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   { \
  52     if (_ta_debug) \
  53       _ta_message x; \
  54   } while (0)
  55
  56 void
  57 _ta_message(const char* format,
  58             ...);
  59
  60 extern int _ta_debug;
  61 extern int _ta_debug_disable_horz_hints;
  62 extern int _ta_debug_disable_vert_hints;
  63 extern int _ta_debug_disable_blue_hints;
  64 extern void* _ta_debug_hints;
  65
  66 #else /* !TA_DEBUG */
  67
  68 #define TA_LOG(x) \
  69   do { } while (0) /* nothing */
  70
  71 #endif /* !TA_DEBUG */
  72
  73
  74 #define TA_ABS(a) ((a) < 0 ? -(a) : (a))
  75
  76 /* from file `ftobjs.h' from FreeType */
  77 #define TA_PAD_FLOOR(x, n) ((x) & ~((n) - 1))
  78 #define TA_PAD_ROUND(x, n) TA_PAD_FLOOR((x) + ((n) / 2), n)
  79 #define TA_PAD_CEIL(x, n) TA_PAD_FLOOR((x) + ((n) - 1), n)
  80
  81 #define TA_PIX_FLOOR(x) ((x) & ~63)
  82 #define TA_PIX_ROUND(x) TA_PIX_FLOOR((x) + 32)
  83 #define TA_PIX_CEIL(x) TA_PIX_FLOOR((x) + 63)
  84
  85
  86 typedef struct TA_WidthRec_
  87 {
  88   FT_Pos org; /* original position/width in font units */
  89   FT_Pos cur; /* current/scaled position/width in device sub-pixels */
  90   FT_Pos fit; /* current/fitted position/width in device sub-pixels */
  91 } TA_WidthRec, *TA_Width;
  92
  93
  94 /* the auto-hinter doesn't need a very high angular accuracy */
  95 typedef FT_Int TA_Angle;
  96
  97 #define TA_ANGLE_PI 256
  98 #define TA_ANGLE_2PI (TA_ANGLE_PI * 2)
  99 #define TA_ANGLE_PI2 (TA_ANGLE_PI / 2)
 100 #define TA_ANGLE_PI4 (TA_ANGLE_PI / 4)
 101
 102 #define TA_ANGLE_DIFF(result, angle1, angle2) \
 103           do \
 104           { \
 105             TA_Angle _delta = (angle2) - (angle1); \
 106 \
 107 \
 108             _delta %= TA_ANGLE_2PI; \
 109             if (_delta < 0) \
 110               _delta += TA_ANGLE_2PI; \
 111 \
 112             if (_delta > TA_ANGLE_PI) \
 113               _delta -= TA_ANGLE_2PI; \
 114 \
 115             result = _delta; \
 116           } while (0)
 117
 118
 119 /* opaque handle to glyph-specific hints -- */
 120 /* see `tahints.h' for more details */
 121 typedef struct TA_GlyphHintsRec_* TA_GlyphHints;
 122
 123
 124 /* a scaler models the target pixel device that will receive */
 125 /* the auto-hinted glyph image */
 126 #define TA_SCALER_FLAG_NO_HORIZONTAL 0x01 /* disable horizontal hinting */
 127 #define TA_SCALER_FLAG_NO_VERTICAL 0x02 /* disable vertical hinting */
 128 #define TA_SCALER_FLAG_NO_ADVANCE 0x04 /* disable advance hinting */
 129
 130 typedef struct TA_ScalerRec_
 131 {
 132   FT_Face face; /* source font face */
 133   FT_Fixed x_scale; /* from font units to 1/64th device pixels */
 134   FT_Fixed y_scale; /* from font units to 1/64th device pixels */
 135   FT_Pos x_delta; /* in 1/64th device pixels */
 136   FT_Pos y_delta; /* in 1/64th device pixels */
 137   FT_Render_Mode render_mode; /* monochrome, anti-aliased, LCD, etc.*/
 138   FT_UInt32 flags; /* additional control flags, see above */
 139 } TA_ScalerRec, *TA_Scaler;
 140
 141 #define TA_SCALER_EQUAL_SCALES(a, b) \
 142           ((a)->x_scale == (b)->x_scale \
 143            && (a)->y_scale == (b)->y_scale \
 144            && (a)->x_delta == (b)->x_delta \
 145            && (a)->y_delta == (b)->y_delta)
 146
 147
 148 /*
 149  *  The list of known scripts.  Each different script corresponds to the
 150  *  following information:
 151  *
 152  *   - A set of Unicode ranges to test whether the face supports the
 153  *     script.
 154  *
 155  *   - A specific global analyzer that will compute global metrics
 156  *     specific to the script.
 157  *
 158  *   - A specific glyph analyzer that will compute segments and
 159  *     edges for each glyph covered by the script.
 160  *
 161  *   - A specific grid-fitting algorithm that will distort the
 162  *     scaled glyph outline according to the results of the glyph
 163  *     analyzer.
 164  *
 165  *  Note that a given analyzer and/or grid-fitting algorithm can be
 166  *  used by more than one script.
 167  */
 168
 169 typedef enum TA_Script_
 170 {
 171   TA_SCRIPT_DUMMY = 0,
 172   TA_SCRIPT_LATIN = 1,
 173   TA_SCRIPT_CJK = 2,
 174   TA_SCRIPT_INDIC = 3,
 175 #ifdef FT_OPTION_AUTOFIT2
 176   TA_SCRIPT_LATIN2 = 4,
 177 #endif
 178
 179   /* add new scripts here; */
 180   /* don't forget to update the list in `taglobal.c' */
 181
 182   TA_SCRIPT_MAX /* do not remove */
 183 } TA_Script;
 184
 185 typedef struct TA_ScriptClassRec_ const* TA_ScriptClass;
 186 typedef struct TA_FaceGlobalsRec_* TA_FaceGlobals;
 187
 188 typedef struct TA_ScriptMetricsRec_
 189 {
 190   TA_ScriptClass clazz;
 191   TA_ScalerRec scaler;
 192   FT_Bool digits_have_same_width;
 193
 194   TA_FaceGlobals globals; /* to access properties */
 195 } TA_ScriptMetricsRec, *TA_ScriptMetrics;
 196
 197
 198 /* this function parses an FT_Face to compute global metrics */
 199 /* for a specific script */
 200 typedef FT_Error
 201 (*TA_Script_InitMetricsFunc)(TA_ScriptMetrics metrics,
 202                              FT_Face face);
 203 typedef void
 204 (*TA_Script_ScaleMetricsFunc)(TA_ScriptMetrics metrics,
 205                               TA_Scaler scaler);
 206 typedef void
 207 (*TA_Script_DoneMetricsFunc)(TA_ScriptMetrics metrics);
 208 typedef FT_Error
 209 (*TA_Script_InitHintsFunc)(TA_GlyphHints hints,
 210                            TA_ScriptMetrics metrics);
 211 typedef void
 212 (*TA_Script_ApplyHintsFunc)(TA_GlyphHints hints,
 213                             FT_Outline* outline,
 214                             TA_ScriptMetrics metrics);
 215
 216
 217 typedef struct TA_Script_UniRangeRec_
 218 {
 219   FT_UInt32 first;
 220   FT_UInt32 last;
 221 } TA_Script_UniRangeRec;
 222
 223 #define TA_UNIRANGE_REC(a, b) \
 224           { (FT_UInt32)(a), (FT_UInt32)(b) }
 225
 226 typedef const TA_Script_UniRangeRec* TA_Script_UniRange;
 227
 228 typedef struct TA_ScriptClassRec_
 229 {
 230   TA_Script script;
 231   TA_Script_UniRange script_uni_ranges; /* last must be { 0, 0 } */
 232   FT_UInt32 standard_char; /* for default width and height */
 233
 234   FT_Offset script_metrics_size;
 235   TA_Script_InitMetricsFunc script_metrics_init;
 236   TA_Script_ScaleMetricsFunc script_metrics_scale;
 237   TA_Script_DoneMetricsFunc script_metrics_done;
 238
 239   TA_Script_InitHintsFunc script_hints_init;
 240   TA_Script_ApplyHintsFunc script_hints_apply;
 241 } TA_ScriptClassRec;
 242
 243 #endif /* __TATYPES_H__ */
 244
 245 /* end of tatypes.h */