lib/talatin.h

   1 /* talatin.h */
   2
   3 /*
   4  * Copyright (C) 2011-2022 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' writing system */
  28
  29 extern const TA_WritingSystemClassRec ta_latin_writing_system_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 #define TA_LATIN_IS_TOP_BLUE(b) \
  40           ((b)->properties & TA_BLUE_PROPERTY_LATIN_TOP)
  41 #define TA_LATIN_IS_SUB_TOP_BLUE(b) \
  42           ((b)->properties & TA_BLUE_PROPERTY_LATIN_SUB_TOP)
  43 #define TA_LATIN_IS_NEUTRAL_BLUE(b) \
  44           ((b)->properties & TA_BLUE_PROPERTY_LATIN_NEUTRAL)
  45 #define TA_LATIN_IS_X_HEIGHT_BLUE(b) \
  46           ((b)->properties & TA_BLUE_PROPERTY_LATIN_X_HEIGHT)
  47 #define TA_LATIN_IS_LONG_BLUE(b) \
  48           ((b)->properties &TA_BLUE_PROPERTY_LATIN_LONG)
  49
  50 #define TA_LATIN_MAX_WIDTHS 16
  51
  52
  53 #define TA_LATIN_BLUE_ACTIVE (1U << 0) /* set if zone height is <= 3/4px */
  54 #define TA_LATIN_BLUE_TOP (1U << 1) /* set if we have a top blue zone */
  55 #define TA_LATIN_BLUE_SUB_TOP (1U << 2) /* set if we have a */
  56                                         /* subscript top blue zone */
  57 #define TA_LATIN_BLUE_NEUTRAL (1U << 3) /* set if we have neutral blue zone */
  58 #define TA_LATIN_BLUE_ADJUSTMENT (1U << 4) /* used for scale adjustment */
  59                                            /* optimization */
  60
  61
  62 typedef struct TA_LatinBlueRec_
  63 {
  64   TA_WidthRec ref;
  65   TA_WidthRec shoot;
  66   FT_Pos ascender;
  67   FT_Pos descender;
  68   FT_UInt flags;
  69 } TA_LatinBlueRec, *TA_LatinBlue;
  70
  71
  72 typedef struct TA_LatinAxisRec_
  73 {
  74   FT_Fixed scale;
  75   FT_Pos delta;
  76
  77   FT_UInt width_count; /* number of used widths */
  78   TA_WidthRec widths[TA_LATIN_MAX_WIDTHS]; /* widths array */
  79   FT_Pos edge_distance_threshold; /* used for creating edges */
  80   FT_Pos standard_width; /* the default stem thickness */
  81   FT_Bool extra_light; /* is standard width very light? */
  82
  83   /* ignored for horizontal metrics */
  84   FT_UInt blue_count; /* does not contain artificial blue zones */
  85   /* we add two artificial blue zones for usWinAscent and usWinDescent */
  86   TA_LatinBlueRec blues[TA_BLUE_STRINGSET_MAX + 2];
  87
  88   FT_Fixed org_scale;
  89   FT_Pos org_delta;
  90 } TA_LatinAxisRec, *TA_LatinAxis;
  91
  92
  93 typedef struct TA_LatinMetricsRec_
  94 {
  95   TA_StyleMetricsRec root;
  96   FT_UInt units_per_em;
  97   TA_LatinAxisRec axis[TA_DIMENSION_MAX];
  98 } TA_LatinMetricsRec, *TA_LatinMetrics;
  99
 100
 101 FT_Error
 102 ta_latin_metrics_init(TA_LatinMetrics metrics,
 103                       FT_Face face,
 104                       FT_Face reference);
 105
 106 void
 107 ta_latin_metrics_scale(TA_LatinMetrics metrics,
 108                        TA_Scaler scaler);
 109
 110 void
 111 ta_latin_metrics_init_widths(TA_LatinMetrics metrics,
 112                              FT_Face face,
 113                              FT_Bool use_cmap);
 114
 115 void
 116 ta_latin_metrics_check_digits(TA_LatinMetrics metrics,
 117                               FT_Face face);
 118
 119
 120 #define TA_LATIN_HINTS_HORZ_SNAP (1U << 0) /* enable stem width snapping */
 121 #define TA_LATIN_HINTS_VERT_SNAP (1U << 1) /* enable stem height snapping */
 122 #define TA_LATIN_HINTS_STEM_ADJUST (1U << 2) /* enable stem width/height */
 123                                              /* adjustment */
 124 #define TA_LATIN_HINTS_MONO (1U << 3) /* indicate monochrome rendering */
 125
 126
 127 #define TA_LATIN_HINTS_DO_HORZ_SNAP(h) \
 128           TA_HINTS_TEST_OTHER(h, TA_LATIN_HINTS_HORZ_SNAP)
 129 #define TA_LATIN_HINTS_DO_VERT_SNAP(h) \
 130           TA_HINTS_TEST_OTHER(h, TA_LATIN_HINTS_VERT_SNAP)
 131 #define TA_LATIN_HINTS_DO_STEM_ADJUST(h) \
 132           TA_HINTS_TEST_OTHER(h, TA_LATIN_HINTS_STEM_ADJUST)
 133 #define TA_LATIN_HINTS_DO_MONO(h) \
 134           TA_HINTS_TEST_OTHER(h, TA_LATIN_HINTS_MONO)
 135
 136
 137 /* the next functions shouldn't normally be exported; */
 138 /* however, other writing systems might like to use these functions as-is */
 139
 140 FT_Error
 141 ta_latin_hints_compute_segments(TA_GlyphHints hints,
 142                                 TA_Dimension dim);
 143 void
 144 ta_latin_hints_link_segments(TA_GlyphHints hints,
 145                              FT_UInt width_count,
 146                              TA_WidthRec* widths,
 147                              TA_Dimension dim);
 148 FT_Error
 149 ta_latin_hints_compute_edges(TA_GlyphHints hints,
 150                              TA_Dimension dim);
 151 FT_Error
 152 ta_latin_hints_detect_features(TA_GlyphHints hints,
 153                                FT_UInt width_count,
 154                                TA_WidthRec* widths,
 155                                TA_Dimension dim);
 156
 157 #endif /* TALATIN_H_ */
 158
 159 /* end of talatin.h */