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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
commit | 6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /modules/freetype2/src/autofit/aftypes.h | |
parent | Initial commit. (diff) | |
download | thunderbird-upstream.tar.xz thunderbird-upstream.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'modules/freetype2/src/autofit/aftypes.h')
-rw-r--r-- | modules/freetype2/src/autofit/aftypes.h | 511 |
1 files changed, 511 insertions, 0 deletions
diff --git a/modules/freetype2/src/autofit/aftypes.h b/modules/freetype2/src/autofit/aftypes.h new file mode 100644 index 0000000000..6615194496 --- /dev/null +++ b/modules/freetype2/src/autofit/aftypes.h @@ -0,0 +1,511 @@ +/**************************************************************************** + * + * aftypes.h + * + * Auto-fitter types (specification only). + * + * Copyright (C) 2003-2023 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. + * + */ + + + /************************************************************************* + * + * 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 1/64 device pixels */ + FT_Fixed y_scale; /* from font units to 1/64 device pixels */ + FT_Pos x_delta; /* in 1/64 device pixels */ + FT_Pos y_delta; /* in 1/64 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 */ |