modules/freetype2/src/autofit/aftypes.h

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  aftypes.h                                                              */
   4 /*                                                                         */
   5 /*    Auto-fitter types (specification only).                              */
   6 /*                                                                         */
   7 /*  Copyright 2003, 2004, 2005, 2006, 2007, 2008 by                        */
   8 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
   9 /*                                                                         */
  10 /*  This file is part of the FreeType project, and may only be used,       */
  11 /*  modified, and distributed under the terms of the FreeType project      */
  12 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  13 /*  this file you indicate that you have read the license and              */
  14 /*  understand and accept it fully.                                        */
  15 /*                                                                         */
  16 /***************************************************************************/
  17
  18
  19   /*************************************************************************
  20    *
  21    *  The auto-fitter is a complete rewrite of the old auto-hinter.
  22    *  Its main feature is the ability to differentiate between different
  23    *  scripts in order to apply language-specific rules.
  24    *
  25    *  The code has also been compartmentized into several entities that
  26    *  should make algorithmic experimentation easier than with the old
  27    *  code.
  28    *
  29    *  Finally, we get rid of the Catharon license, since this code is
  30    *  released under the FreeType one.
  31    *
  32    *************************************************************************/
  33
  34
  35 #ifndef __AFTYPES_H__
  36 #define __AFTYPES_H__
  37
  38 #include <ft2build.h>
  39
  40 #include FT_FREETYPE_H
  41 #include FT_OUTLINE_H
  42 #include FT_INTERNAL_OBJECTS_H
  43 #include FT_INTERNAL_DEBUG_H
  44
  45
  46 FT_BEGIN_HEADER
  47
  48   /*************************************************************************/
  49   /*************************************************************************/
  50   /*****                                                               *****/
  51   /*****                    D E B U G G I N G                          *****/
  52   /*****                                                               *****/
  53   /*************************************************************************/
  54   /*************************************************************************/
  55
  56 #define xxAF_USE_WARPER  /* only define to use warp hinting */
  57 #define xxAF_DEBUG
  58
  59 #ifdef AF_DEBUG
  60
  61 #include <stdio.h>
  62 #define AF_LOG( x )  do { if ( _af_debug ) printf x; } while ( 0 )
  63
  64 extern int    _af_debug;
  65 extern int    _af_debug_disable_horz_hints;
  66 extern int    _af_debug_disable_vert_hints;
  67 extern int    _af_debug_disable_blue_hints;
  68 extern void*  _af_debug_hints;
  69
  70 #else /* !AF_DEBUG */
  71
  72 #define AF_LOG( x )  do ; while ( 0 )        /* nothing */
  73
  74 #endif /* !AF_DEBUG */
  75
  76
  77   /*************************************************************************/
  78   /*************************************************************************/
  79   /*****                                                               *****/
  80   /*****                 U T I L I T Y   S T U F F                     *****/
  81   /*****                                                               *****/
  82   /*************************************************************************/
  83   /*************************************************************************/
  84
  85   typedef struct  AF_WidthRec_
  86   {
  87     FT_Pos  org;  /* original position/width in font units              */
  88     FT_Pos  cur;  /* current/scaled position/width in device sub-pixels */
  89     FT_Pos  fit;  /* current/fitted position/width in device sub-pixels */
  90
  91   } AF_WidthRec, *AF_Width;
  92
  93
  94   FT_LOCAL( void )
  95   af_sort_pos( FT_UInt  count,
  96                FT_Pos*  table );
  97
  98   FT_LOCAL( void )
  99   af_sort_widths( FT_UInt   count,
 100                   AF_Width  widths );
 101
 102
 103   /*************************************************************************/
 104   /*************************************************************************/
 105   /*****                                                               *****/
 106   /*****                   A N G L E   T Y P E S                       *****/
 107   /*****                                                               *****/
 108   /*************************************************************************/
 109   /*************************************************************************/
 110
 111   /*
 112    *  The auto-fitter doesn't need a very high angular accuracy;
 113    *  this allows us to speed up some computations considerably with a
 114    *  light Cordic algorithm (see afangles.c).
 115    */
 116
 117   typedef FT_Int  AF_Angle;
 118
 119
 120 #define AF_ANGLE_PI   256
 121 #define AF_ANGLE_2PI  ( AF_ANGLE_PI * 2 )
 122 #define AF_ANGLE_PI2  ( AF_ANGLE_PI / 2 )
 123 #define AF_ANGLE_PI4  ( AF_ANGLE_PI / 4 )
 124
 125
 126 #if 0
 127   /*
 128    *  compute the angle of a given 2-D vector
 129    */
 130   FT_LOCAL( AF_Angle )
 131   af_angle_atan( FT_Pos  dx,
 132                  FT_Pos  dy );
 133
 134
 135   /*
 136    *  compute `angle2 - angle1'; the result is always within
 137    *  the range [-AF_ANGLE_PI .. AF_ANGLE_PI - 1]
 138    */
 139   FT_LOCAL( AF_Angle )
 140   af_angle_diff( AF_Angle  angle1,
 141                  AF_Angle  angle2 );
 142 #endif /* 0 */
 143
 144
 145 #define AF_ANGLE_DIFF( result, angle1, angle2 ) \
 146   FT_BEGIN_STMNT                                \
 147     AF_Angle  _delta = (angle2) - (angle1);     \
 148                                                 \
 149                                                 \
 150     _delta %= AF_ANGLE_2PI;                     \
 151     if ( _delta < 0 )                           \
 152       _delta += AF_ANGLE_2PI;                   \
 153                                                 \
 154     if ( _delta > AF_ANGLE_PI )                 \
 155       _delta -= AF_ANGLE_2PI;                   \
 156                                                 \
 157     result = _delta;                            \
 158   FT_END_STMNT
 159
 160
 161   /*************************************************************************/
 162   /*************************************************************************/
 163   /*****                                                               *****/
 164   /*****                    O U T L I N E S                            *****/
 165   /*****                                                               *****/
 166   /*************************************************************************/
 167   /*************************************************************************/
 168
 169   /*  opaque handle to glyph-specific hints -- see `afhints.h' for more
 170    *  details
 171    */
 172   typedef struct AF_GlyphHintsRec_*  AF_GlyphHints;
 173
 174   /*  This structure is used to model an input glyph outline to
 175    *  the auto-hinter.  The latter will set the `hints' field
 176    *  depending on the glyph's script.
 177    */
 178   typedef struct  AF_OutlineRec_
 179   {
 180     FT_Face        face;
 181     FT_Outline     outline;
 182     FT_UInt        outline_resolution;
 183
 184     FT_Int         advance;
 185     FT_UInt        metrics_resolution;
 186
 187     AF_GlyphHints  hints;
 188
 189   } AF_OutlineRec;
 190
 191
 192   /*************************************************************************/
 193   /*************************************************************************/
 194   /*****                                                               *****/
 195   /*****                       S C A L E R S                           *****/
 196   /*****                                                               *****/
 197   /*************************************************************************/
 198   /*************************************************************************/
 199
 200   /*
 201    *  A scaler models the target pixel device that will receive the
 202    *  auto-hinted glyph image.
 203    */
 204
 205   typedef enum  AF_ScalerFlags_
 206   {
 207     AF_SCALER_FLAG_NO_HORIZONTAL = 1,  /* disable horizontal hinting */
 208     AF_SCALER_FLAG_NO_VERTICAL   = 2,  /* disable vertical hinting   */
 209     AF_SCALER_FLAG_NO_ADVANCE    = 4   /* disable advance hinting    */
 210
 211   } AF_ScalerFlags;
 212
 213
 214   typedef struct  AF_ScalerRec_
 215   {
 216     FT_Face         face;        /* source font face                        */
 217     FT_Fixed        x_scale;     /* from font units to 1/64th device pixels */
 218     FT_Fixed        y_scale;     /* from font units to 1/64th device pixels */
 219     FT_Pos          x_delta;     /* in 1/64th device pixels                 */
 220     FT_Pos          y_delta;     /* in 1/64th device pixels                 */
 221     FT_Render_Mode  render_mode; /* monochrome, anti-aliased, LCD, etc.     */
 222     FT_UInt32       flags;       /* additional control flags, see above     */
 223
 224   } AF_ScalerRec, *AF_Scaler;
 225
 226
 227 #define AF_SCALER_EQUAL_SCALES( a, b )      \
 228           ( (a)->x_scale == (b)->x_scale && \
 229             (a)->y_scale == (b)->y_scale && \
 230             (a)->x_delta == (b)->x_delta && \
 231             (a)->y_delta == (b)->y_delta )
 232
 233
 234   /*************************************************************************/
 235   /*************************************************************************/
 236   /*****                                                               *****/
 237   /*****                       S C R I P T S                           *****/
 238   /*****                                                               *****/
 239   /*************************************************************************/
 240   /*************************************************************************/
 241
 242   /*
 243    *  The list of know scripts.  Each different script corresponds to the
 244    *  following information:
 245    *
 246    *   - A set of Unicode ranges to test whether the face supports the
 247    *     script.
 248    *
 249    *   - A specific global analyzer that will compute global metrics
 250    *     specific to the script.
 251    *
 252    *   - A specific glyph analyzer that will compute segments and
 253    *     edges for each glyph covered by the script.
 254    *
 255    *   - A specific grid-fitting algorithm that will distort the
 256    *     scaled glyph outline according to the results of the glyph
 257    *     analyzer.
 258    *
 259    *  Note that a given analyzer and/or grid-fitting algorithm can be
 260    *  used by more than one script.
 261    */
 262
 263   typedef enum  AF_Script_
 264   {
 265     AF_SCRIPT_NONE  = 0,
 266     AF_SCRIPT_LATIN = 1,
 267     AF_SCRIPT_CJK   = 2,
 268     AF_SCRIPT_INDIC = 3,
 269 #ifdef FT_OPTION_AUTOFIT2
 270     AF_SCRIPT_LATIN2,
 271 #endif
 272
 273     /* add new scripts here.  Don't forget to update the list in */
 274     /* `afglobal.c'.                                             */
 275
 276     AF_SCRIPT_MAX   /* do not remove */
 277
 278   } AF_Script;
 279
 280
 281   typedef struct AF_ScriptClassRec_ const*  AF_ScriptClass;
 282
 283   typedef struct  AF_ScriptMetricsRec_
 284   {
 285     AF_ScriptClass  clazz;
 286     AF_ScalerRec    scaler;
 287
 288   } AF_ScriptMetricsRec, *AF_ScriptMetrics;
 289
 290
 291   /*  This function parses an FT_Face to compute global metrics for
 292    *  a specific script.
 293    */
 294   typedef FT_Error
 295   (*AF_Script_InitMetricsFunc)( AF_ScriptMetrics  metrics,
 296                                 FT_Face           face );
 297
 298   typedef void
 299   (*AF_Script_ScaleMetricsFunc)( AF_ScriptMetrics  metrics,
 300                                  AF_Scaler         scaler );
 301
 302   typedef void
 303   (*AF_Script_DoneMetricsFunc)( AF_ScriptMetrics  metrics );
 304
 305
 306   typedef FT_Error
 307   (*AF_Script_InitHintsFunc)( AF_GlyphHints     hints,
 308                               AF_ScriptMetrics  metrics );
 309
 310   typedef void
 311   (*AF_Script_ApplyHintsFunc)( AF_GlyphHints     hints,
 312                                FT_Outline*       outline,
 313                                AF_ScriptMetrics  metrics );
 314
 315
 316   typedef struct  AF_Script_UniRangeRec_
 317   {
 318     FT_UInt32  first;
 319     FT_UInt32  last;
 320
 321   } AF_Script_UniRangeRec;
 322
 323   typedef const AF_Script_UniRangeRec  *AF_Script_UniRange;
 324
 325
 326   typedef struct  AF_ScriptClassRec_
 327   {
 328     AF_Script                   script;
 329     AF_Script_UniRange          script_uni_ranges; /* last must be { 0, 0 } */
 330
 331     FT_UInt                     script_metrics_size;
 332     AF_Script_InitMetricsFunc   script_metrics_init;
 333     AF_Script_ScaleMetricsFunc  script_metrics_scale;
 334     AF_Script_DoneMetricsFunc   script_metrics_done;
 335
 336     AF_Script_InitHintsFunc     script_hints_init;
 337     AF_Script_ApplyHintsFunc    script_hints_apply;
 338
 339   } AF_ScriptClassRec;
 340
 341
 342 /* */
 343
 344 FT_END_HEADER
 345
 346 #endif /* __AFTYPES_H__ */
 347
 348
 349 /* END */