| /**************************************************************************** |
| * |
| * aftypes.h |
| * |
| * Auto-fitter types (specification only). |
| * |
| * Copyright (C) 2003-2021 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. |
| * |
| */ |
| |
| |
| /************************************************************************* |
| * |
| * The auto-fitter is a complete rewrite of the old auto-hinter. |
| * Its main feature is the ability to differentiate between different |
| * writing systems and scripts in order to apply specific rules. |
| * |
| * The code has also been compartmentalized into several entities that |
| * should make algorithmic experimentation easier than with the old |
| * code. |
| * |
| *************************************************************************/ |
| |
| |
| #ifndef AFTYPES_H_ |
| #define AFTYPES_H_ |
| |
| |
| #include <freetype/freetype.h> |
| #include <freetype/ftoutln.h> |
| #include <freetype/internal/ftobjs.h> |
| #include <freetype/internal/ftdebug.h> |
| |
| #include "afblue.h" |
| |
| #ifdef FT_DEBUG_AUTOFIT |
| #include FT_CONFIG_STANDARD_LIBRARY_H |
| #endif |
| |
| |
| FT_BEGIN_HEADER |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /***** *****/ |
| /***** D E B U G G I N G *****/ |
| /***** *****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| #ifdef FT_DEBUG_AUTOFIT |
| |
| extern int _af_debug_disable_horz_hints; |
| extern int _af_debug_disable_vert_hints; |
| extern int _af_debug_disable_blue_hints; |
| extern void* _af_debug_hints; |
| |
| #endif /* FT_DEBUG_AUTOFIT */ |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /***** *****/ |
| /***** U T I L I T Y S T U F F *****/ |
| /***** *****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| typedef struct AF_WidthRec_ |
| { |
| FT_Pos org; /* original position/width in font units */ |
| FT_Pos cur; /* current/scaled position/width in device subpixels */ |
| FT_Pos fit; /* current/fitted position/width in device subpixels */ |
| |
| } AF_WidthRec, *AF_Width; |
| |
| |
| FT_LOCAL( void ) |
| af_sort_pos( FT_UInt count, |
| FT_Pos* table ); |
| |
| FT_LOCAL( void ) |
| af_sort_and_quantize_widths( FT_UInt* count, |
| AF_Width widths, |
| FT_Pos threshold ); |
| |
| |
| /* |
| * opaque handle to glyph-specific hints -- see `afhints.h' for more |
| * details |
| */ |
| typedef struct AF_GlyphHintsRec_* AF_GlyphHints; |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /***** *****/ |
| /***** S C A L E R S *****/ |
| /***** *****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| /* |
| * A scaler models the target pixel device that will receive the |
| * auto-hinted glyph image. |
| */ |
| |
| #define AF_SCALER_FLAG_NO_HORIZONTAL 1U /* disable horizontal hinting */ |
| #define AF_SCALER_FLAG_NO_VERTICAL 2U /* disable vertical hinting */ |
| #define AF_SCALER_FLAG_NO_ADVANCE 4U /* disable advance hinting */ |
| |
| |
| typedef struct AF_ScalerRec_ |
| { |
| FT_Face face; /* source font face */ |
| FT_Fixed x_scale; /* from font units to 1/64th device pixels */ |
| FT_Fixed y_scale; /* from font units to 1/64th device pixels */ |
| FT_Pos x_delta; /* in 1/64th device pixels */ |
| FT_Pos y_delta; /* in 1/64th device pixels */ |
| FT_Render_Mode render_mode; /* monochrome, anti-aliased, LCD, etc. */ |
| FT_UInt32 flags; /* additional control flags, see above */ |
| |
| } AF_ScalerRec, *AF_Scaler; |
| |
| |
| #define AF_SCALER_EQUAL_SCALES( a, b ) \ |
| ( (a)->x_scale == (b)->x_scale && \ |
| (a)->y_scale == (b)->y_scale && \ |
| (a)->x_delta == (b)->x_delta && \ |
| (a)->y_delta == (b)->y_delta ) |
| |
| |
| typedef struct AF_StyleMetricsRec_* AF_StyleMetrics; |
| |
| /* |
| * This function parses an FT_Face to compute global metrics for |
| * a specific style. |
| */ |
| typedef FT_Error |
| (*AF_WritingSystem_InitMetricsFunc)( AF_StyleMetrics metrics, |
| FT_Face face ); |
| |
| typedef void |
| (*AF_WritingSystem_ScaleMetricsFunc)( AF_StyleMetrics metrics, |
| AF_Scaler scaler ); |
| |
| typedef void |
| (*AF_WritingSystem_DoneMetricsFunc)( AF_StyleMetrics metrics ); |
| |
| typedef void |
| (*AF_WritingSystem_GetStdWidthsFunc)( AF_StyleMetrics metrics, |
| FT_Pos* stdHW, |
| FT_Pos* stdVW ); |
| |
| |
| typedef FT_Error |
| (*AF_WritingSystem_InitHintsFunc)( AF_GlyphHints hints, |
| AF_StyleMetrics metrics ); |
| |
| typedef FT_Error |
| (*AF_WritingSystem_ApplyHintsFunc)( FT_UInt glyph_index, |
| AF_GlyphHints hints, |
| FT_Outline* outline, |
| AF_StyleMetrics metrics ); |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /***** *****/ |
| /***** W R I T I N G S Y S T E M S *****/ |
| /***** *****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| /* |
| * 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 that computes global metrics specific to |
| * the script (based on script-specific characters to identify ascender |
| * height, x-height, etc.), |
| * |
| * - a specific glyph analyzer that computes segments and edges for each |
| * glyph covered by the script, |
| * |
| * - a specific grid-fitting algorithm that distorts the scaled glyph |
| * outline according to the results of the glyph analyzer. |
| */ |
| |
| #undef WRITING_SYSTEM |
| #define WRITING_SYSTEM( ws, WS ) \ |
| AF_WRITING_SYSTEM_ ## WS, |
| |
| /* The list of known writing systems. */ |
| typedef enum AF_WritingSystem_ |
| { |
| |
| #include "afws-iter.h" |
| |
| AF_WRITING_SYSTEM_MAX /* do not remove */ |
| |
| } AF_WritingSystem; |
| |
| |
| typedef struct AF_WritingSystemClassRec_ |
| { |
| AF_WritingSystem writing_system; |
| |
| FT_Offset style_metrics_size; |
| AF_WritingSystem_InitMetricsFunc style_metrics_init; |
| AF_WritingSystem_ScaleMetricsFunc style_metrics_scale; |
| AF_WritingSystem_DoneMetricsFunc style_metrics_done; |
| AF_WritingSystem_GetStdWidthsFunc style_metrics_getstdw; |
| |
| AF_WritingSystem_InitHintsFunc style_hints_init; |
| AF_WritingSystem_ApplyHintsFunc style_hints_apply; |
| |
| } AF_WritingSystemClassRec; |
| |
| typedef const AF_WritingSystemClassRec* AF_WritingSystemClass; |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /***** *****/ |
| /***** S C R I P T S *****/ |
| /***** *****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| /* |
| * Each script is associated with two sets of Unicode ranges to test |
| * whether the font face supports the script, and which non-base |
| * characters the script contains. |
| * |
| * We use four-letter script tags from the OpenType specification, |
| * extended by `NONE', which indicates `no script'. |
| */ |
| |
| #undef SCRIPT |
| #define SCRIPT( s, S, d, h, H, ss ) \ |
| AF_SCRIPT_ ## S, |
| |
| /* The list of known scripts. */ |
| typedef enum AF_Script_ |
| { |
| |
| #include "afscript.h" |
| |
| AF_SCRIPT_MAX /* do not remove */ |
| |
| } AF_Script; |
| |
| |
| typedef struct AF_Script_UniRangeRec_ |
| { |
| FT_UInt32 first; |
| FT_UInt32 last; |
| |
| } AF_Script_UniRangeRec; |
| |
| #define AF_UNIRANGE_REC( a, b ) { (FT_UInt32)(a), (FT_UInt32)(b) } |
| |
| typedef const AF_Script_UniRangeRec* AF_Script_UniRange; |
| |
| |
| typedef struct AF_ScriptClassRec_ |
| { |
| AF_Script script; |
| |
| /* last element in the ranges must be { 0, 0 } */ |
| AF_Script_UniRange script_uni_ranges; |
| AF_Script_UniRange script_uni_nonbase_ranges; |
| |
| FT_Bool top_to_bottom_hinting; |
| |
| const char* standard_charstring; /* for default width and height */ |
| |
| } 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; |
| |
| |
| #define AF_HINTING_BOTTOM_TO_TOP 0 |
| #define AF_HINTING_TOP_TO_BOTTOM 1 |
| |
| |
| /* Declare and define vtables for classes */ |
| #define AF_DECLARE_WRITING_SYSTEM_CLASS( writing_system_class ) \ |
| FT_CALLBACK_TABLE const AF_WritingSystemClassRec \ |
| writing_system_class; |
| |
| #define AF_DEFINE_WRITING_SYSTEM_CLASS( \ |
| writing_system_class, \ |
| system, \ |
| m_size, \ |
| m_init, \ |
| m_scale, \ |
| m_done, \ |
| m_stdw, \ |
| h_init, \ |
| h_apply ) \ |
| FT_CALLBACK_TABLE_DEF \ |
| const AF_WritingSystemClassRec writing_system_class = \ |
| { \ |
| system, \ |
| \ |
| m_size, \ |
| \ |
| m_init, \ |
| m_scale, \ |
| m_done, \ |
| m_stdw, \ |
| \ |
| h_init, \ |
| h_apply \ |
| }; |
| |
| |
| #define AF_DECLARE_SCRIPT_CLASS( script_class ) \ |
| FT_CALLBACK_TABLE const AF_ScriptClassRec \ |
| script_class; |
| |
| #define AF_DEFINE_SCRIPT_CLASS( \ |
| script_class, \ |
| script, \ |
| ranges, \ |
| nonbase_ranges, \ |
| top_to_bottom, \ |
| std_charstring ) \ |
| FT_CALLBACK_TABLE_DEF \ |
| const AF_ScriptClassRec script_class = \ |
| { \ |
| script, \ |
| ranges, \ |
| nonbase_ranges, \ |
| top_to_bottom, \ |
| std_charstring, \ |
| }; |
| |
| |
| #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 \ |
| }; |
| |
| /* */ |
| |
| |
| FT_END_HEADER |
| |
| #endif /* AFTYPES_H_ */ |
| |
| |
| /* END */ |
