lib/talatin.h

   1 /* talatin.h */
   2
   3 /*
   4  * Copyright (C) 2011-2013 by Werner Lemberg.
   5  *
   6  * This file is part of the ttfautohint library, and may only be used,
   7  * modified, and distributed under the terms given in `COPYING'.  By
   8  * continuing to use, modify, or distribute this file you indicate that you
   9  * have read `COPYING' and understand and accept it fully.
  10  *
  11  * The file `COPYING' mentioned in the previous paragraph is distributed
  12  * with the ttfautohint library.
  13  */
  14
  15
  16 /* originally file `aflatin.h' (2011-Mar-28) from FreeType */
  17
  18 /* heavily modified 2011 by Werner Lemberg <wl@gnu.org> */
  19
  20 #ifndef __TALATIN_H__
  21 #define __TALATIN_H__
  22
  23 #include "tatypes.h"
  24 #include "tahints.h"
  25
  26
  27 /* the latin-specific script class */
  28
  29 extern const TA_ScriptClassRec ta_latin_script_class;
  30
  31
  32 /* constants are given with units_per_em == 2048 in mind */
  33 #define TA_LATIN_CONSTANT(metrics, c) \
  34           (((c) * (FT_Long)((TA_LatinMetrics)(metrics))->units_per_em) / 2048)
  35
  36
  37 /* Latin (global) metrics management */
  38
  39 enum
  40 {
  41   TA_LATIN_BLUE_CAPITAL_TOP,
  42   TA_LATIN_BLUE_CAPITAL_BOTTOM,
  43   TA_LATIN_BLUE_SMALL_F_TOP,
  44   TA_LATIN_BLUE_SMALL_TOP,
  45   TA_LATIN_BLUE_SMALL_BOTTOM,
  46   TA_LATIN_BLUE_SMALL_MINOR,
  47
  48   TA_LATIN_BLUE_MAX
  49 };
  50
  51
  52 #define TA_LATIN_IS_TOP_BLUE(b) \
  53           ((b) == TA_LATIN_BLUE_CAPITAL_TOP \
  54            || (b) == TA_LATIN_BLUE_SMALL_F_TOP \
  55            || (b) == TA_LATIN_BLUE_SMALL_TOP)
  56
  57 #define TA_LATIN_MAX_WIDTHS 16
  58 #define TA_LATIN_MAX_BLUES TA_LATIN_BLUE_MAX
  59
  60
  61 #define TA_LATIN_BLUE_ACTIVE  (1 << 0) /* set if zone height is <= 3/4px */
  62 #define TA_LATIN_BLUE_TOP (1 << 1) /* result of TA_LATIN_IS_TOP_BLUE */
  63 #define TA_LATIN_BLUE_ADJUSTMENT (1 << 2) /* used for scale adjustment */
  64                                           /* optimization */
  65
  66
  67 typedef struct TA_LatinBlueRec_
  68 {
  69   TA_WidthRec ref;
  70   TA_WidthRec shoot;
  71   FT_UInt flags;
  72 } TA_LatinBlueRec, *TA_LatinBlue;
  73
  74
  75 typedef struct TA_LatinAxisRec_
  76 {
  77   FT_Fixed scale;
  78   FT_Pos delta;
  79
  80   FT_UInt width_count; /* number of used widths */
  81   TA_WidthRec widths[TA_LATIN_MAX_WIDTHS]; /* widths array */
  82   FT_Pos edge_distance_threshold; /* used for creating edges */
  83   FT_Pos standard_width; /* the default stem thickness */
  84   FT_Bool extra_light; /* is standard width very light? */
  85
  86   /* ignored for horizontal metrics */
  87   FT_UInt blue_count;
  88   /* we add two blue zones for usWinAscent and usWinDescent */
  89   TA_LatinBlueRec blues[TA_LATIN_BLUE_MAX + 2];
  90
  91   FT_Fixed org_scale;
  92   FT_Pos org_delta;
  93 } TA_LatinAxisRec, *TA_LatinAxis;
  94
  95
  96 typedef struct TA_LatinMetricsRec_
  97 {
  98   TA_ScriptMetricsRec root;
  99   FT_UInt units_per_em;
 100   TA_LatinAxisRec axis[TA_DIMENSION_MAX];
 101 } TA_LatinMetricsRec, *TA_LatinMetrics;
 102
 103
 104 FT_Error
 105 ta_latin_metrics_init(TA_LatinMetrics metrics,
 106                       FT_Face face);
 107
 108 void
 109 ta_latin_metrics_scale(TA_LatinMetrics metrics,
 110                        TA_Scaler scaler);
 111
 112 void
 113 ta_latin_metrics_init_widths(TA_LatinMetrics metrics,
 114                              FT_Face face);
 115
 116 void
 117 ta_latin_metrics_check_digits(TA_LatinMetrics metrics,
 118                               FT_Face face);
 119
 120
 121 #define TA_LATIN_HINTS_HORZ_SNAP (1 << 0) /* enable stem width snapping */
 122 #define TA_LATIN_HINTS_VERT_SNAP (1 << 1) /* enable stem height snapping */
 123 #define TA_LATIN_HINTS_STEM_ADJUST (1 << 2) /* enable stem width/height */
 124                                             /* adjustment */
 125 #define TA_LATIN_HINTS_MONO (1 << 3) /* indicate monochrome rendering */
 126
 127
 128 #define TA_LATIN_HINTS_DO_HORZ_SNAP(h) \
 129           TA_HINTS_TEST_OTHER(h, TA_LATIN_HINTS_HORZ_SNAP)
 130 #define TA_LATIN_HINTS_DO_VERT_SNAP(h) \
 131           TA_HINTS_TEST_OTHER(h, TA_LATIN_HINTS_VERT_SNAP)
 132 #define TA_LATIN_HINTS_DO_STEM_ADJUST(h) \
 133           TA_HINTS_TEST_OTHER(h, TA_LATIN_HINTS_STEM_ADJUST)
 134 #define TA_LATIN_HINTS_DO_MONO(h) \
 135           TA_HINTS_TEST_OTHER(h, TA_LATIN_HINTS_MONO)
 136
 137
 138 /* the next functions shouldn't normally be exported; */
 139 /* however, other scripts might like to use these functions as-is */
 140
 141 FT_Error
 142 ta_latin_hints_compute_segments(TA_GlyphHints hints,
 143                                 TA_Dimension dim);
 144 void
 145 ta_latin_hints_link_segments(TA_GlyphHints hints,
 146                              TA_Dimension dim);
 147 FT_Error
 148 ta_latin_hints_compute_edges(TA_GlyphHints hints,
 149                              TA_Dimension dim);
 150 FT_Error
 151 ta_latin_hints_detect_features(TA_GlyphHints hints,
 152                                TA_Dimension dim);
 153
 154 #endif /* __TALATIN_H__ */
 155
 156 /* end of talatin.h */