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+/***************************************************************************/
+/*                                                                         */
+/*  aftypes.h                                                              */
+/*                                                                         */
+/*    Auto-fitter types (specification only).                              */
+/*                                                                         */
+/*  Copyright 2003-2018 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 "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
+
+
+  /*************************************************************************/
+  /*************************************************************************/
+  /*****                                                               *****/
+  /*****                 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 );
+
+
+  /*************************************************************************/
+  /*************************************************************************/
+  /*****                                                               *****/
+  /*****                   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);     \
+                                                \
+                                                \
+    while ( _delta <= -AF_ANGLE_PI )            \
+      _delta += AF_ANGLE_2PI;                   \
+                                                \
+    while ( _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.
+   */
+
+#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    */
+#define AF_SCALER_FLAG_NO_WARPER      8U /* disable warper             */
+
+
+  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.
+   */
+
+#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                          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 */