lib/talatin.h

   1 /* talatin.h */
   2
   3 /*
   4  * Copyright (C) 2011-2014 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_X_HEIGHT_BLUE(b) \
  42           ((b)->properties & TA_BLUE_PROPERTY_LATIN_X_HEIGHT)
  43 #define TA_LATIN_IS_LONG_BLUE(b) \
  44           ((b)->properties &TA_BLUE_PROPERTY_LATIN_LONG)
  45
  46 #define TA_LATIN_MAX_WIDTHS 16
  47
  48
  49 #define TA_LATIN_BLUE_ACTIVE  (1 << 0) /* set if zone height is <= 3/4px */
  50 #define TA_LATIN_BLUE_TOP (1 << 1) /* result of TA_LATIN_IS_TOP_BLUE */
  51 #define TA_LATIN_BLUE_ADJUSTMENT (1 << 2) /* used for scale adjustment */
  52                                           /* optimization */
  53
  54
  55 typedef struct TA_LatinBlueRec_
  56 {
  57   TA_WidthRec ref;
  58   TA_WidthRec shoot;
  59   FT_UInt flags;
  60 } TA_LatinBlueRec, *TA_LatinBlue;
  61
  62
  63 typedef struct TA_LatinAxisRec_
  64 {
  65   FT_Fixed scale;
  66   FT_Pos delta;
  67
  68   FT_UInt width_count; /* number of used widths */
  69   TA_WidthRec widths[TA_LATIN_MAX_WIDTHS]; /* widths array */
  70   FT_Pos edge_distance_threshold; /* used for creating edges */
  71   FT_Pos standard_width; /* the default stem thickness */
  72   FT_Bool extra_light; /* is standard width very light? */
  73
  74   /* ignored for horizontal metrics */
  75   FT_UInt blue_count;
  76   /* we add two blue zones for usWinAscent and usWinDescent */
  77   TA_LatinBlueRec blues[TA_BLUE_STRINGSET_MAX + 2];
  78
  79   FT_Fixed org_scale;
  80   FT_Pos org_delta;
  81 } TA_LatinAxisRec, *TA_LatinAxis;
  82
  83
  84 typedef struct TA_LatinMetricsRec_
  85 {
  86   TA_StyleMetricsRec root;
  87   FT_UInt units_per_em;
  88   TA_LatinAxisRec axis[TA_DIMENSION_MAX];
  89 } TA_LatinMetricsRec, *TA_LatinMetrics;
  90
  91
  92 FT_Error
  93 ta_latin_metrics_init(TA_LatinMetrics metrics,
  94                       FT_Face face);
  95
  96 void
  97 ta_latin_metrics_scale(TA_LatinMetrics metrics,
  98                        TA_Scaler scaler);
  99
 100 void
 101 ta_latin_metrics_init_widths(TA_LatinMetrics metrics,
 102                              FT_Face face);
 103
 104 void
 105 ta_latin_metrics_check_digits(TA_LatinMetrics metrics,
 106                               FT_Face face);
 107
 108
 109 #define TA_LATIN_HINTS_HORZ_SNAP (1 << 0) /* enable stem width snapping */
 110 #define TA_LATIN_HINTS_VERT_SNAP (1 << 1) /* enable stem height snapping */
 111 #define TA_LATIN_HINTS_STEM_ADJUST (1 << 2) /* enable stem width/height */
 112                                             /* adjustment */
 113 #define TA_LATIN_HINTS_MONO (1 << 3) /* indicate monochrome rendering */
 114
 115
 116 #define TA_LATIN_HINTS_DO_HORZ_SNAP(h) \
 117           TA_HINTS_TEST_OTHER(h, TA_LATIN_HINTS_HORZ_SNAP)
 118 #define TA_LATIN_HINTS_DO_VERT_SNAP(h) \
 119           TA_HINTS_TEST_OTHER(h, TA_LATIN_HINTS_VERT_SNAP)
 120 #define TA_LATIN_HINTS_DO_STEM_ADJUST(h) \
 121           TA_HINTS_TEST_OTHER(h, TA_LATIN_HINTS_STEM_ADJUST)
 122 #define TA_LATIN_HINTS_DO_MONO(h) \
 123           TA_HINTS_TEST_OTHER(h, TA_LATIN_HINTS_MONO)
 124
 125
 126 /* the next functions shouldn't normally be exported; */
 127 /* however, other writing systems might like to use these functions as-is */
 128
 129 FT_Error
 130 ta_latin_hints_compute_segments(TA_GlyphHints hints,
 131                                 TA_Dimension dim);
 132 void
 133 ta_latin_hints_link_segments(TA_GlyphHints hints,
 134                              FT_UInt width_count,
 135                              TA_WidthRec* widths,
 136                              TA_Dimension dim);
 137 FT_Error
 138 ta_latin_hints_compute_edges(TA_GlyphHints hints,
 139                              TA_Dimension dim);
 140 FT_Error
 141 ta_latin_hints_detect_features(TA_GlyphHints hints,
 142                                FT_UInt width_count,
 143                                TA_WidthRec* widths,
 144                                TA_Dimension dim);
 145
 146 #endif /* __TALATIN_H__ */
 147
 148 /* end of talatin.h */