lib/ta.h

   1 /* ta.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 #ifndef __TA_H__
  17 #define __TA_H__
  18
  19 #include <config.h>
  20
  21 #include <ft2build.h>
  22 #include FT_FREETYPE_H
  23 #include FT_TRUETYPE_TABLES_H
  24 #include FT_TRUETYPE_TAGS_H
  25
  26 #include <ttfautohint.h>
  27 #include <sds.h>
  28 #include <numberset.h>
  29
  30 #include "taloader.h"
  31 #include "taglobal.h"
  32 #include "tadummy.h"
  33 #include "talatin.h"
  34
  35
  36 #define TTFAUTOHINT_GLYPH ".ttfautohint"
  37 #define TTFAUTOHINT_GLYPH_FIRST_BYTE "\x0C" /* first byte is string length */
  38 #define TTFAUTOHINT_GLYPH_LEN 13
  39
  40 /* these macros convert 16bit and 32bit numbers into single bytes */
  41 /* using the byte order needed within SFNT files */
  42
  43 #define HIGH(x) (FT_Byte)(((x) & 0xFF00) >> 8)
  44 #define LOW(x) ((x) & 0x00FF)
  45
  46 #define BYTE1(x) (FT_Byte)(((x) & 0xFF000000UL) >> 24);
  47 #define BYTE2(x) (FT_Byte)(((x) & 0x00FF0000UL) >> 16);
  48 #define BYTE3(x) (FT_Byte)(((x) & 0x0000FF00UL) >> 8);
  49 #define BYTE4(x) ((x) & 0x000000FFUL);
  50
  51
  52 /* an SFNT tag for our information table */
  53 #define TTAG_TTFA FT_MAKE_TAG('T', 'T', 'F', 'A')
  54
  55 /* the length of a dummy `DSIG' table */
  56 #define DSIG_LEN 8
  57
  58 /* the length of our `gasp' table */
  59 #define GASP_LEN 8
  60
  61 /* an empty slot in the table info array */
  62 #define MISSING (FT_ULong)~0
  63
  64 /* the offset to the loca table format in the `head' table */
  65 #define LOCA_FORMAT_OFFSET 51
  66
  67 /* various offsets within the `maxp' table */
  68 #define MAXP_NUM_GLYPHS 4
  69 #define MAXP_MAX_COMPOSITE_POINTS 10
  70 #define MAXP_MAX_COMPOSITE_CONTOURS 12
  71 #define MAXP_MAX_ZONES_OFFSET 14
  72 #define MAXP_MAX_TWILIGHT_POINTS_OFFSET 16
  73 #define MAXP_MAX_STORAGE_OFFSET 18
  74 #define MAXP_MAX_FUNCTION_DEFS_OFFSET 20
  75 #define MAXP_MAX_INSTRUCTION_DEFS_OFFSET 22
  76 #define MAXP_MAX_STACK_ELEMENTS_OFFSET 24
  77 #define MAXP_MAX_INSTRUCTIONS_OFFSET 26
  78 #define MAXP_MAX_COMPONENTS_OFFSET 28
  79
  80 #define MAXP_LEN 32
  81
  82 /* the offset of the type flags field in the `OS/2' table */
  83 #define OS2_FSTYPE_OFFSET 8
  84
  85
  86 /* flags in composite glyph records */
  87 #define ARGS_ARE_WORDS 0x0001
  88 #define ARGS_ARE_XY_VALUES 0x0002
  89 #define WE_HAVE_A_SCALE 0x0008
  90 #define MORE_COMPONENTS 0x0020
  91 #define WE_HAVE_AN_XY_SCALE 0x0040
  92 #define WE_HAVE_A_2X2 0x0080
  93 #define WE_HAVE_INSTR 0x0100
  94
  95 /* flags in simple glyph records */
  96 #define ON_CURVE 0x01
  97 #define X_SHORT_VECTOR 0x02
  98 #define Y_SHORT_VECTOR 0x04
  99 #define REPEAT 0x08
 100 #define SAME_X 0x10
 101 #define SAME_Y 0x20
 102
 103
 104 /* a single glyph */
 105 typedef struct GLYPH_
 106 {
 107   FT_ULong len1; /* number of bytes before instruction related data */
 108   FT_ULong len2; /* number of bytes after instruction related data; */
 109                  /* if zero, this indicates a composite glyph */
 110   FT_Byte* buf; /* extracted glyph data (without instruction related data) */
 111   FT_ULong flags_offset; /* offset to last flag in a composite glyph */
 112
 113   FT_ULong ins_len; /* number of new instructions */
 114   FT_Byte* ins_buf; /* new instruction data */
 115
 116   FT_Short num_contours; /* >= 0 for simple glyphs */
 117   FT_UShort num_points; /* number of points in a simple glyph */
 118
 119   FT_UShort num_components;
 120   FT_UShort* components; /* the subglyph indices of a composite glyph */
 121
 122   FT_UShort num_pointsums;
 123   FT_UShort* pointsums; /* the pointsums of all composite elements */
 124                         /* (after walking recursively over all subglyphs) */
 125
 126   FT_UShort num_composite_contours; /* after recursion */
 127 } GLYPH;
 128
 129 /* a representation of the data in the `glyf' table */
 130 typedef struct glyf_Data_
 131 {
 132   FT_UShort num_glyphs;
 133   GLYPH* glyphs;
 134
 135   /* this field gives the `master' globals for a `glyf' table; */
 136   /* see function `TA_sfnt_handle_coverage' */
 137   TA_FaceGlobals master_globals;
 138   /* for coverage bookkeeping */
 139   FT_Bool adjusted;
 140
 141   /* if a `glyf' table gets used in more than one subfont, */
 142   /* so do `cvt', `fpgm', and `prep' tables: */
 143   /* these four tables are always handled in parallel */
 144   FT_ULong cvt_idx;
 145   FT_ULong fpgm_idx;
 146   FT_ULong prep_idx;
 147
 148   /* styles present in a font get a running number */
 149   FT_UInt style_ids[TA_STYLE_MAX];
 150   FT_UInt num_used_styles;
 151
 152   /* we have separate CVT data for each style */
 153   FT_UInt cvt_offsets[TA_STYLE_MAX];
 154   FT_UInt cvt_horz_width_sizes[TA_STYLE_MAX];
 155   FT_UInt cvt_vert_width_sizes[TA_STYLE_MAX];
 156   FT_UInt cvt_blue_zone_sizes[TA_STYLE_MAX];
 157   FT_UInt cvt_blue_adjustment_offsets[TA_STYLE_MAX];
 158 } glyf_Data;
 159
 160 /* an SFNT table */
 161 typedef struct SFNT_Table_
 162 {
 163   FT_ULong tag;
 164   FT_ULong len;
 165   FT_Byte* buf; /* the table data */
 166   FT_ULong offset; /* from beginning of file */
 167   FT_ULong checksum;
 168   void* data; /* used e.g. for `glyf' table data */
 169   FT_Bool processed;
 170 } SFNT_Table;
 171
 172 /* we use indices into the SFNT table array to */
 173 /* represent table info records of the TTF header */
 174 typedef FT_ULong SFNT_Table_Info;
 175
 176 /* this structure is used to model a TTF or a subfont within a TTC */
 177 typedef struct SFNT_
 178 {
 179   FT_Face face;
 180
 181   SFNT_Table_Info* table_infos;
 182   FT_ULong num_table_infos;
 183
 184   /* various SFNT table indices */
 185   FT_ULong glyf_idx;
 186   FT_ULong loca_idx;
 187   FT_ULong head_idx;
 188   FT_ULong hmtx_idx;
 189   FT_ULong maxp_idx;
 190   FT_ULong name_idx;
 191   FT_ULong post_idx;
 192   FT_ULong OS2_idx;
 193   FT_ULong GPOS_idx;
 194
 195   /* values necessary to update the `maxp' table */
 196   FT_UShort max_composite_points;
 197   FT_UShort max_composite_contours;
 198   FT_UShort max_storage;
 199   FT_UShort max_stack_elements;
 200   FT_UShort max_twilight_points;
 201   FT_UShort max_instructions;
 202   FT_UShort max_components;
 203 } SFNT;
 204
 205 typedef struct Control_ Control;
 206
 207 /* our font object; the `FONT' typedef is in `taloader.h' */
 208 struct FONT_
 209 {
 210   FT_Library lib;
 211
 212   FT_Byte* in_buf;
 213   size_t in_len;
 214
 215   FT_Byte* out_buf;
 216   size_t out_len;
 217
 218   char* control_buf;
 219   size_t control_len;
 220
 221   SFNT* sfnts;
 222   FT_Long num_sfnts;
 223
 224   SFNT_Table* tables;
 225   FT_ULong num_tables;
 226
 227   FT_Bool have_DSIG;
 228
 229   /* we have a single `gasp' table for all subfonts */
 230   FT_ULong gasp_idx;
 231
 232   /* the control instructions */
 233   Control* control;
 234
 235   /* two generic pointers into the control instructions tree */
 236   void* control_data_head;
 237   void* control_data_cur;
 238
 239   /* two fields for handling one-point segment directions */
 240   /* of the current glyph */
 241   void* control_segment_dirs_head;
 242   void* control_segment_dirs_cur;
 243
 244   TA_LoaderRec loader[1]; /* the interface to the autohinter */
 245
 246   /* configuration options */
 247   TA_Progress_Func progress;
 248   void* progress_data;
 249   TA_Info_Func info;
 250   void* info_data;
 251   FT_UInt hinting_range_min;
 252   FT_UInt hinting_range_max;
 253   FT_UInt hinting_limit;
 254   FT_UInt increase_x_height;
 255   number_range* x_height_snapping_exceptions;
 256   FT_UInt fallback_stem_width;
 257   FT_Bool gray_strong_stem_width;
 258   FT_Bool gdi_cleartype_strong_stem_width;
 259   FT_Bool dw_cleartype_strong_stem_width;
 260   FT_Bool windows_compatibility;
 261   FT_Bool adjust_subglyphs;
 262   FT_Bool hint_composites;
 263   FT_Bool ignore_restrictions;
 264   TA_Style fallback_style;
 265   TA_Script default_script;
 266   FT_Bool symbol;
 267   FT_Bool dehint;
 268   FT_Bool debug;
 269   FT_Bool TTFA_info;
 270 };
 271
 272
 273 #include "tatables.h"
 274 #include "tabytecode.h"
 275 #include "tacontrol.h"
 276
 277
 278 /* in file `tascript.c' */
 279 extern const char* script_names[];
 280
 281
 282 const char*
 283 TA_get_error_message(FT_Error error);
 284
 285 char*
 286 TA_font_dump_parameters(FONT* font,
 287                         FT_Bool format);
 288
 289 void
 290 TA_get_current_time(FT_ULong* high,
 291                     FT_ULong* low);
 292
 293 FT_Byte*
 294 TA_build_push(FT_Byte* bufp,
 295               FT_UInt* args,
 296               FT_UInt num_args,
 297               FT_Bool need_words,
 298               FT_Bool optimize);
 299
 300 FT_Error
 301 TA_font_init(FONT* font);
 302 void
 303 TA_font_unload(FONT* font,
 304                const char* in_buf,
 305                char** out_bufp,
 306                const char* control_buf);
 307
 308 FT_Error
 309 TA_font_file_read(FONT* font,
 310                   FILE* in_file);
 311 FT_Error
 312 TA_font_file_write(FONT* font,
 313                    FILE* out_file);
 314 FT_Error
 315 TA_control_file_read(FONT* font,
 316                      FILE* control_file);
 317
 318 FT_Error
 319 TA_sfnt_build_glyph_instructions(SFNT* sfnt,
 320                                  FONT* font,
 321                                  FT_Long idx);
 322
 323 FT_Error
 324 TA_sfnt_split_into_SFNT_tables(SFNT* sfnt,
 325                                FONT* font);
 326
 327 FT_Error
 328 TA_sfnt_build_cvt_table(SFNT* sfnt,
 329                         FONT* font);
 330
 331 FT_Error
 332 TA_table_build_TTFA(FT_Byte** TTFA,
 333                     FT_ULong* TTFA_len,
 334                     FONT* font);
 335
 336 FT_Error
 337 TA_table_build_DSIG(FT_Byte** DSIG);
 338
 339 FT_Error
 340 TA_sfnt_build_fpgm_table(SFNT* sfnt,
 341                          FONT* font);
 342
 343 FT_Error
 344 TA_sfnt_build_gasp_table(SFNT* sfnt,
 345                          FONT* font);
 346
 347 FT_Error
 348 TA_sfnt_split_glyf_table(SFNT* sfnt,
 349                          FONT* font);
 350 FT_Error
 351 TA_sfnt_build_glyf_table(SFNT* sfnt,
 352                          FONT* font);
 353 FT_Error
 354 TA_sfnt_create_glyf_data(SFNT* sfnt,
 355                          FONT* font);
 356 FT_Error
 357 TA_sfnt_handle_coverage(SFNT* sfnt,
 358                         FONT* font);
 359 void
 360 TA_sfnt_adjust_coverage(SFNT* sfnt,
 361                         FONT* font);
 362 #if 0
 363 void
 364 TA_sfnt_copy_master_coverage(SFNT* sfnt,
 365                              FONT* font);
 366 #endif
 367
 368 FT_Error
 369 TA_sfnt_update_GPOS_table(SFNT* sfnt,
 370                           FONT* font);
 371
 372 FT_Error
 373 TA_sfnt_update_hmtx_table(SFNT* sfnt,
 374                           FONT* font);
 375
 376 FT_Error
 377 TA_sfnt_build_loca_table(SFNT* sfnt,
 378                          FONT* font);
 379
 380 FT_Error
 381 TA_sfnt_update_maxp_table(SFNT* sfnt,
 382                           FONT* font);
 383
 384 FT_Error
 385 TA_sfnt_update_post_table(SFNT* sfnt,
 386                           FONT* font);
 387
 388 FT_Error
 389 TA_sfnt_update_name_table(SFNT* sfnt,
 390                           FONT* font);
 391
 392 FT_Error
 393 TA_sfnt_build_prep_table(SFNT* sfnt,
 394                          FONT* font);
 395
 396 FT_Error
 397 TA_sfnt_build_TTF_header(SFNT* sfnt,
 398                          FONT* font,
 399                          FT_Byte** header_buf,
 400                          FT_ULong* header_len,
 401                          FT_Int do_complete);
 402 FT_Error
 403 TA_font_build_TTF(FONT* font);
 404
 405 FT_Error
 406 TA_font_build_TTC(FONT* font);
 407
 408 #endif /* __TA_H__ */
 409
 410 /* end of ta.h */