src/autofit/aflatin.h

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  aflatin.h                                                              */
   4 /*                                                                         */
   5 /*    Auto-fitter hinting routines for latin writing system                */
   6 /*    (specification).                                                     */
   7 /*                                                                         */
   8 /*  Copyright 2003-2007, 2009, 2011-2014 by                                */
   9 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
  10 /*                                                                         */
  11 /*  This file is part of the FreeType project, and may only be used,       */
  12 /*  modified, and distributed under the terms of the FreeType project      */
  13 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  14 /*  this file you indicate that you have read the license and              */
  15 /*  understand and accept it fully.                                        */
  16 /*                                                                         */
  17 /***************************************************************************/
  18
  19
  20 #ifndef __AFLATIN_H__
  21 #define __AFLATIN_H__
  22
  23 #include "afhints.h"
  24
  25
  26 FT_BEGIN_HEADER
  27
  28   /* the `latin' writing system */
  29
  30   AF_DECLARE_WRITING_SYSTEM_CLASS( af_latin_writing_system_class )
  31
  32
  33   /* constants are given with units_per_em == 2048 in mind */
  34 #define AF_LATIN_CONSTANT( metrics, c )                                      \
  35   ( ( (c) * (FT_Long)( (AF_LatinMetrics)(metrics) )->units_per_em ) / 2048 )
  36
  37
  38   /*************************************************************************/
  39   /*************************************************************************/
  40   /*****                                                               *****/
  41   /*****            L A T I N   G L O B A L   M E T R I C S            *****/
  42   /*****                                                               *****/
  43   /*************************************************************************/
  44   /*************************************************************************/
  45
  46
  47   /*
  48    *  The following declarations could be embedded in the file `aflatin.c';
  49    *  they have been made semi-public to allow alternate writing system
  50    *  hinters to re-use some of them.
  51    */
  52
  53
  54 #define AF_LATIN_IS_TOP_BLUE( b ) \
  55           ( (b)->properties & AF_BLUE_PROPERTY_LATIN_TOP )
  56 #define AF_LATIN_IS_NEUTRAL_BLUE( b ) \
  57           ( (b)->properties & AF_BLUE_PROPERTY_LATIN_NEUTRAL )
  58 #define AF_LATIN_IS_X_HEIGHT_BLUE( b ) \
  59           ( (b)->properties & AF_BLUE_PROPERTY_LATIN_X_HEIGHT )
  60 #define AF_LATIN_IS_LONG_BLUE( b ) \
  61           ( (b)->properties & AF_BLUE_PROPERTY_LATIN_LONG )
  62
  63 #define AF_LATIN_MAX_WIDTHS  16
  64
  65
  66   enum
  67   {
  68     AF_LATIN_BLUE_ACTIVE     = 1 << 0, /* set if zone height is <= 3/4px   */
  69     AF_LATIN_BLUE_TOP        = 1 << 1, /* set if we have a top blue zone   */
  70     AF_LATIN_BLUE_NEUTRAL    = 1 << 2, /* set if we have neutral blue zone */
  71     AF_LATIN_BLUE_ADJUSTMENT = 1 << 3, /* used for scale adjustment        */
  72                                        /* optimization                     */
  73     AF_LATIN_BLUE_FLAG_MAX
  74   };
  75
  76
  77   typedef struct  AF_LatinBlueRec_
  78   {
  79     AF_WidthRec  ref;
  80     AF_WidthRec  shoot;
  81     FT_UInt      flags;
  82
  83   } AF_LatinBlueRec, *AF_LatinBlue;
  84
  85
  86   typedef struct  AF_LatinAxisRec_
  87   {
  88     FT_Fixed         scale;
  89     FT_Pos           delta;
  90
  91     FT_UInt          width_count;                 /* number of used widths */
  92     AF_WidthRec      widths[AF_LATIN_MAX_WIDTHS]; /* widths array          */
  93     FT_Pos           edge_distance_threshold;   /* used for creating edges */
  94     FT_Pos           standard_width;         /* the default stem thickness */
  95     FT_Bool          extra_light;         /* is standard width very light? */
  96
  97     /* ignored for horizontal metrics */
  98     FT_UInt          blue_count;
  99     AF_LatinBlueRec  blues[AF_BLUE_STRINGSET_MAX];
 100
 101     FT_Fixed         org_scale;
 102     FT_Pos           org_delta;
 103
 104   } AF_LatinAxisRec, *AF_LatinAxis;
 105
 106
 107   typedef struct  AF_LatinMetricsRec_
 108   {
 109     AF_StyleMetricsRec  root;
 110     FT_UInt             units_per_em;
 111     AF_LatinAxisRec     axis[AF_DIMENSION_MAX];
 112
 113   } AF_LatinMetricsRec, *AF_LatinMetrics;
 114
 115
 116   FT_LOCAL( FT_Error )
 117   af_latin_metrics_init( AF_LatinMetrics  metrics,
 118                          FT_Face          face );
 119
 120   FT_LOCAL( void )
 121   af_latin_metrics_scale( AF_LatinMetrics  metrics,
 122                           AF_Scaler        scaler );
 123
 124   FT_LOCAL( void )
 125   af_latin_metrics_init_widths( AF_LatinMetrics  metrics,
 126                                 FT_Face          face );
 127
 128   FT_LOCAL( void )
 129   af_latin_metrics_check_digits( AF_LatinMetrics  metrics,
 130                                  FT_Face          face );
 131
 132
 133   /*************************************************************************/
 134   /*************************************************************************/
 135   /*****                                                               *****/
 136   /*****           L A T I N   G L Y P H   A N A L Y S I S             *****/
 137   /*****                                                               *****/
 138   /*************************************************************************/
 139   /*************************************************************************/
 140
 141   enum
 142   {
 143     AF_LATIN_HINTS_HORZ_SNAP   = 1 << 0, /* enable stem width snapping  */
 144     AF_LATIN_HINTS_VERT_SNAP   = 1 << 1, /* enable stem height snapping */
 145     AF_LATIN_HINTS_STEM_ADJUST = 1 << 2, /* enable stem width/height    */
 146                                          /* adjustment                  */
 147     AF_LATIN_HINTS_MONO        = 1 << 3  /* indicate monochrome         */
 148                                          /* rendering                   */
 149   };
 150
 151
 152 #define AF_LATIN_HINTS_DO_HORZ_SNAP( h )             \
 153   AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_HORZ_SNAP )
 154
 155 #define AF_LATIN_HINTS_DO_VERT_SNAP( h )             \
 156   AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_VERT_SNAP )
 157
 158 #define AF_LATIN_HINTS_DO_STEM_ADJUST( h )             \
 159   AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_STEM_ADJUST )
 160
 161 #define AF_LATIN_HINTS_DO_MONO( h )             \
 162   AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_MONO )
 163
 164
 165   /*
 166    *  The next functions shouldn't normally be exported.  However, other
 167    *  writing systems might like to use these functions as-is.
 168    */
 169   FT_LOCAL( FT_Error )
 170   af_latin_hints_compute_segments( AF_GlyphHints  hints,
 171                                    AF_Dimension   dim );
 172
 173   FT_LOCAL( void )
 174   af_latin_hints_link_segments( AF_GlyphHints  hints,
 175                                 FT_UInt        width_count,
 176                                 AF_WidthRec*   widths,
 177                                 AF_Dimension   dim );
 178
 179   FT_LOCAL( FT_Error )
 180   af_latin_hints_compute_edges( AF_GlyphHints  hints,
 181                                 AF_Dimension   dim );
 182
 183   FT_LOCAL( FT_Error )
 184   af_latin_hints_detect_features( AF_GlyphHints  hints,
 185                                   FT_UInt        width_count,
 186                                   AF_WidthRec*   widths,
 187                                   AF_Dimension   dim );
 188
 189 /* */
 190
 191 FT_END_HEADER
 192
 193 #endif /* __AFLATIN_H__ */
 194
 195
 196 /* END */