do not implement file or + * stream attachments. + */ + FT_EXPORT( FT_Error ) + FT_Attach_Stream( FT_Face face, + const FT_Open_Args* parameters ); + + + /************************************************************************** + * + * @function: + * FT_Reference_Face + * + * @description: + * A counter gets initialized to~1 at the time an @FT_Face structure is + * created. This function increments the counter. @FT_Done_Face then + * only destroys a face if the counter is~1, otherwise it simply + * decrements the counter. + * + * This function helps in managing life-cycles of structures that + * reference @FT_Face objects. + * + * @input: + * face :: + * A handle to a target face object. + * + * @return: + * FreeType error code. 0~means success. + * + * @since: + * 2.4.2 + * + */ + FT_EXPORT( FT_Error ) + FT_Reference_Face( FT_Face face ); + + + /************************************************************************** + * + * @function: + * FT_Done_Face + * + * @description: + * Discard a given face object, as well as all of its child slots and + * sizes. + * + * @input: + * face :: + * A handle to a target face object. + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * See the discussion of reference counters in the description of + * @FT_Reference_Face. + */ + FT_EXPORT( FT_Error ) + FT_Done_Face( FT_Face face ); + + + /************************************************************************** + * + * @function: + * FT_Select_Size + * + * @description: + * 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. + * + * @input: + * strike_index :: + * The index of the bitmap strike in the `available_sizes` field of + * @FT_FaceRec structure. + * + * @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 ); + + + /************************************************************************** + * + * @enum: + * FT_Size_Request_Type + * + * @description: + * 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 `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 of + * @FT_FaceRec are used to determine the horizontal and vertical + * scaling value, respectively. + * + * FT_SIZE_REQUEST_TYPE_CELL :: + * The `max_advance_width` field of @FT_FaceRec is used to determine + * the horizontal scaling value; the vertical scaling value is + * determined the same way as @FT_SIZE_REQUEST_TYPE_REAL_DIM does. + * Finally, both scaling values are set to the smaller one. This type + * is useful if you want to specify the font size for, say, a window of + * a given dimension and 80x24 cells. + * + * FT_SIZE_REQUEST_TYPE_SCALES :: + * Specify the scaling values directly. + * + * @note: + * The above descriptions only apply to scalable formats. For bitmap + * formats, the behaviour is up to the driver. + * + * See the note section of @FT_Size_Metrics if you wonder how size + * requesting relates to scaling values. + */ + typedef enum FT_Size_Request_Type_ + { + FT_SIZE_REQUEST_TYPE_NOMINAL, + FT_SIZE_REQUEST_TYPE_REAL_DIM, + FT_SIZE_REQUEST_TYPE_BBOX, + FT_SIZE_REQUEST_TYPE_CELL, + FT_SIZE_REQUEST_TYPE_SCALES, + + FT_SIZE_REQUEST_TYPE_MAX + + } FT_Size_Request_Type; + + + /************************************************************************** + * + * @struct: + * FT_Size_RequestRec + * + * @description: + * A structure to model a size request. + * + * @fields: + * type :: + * See @FT_Size_Request_Type. + * + * width :: + * The desired width, given as a 26.6 fractional point value (with 72pt + * = 1in). + * + * height :: + * The desired height, given as a 26.6 fractional point value (with + * 72pt = 1in). + * + * 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 (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, 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; + FT_Long width; + FT_Long height; + FT_UInt horiResolution; + FT_UInt vertResolution; + + } FT_Size_RequestRec; + + + /************************************************************************** + * + * @struct: + * FT_Size_Request + * + * @description: + * A handle to a size request structure. + */ + typedef struct FT_Size_RequestRec_ *FT_Size_Request; + + + /************************************************************************** + * + * @function: + * FT_Request_Size + * + * @description: + * Resize the scale of the active @FT_Size object in a face. + * + * @inout: + * face :: + * A handle to a target face object. + * + * @input: + * req :: + * A pointer to a @FT_Size_RequestRec. + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * Although drivers may select the bitmap strike matching the request, + * you should not rely on this if you intend to select a particular + * bitmap strike. Use @FT_Select_Size instead in that case. + * + * The relation between the requested size and the resulting glyph 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 + * '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 are + * treated as @FT_LOAD_NO_SCALE. + * + * Don't use this function if you are using the FreeType cache API. + */ + FT_EXPORT( FT_Error ) + FT_Request_Size( FT_Face face, + FT_Size_Request req ); + + + /************************************************************************** + * + * @function: + * FT_Set_Char_Size + * + * @description: + * Call @FT_Request_Size to request the nominal size (in points). + * + * @inout: + * face :: + * A handle to a target face object. + * + * @input: + * char_width :: + * The nominal width, in 26.6 fractional points. + * + * char_height :: + * The nominal height, in 26.6 fractional points. + * + * horz_resolution :: + * The horizontal resolution in dpi. + * + * vert_resolution :: + * The vertical resolution in dpi. + * + * @return: + * 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. + * + * If either the horizontal or vertical resolution is zero, it is set + * equal to the other value. + * + * A character width or height smaller than 1pt is set to 1pt; if both + * resolution values are zero, they are set to 72dpi. + * + * Don't use this function if you are using the FreeType cache API. + */ + FT_EXPORT( FT_Error ) + FT_Set_Char_Size( FT_Face face, + FT_F26Dot6 char_width, + FT_F26Dot6 char_height, + FT_UInt horz_resolution, + FT_UInt vert_resolution ); + + + /************************************************************************** + * + * @function: + * FT_Set_Pixel_Sizes + * + * @description: + * Call @FT_Request_Size to request the nominal size (in pixels). + * + * @inout: + * face :: + * A handle to the target face object. + * + * @input: + * pixel_width :: + * The nominal width, in pixels. + * + * pixel_height :: + * The nominal height, in pixels. + * + * @return: + * 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 + * understand how requested sizes relate to actual sizes. + * + * Don't use this function if you are using the FreeType cache API. + */ + FT_EXPORT( FT_Error ) + FT_Set_Pixel_Sizes( FT_Face face, + FT_UInt pixel_width, + FT_UInt pixel_height ); + + + /************************************************************************** + * + * @function: + * FT_Load_Glyph + * + * @description: + * Load a glyph into the glyph slot of a face object. + * + * @inout: + * face :: + * A handle to the target face object where the glyph is loaded. + * + * @input: + * glyph_index :: + * The index of the glyph in the font file. For CID-keyed fonts + * (either in PS or in CFF format) this argument specifies the CID + * value. + * + * load_flags :: + * A flag indicating what to load for this glyph. The @FT_LOAD_XXX + * flags can be used to control the glyph loading process (e.g., + * whether the outline should be scaled, whether to load bitmaps or + * not, whether to hint the outline, etc). + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * For proper scaling and hinting, the active @FT_Size object owned by + * the face has to be meaningfully initialized by calling + * @FT_Set_Char_Size before this function, for example. The loaded + * glyph may be transformed. See @FT_Set_Transform for the details. + * + * For subsetted CID-keyed fonts, `FT_Err_Invalid_Argument` is returned + * for invalid CID values (this is, for CID values that 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, + FT_Int32 load_flags ); + + + /************************************************************************** + * + * @function: + * FT_Load_Char + * + * @description: + * 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 is loaded. + * + * @input: + * char_code :: + * The glyph's character code, according to the current charmap used in + * the face. + * + * load_flags :: + * A flag indicating what to load for this glyph. The @FT_LOAD_XXX + * constants can be used to control the glyph loading process (e.g., + * whether the outline should be scaled, whether to load bitmaps or + * not, whether to hint the outline, etc). + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * 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, + FT_Int32 load_flags ); + + + /************************************************************************** + * + * @enum: + * FT_LOAD_XXX + * + * @description: + * 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 :: + * Corresponding to~0, this value is used as the default glyph load + * operation. In this case, the following happens: + * + * 1. FreeType looks for a bitmap for the glyph corresponding to the + * face's current size. If one is found, the function returns. The + * bitmap data can be accessed from the glyph slot (see note below). + * + * 2. If no embedded bitmap is searched 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 + * bitmaps. The following flags are used to modify this default + * behaviour to more specific and useful cases. + * + * FT_LOAD_NO_SCALE :: + * Don't scale the loaded outline glyph but keep it in font units. + * This flag is also assumed if @FT_Size owned by the face was not + * properly initialized. + * + * This flag implies @FT_LOAD_NO_HINTING and @FT_LOAD_NO_BITMAP, and + * unsets @FT_LOAD_RENDER. + * + * If the font is 'tricky' (see @FT_FACE_FLAG_TRICKY for more), using + * `FT_LOAD_NO_SCALE` usually yields meaningless outlines because the + * subglyphs must be scaled and positioned with hinting instructions. + * This can be solved by loading the font without `FT_LOAD_NO_SCALE` + * and setting the character size to `font->units_per_EM`. + * + * FT_LOAD_NO_HINTING :: + * Disable hinting. This generally generates 'blurrier' bitmap glyphs + * when the glyphs are rendered in any of the anti-aliased modes. See + * also the note below. + * + * This flag is implied by @FT_LOAD_NO_SCALE. + * + * FT_LOAD_RENDER :: + * Call @FT_Render_Glyph after the glyph is loaded. By default, the + * glyph is rendered in @FT_RENDER_MODE_NORMAL mode. This can be + * overridden by @FT_LOAD_TARGET_XXX or @FT_LOAD_MONOCHROME. + * + * This flag is unset by @FT_LOAD_NO_SCALE. + * + * FT_LOAD_NO_BITMAP :: + * Ignore bitmap strikes when loading. Bitmap-only fonts ignore this + * flag. + * + * @FT_LOAD_NO_SCALE always sets this flag. + * + * FT_LOAD_SBITS_ONLY :: + * [Since 2.12] This is the opposite of @FT_LOAD_NO_BITMAP, more or + * less: @FT_Load_Glyph returns `FT_Err_Invalid_Argument` if the face + * contains a bitmap strike for the given size (or the strike selected + * by @FT_Select_Size) but there is no glyph in the strike. + * + * Note that this load flag was part of FreeType since version 2.0.6 + * but previously tagged as internal. + * + * FT_LOAD_VERTICAL_LAYOUT :: + * Load the glyph for vertical text layout. In particular, the + * `advance` value in the @FT_GlyphSlotRec structure is set to the + * `vertAdvance` value of the `metrics` field. + * + * In case @FT_HAS_VERTICAL doesn't return true, you shouldn't use this + * flag currently. Reason is that in this case vertical metrics get + * synthesized, and those values are not always consistent across + * various font formats. + * + * FT_LOAD_FORCE_AUTOHINT :: + * Prefer the auto-hinter over the font's native hinter. See also the + * note below. + * + * FT_LOAD_PEDANTIC :: + * Make the font driver perform pedantic verifications during glyph + * loading and hinting. 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 result + * in partially hinted or distorted glyphs in case a glyph's bytecode + * is buggy. + * + * FT_LOAD_NO_RECURSE :: + * Don't load composite glyphs recursively. Instead, the font driver + * fills the `num_subglyph` and `subglyphs` values of the glyph slot; + * it also sets `glyph->format` to @FT_GLYPH_FORMAT_COMPOSITE. The + * description of subglyphs can then be accessed with + * @FT_Get_SubGlyph_Info. + * + * Don't use this flag for retrieving metrics information since some + * font drivers only return rudimentary data. + * + * This flag implies @FT_LOAD_NO_SCALE and @FT_LOAD_IGNORE_TRANSFORM. + * + * FT_LOAD_IGNORE_TRANSFORM :: + * 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 + * render an outline glyph to a 1-bit monochrome bitmap glyph, with + * 8~pixels packed into each byte of the bitmap data. + * + * Note that this has no effect on the hinting algorithm used. You + * should rather use @FT_LOAD_TARGET_MONO so that the + * monochrome-optimized hinting algorithm is used. + * + * FT_LOAD_LINEAR_DESIGN :: + * Keep `linearHoriAdvance` and `linearVertAdvance` fields of + * @FT_GlyphSlotRec in font units. See @FT_GlyphSlotRec for details. + * + * FT_LOAD_NO_AUTOHINT :: + * Disable the auto-hinter. See also the note below. + * + * FT_LOAD_COLOR :: + * Load colored glyphs. FreeType searches in the following order; + * there are slight differences depending on the font format. + * + * [Since 2.5] Load embedded color bitmap images (provided + * @FT_LOAD_NO_BITMAP is not set). The resulting color bitmaps, if + * available, have the @FT_PIXEL_MODE_BGRA format, with pre-multiplied + * color channels. If the flag is not set and color bitmaps are found, + * they are converted to 256-level gray bitmaps, using the + * @FT_PIXEL_MODE_GRAY format. + * + * [Since 2.12] If the glyph index maps to an entry in the face's + * 'SVG~' table, load the associated SVG document from this table and + * set the `format` field of @FT_GlyphSlotRec to @FT_GLYPH_FORMAT_SVG. + * Note that FreeType itself can't render SVG documents; however, the + * library provides hooks to seamlessly integrate an external renderer. + * See sections @ot_svg_driver and @svg_fonts for more. + * + * [Since 2.10, experimental] If the glyph index maps to an entry in + * the face's 'COLR' table with a 'CPAL' palette table (as defined in + * the OpenType specification), make @FT_Render_Glyph provide a default + * blending of the color glyph layers associated with the glyph index, + * using the same bitmap format as embedded color bitmap images. This + * is mainly for convenience and works only for glyphs in 'COLR' v0 + * tables (or glyphs in 'COLR' v1 tables that exclusively use v0 + * features). For full control of color layers use + * @FT_Get_Color_Glyph_Layer and FreeType's color functions like + * @FT_Palette_Select instead of setting @FT_LOAD_COLOR for rendering + * so that the client application can handle blending by itself. + * + * FT_LOAD_COMPUTE_METRICS :: + * [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. + * + * FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH :: + * Ignored. Deprecated. + * + * @note: + * By default, hinting is enabled and the font's native hinter (see + * @FT_FACE_FLAG_HINTER) is preferred over the auto-hinter. You can + * disable hinting by setting @FT_LOAD_NO_HINTING or change the + * precedence by setting @FT_LOAD_FORCE_AUTOHINT. You can also set + * @FT_LOAD_NO_AUTOHINT in case you don't want the auto-hinter to be used + * at all. + * + * See the description of @FT_FACE_FLAG_TRICKY for a special exception + * (affecting only a handful of Asian fonts). + * + * Besides deciding which hinter to use, you can also decide which + * hinting algorithm to use. See @FT_LOAD_TARGET_XXX for details. + * + * Note that the auto-hinter needs a valid Unicode cmap (either a native + * one or synthesized by FreeType) for producing correct results. If a + * font provides an incorrect mapping (for example, assigning the + * character code U+005A, LATIN CAPITAL LETTER~Z, to a glyph depicting a + * mathematical integral sign), the auto-hinter might produce useless + * results. + * + */ +#define FT_LOAD_DEFAULT 0x0 +#define FT_LOAD_NO_SCALE ( 1L << 0 ) +#define FT_LOAD_NO_HINTING ( 1L << 1 ) +#define FT_LOAD_RENDER ( 1L << 2 ) +#define FT_LOAD_NO_BITMAP ( 1L << 3 ) +#define FT_LOAD_VERTICAL_LAYOUT ( 1L << 4 ) +#define FT_LOAD_FORCE_AUTOHINT ( 1L << 5 ) +#define FT_LOAD_CROP_BITMAP ( 1L << 6 ) +#define FT_LOAD_PEDANTIC ( 1L << 7 ) +#define FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH ( 1L << 9 ) +#define FT_LOAD_NO_RECURSE ( 1L << 10 ) +#define FT_LOAD_IGNORE_TRANSFORM ( 1L << 11 ) +#define FT_LOAD_MONOCHROME ( 1L << 12 ) +#define FT_LOAD_LINEAR_DESIGN ( 1L << 13 ) +#define FT_LOAD_SBITS_ONLY ( 1L << 14 ) +#define FT_LOAD_NO_AUTOHINT ( 1L << 15 ) + /* 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 */ +#define FT_LOAD_ADVANCE_ONLY ( 1L << 8 ) +#define FT_LOAD_SVG_ONLY ( 1L << 23 ) + + + /************************************************************************** + * + * @enum: + * FT_LOAD_TARGET_XXX + * + * @description: + * 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. + * + * 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 :: + * 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 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. + * + * 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 + * output. The result is probably unpleasant if the glyph is rendered + * in non-monochrome modes. + * + * Note that for outline fonts only the TrueType font driver has proper + * monochrome hinting support, provided the TTFs contain hints for B/W + * rendering (which most fonts no longer provide). If these conditions + * are not met it is very likely that you get ugly results at smaller + * sizes. + * + * FT_LOAD_TARGET_LCD :: + * A variant of @FT_LOAD_TARGET_LIGHT optimized for horizontally + * decimated LCD displays. + * + * FT_LOAD_TARGET_LCD_V :: + * A variant of @FT_LOAD_TARGET_NORMAL optimized for vertically + * decimated LCD displays. + * + * @note: + * You should use only _one_ of the `FT_LOAD_TARGET_XXX` values in your + * `load_flags`. They can't be ORed. + * + * 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 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 + * rendering mode. As an example, it is possible to use the 'light' + * hinting algorithm and have the results rendered in horizontal LCD + * pixel mode, with code like + * + * ``` + * FT_Load_Glyph( face, glyph_index, + * load_flags | FT_LOAD_TARGET_LIGHT ); + * + * 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_STATIC_CAST( FT_Int32, (x) & 15 ) << 16 ) + +#define FT_LOAD_TARGET_NORMAL FT_LOAD_TARGET_( FT_RENDER_MODE_NORMAL ) +#define FT_LOAD_TARGET_LIGHT FT_LOAD_TARGET_( FT_RENDER_MODE_LIGHT ) +#define FT_LOAD_TARGET_MONO FT_LOAD_TARGET_( FT_RENDER_MODE_MONO ) +#define FT_LOAD_TARGET_LCD FT_LOAD_TARGET_( FT_RENDER_MODE_LCD ) +#define FT_LOAD_TARGET_LCD_V FT_LOAD_TARGET_( FT_RENDER_MODE_LCD_V ) + + + /************************************************************************** + * + * @macro: + * FT_LOAD_TARGET_MODE + * + * @description: + * Return the @FT_Render_Mode corresponding to a given + * @FT_LOAD_TARGET_XXX value. + * + */ +#define FT_LOAD_TARGET_MODE( x ) \ + FT_STATIC_CAST( FT_Render_Mode, ( (x) >> 16 ) & 15 ) + + + /************************************************************************** + * + * @function: + * FT_Set_Transform + * + * @description: + * 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 `NULL` for the + * identity matrix. + * delta :: + * A pointer to the translation vector. Use `NULL` for the null + * vector. + * + * @note: + * This function is provided as a convenience, but keep in mind that + * @FT_Matrix coefficients are only 16.16 fixed-point values, which can + * limit the accuracy of the results. Using floating-point computations + * to perform the transform directly in client code instead will always + * yield better numbers. + * + * The transformation is only applied to scalable image formats after the + * glyph has been loaded. It means that hinting is unaltered by the + * transformation and is performed on the character size given in the + * last call to @FT_Set_Char_Size or @FT_Set_Pixel_Sizes. + * + * Note that this also transforms the `face.glyph.advance` field, but + * **not** the values in `face.glyph.metrics`. + */ + FT_EXPORT( void ) + FT_Set_Transform( FT_Face face, + FT_Matrix* matrix, + FT_Vector* delta ); + + + /************************************************************************** + * + * @function: + * FT_Get_Transform + * + * @description: + * Return the transformation that is applied to glyph images when they + * are loaded into a glyph slot through @FT_Load_Glyph. See + * @FT_Set_Transform for more details. + * + * @input: + * face :: + * A handle to the source face object. + * + * @output: + * matrix :: + * A pointer to a transformation's 2x2 matrix. Set this to NULL if you + * are not interested in the value. + * + * delta :: + * A pointer to a translation vector. Set this to NULL if you are not + * interested in the value. + * + * @since: + * 2.11 + * + */ + FT_EXPORT( void ) + FT_Get_Transform( FT_Face face, + FT_Matrix* matrix, + FT_Vector* delta ); + + + /************************************************************************** + * + * @enum: + * FT_Render_Mode + * + * @description: + * 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, + * indicating pixel coverage. Use linear alpha blending and gamma + * correction to correctly render non-monochrome glyph bitmaps onto a + * surface; see @FT_Render_Glyph. + * + * The @FT_RENDER_MODE_SDF is a special render mode that uses up to 256 + * distance values, indicating the signed distance from the grid position + * to the nearest outline. + * + * @values: + * FT_RENDER_MODE_NORMAL :: + * 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 defined as + * a separate value because render modes are also used indirectly to + * define hinting algorithm selectors. See @FT_LOAD_TARGET_XXX for + * details. + * + * FT_RENDER_MODE_MONO :: + * This mode corresponds to 1-bit bitmaps (with 2~levels of opacity). + * + * FT_RENDER_MODE_LCD :: + * 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 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. + * + * FT_RENDER_MODE_SDF :: + * This mode corresponds to 8-bit, single-channel signed distance field + * (SDF) bitmaps. Each pixel in the SDF grid is the value from the + * pixel's position to the nearest glyph's outline. The distances are + * calculated from the center of the pixel and are positive if they are + * filled by the outline (i.e., inside the outline) and negative + * otherwise. Check the note below on how to convert the output values + * to usable data. + * + * @note: + * The selected render mode only affects vector glyphs of a font. + * Embedded bitmaps often have a different pixel mode like + * @FT_PIXEL_MODE_MONO. You can use @FT_Bitmap_Convert to transform them + * into 8-bit pixmaps. + * + * For @FT_RENDER_MODE_SDF the output bitmap buffer contains normalized + * distances that are packed into unsigned 8-bit values. To get pixel + * values in floating point representation use the following pseudo-C + * code for the conversion. + * + * ``` + * // Load glyph and render using FT_RENDER_MODE_SDF, + * // then use the output buffer as follows. + * + * ... + * FT_Byte buffer = glyph->bitmap->buffer; + * + * + * for pixel in buffer + * { + * // `sd` is the signed distance and `spread` is the current spread; + * // the default spread is 2 and can be changed. + * + * float sd = (float)pixel - 128.0f; + * + * + * // Convert to pixel values. + * sd = ( sd / 128.0f ) * spread; + * + * // Store `sd` in a buffer or use as required. + * } + * + * ``` + * + * FreeType has two rasterizers for generating SDF, namely: + * + * 1. `sdf` for generating SDF directly from glyph's outline, and + * + * 2. `bsdf` for generating SDF from rasterized bitmaps. + * + * Depending on the glyph type (i.e., outline or bitmap), one of the two + * rasterizers is chosen at runtime and used for generating SDFs. To + * force the use of `bsdf` you should render the glyph with any of the + * FreeType's other rendering modes (e.g., `FT_RENDER_MODE_NORMAL`) and + * then re-render with `FT_RENDER_MODE_SDF`. + * + * There are some issues with stability and possible failures of the SDF + * renderers (specifically `sdf`). + * + * 1. The `sdf` rasterizer is sensitive to really small features (e.g., + * sharp turns that are less than 1~pixel) and imperfections in the + * glyph's outline, causing artifacts in the final output. + * + * 2. The `sdf` rasterizer has limited support for handling intersecting + * contours and *cannot* handle self-intersecting contours whatsoever. + * Self-intersection happens when a single connected contour + * intersects itself at some point; having these in your font + * definitely poses a problem to the rasterizer and cause artifacts, + * too. + * + * 3. Generating SDF for really small glyphs may result in undesirable + * output; the pixel grid (which stores distance information) becomes + * too coarse. + * + * 4. Since the output buffer is normalized, precision at smaller spreads + * is greater than precision at larger spread values because the + * output range of [0..255] gets mapped to a smaller SDF range. A + * spread of~2 should be sufficient in most cases. + * + * Points (1) and (2) can be avoided by using the `bsdf` rasterizer, + * which is more stable than the `sdf` rasterizer in general. + * + */ + typedef enum FT_Render_Mode_ + { + FT_RENDER_MODE_NORMAL = 0, + FT_RENDER_MODE_LIGHT, + FT_RENDER_MODE_MONO, + FT_RENDER_MODE_LCD, + FT_RENDER_MODE_LCD_V, + FT_RENDER_MODE_SDF, + + FT_RENDER_MODE_MAX + + } FT_Render_Mode; + + + /* these constants are deprecated; use the corresponding */ + /* `FT_Render_Mode` values instead */ +#define ft_render_mode_normal FT_RENDER_MODE_NORMAL +#define ft_render_mode_mono FT_RENDER_MODE_MONO + + + /************************************************************************** + * + * @function: + * FT_Render_Glyph + * + * @description: + * Convert a given glyph image to a bitmap. It does so by inspecting the + * glyph image format, finding the relevant renderer, and invoking it. + * + * @inout: + * slot :: + * A handle to the glyph slot containing the image to convert. + * + * @input: + * render_mode :: + * The render mode used to render the glyph image into a bitmap. See + * @FT_Render_Mode for a list of possible values. + * + * If @FT_RENDER_MODE_NORMAL is used, a previous call of @FT_Load_Glyph + * with flag @FT_LOAD_COLOR makes `FT_Render_Glyph` provide a default + * blending of colored glyph layers associated with the current glyph + * slot (provided the font contains such layers) instead of rendering + * the glyph slot's outline. This is an experimental feature; see + * @FT_LOAD_COLOR for more information. + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * 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 anti-aliased 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_rendering. 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, + FT_Render_Mode render_mode ); + + + /************************************************************************** + * + * @enum: + * FT_Kerning_Mode + * + * @description: + * An enumeration to specify the format of kerning values returned by + * @FT_Get_Kerning. + * + * @values: + * FT_KERNING_DEFAULT :: + * Return grid-fitted kerning distances in 26.6 fractional pixels. + * + * FT_KERNING_UNFITTED :: + * Return un-grid-fitted kerning distances in 26.6 fractional pixels. + * + * FT_KERNING_UNSCALED :: + * Return the kerning vector in original font units. + * + * @note: + * `FT_KERNING_DEFAULT` returns full pixel values; it also makes 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_UNFITTED, + FT_KERNING_UNSCALED + + } FT_Kerning_Mode; + + + /* these constants are deprecated; use the corresponding */ + /* `FT_Kerning_Mode` values instead */ +#define ft_kerning_default FT_KERNING_DEFAULT +#define ft_kerning_unfitted FT_KERNING_UNFITTED +#define ft_kerning_unscaled FT_KERNING_UNSCALED + + + /************************************************************************** + * + * @function: + * FT_Get_Kerning + * + * @description: + * Return the kerning vector between two glyphs of the same face. + * + * @input: + * face :: + * A handle to a source face object. + * + * left_glyph :: + * The index of the left glyph in the kern pair. + * + * right_glyph :: + * The index of the right glyph in the kern pair. + * + * kern_mode :: + * See @FT_Kerning_Mode for more information. Determines the scale and + * dimension of the returned kerning vector. + * + * @output: + * akerning :: + * The kerning vector. This is either in font units, fractional pixels + * (26.6 format), or pixels for scalable formats, and in pixels for + * fixed-sizes formats. + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * Only horizontal layouts (left-to-right & right-to-left) are supported + * by this method. Other layouts, or more sophisticated kernings, are + * out of the scope of this API function -- they can be implemented + * through format-specific interfaces. + * + * 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, + FT_UInt right_glyph, + FT_UInt kern_mode, + FT_Vector *akerning ); + + + /************************************************************************** + * + * @function: + * FT_Get_Track_Kerning + * + * @description: + * Return the track kerning for a given face object at a given size. + * + * @input: + * face :: + * A handle to a source face object. + * + * point_size :: + * The point size in 16.16 fractional points. + * + * degree :: + * The degree of tightness. Increasingly negative values represent + * tighter track kerning, while increasingly positive values represent + * looser track kerning. Value zero means no track kerning. + * + * @output: + * akerning :: + * The kerning in 16.16 fractional points, to be uniformly applied + * between all glyphs. + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * Currently, only the Type~1 font driver supports track kerning, using + * data from AFM files (if attached with @FT_Attach_File or + * @FT_Attach_Stream). + * + * Only very few AFM files come with track kerning data; please refer to + * Adobe's AFM specification for more details. + */ + FT_EXPORT( FT_Error ) + FT_Get_Track_Kerning( FT_Face face, + FT_Fixed point_size, + FT_Int degree, + FT_Fixed* akerning ); + + + /************************************************************************** + * + * @function: + * FT_Select_Charmap + * + * @description: + * Select a given charmap by its encoding tag (as listed in + * `freetype.h`). + * + * @inout: + * face :: + * A handle to the source face object. + * + * @input: + * encoding :: + * A handle to the selected encoding. + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * This function returns an error if no charmap in the face corresponds + * to the encoding queried here. + * + * Because many fonts contain more than a single cmap for Unicode + * encoding, this function has some special code to select the one that + * covers Unicode best ('best' in the sense that a UCS-4 cmap is + * preferred to a UCS-2 cmap). It is thus preferable to @FT_Set_Charmap + * in this case. + */ + FT_EXPORT( FT_Error ) + FT_Select_Charmap( FT_Face face, + FT_Encoding encoding ); + + + /************************************************************************** + * + * @function: + * FT_Set_Charmap + * + * @description: + * Select a given charmap for character code to glyph index mapping. + * + * @inout: + * face :: + * A handle to the source face object. + * + * @input: + * charmap :: + * A handle to the selected charmap. + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * This function returns an error if the charmap is not part of the face + * (i.e., if it is not listed in the `face->charmaps` table). + * + * 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, + FT_CharMap charmap ); + + + /************************************************************************** + * + * @function: + * FT_Get_Charmap_Index + * + * @description: + * Retrieve index of a given charmap. + * + * @input: + * charmap :: + * A handle to a charmap. + * + * @return: + * The index into the array of character maps within the face to which + * `charmap` belongs. If an error occurs, -1 is returned. + * + */ + FT_EXPORT( FT_Int ) + FT_Get_Charmap_Index( FT_CharMap charmap ); + + + /************************************************************************** + * + * @function: + * FT_Get_Char_Index + * + * @description: + * Return the glyph index of a given character code. This function uses + * the currently selected charmap to do the mapping. + * + * @input: + * face :: + * A handle to the source face object. + * + * charcode :: + * The character code. + * + * @return: + * The glyph index. 0~means 'undefined character code'. + * + * @note: + * If you use FreeType to manipulate the contents of font files directly, + * be aware that the glyph index returned by this function doesn't always + * correspond to the internal indices used within the file. This is done + * to ensure that value~0 always corresponds to the 'missing glyph'. If + * the first glyph is not named '.notdef', then for Type~1 and Type~42 + * fonts, '.notdef' will be moved into the glyph ID~0 position, and + * whatever was there will be moved to the position '.notdef' had. For + * Type~1 fonts, if there is no '.notdef' glyph at all, then one will be + * created at index~0 and whatever was there will be moved to the last + * index -- Type~42 fonts are considered invalid under this condition. + */ + FT_EXPORT( FT_UInt ) + FT_Get_Char_Index( FT_Face face, + FT_ULong charcode ); + + + /************************************************************************** + * + * @function: + * FT_Get_First_Char + * + * @description: + * 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. + * + * @output: + * agindex :: + * Glyph index of first character code. 0~if charmap is empty. + * + * @return: + * The charmap's first character code. + * + * @note: + * You should use this function together with @FT_Get_Next_Char to parse + * all character codes available in a given charmap. The code should + * look like this: + * + * ``` + * FT_ULong charcode; + * FT_UInt gindex; + * + * + * charcode = FT_Get_First_Char( face, &gindex ); + * while ( gindex != 0 ) + * { + * ... do something with (charcode,gindex) pair ... + * + * charcode = FT_Get_Next_Char( face, charcode, &gindex ); + * } + * ``` + * + * Be aware that character codes can have values up to 0xFFFFFFFF; this + * might happen for non-Unicode or malformed cmaps. However, even with + * regular Unicode encoding, so-called 'last resort fonts' (using SFNT + * cmap format 13, see function @FT_Get_CMap_Format) normally have + * entries for all Unicode characters up to 0x1FFFFF, which can cause *a + * lot* of iterations. + * + * Note that `*agindex` is set to~0 if the charmap is empty. The result + * itself can be~0 in two cases: if the charmap is empty or if the + * value~0 is the first valid character code. + */ + FT_EXPORT( FT_ULong ) + FT_Get_First_Char( FT_Face face, + FT_UInt *agindex ); + + + /************************************************************************** + * + * @function: + * FT_Get_Next_Char + * + * @description: + * Return the next character code in the current charmap of a given face + * following the value `char_code`, as well as the corresponding glyph + * index. + * + * @input: + * face :: + * A handle to the source face object. + * + * char_code :: + * The starting character code. + * + * @output: + * agindex :: + * Glyph index of next character code. 0~if charmap is empty. + * + * @return: + * The charmap's next character code. + * + * @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 that + * function for a simple code example. + * + * Note that `*agindex` is set to~0 when there are no more codes in the + * charmap. + */ + FT_EXPORT( FT_ULong ) + FT_Get_Next_Char( FT_Face face, + FT_ULong char_code, + 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. + * + * @example: + * Here is 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 only works + * for those faces where @FT_HAS_GLYPH_NAMES returns true. + * + * @input: + * face :: + * A handle to the source face object. + * + * glyph_name :: + * The glyph name. + * + * @return: + * The glyph index. 0~means 'undefined character code'. + * + * @note: + * Acceptable glyph names might come from the [Adobe Glyph + * List](https://github.com/adobe-type-tools/agl-aglfn). See + * @FT_Get_Glyph_Name for the inverse functionality. + * + * This function has limited capabilities if the config macro + * `FT_CONFIG_OPTION_POSTSCRIPT_NAMES` is not defined in `ftoption.h`: + * It then works only for fonts that actually embed glyph names (which + * many recent OpenType fonts do not). + */ + FT_EXPORT( FT_UInt ) + FT_Get_Name_Index( FT_Face face, + const FT_String* glyph_name ); + + + /************************************************************************** + * + * @function: + * FT_Get_Glyph_Name + * + * @description: + * Retrieve the ASCII name of a given glyph in a face. This only works + * for those faces where @FT_HAS_GLYPH_NAMES returns true. + * + * @input: + * face :: + * A handle to a source face object. + * + * glyph_index :: + * The glyph index. + * + * buffer_max :: + * The maximum number of bytes available in the buffer. + * + * @output: + * buffer :: + * A pointer to a target buffer where the name is copied to. + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * An error is returned if the face doesn't provide glyph names or if the + * glyph index is invalid. In all cases of failure, the first byte of + * `buffer` is set to~0 to indicate an empty name. + * + * The glyph name is truncated to fit within the buffer if it is too + * long. The returned string is always zero-terminated. + * + * Be aware that FreeType reorders glyph indices internally so that glyph + * index~0 always corresponds to the 'missing glyph' (called '.notdef'). + * + * This function has limited capabilities if the config macro + * `FT_CONFIG_OPTION_POSTSCRIPT_NAMES` is not defined in `ftoption.h`: + * It then works only for fonts that actually embed glyph names (which + * many recent OpenType fonts do not). + */ + FT_EXPORT( FT_Error ) + FT_Get_Glyph_Name( FT_Face face, + FT_UInt glyph_index, + FT_Pointer buffer, + FT_UInt buffer_max ); + + + /************************************************************************** + * + * @function: + * FT_Get_Postscript_Name + * + * @description: + * Retrieve the ASCII PostScript name of a given face, if available. + * This only works with PostScript, TrueType, and OpenType fonts. + * + * @input: + * face :: + * A handle to the source face object. + * + * @return: + * A pointer to the face's PostScript name. `NULL` if unavailable. + * + * @note: + * The returned pointer is owned by the face and 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 ); + + + /************************************************************************** + * + * @enum: + * FT_SUBGLYPH_FLAG_XXX + * + * @description: + * 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). + * + * https://docs.microsoft.com/en-us/typography/opentype/spec/glyf#composite-glyph-description + * + * @values: + * FT_SUBGLYPH_FLAG_ARGS_ARE_WORDS :: + * FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES :: + * FT_SUBGLYPH_FLAG_ROUND_XY_TO_GRID :: + * FT_SUBGLYPH_FLAG_SCALE :: + * FT_SUBGLYPH_FLAG_XY_SCALE :: + * FT_SUBGLYPH_FLAG_2X2 :: + * FT_SUBGLYPH_FLAG_USE_MY_METRICS :: + * + */ +#define FT_SUBGLYPH_FLAG_ARGS_ARE_WORDS 1 +#define FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES 2 +#define FT_SUBGLYPH_FLAG_ROUND_XY_TO_GRID 4 +#define FT_SUBGLYPH_FLAG_SCALE 8 +#define FT_SUBGLYPH_FLAG_XY_SCALE 0x40 +#define FT_SUBGLYPH_FLAG_2X2 0x80 +#define FT_SUBGLYPH_FLAG_USE_MY_METRICS 0x200 + + + /************************************************************************** + * + * @function: + * FT_Get_SubGlyph_Info + * + * @description: + * Retrieve a description of a given subglyph. Only use it if + * `glyph->format` is @FT_GLYPH_FORMAT_COMPOSITE; an error is returned + * otherwise. + * + * @input: + * glyph :: + * The source glyph slot. + * + * sub_index :: + * The index of the subglyph. Must be less than + * `glyph->num_subglyphs`. + * + * @output: + * p_index :: + * The glyph index of the subglyph. + * + * p_flags :: + * The subglyph flags, see @FT_SUBGLYPH_FLAG_XXX. + * + * p_arg1 :: + * The subglyph's first argument (if any). + * + * p_arg2 :: + * The subglyph's second argument (if any). + * + * p_transform :: + * The subglyph transformation (if any). + * + * @return: + * FreeType error code. 0~means success. + * + * @note: + * The values of `*p_arg1`, `*p_arg2`, and `*p_transform` must be + * interpreted depending on the flags returned in `*p_flags`. See the + * OpenType specification for details. + * + * https://docs.microsoft.com/en-us/typography/opentype/spec/glyf#composite-glyph-description + * + */ + FT_EXPORT( FT_Error ) + FT_Get_SubGlyph_Info( FT_GlyphSlot glyph, + FT_UInt sub_index, + FT_Int *p_index, + FT_UInt *p_flags, + FT_Int *p_arg1, + FT_Int *p_arg2, + FT_Matrix *p_transform ); + + + /************************************************************************** + * + * @enum: + * FT_FSTYPE_XXX + * + * @description: + * A list of bit flags used in the `fsType` field of the OS/2 table in a + * TrueType or OpenType font and the `FSType` entry in a PostScript font. + * These bit flags are returned by @FT_Get_FSType_Flags; they inform + * client applications of embedding and subsetting restrictions + * associated with a font. + * + * See + * https://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/FontPolicies.pdf + * for more details. + * + * @values: + * FT_FSTYPE_INSTALLABLE_EMBEDDING :: + * Fonts with no fsType bit set may be embedded and permanently + * installed on the remote system by an application. + * + * FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING :: + * Fonts that have only this bit set must not be modified, embedded or + * exchanged in any manner without first obtaining permission of the + * font software copyright owner. + * + * FT_FSTYPE_PREVIEW_AND_PRINT_EMBEDDING :: + * 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 :: + * 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 :: + * The font may not be subsetted prior to embedding. + * + * FT_FSTYPE_BITMAP_EMBEDDING_ONLY :: + * 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. + */ +#define FT_FSTYPE_INSTALLABLE_EMBEDDING 0x0000 +#define FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING 0x0002 +#define FT_FSTYPE_PREVIEW_AND_PRINT_EMBEDDING 0x0004 +#define FT_FSTYPE_EDITABLE_EMBEDDING 0x0008 +#define FT_FSTYPE_NO_SUBSETTING 0x0100 +#define FT_FSTYPE_BITMAP_EMBEDDING_ONLY 0x0200 + + + /************************************************************************** + * + * @function: + * FT_Get_FSType_Flags + * + * @description: + * Return the `fsType` flags for a font. + * + * @input: + * face :: + * A handle to the source face object. + * + * @return: + * The `fsType` flags, see @FT_FSTYPE_XXX. + * + * @note: + * Use this function rather than directly reading the `fs_type` field in + * the @PS_FontInfoRec structure, which is only guaranteed to return the + * correct results for Type~1 fonts. + * + * @since: + * 2.3.8 + * + */ + FT_EXPORT( FT_UShort ) + FT_Get_FSType_Flags( FT_Face face ); + + + /************************************************************************** + * + * @section: + * glyph_variants + * + * @title: + * Unicode Variation Sequences + * + * @abstract: + * The FreeType~2 interface to Unicode Variation Sequences (UVS), using + * the SFNT cmap format~14. + * + * @description: + * 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. + * + */ + + + /************************************************************************** + * + * @function: + * FT_Face_GetCharVariantIndex + * + * @description: + * Return the glyph index of a given character code as modified by the + * variation selector. + * + * @input: + * face :: + * A handle to the source face object. + * + * charcode :: + * The character code point in Unicode. + * + * variantSelector :: + * The Unicode code point of the variation selector. + * + * @return: + * The glyph index. 0~means either 'undefined character code', or + * 'undefined selector code', or 'no variation selector cmap subtable', + * or 'current CharMap is not Unicode'. + * + * @note: + * If you use FreeType to manipulate the contents of font files directly, + * be aware that the glyph index returned by this function doesn't always + * correspond to the internal indices used within the file. This is done + * to ensure that value~0 always corresponds to the 'missing glyph'. + * + * This function is only meaningful if + * a) the font has a variation selector cmap sub table, and + * b) the current charmap has a Unicode encoding. + * + * @since: + * 2.3.6 + * + */ + FT_EXPORT( FT_UInt ) + FT_Face_GetCharVariantIndex( FT_Face face, + FT_ULong charcode, + FT_ULong variantSelector ); + + + /************************************************************************** + * + * @function: + * FT_Face_GetCharVariantIsDefault + * + * @description: + * Check whether this variation of this Unicode character is the one to + * be found in the charmap. + * + * @input: + * face :: + * A handle to the source face object. + * + * charcode :: + * The character codepoint in Unicode. + * + * variantSelector :: + * The Unicode codepoint of the variation selector. + * + * @return: + * 1~if found in the standard (Unicode) cmap, 0~if found in the variation + * selector cmap, or -1 if it is not a variation. + * + * @note: + * This function is only meaningful if the font has a variation selector + * cmap subtable. + * + * @since: + * 2.3.6 + * + */ + FT_EXPORT( FT_Int ) + FT_Face_GetCharVariantIsDefault( FT_Face face, + FT_ULong charcode, + FT_ULong variantSelector ); + + + /************************************************************************** + * + * @function: + * FT_Face_GetVariantSelectors + * + * @description: + * Return a zero-terminated list of Unicode variation selectors found in + * the font. + * + * @input: + * face :: + * A handle to the source face object. + * + * @return: + * A pointer to an array of selector code points, or `NULL` if there is + * no valid variation selector cmap subtable. + * + * @note: + * The last item in the array is~0; the array is owned by the @FT_Face + * object but can be overwritten or released on the next call to a + * FreeType function. + * + * @since: + * 2.3.6 + * + */ + FT_EXPORT( FT_UInt32* ) + FT_Face_GetVariantSelectors( FT_Face face ); + + + /************************************************************************** + * + * @function: + * FT_Face_GetVariantsOfChar + * + * @description: + * Return a zero-terminated list of Unicode variation selectors found for + * the specified character code. + * + * @input: + * face :: + * A handle to the source face object. + * + * charcode :: + * The character codepoint in Unicode. + * + * @return: + * 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. + * + * @note: + * The last item in the array is~0; the array is owned by the @FT_Face + * object but can be overwritten or released on the next call to a + * FreeType function. + * + * @since: + * 2.3.6 + * + */ + FT_EXPORT( FT_UInt32* ) + FT_Face_GetVariantsOfChar( FT_Face face, + FT_ULong charcode ); + + + /************************************************************************** + * + * @function: + * FT_Face_GetCharsOfVariant + * + * @description: + * Return a zero-terminated list of Unicode character codes found for the + * specified variation selector. + * + * @input: + * face :: + * A handle to the source face object. + * + * variantSelector :: + * 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 variation selector is invalid. + * + * @note: + * The last item in the array is~0; the array is owned by the @FT_Face + * object but can be overwritten or released on the next call to a + * FreeType function. + * + * @since: + * 2.3.6 + * + */ + FT_EXPORT( FT_UInt32* ) + FT_Face_GetCharsOfVariant( FT_Face face, + FT_ULong variantSelector ); + + + /************************************************************************** + * + * @section: + * computations + * + * @title: + * Computations + * + * @abstract: + * Crunching fixed numbers and vectors. + * + * @description: + * This section contains various functions used to perform computations + * on 16.16 fixed-point numbers or 2D vectors. FreeType does not use + * floating-point data types. + * + * **Attention**: Most arithmetic functions take `FT_Long` as arguments. + * For historical reasons, FreeType was designed under the assumption + * that `FT_Long` is a 32-bit integer; results can thus be undefined if + * the arguments don't fit into 32 bits. + * + * @order: + * FT_MulDiv + * FT_MulFix + * FT_DivFix + * FT_RoundFix + * FT_CeilFix + * FT_FloorFix + * FT_Vector_Transform + * FT_Matrix_Multiply + * FT_Matrix_Invert + * + */ + + + /************************************************************************** + * + * @function: + * FT_MulDiv + * + * @description: + * 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: + * The result of `(a*b)/c`. This function never traps when trying to + * divide by zero; it simply returns 'MaxInt' or 'MinInt' depending on + * the signs of `a` and `b`. + */ + FT_EXPORT( FT_Long ) + FT_MulDiv( FT_Long a, + FT_Long b, + FT_Long c ); + + + /************************************************************************** + * + * @function: + * FT_MulFix + * + * @description: + * 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). + * + * @return: + * The result of `(a*b)/0x10000`. + * + * @note: + * This function has been optimized for the case where the absolute value + * of `a` is less than 2048, and `b` is a 16.16 scaling factor. As this + * happens mainly when scaling from notional units to fractional pixels + * in FreeType, it resulted in noticeable speed improvements between + * versions 2.x and 1.x. + * + * As a conclusion, always try to place a 16.16 factor as the _second_ + * argument of this function; this can make a great difference. + */ + FT_EXPORT( FT_Long ) + FT_MulFix( FT_Long a, + FT_Long b ); + + + /************************************************************************** + * + * @function: + * FT_DivFix + * + * @description: + * 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: + * The result of `(a*0x10000)/b`. + */ + FT_EXPORT( FT_Long ) + FT_DivFix( FT_Long a, + FT_Long b ); + + + /************************************************************************** + * + * @function: + * FT_RoundFix + * + * @description: + * Round a 16.16 fixed number. + * + * @input: + * a :: + * The number to be rounded. + * + * @return: + * `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 ); + + + /************************************************************************** + * + * @function: + * FT_CeilFix + * + * @description: + * Compute the smallest following integer of a 16.16 fixed number. + * + * @input: + * a :: + * The number for which the ceiling function is to be computed. + * + * @return: + * `a` rounded towards plus infinity. + * + * @note: + * The function uses wrap-around arithmetic. + */ + FT_EXPORT( FT_Fixed ) + FT_CeilFix( FT_Fixed a ); + + + /************************************************************************** + * + * @function: + * FT_FloorFix + * + * @description: + * Compute the largest previous integer of a 16.16 fixed number. + * + * @input: + * a :: + * The number for which the floor function is to be computed. + * + * @return: + * `a` rounded towards minus infinity. + */ + FT_EXPORT( FT_Fixed ) + FT_FloorFix( FT_Fixed a ); + + + /************************************************************************** + * + * @function: + * FT_Vector_Transform + * + * @description: + * Transform a single vector through a 2x2 matrix. + * + * @inout: + * vector :: + * The target vector to transform. + * + * @input: + * matrix :: + * A pointer to the source 2x2 matrix. + * + * @note: + * The result is undefined if either `vector` or `matrix` is invalid. + */ + FT_EXPORT( void ) + FT_Vector_Transform( FT_Vector* vector, + const FT_Matrix* matrix ); + + + /************************************************************************** + * + * @section: + * version + * + * @title: + * FreeType Version + * + * @abstract: + * Functions and macros related to FreeType versions. + * + * @description: + * Note that those functions and macros are of limited use because even a + * new release of FreeType with only documentation changes increases the + * version number. + * + * @order: + * FT_Library_Version + * + * FREETYPE_MAJOR + * FREETYPE_MINOR + * FREETYPE_PATCH + * + * FT_Face_CheckTrueTypePatents + * FT_Face_SetUnpatentedHinting + * + */ + + + /************************************************************************** + * + * @enum: + * FREETYPE_XXX + * + * @description: + * These three macros identify the FreeType source code version. Use + * @FT_Library_Version to access them at runtime. + * + * @values: + * FREETYPE_MAJOR :: + * The major version number. + * FREETYPE_MINOR :: + * The minor version number. + * FREETYPE_PATCH :: + * The patch level. + * + * @note: + * The version number of FreeType if built as a dynamic link library with + * the 'libtool' package is _not_ controlled by these three macros. + * + */ +#define FREETYPE_MAJOR 2 +#define FREETYPE_MINOR 13 +#define FREETYPE_PATCH 0 + + + /************************************************************************** + * + * @function: + * FT_Library_Version + * + * @description: + * Return the version of the FreeType library being used. This is useful + * when dynamically linking to the library, since one cannot use the + * macros @FREETYPE_MAJOR, @FREETYPE_MINOR, and @FREETYPE_PATCH. + * + * @input: + * library :: + * A source library handle. + * + * @output: + * amajor :: + * The major version number. + * + * aminor :: + * The minor version number. + * + * apatch :: + * The patch version number. + * + * @note: + * The reason why this function takes a `library` argument is because + * certain programs implement library initialization in a custom way that + * doesn't use @FT_Init_FreeType. + * + * In such cases, the library version might not be available before the + * library object has been created. + */ + FT_EXPORT( void ) + FT_Library_Version( FT_Library library, + FT_Int *amajor, + FT_Int *aminor, + FT_Int *apatch ); + + + /************************************************************************** + * + * @function: + * FT_Face_CheckTrueTypePatents + * + * @description: + * Deprecated, does nothing. + * + * @input: + * face :: + * A face handle. + * + * @return: + * Always returns false. + * + * @note: + * Since May 2010, TrueType hinting is no longer patented. + * + * @since: + * 2.3.5 + * + */ + FT_EXPORT( FT_Bool ) + FT_Face_CheckTrueTypePatents( FT_Face face ); + + + /************************************************************************** + * + * @function: + * FT_Face_SetUnpatentedHinting + * + * @description: + * Deprecated, does nothing. + * + * @input: + * face :: + * A face handle. + * + * value :: + * New boolean setting. + * + * @return: + * Always returns false. + * + * @note: + * Since May 2010, TrueType hinting is no longer patented. + * + * @since: + * 2.3.5 + * + */ + FT_EXPORT( FT_Bool ) + FT_Face_SetUnpatentedHinting( FT_Face face, + FT_Bool value ); + + /* */ + + +FT_END_HEADER + +#endif /* FREETYPE_H_ */ + + +/* END */ |