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      1 /***************************************************************************/
      2 /*                                                                         */
      3 /*  aflatin.h                                                              */
      4 /*                                                                         */
      5 /*    Auto-fitter hinting routines for latin writing system                */
      6 /*    (specification).                                                     */
      7 /*                                                                         */
      8 /*  Copyright 2003-2015 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 #define AF_LATIN_BLUE_ACTIVE      ( 1U << 0 ) /* zone height is <= 3/4px   */
     67 #define AF_LATIN_BLUE_TOP         ( 1U << 1 ) /* we have a top blue zone   */
     68 #define AF_LATIN_BLUE_NEUTRAL     ( 1U << 2 ) /* we have neutral blue zone */
     69 #define AF_LATIN_BLUE_ADJUSTMENT  ( 1U << 3 ) /* used for scale adjustment */
     70                                               /* optimization              */
     71 
     72 
     73   typedef struct  AF_LatinBlueRec_
     74   {
     75     AF_WidthRec  ref;
     76     AF_WidthRec  shoot;
     77     FT_UInt      flags;
     78 
     79   } AF_LatinBlueRec, *AF_LatinBlue;
     80 
     81 
     82   typedef struct  AF_LatinAxisRec_
     83   {
     84     FT_Fixed         scale;
     85     FT_Pos           delta;
     86 
     87     FT_UInt          width_count;                 /* number of used widths */
     88     AF_WidthRec      widths[AF_LATIN_MAX_WIDTHS]; /* widths array          */
     89     FT_Pos           edge_distance_threshold;   /* used for creating edges */
     90     FT_Pos           standard_width;         /* the default stem thickness */
     91     FT_Bool          extra_light;         /* is standard width very light? */
     92 
     93     /* ignored for horizontal metrics */
     94     FT_UInt          blue_count;
     95     AF_LatinBlueRec  blues[AF_BLUE_STRINGSET_MAX];
     96 
     97     FT_Fixed         org_scale;
     98     FT_Pos           org_delta;
     99 
    100   } AF_LatinAxisRec, *AF_LatinAxis;
    101 
    102 
    103   typedef struct  AF_LatinMetricsRec_
    104   {
    105     AF_StyleMetricsRec  root;
    106     FT_UInt             units_per_em;
    107     AF_LatinAxisRec     axis[AF_DIMENSION_MAX];
    108 
    109   } AF_LatinMetricsRec, *AF_LatinMetrics;
    110 
    111 
    112   FT_LOCAL( FT_Error )
    113   af_latin_metrics_init( AF_LatinMetrics  metrics,
    114                          FT_Face          face );
    115 
    116   FT_LOCAL( void )
    117   af_latin_metrics_scale( AF_LatinMetrics  metrics,
    118                           AF_Scaler        scaler );
    119 
    120   FT_LOCAL( void )
    121   af_latin_metrics_init_widths( AF_LatinMetrics  metrics,
    122                                 FT_Face          face );
    123 
    124   FT_LOCAL( void )
    125   af_latin_metrics_check_digits( AF_LatinMetrics  metrics,
    126                                  FT_Face          face );
    127 
    128 
    129   /*************************************************************************/
    130   /*************************************************************************/
    131   /*****                                                               *****/
    132   /*****           L A T I N   G L Y P H   A N A L Y S I S             *****/
    133   /*****                                                               *****/
    134   /*************************************************************************/
    135   /*************************************************************************/
    136 
    137 #define AF_LATIN_HINTS_HORZ_SNAP    ( 1U << 0 ) /* stem width snapping  */
    138 #define AF_LATIN_HINTS_VERT_SNAP    ( 1U << 1 ) /* stem height snapping */
    139 #define AF_LATIN_HINTS_STEM_ADJUST  ( 1U << 2 ) /* stem width/height    */
    140                                                 /* adjustment           */
    141 #define AF_LATIN_HINTS_MONO         ( 1U << 3 ) /* monochrome rendering */
    142 
    143 
    144 #define AF_LATIN_HINTS_DO_HORZ_SNAP( h )             \
    145   AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_HORZ_SNAP )
    146 
    147 #define AF_LATIN_HINTS_DO_VERT_SNAP( h )             \
    148   AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_VERT_SNAP )
    149 
    150 #define AF_LATIN_HINTS_DO_STEM_ADJUST( h )             \
    151   AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_STEM_ADJUST )
    152 
    153 #define AF_LATIN_HINTS_DO_MONO( h )             \
    154   AF_HINTS_TEST_OTHER( h, AF_LATIN_HINTS_MONO )
    155 
    156 
    157   /*
    158    *  The next functions shouldn't normally be exported.  However, other
    159    *  writing systems might like to use these functions as-is.
    160    */
    161   FT_LOCAL( FT_Error )
    162   af_latin_hints_compute_segments( AF_GlyphHints  hints,
    163                                    AF_Dimension   dim );
    164 
    165   FT_LOCAL( void )
    166   af_latin_hints_link_segments( AF_GlyphHints  hints,
    167                                 FT_UInt        width_count,
    168                                 AF_WidthRec*   widths,
    169                                 AF_Dimension   dim );
    170 
    171   FT_LOCAL( FT_Error )
    172   af_latin_hints_compute_edges( AF_GlyphHints  hints,
    173                                 AF_Dimension   dim );
    174 
    175   FT_LOCAL( FT_Error )
    176   af_latin_hints_detect_features( AF_GlyphHints  hints,
    177                                   FT_UInt        width_count,
    178                                   AF_WidthRec*   widths,
    179                                   AF_Dimension   dim );
    180 
    181 /* */
    182 
    183 FT_END_HEADER
    184 
    185 #endif /* __AFLATIN_H__ */
    186 
    187 
    188 /* END */
    189