lib/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 /* enable one of the following three definitions for debugging */
  30 /* #define TA_DEBUG */
  31 /* #define TA_DEBUG_HORZ */
  32 #define TA_DEBUG_VERT
  33
  34 #if defined TA_DEBUG_HORZ
  35 #  define TA_DEBUG_STARTDIM TA_DIMENSION_HORZ
  36 #  define TA_DEBUG_ENDDIM TA_DIMENSION_HORZ
  37 #  define TA_DEBUG
  38 #elif defined TA_DEBUG_VERT
  39 #  define TA_DEBUG_STARTDIM TA_DIMENSION_VERT
  40 #  define TA_DEBUG_ENDDIM TA_DIMENSION_VERT
  41 #  define TA_DEBUG
  42 #elif defined TA_DEBUG
  43 #  define TA_DEBUG_STARTDIM TA_DIMENSION_VERT
  44 #  define TA_DEBUG_ENDDIM TA_DIMENSION_HORZ
  45 #endif
  46
  47 #ifdef TA_DEBUG
  48
  49 #define TA_LOG(x) \
  50   do { \
  51     if (_ta_debug) \
  52       _ta_message x; \
  53   } while (0)
  54
  55 void
  56 _ta_message(const char *format,
  57             ...);
  58
  59 extern int _ta_debug;
  60 extern int _ta_debug_disable_horz_hints;
  61 extern int _ta_debug_disable_vert_hints;
  62 extern int _ta_debug_disable_blue_hints;
  63 extern void* _ta_debug_hints;
  64
  65 #else /* !TA_DEBUG */
  66
  67 #define TA_LOG(x) \
  68   do { } while (0) /* nothing */
  69
  70 #endif /* !TA_DEBUG */
  71
  72
  73 #define TA_ABS(a) ((a) < 0 ? -(a) : (a))
  74
  75 /* from file `ftobjs.h' from FreeType */
  76 #define TA_PAD_FLOOR(x, n) ((x) & ~((n) - 1))
  77 #define TA_PAD_ROUND(x, n) TA_PAD_FLOOR((x) + ((n) / 2), n)
  78 #define TA_PAD_CEIL(x, n) TA_PAD_FLOOR((x) + ((n) - 1), n)
  79
  80 #define TA_PIX_FLOOR(x) ((x) & ~63)
  81 #define TA_PIX_ROUND(x) TA_PIX_FLOOR((x) + 32)
  82 #define TA_PIX_CEIL(x) TA_PIX_FLOOR((x) + 63)
  83
  84
  85 typedef struct TA_WidthRec_
  86 {
  87   FT_Pos org; /* original position/width in font units */
  88   FT_Pos cur; /* current/scaled position/width in device sub-pixels */
  89   FT_Pos fit; /* current/fitted position/width in device sub-pixels */
  90 } TA_WidthRec, *TA_Width;
  91
  92
  93 /* the auto-hinter doesn't need a very high angular accuracy */
  94 typedef FT_Int TA_Angle;
  95
  96 #define TA_ANGLE_PI 256
  97 #define TA_ANGLE_2PI (TA_ANGLE_PI * 2)
  98 #define TA_ANGLE_PI2 (TA_ANGLE_PI / 2)
  99 #define TA_ANGLE_PI4 (TA_ANGLE_PI / 4)
 100
 101 #define TA_ANGLE_DIFF(result, angle1, angle2) \
 102           do { \
 103             TA_Angle _delta = (angle2) - (angle1); \
 104 \
 105 \
 106             _delta %= TA_ANGLE_2PI; \
 107             if (_delta < 0) \
 108               _delta += TA_ANGLE_2PI; \
 109 \
 110             if (_delta > TA_ANGLE_PI) \
 111               _delta -= TA_ANGLE_2PI; \
 112 \
 113             result = _delta; \
 114           } while (0)
 115
 116
 117 /* opaque handle to glyph-specific hints -- */
 118 /* see `tahints.h' for more details */
 119 typedef struct TA_GlyphHintsRec_* TA_GlyphHints;
 120
 121
 122 /* a scaler models the target pixel device that will receive */
 123 /* the auto-hinted glyph image */
 124 #define TA_SCALER_FLAG_NO_HORIZONTAL 0x01 /* disable horizontal hinting */
 125 #define TA_SCALER_FLAG_NO_VERTICAL 0x02 /* disable vertical hinting */
 126 #define TA_SCALER_FLAG_NO_ADVANCE 0x04 /* disable advance hinting */
 127
 128 typedef struct TA_ScalerRec_
 129 {
 130   FT_Face face; /* source font face */
 131   FT_Fixed x_scale; /* from font units to 1/64th device pixels */
 132   FT_Fixed y_scale; /* from font units to 1/64th device pixels */
 133   FT_Pos x_delta; /* in 1/64th device pixels */
 134   FT_Pos y_delta; /* in 1/64th device pixels */
 135   FT_Render_Mode render_mode; /* monochrome, anti-aliased, LCD, etc.*/
 136   FT_UInt32 flags; /* additional control flags, see above */
 137 } TA_ScalerRec, *TA_Scaler;
 138
 139 #define TA_SCALER_EQUAL_SCALES(a, b) \
 140           ((a)->x_scale == (b)->x_scale \
 141            && (a)->y_scale == (b)->y_scale \
 142            && (a)->x_delta == (b)->x_delta \
 143            && (a)->y_delta == (b)->y_delta)
 144
 145
 146 /*
 147  *  The list of known scripts.  Each different script corresponds to the
 148  *  following information:
 149  *
 150  *   - A set of Unicode ranges to test whether the face supports the
 151  *     script.
 152  *
 153  *   - A specific global analyzer that will compute global metrics
 154  *     specific to the script.
 155  *
 156  *   - A specific glyph analyzer that will compute segments and
 157  *     edges for each glyph covered by the script.
 158  *
 159  *   - A specific grid-fitting algorithm that will distort the
 160  *     scaled glyph outline according to the results of the glyph
 161  *     analyzer.
 162  *
 163  *  Note that a given analyzer and/or grid-fitting algorithm can be
 164  *  used by more than one script.
 165  */
 166
 167 typedef enum TA_Script_
 168 {
 169   TA_SCRIPT_NONE = 0,
 170   TA_SCRIPT_LATIN = 1,
 171   TA_SCRIPT_CJK = 2,
 172   TA_SCRIPT_INDIC = 3,
 173 #ifdef FT_OPTION_AUTOFIT2
 174   TA_SCRIPT_LATIN2 = 4,
 175 #endif
 176
 177   /* add new scripts here; */
 178   /* don't forget to update the list in `taglobal.c' */
 179
 180   TA_SCRIPT_MAX /* do not remove */
 181 } TA_Script;
 182
 183 typedef struct TA_ScriptClassRec_ const* TA_ScriptClass;
 184 typedef struct TA_FaceGlobalsRec_* TA_FaceGlobals;
 185
 186 typedef struct TA_ScriptMetricsRec_
 187 {
 188   TA_ScriptClass clazz;
 189   TA_ScalerRec scaler;
 190   FT_Bool digits_have_same_width;
 191
 192   TA_FaceGlobals globals; /* to access properties */
 193 } TA_ScriptMetricsRec, *TA_ScriptMetrics;
 194
 195
 196 /* this function parses an FT_Face to compute global metrics */
 197 /* for a specific script */
 198 typedef FT_Error
 199 (*TA_Script_InitMetricsFunc)(TA_ScriptMetrics metrics,
 200                              FT_Face face);
 201 typedef void
 202 (*TA_Script_ScaleMetricsFunc)(TA_ScriptMetrics metrics,
 203                               TA_Scaler scaler);
 204 typedef void
 205 (*TA_Script_DoneMetricsFunc)(TA_ScriptMetrics metrics);
 206 typedef FT_Error
 207 (*TA_Script_InitHintsFunc)(TA_GlyphHints hints,
 208                            TA_ScriptMetrics metrics);
 209 typedef void
 210 (*TA_Script_ApplyHintsFunc)(TA_GlyphHints hints,
 211                             FT_Outline* outline,
 212                             TA_ScriptMetrics metrics);
 213
 214
 215 typedef struct TA_Script_UniRangeRec_
 216 {
 217   FT_UInt32 first;
 218   FT_UInt32 last;
 219 } TA_Script_UniRangeRec;
 220
 221 #define TA_UNIRANGE_REC(a, b) \
 222           { (FT_UInt32)(a), (FT_UInt32)(b) }
 223
 224 typedef const TA_Script_UniRangeRec* TA_Script_UniRange;
 225
 226 typedef struct TA_ScriptClassRec_
 227 {
 228   TA_Script script;
 229   TA_Script_UniRange script_uni_ranges; /* last must be { 0, 0 } */
 230
 231   FT_Offset script_metrics_size;
 232   TA_Script_InitMetricsFunc script_metrics_init;
 233   TA_Script_ScaleMetricsFunc script_metrics_scale;
 234   TA_Script_DoneMetricsFunc script_metrics_done;
 235
 236   TA_Script_InitHintsFunc script_hints_init;
 237   TA_Script_ApplyHintsFunc script_hints_apply;
 238 } TA_ScriptClassRec;
 239
 240 #endif /* __TATYPES_H__ */
 241
 242 /* end of tatypes.h */