ref: e921bdebdee3525b0d74053ad5752c59868bf98d
dir: /src/autofit/aftypes.h/
/***************************************************************************/
/* */
/* aftypes.h */
/* */
/* Auto-fitter types (specification only). */
/* */
/* Copyright 2003-2009, 2011-2013 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 in order to apply script-specific rules.
*
* The code has also been compartmentized into several entities that
* should make algorithmic experimentation easier than with the old
* code.
*
*************************************************************************/
#ifndef __AFTYPES_H__
#define __AFTYPES_H__
#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_OUTLINE_H
#include FT_INTERNAL_OBJECTS_H
#include FT_INTERNAL_DEBUG_H
#include "afblue.h"
FT_BEGIN_HEADER
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** D E B U G G I N G *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
#ifdef FT_DEBUG_AUTOFIT
#include FT_CONFIG_STANDARD_LIBRARY_H
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 sub-pixels */
FT_Pos fit; /* current/fitted position/width in device sub-pixels */
} 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 );
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** A N G L E T Y P E S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*
* The auto-fitter doesn't need a very high angular accuracy;
* this allows us to speed up some computations considerably with a
* light Cordic algorithm (see afangles.c).
*/
typedef FT_Int AF_Angle;
#define AF_ANGLE_PI 256
#define AF_ANGLE_2PI ( AF_ANGLE_PI * 2 )
#define AF_ANGLE_PI2 ( AF_ANGLE_PI / 2 )
#define AF_ANGLE_PI4 ( AF_ANGLE_PI / 4 )
#if 0
/*
* compute the angle of a given 2-D vector
*/
FT_LOCAL( AF_Angle )
af_angle_atan( FT_Pos dx,
FT_Pos dy );
/*
* compute `angle2 - angle1'; the result is always within
* the range [-AF_ANGLE_PI .. AF_ANGLE_PI - 1]
*/
FT_LOCAL( AF_Angle )
af_angle_diff( AF_Angle angle1,
AF_Angle angle2 );
#endif /* 0 */
#define AF_ANGLE_DIFF( result, angle1, angle2 ) \
FT_BEGIN_STMNT \
AF_Angle _delta = (angle2) - (angle1); \
\
\
_delta %= AF_ANGLE_2PI; \
if ( _delta < 0 ) \
_delta += AF_ANGLE_2PI; \
\
if ( _delta > AF_ANGLE_PI ) \
_delta -= AF_ANGLE_2PI; \
\
result = _delta; \
FT_END_STMNT
/* 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.
*/
typedef enum AF_ScalerFlags_
{
AF_SCALER_FLAG_NO_HORIZONTAL = 1, /* disable horizontal hinting */
AF_SCALER_FLAG_NO_VERTICAL = 2, /* disable vertical hinting */
AF_SCALER_FLAG_NO_ADVANCE = 4 /* disable advance hinting */
} AF_ScalerFlags;
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 )
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** 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;
/* This function parses an FT_Face to compute global metrics for
* a specific script.
*/
typedef FT_Error
(*AF_Script_InitMetricsFunc)( AF_ScriptMetrics metrics,
FT_Face face );
typedef void
(*AF_Script_ScaleMetricsFunc)( AF_ScriptMetrics metrics,
AF_Scaler scaler );
typedef void
(*AF_Script_DoneMetricsFunc)( AF_ScriptMetrics metrics );
typedef FT_Error
(*AF_Script_InitHintsFunc)( AF_GlyphHints hints,
AF_ScriptMetrics metrics );
typedef void
(*AF_Script_ApplyHintsFunc)( AF_GlyphHints hints,
FT_Outline* outline,
AF_ScriptMetrics metrics );
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** W R I T I N G S Y S T E M S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*
* 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
* 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
* 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.
*/
#define __AFWRTSYS_H__ /* don't load header files */
#undef WRITING_SYSTEM
#define WRITING_SYSTEM( ws, WS ) \
AF_WRITING_SYSTEM_ ## WS,
/* The list of known writing systems. */
typedef enum AF_WritingSystem_
{
#include "afwrtsys.h"
AF_WRITING_SYSTEM_MAX /* do not remove */
} AF_WritingSystem;
#undef __AFWRTSYS_H__
typedef struct AF_WritingSystemClassRec_
{
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;
AF_Script_InitHintsFunc script_hints_init;
AF_Script_ApplyHintsFunc script_hints_apply;
} AF_WritingSystemClassRec;
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** S C R I P T S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*
* 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.
*
* We use four-letter script tags from the OpenType specification.
*/
#undef SCRIPT
#define SCRIPT( s, S, d ) \
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;
AF_Blue_Stringset blue_stringset;
AF_WritingSystem writing_system;
AF_Script_UniRange script_uni_ranges; /* last must be { 0, 0 } */
FT_UInt32 standard_char; /* for default width and height */
} AF_ScriptClassRec;
/* Declare and define vtables for classes */
#ifndef FT_CONFIG_OPTION_PIC
#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, \
h_init, \
h_apply ) \
FT_CALLBACK_TABLE_DEF \
const AF_WritingSystemClassRec writing_system_class = \
{ \
system, \
\
m_size, \
\
m_init, \
m_scale, \
m_done, \
\
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_, \
blue_stringset_, \
writing_system_, \
ranges, \
std_char ) \
FT_CALLBACK_TABLE_DEF \
const AF_ScriptClassRec script_class = \
{ \
script_, \
blue_stringset_, \
writing_system_, \
ranges, \
std_char \
};
#else /* FT_CONFIG_OPTION_PIC */
#define AF_DECLARE_WRITING_SYSTEM_CLASS( writing_system_class ) \
FT_LOCAL( void ) \
FT_Init_Class_ ## writing_system_class( AF_WritingSystemClassRec* ac );
#define AF_DEFINE_WRITING_SYSTEM_CLASS( \
writing_system_class, \
system, \
m_size, \
m_init, \
m_scale, \
m_done, \
h_init, \
h_apply ) \
FT_LOCAL_DEF( void ) \
FT_Init_Class_ ## writing_system_class( AF_WritingSystemClassRec* ac ) \
{ \
ac->writing_system = system; \
\
ac->script_metrics_size = m_size; \
\
ac->script_metrics_init = m_init; \
ac->script_metrics_scale = m_scale; \
ac->script_metrics_done = m_done; \
\
ac->script_hints_init = h_init; \
ac->script_hints_apply = h_apply; \
}
#define AF_DECLARE_SCRIPT_CLASS( script_class ) \
FT_LOCAL( void ) \
FT_Init_Class_ ## script_class( AF_ScriptClassRec* ac );
#define AF_DEFINE_SCRIPT_CLASS( \
script_class, \
script_, \
blue_string_set_, \
writing_system_, \
ranges, \
std_char ) \
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; \
}
#endif /* FT_CONFIG_OPTION_PIC */
/* */
FT_END_HEADER
#endif /* __AFTYPES_H__ */
/* END */