src/tatypes.h

   1 /* tatypes.h */
   2
   3 /*
   4  * Copyright (C) 2011-2012 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 `aftypes.h' (2011-Mar-30) from FreeType */
  17
  18 /* heavily modified 2011 by Werner Lemberg <wl@gnu.org> */
  19
  20 #ifndef __TATYPES_H__
  21 #define __TATYPES_H__
  22
  23 #include <ft2build.h>
  24
  25 #include FT_FREETYPE_H
  26 #include FT_OUTLINE_H
  27
  28
  29 /* #define TA_DEBUG */
  30
  31 #ifdef TA_DEBUG
  32
  33 #include <stdlib.h>
  34
  35 #define TA_LOG(x) \
  36   do { \
  37     if (_ta_debug) \
  38       printf x; \
  39   } while (0)
  40
  41 extern int _ta_debug;
  42 extern int _ta_debug_disable_horz_hints;
  43 extern int _ta_debug_disable_vert_hints;
  44 extern int _ta_debug_disable_blue_hints;
  45 extern void* _ta_debug_hints;
  46
  47 #else /* !TA_DEBUG */
  48
  49 #define TA_LOG(x) \
  50   do { } while (0) /* nothing */
  51
  52 #endif /* !TA_DEBUG */
  53
  54
  55 #define TA_ABS(a) ((a) < 0 ? -(a) : (a))
  56
  57 /* from file `ftobjs.h' from FreeType */
  58 #define TA_PAD_FLOOR(x, n) ((x) & ~((n) - 1))
  59 #define TA_PAD_ROUND(x, n) TA_PAD_FLOOR((x) + ((n) / 2), n)
  60 #define TA_PAD_CEIL(x, n) TA_PAD_FLOOR((x) + ((n) - 1), n)
  61
  62 #define TA_PIX_FLOOR(x) ((x) & ~63)
  63 #define TA_PIX_ROUND(x) TA_PIX_FLOOR((x) + 32)
  64 #define TA_PIX_CEIL(x) TA_PIX_FLOOR((x) + 63)
  65
  66
  67 typedef struct TA_WidthRec_
  68 {
  69   FT_Pos org; /* original position/width in font units */
  70   FT_Pos cur; /* current/scaled position/width in device sub-pixels */
  71   FT_Pos fit; /* current/fitted position/width in device sub-pixels */
  72 } TA_WidthRec, *TA_Width;
  73
  74
  75 /* the auto-hinter doesn't need a very high angular accuracy */
  76 typedef FT_Int TA_Angle;
  77
  78 #define TA_ANGLE_PI 256
  79 #define TA_ANGLE_2PI (TA_ANGLE_PI * 2)
  80 #define TA_ANGLE_PI2 (TA_ANGLE_PI / 2)
  81 #define TA_ANGLE_PI4 (TA_ANGLE_PI / 4)
  82
  83 #define TA_ANGLE_DIFF(result, angle1, angle2) \
  84           do { \
  85             TA_Angle _delta = (angle2) - (angle1); \
  86 \
  87 \
  88             _delta %= TA_ANGLE_2PI; \
  89             if (_delta < 0) \
  90               _delta += TA_ANGLE_2PI; \
  91 \
  92             if (_delta > TA_ANGLE_PI) \
  93               _delta -= TA_ANGLE_2PI; \
  94 \
  95             result = _delta; \
  96           } while (0)
  97
  98
  99 /* opaque handle to glyph-specific hints -- */
 100 /* see `tahints.h' for more details */
 101 typedef struct TA_GlyphHintsRec_* TA_GlyphHints;
 102
 103
 104 /* a scaler models the target pixel device that will receive */
 105 /* the auto-hinted glyph image */
 106 #define TA_SCALER_FLAG_NO_HORIZONTAL 1 /* disable horizontal hinting */
 107 #define TA_SCALER_FLAG_NO_VERTICAL 2 /* disable vertical hinting */
 108 #define TA_SCALER_FLAG_NO_ADVANCE 4 /* disable advance hinting */
 109
 110 typedef struct TA_ScalerRec_
 111 {
 112   FT_Face face; /* source font face */
 113   FT_Fixed x_scale; /* from font units to 1/64th device pixels */
 114   FT_Fixed y_scale; /* from font units to 1/64th device pixels */
 115   FT_Pos x_delta; /* in 1/64th device pixels */
 116   FT_Pos y_delta; /* in 1/64th device pixels */
 117   FT_Render_Mode render_mode; /* monochrome, anti-aliased, LCD, etc.*/
 118   FT_UInt32 flags; /* additional control flags, see above */
 119 } TA_ScalerRec, *TA_Scaler;
 120
 121 #define TA_SCALER_EQUAL_SCALES(a, b) \
 122           ((a)->x_scale == (b)->x_scale \
 123            && (a)->y_scale == (b)->y_scale \
 124            && (a)->x_delta == (b)->x_delta \
 125            && (a)->y_delta == (b)->y_delta)
 126
 127
 128 /*
 129  *  The list of known scripts.  Each different script corresponds to the
 130  *  following information:
 131  *
 132  *   - A set of Unicode ranges to test whether the face supports the
 133  *     script.
 134  *
 135  *   - A specific global analyzer that will compute global metrics
 136  *     specific to the script.
 137  *
 138  *   - A specific glyph analyzer that will compute segments and
 139  *     edges for each glyph covered by the script.
 140  *
 141  *   - A specific grid-fitting algorithm that will distort the
 142  *     scaled glyph outline according to the results of the glyph
 143  *     analyzer.
 144  *
 145  *  Note that a given analyzer and/or grid-fitting algorithm can be
 146  *  used by more than one script.
 147  */
 148
 149 typedef enum TA_Script_
 150 {
 151   TA_SCRIPT_NONE = 0,
 152   TA_SCRIPT_LATIN = 1,
 153   TA_SCRIPT_CJK = 2,
 154   TA_SCRIPT_INDIC = 3,
 155 #ifdef FT_OPTION_AUTOFIT2
 156   TA_SCRIPT_LATIN2 = 4,
 157 #endif
 158
 159   /* add new scripts here; */
 160   /* don't forget to update the list in `taglobal.c' */
 161
 162   TA_SCRIPT_MAX /* do not remove */
 163 } TA_Script;
 164
 165 typedef struct TA_ScriptClassRec_ const* TA_ScriptClass;
 166
 167 typedef struct TA_ScriptMetricsRec_
 168 {
 169   TA_ScriptClass clazz;
 170   TA_ScalerRec scaler;
 171   FT_Bool digits_have_same_width;
 172 } TA_ScriptMetricsRec, *TA_ScriptMetrics;
 173
 174
 175 /* this function parses an FT_Face to compute global metrics */
 176 /* for a specific script */
 177 typedef FT_Error
 178 (*TA_Script_InitMetricsFunc)(TA_ScriptMetrics metrics,
 179                              FT_Face face);
 180 typedef void
 181 (*TA_Script_ScaleMetricsFunc)(TA_ScriptMetrics metrics,
 182                               TA_Scaler scaler);
 183 typedef void
 184 (*TA_Script_DoneMetricsFunc)(TA_ScriptMetrics metrics);
 185 typedef FT_Error
 186 (*TA_Script_InitHintsFunc)(TA_GlyphHints hints,
 187                            TA_ScriptMetrics metrics);
 188 typedef void
 189 (*TA_Script_ApplyHintsFunc)(TA_GlyphHints hints,
 190                             FT_Outline* outline,
 191                             TA_ScriptMetrics metrics);
 192
 193
 194 typedef struct TA_Script_UniRangeRec_
 195 {
 196   FT_UInt32 first;
 197   FT_UInt32 last;
 198 } TA_Script_UniRangeRec;
 199
 200 #define TA_UNIRANGE_REC(a, b) \
 201           { (FT_UInt32)(a), (FT_UInt32)(b) }
 202
 203 typedef const TA_Script_UniRangeRec *TA_Script_UniRange;
 204
 205 typedef struct TA_ScriptClassRec_
 206 {
 207   TA_Script script;
 208   TA_Script_UniRange script_uni_ranges; /* last must be { 0, 0 } */
 209
 210   FT_Offset script_metrics_size;
 211   TA_Script_InitMetricsFunc script_metrics_init;
 212   TA_Script_ScaleMetricsFunc script_metrics_scale;
 213   TA_Script_DoneMetricsFunc script_metrics_done;
 214
 215   TA_Script_InitHintsFunc script_hints_init;
 216   TA_Script_ApplyHintsFunc script_hints_apply;
 217 } TA_ScriptClassRec;
 218
 219 #endif /* __TATYPES_H__ */
 220
 221 /* end of tatypes.h */