diff options
Diffstat (limited to 'src/autofit/aftypes.h')
| -rw-r--r-- | src/autofit/aftypes.h | 310 |
1 files changed, 232 insertions, 78 deletions
diff --git a/src/autofit/aftypes.h b/src/autofit/aftypes.h index cda1f89..61badd1 100644 --- a/src/autofit/aftypes.h +++ b/src/autofit/aftypes.h @@ -4,7 +4,7 @@ /* */ /* Auto-fitter types (specification only). */ /* */ -/* Copyright 2003-2009, 2011-2013 by */ +/* Copyright 2003-2009, 2011-2014 by */ /* David Turner, Robert Wilhelm, and Werner Lemberg. */ /* */ /* This file is part of the FreeType project, and may only be used, */ @@ -20,7 +20,7 @@ * * The auto-fitter is a complete rewrite of the old auto-hinter. * Its main feature is the ability to differentiate between different - * writing systems in order to apply script-specific rules. + * writing systems and scripts in order to apply specific rules. * * The code has also been compartmentized into several entities that * should make algorithmic experimentation easier than with the old @@ -197,55 +197,31 @@ extern void* _af_debug_hints; (a)->y_delta == (b)->y_delta ) - /*************************************************************************/ - /*************************************************************************/ - /***** *****/ - /***** S C R I P T M E T R I C S *****/ - /***** *****/ - /*************************************************************************/ - /*************************************************************************/ - - /* This is the main structure which combines writing systems and script */ - /* data (for a given face object, see below). */ - - typedef struct AF_WritingSystemClassRec_ const* AF_WritingSystemClass; - typedef struct AF_ScriptClassRec_ const* AF_ScriptClass; - typedef struct AF_FaceGlobalsRec_* AF_FaceGlobals; - - typedef struct AF_ScriptMetricsRec_ - { - AF_ScriptClass script_class; - AF_ScalerRec scaler; - FT_Bool digits_have_same_width; - - AF_FaceGlobals globals; /* to access properties */ - - } AF_ScriptMetricsRec, *AF_ScriptMetrics; - + typedef struct AF_StyleMetricsRec_* AF_StyleMetrics; /* This function parses an FT_Face to compute global metrics for - * a specific script. + * a specific style. */ typedef FT_Error - (*AF_Script_InitMetricsFunc)( AF_ScriptMetrics metrics, - FT_Face face ); + (*AF_WritingSystem_InitMetricsFunc)( AF_StyleMetrics metrics, + FT_Face face ); typedef void - (*AF_Script_ScaleMetricsFunc)( AF_ScriptMetrics metrics, - AF_Scaler scaler ); + (*AF_WritingSystem_ScaleMetricsFunc)( AF_StyleMetrics metrics, + AF_Scaler scaler ); typedef void - (*AF_Script_DoneMetricsFunc)( AF_ScriptMetrics metrics ); + (*AF_WritingSystem_DoneMetricsFunc)( AF_StyleMetrics metrics ); typedef FT_Error - (*AF_Script_InitHintsFunc)( AF_GlyphHints hints, - AF_ScriptMetrics metrics ); + (*AF_WritingSystem_InitHintsFunc)( AF_GlyphHints hints, + AF_StyleMetrics metrics ); typedef void - (*AF_Script_ApplyHintsFunc)( AF_GlyphHints hints, - FT_Outline* outline, - AF_ScriptMetrics metrics ); + (*AF_WritingSystem_ApplyHintsFunc)( AF_GlyphHints hints, + FT_Outline* outline, + AF_StyleMetrics metrics ); /*************************************************************************/ @@ -257,14 +233,14 @@ extern void* _af_debug_hints; /*************************************************************************/ /* - * In FreeType, a writing system consists of multiple scripts which can - * be handled similarly *in a typographical way*; the relationship is not - * based on history. For example, both the Greek and the unrelated + * For the auto-hinter, a writing system consists of multiple scripts that + * can be handled similarly *in a typographical way*; the relationship is + * not based on history. For example, both the Greek and the unrelated * Armenian scripts share the same features like ascender, descender, * x-height, etc. Essentially, a writing system is covered by a * submodule of the auto-fitter; it contains * - * - a specific global analyzer which computes global metrics specific to + * - a specific global analyzer that computes global metrics specific to * the script (based on script-specific characters to identify ascender * height, x-height, etc.), * @@ -297,16 +273,18 @@ extern void* _af_debug_hints; { AF_WritingSystem writing_system; - FT_Offset script_metrics_size; - AF_Script_InitMetricsFunc script_metrics_init; - AF_Script_ScaleMetricsFunc script_metrics_scale; - AF_Script_DoneMetricsFunc script_metrics_done; + FT_Offset style_metrics_size; + AF_WritingSystem_InitMetricsFunc style_metrics_init; + AF_WritingSystem_ScaleMetricsFunc style_metrics_scale; + AF_WritingSystem_DoneMetricsFunc style_metrics_done; - AF_Script_InitHintsFunc script_hints_init; - AF_Script_ApplyHintsFunc script_hints_apply; + AF_WritingSystem_InitHintsFunc style_hints_init; + AF_WritingSystem_ApplyHintsFunc style_hints_apply; } AF_WritingSystemClassRec; + typedef const AF_WritingSystemClassRec* AF_WritingSystemClass; + /*************************************************************************/ /*************************************************************************/ @@ -317,15 +295,15 @@ extern void* _af_debug_hints; /*************************************************************************/ /* - * Each script is associated with a set of Unicode ranges which gets used - * to test whether the font face supports the script. It also references - * the writing system it belongs to. + * Each script is associated with a set of Unicode ranges that gets used + * to test whether the font face supports the script. * - * We use four-letter script tags from the OpenType specification. + * We use four-letter script tags from the OpenType specification, + * extended by `NONE', which indicates `no script'. */ #undef SCRIPT -#define SCRIPT( s, S, d ) \ +#define SCRIPT( s, S, d, h, sc1, sc2, sc3 ) \ AF_SCRIPT_ ## S, /* The list of known scripts. */ @@ -353,15 +331,147 @@ extern void* _af_debug_hints; typedef struct AF_ScriptClassRec_ { - AF_Script script; - AF_Blue_Stringset blue_stringset; - AF_WritingSystem writing_system; + AF_Script script; AF_Script_UniRange script_uni_ranges; /* last must be { 0, 0 } */ - FT_UInt32 standard_char; /* for default width and height */ + + FT_UInt32 standard_char1; /* for default width and height */ + FT_UInt32 standard_char2; /* ditto */ + FT_UInt32 standard_char3; /* ditto */ } AF_ScriptClassRec; + typedef const AF_ScriptClassRec* AF_ScriptClass; + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** C O V E R A G E S *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + + /* + * Usually, a font contains more glyphs than can be addressed by its + * character map. + * + * In the PostScript font world, encoding vectors specific to a given + * task are used to select such glyphs, and these glyphs can be often + * recognized by having a suffix in its glyph names. For example, a + * superscript glyph `A' might be called `A.sup'. Unfortunately, this + * naming scheme is not standardized and thus unusable for us. + * + * In the OpenType world, a better solution was invented, namely + * `features', which cleanly separate a character's input encoding from + * the corresponding glyph's appearance, and which don't use glyph names + * at all. For our purposes, and slightly generalized, an OpenType + * feature is a name of a mapping that maps character codes to + * non-standard glyph indices (features get used for other things also). + * For example, the `sups' feature provides superscript glyphs, thus + * mapping character codes like `A' or `B' to superscript glyph + * representation forms. How this mapping happens is completely + * uninteresting to us. + * + * For the auto-hinter, a `coverage' represents all glyphs of an OpenType + * feature collected in a set (as listed below) that can be hinted + * together. To continue the above example, superscript glyphs must not + * be hinted together with normal glyphs because the blue zones + * completely differ. + * + * Note that FreeType itself doesn't compute coverages; it only provides + * the glyphs addressable by the default Unicode character map. Instead, + * we use the HarfBuzz library (if available), which has many functions + * exactly for this purpose. + * + * AF_COVERAGE_DEFAULT is special: It should cover everything that isn't + * listed separately (including the glyphs addressable by the character + * map). In case HarfBuzz isn't available, it exactly covers the glyphs + * addressable by the character map. + * + */ + +#undef COVERAGE +#define COVERAGE( name, NAME, description, \ + tag1, tag2, tag3, tag4 ) \ + AF_COVERAGE_ ## NAME, + + + typedef enum AF_Coverage_ + { +#include "afcover.h" + + AF_COVERAGE_DEFAULT + + } AF_Coverage; + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** S T Y L E S *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + + /* + * The topmost structure for modelling the auto-hinter glyph input data + * is a `style class', grouping everything together. + */ + +#undef STYLE +#define STYLE( s, S, d, ws, sc, ss, c ) \ + AF_STYLE_ ## S, + + /* The list of known styles. */ + typedef enum AF_Style_ + { + +#include "afstyles.h" + + AF_STYLE_MAX /* do not remove */ + + } AF_Style; + + + typedef struct AF_StyleClassRec_ + { + AF_Style style; + + AF_WritingSystem writing_system; + AF_Script script; + AF_Blue_Stringset blue_stringset; + AF_Coverage coverage; + + } AF_StyleClassRec; + + typedef const AF_StyleClassRec* AF_StyleClass; + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** S T Y L E M E T R I C S *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + + typedef struct AF_FaceGlobalsRec_* AF_FaceGlobals; + + /* This is the main structure that combines everything. Autofit modules */ + /* specific to writing systems derive their structures from it, for */ + /* example `AF_LatinMetrics'. */ + + typedef struct AF_StyleMetricsRec_ + { + AF_StyleClass style_class; + AF_ScalerRec scaler; + FT_Bool digits_have_same_width; + + AF_FaceGlobals globals; /* to access properties */ + + } AF_StyleMetricsRec; + /* Declare and define vtables for classes */ #ifndef FT_CONFIG_OPTION_PIC @@ -401,19 +511,41 @@ extern void* _af_debug_hints; #define AF_DEFINE_SCRIPT_CLASS( \ script_class, \ - script_, \ - blue_stringset_, \ - writing_system_, \ + script, \ ranges, \ - std_char ) \ + std_char1, \ + std_char2, \ + std_char3 ) \ FT_CALLBACK_TABLE_DEF \ const AF_ScriptClassRec script_class = \ { \ - script_, \ - blue_stringset_, \ - writing_system_, \ + script, \ ranges, \ - std_char \ + std_char1, \ + std_char2, \ + std_char3 \ + }; + + +#define AF_DECLARE_STYLE_CLASS( style_class ) \ + FT_CALLBACK_TABLE const AF_StyleClassRec \ + style_class; + +#define AF_DEFINE_STYLE_CLASS( \ + style_class, \ + style, \ + writing_system, \ + script, \ + blue_stringset, \ + coverage ) \ + FT_CALLBACK_TABLE_DEF \ + const AF_StyleClassRec style_class = \ + { \ + style, \ + writing_system, \ + script, \ + blue_stringset, \ + coverage \ }; #else /* FT_CONFIG_OPTION_PIC */ @@ -434,16 +566,16 @@ extern void* _af_debug_hints; FT_LOCAL_DEF( void ) \ FT_Init_Class_ ## writing_system_class( AF_WritingSystemClassRec* ac ) \ { \ - ac->writing_system = system; \ + ac->writing_system = system; \ \ - ac->script_metrics_size = m_size; \ + ac->style_metrics_size = m_size; \ \ - ac->script_metrics_init = m_init; \ - ac->script_metrics_scale = m_scale; \ - ac->script_metrics_done = m_done; \ + ac->style_metrics_init = m_init; \ + ac->style_metrics_scale = m_scale; \ + ac->style_metrics_done = m_done; \ \ - ac->script_hints_init = h_init; \ - ac->script_hints_apply = h_apply; \ + ac->style_hints_init = h_init; \ + ac->style_hints_apply = h_apply; \ } @@ -454,18 +586,40 @@ extern void* _af_debug_hints; #define AF_DEFINE_SCRIPT_CLASS( \ script_class, \ script_, \ - blue_string_set_, \ - writing_system_, \ ranges, \ - std_char ) \ + std_char1, \ + std_char2, \ + std_char3 ) \ FT_LOCAL_DEF( void ) \ FT_Init_Class_ ## script_class( AF_ScriptClassRec* ac ) \ { \ ac->script = script_; \ - ac->blue_stringset = blue_stringset_; \ - ac->writing_system = writing_system_; \ ac->script_uni_ranges = ranges; \ - ac->standard_char = std_char; \ + ac->standard_char1 = std_char1; \ + ac->standard_char2 = std_char2; \ + ac->standard_char3 = std_char3; \ + } + + +#define AF_DECLARE_STYLE_CLASS( style_class ) \ + FT_LOCAL( void ) \ + FT_Init_Class_ ## style_class( AF_StyleClassRec* ac ); + +#define AF_DEFINE_STYLE_CLASS( \ + style_class, \ + style_, \ + writing_system_, \ + script_, \ + blue_stringset_, \ + coverage_ ) \ + FT_LOCAL_DEF( void ) \ + FT_Init_Class_ ## style_class( AF_StyleClassRec* ac ) \ + { \ + ac->style = style_; \ + ac->writing_system = writing_system_; \ + ac->script = script_; \ + ac->blue_stringset = blue_stringset_; \ + ac->coverage = coverage_; \ } #endif /* FT_CONFIG_OPTION_PIC */ |