font.h 31.7 KB
Newer Older
Kenichi Handa's avatar
Kenichi Handa committed
1
/* font.h -- Interface definition for font handling.
2
   Copyright (C) 2006-2013 Free Software Foundation, Inc.
3
   Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011
Kenichi Handa's avatar
Kenichi Handa committed
4 5 6 7 8
     National Institute of Advanced Industrial Science and Technology (AIST)
     Registration Number H13PRO009

This file is part of GNU Emacs.

9
GNU Emacs is free software: you can redistribute it and/or modify
Kenichi Handa's avatar
Kenichi Handa committed
10
it under the terms of the GNU General Public License as published by
11 12
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Kenichi Handa's avatar
Kenichi Handa committed
13 14 15 16 17 18 19

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
20
along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
Kenichi Handa's avatar
Kenichi Handa committed
21 22 23 24 25

#ifndef EMACS_FONT_H
#define EMACS_FONT_H

#include "ccl.h"
Daniel Colascione's avatar
Daniel Colascione committed
26
#include "frame.h"
Kenichi Handa's avatar
Kenichi Handa committed
27 28 29 30 31

/* We have three types of Lisp objects related to font.

   FONT-SPEC

32
	Pseudo vector (length FONT_SPEC_MAX) of font properties.  Some
Kenichi Handa's avatar
Kenichi Handa committed
33 34 35
	properties can be left unspecified (i.e. nil).  Emacs asks
	font-drivers to find a font by FONT-SPEC.  A fontset entry
	specifies requisite properties whereas a face specifies just
36
	preferable properties.
Kenichi Handa's avatar
Kenichi Handa committed
37 38 39

   FONT-ENTITY

40
	Pseudo vector (length FONT_ENTITY_MAX) of fully instantiated
41
	font properties that a font-driver returns upon a request of
Kenichi Handa's avatar
Kenichi Handa committed
42 43
	FONT-SPEC.

44
	Note: Only the method `list' and `match' of a font-driver can
45
	create this object, and it should never be modified by Lisp.
Kenichi Handa's avatar
Kenichi Handa committed
46 47 48

   FONT-OBJECT

49
	Pseudo vector (length FONT_OBJECT_MAX) of an opened font.
Kenichi Handa's avatar
Kenichi Handa committed
50

51 52 53 54
	Lisp object encapsulating "struct font".  This corresponds to
	an opened font.

	Note: Only the method `open' of a font-driver can create this
55
	object, and it should never be modified by Lisp.  */
56 57

extern Lisp_Object Qfont_spec, Qfont_entity, Qfont_object;
Kenichi Handa's avatar
Kenichi Handa committed
58 59 60 61 62 63 64 65 66

/* An enumerator for each font property.  This is used as an index to
   the vector of FONT-SPEC and FONT-ENTITY.

   Note: The order is important and should not be changed.  */

enum font_property_index
  {
    /* FONT-TYPE is a symbol indicating a font backend; currently `x',
67
       `xft', and `ftx' are available on X, `uniscribe' and `gdi' on
Juanma Barranquero's avatar
Juanma Barranquero committed
68
       Windows, and `ns' under Cocoa / GNUstep.  */
Kenichi Handa's avatar
Kenichi Handa committed
69 70 71 72 73 74 75 76 77 78 79 80
    FONT_TYPE_INDEX,

    /* FONT-FOUNDRY is a foundry name (symbol).  */
    FONT_FOUNDRY_INDEX,

    /* FONT-FAMILY is a family name (symbol).  */
    FONT_FAMILY_INDEX,

    /* FONT-ADSTYLE is an additional style name (symbol).  */
    FONT_ADSTYLE_INDEX,

    /* FONT-REGISTRY is a combination of a charset-registry and
81
       charset-encoding name (symbol).  */
Kenichi Handa's avatar
Kenichi Handa committed
82 83 84
    FONT_REGISTRY_INDEX,

    /* FONT-WEIGHT is a numeric value of weight (e.g. medium, bold) of
85
       the font.  The lowest 8 bits is an index determining the
86 87
       symbolic name, and the higher bits is the actual numeric value
       defined in `font-weight-table'. */
Kenichi Handa's avatar
Kenichi Handa committed
88 89 90
    FONT_WEIGHT_INDEX,

    /* FONT-SLANT is a numeric value of slant (e.g. r, i, o) of the
91
       font.  The lowest 8 bits is an index determining the symbolic
92 93
       name, and the higher bits is the actual numeric value defined
       in `font-slant-table'.  */
Kenichi Handa's avatar
Kenichi Handa committed
94 95
    FONT_SLANT_INDEX,

96
    /* FONT-WIDTH is a numeric value of setwidth (e.g. normal) of the
97
       font.  The lowest 8 bits is an index determining the symbolic
98 99
       name, and the higher bits is the actual numeric value defined
       `font-width-table'.  */
Kenichi Handa's avatar
Kenichi Handa committed
100 101 102
    FONT_WIDTH_INDEX,

    /* FONT-SIZE is a size of the font.  If integer, it is a pixel
103 104
       size.  For a font-spec, the value can be a float specifying
       the point size.  The value zero means that the font is
105
       scalable.  */
Kenichi Handa's avatar
Kenichi Handa committed
106 107
    FONT_SIZE_INDEX,

108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127
    /* FONT-DPI is a resolution (dot per inch) for which the font is
       designed. */
    FONT_DPI_INDEX,

    /* FONT-SPACING is a spacing (mono, proportional, charcell) of the
       font (integer; one of enum font_spacing).  */
    FONT_SPACING_INDEX,

    /* FONT-AVGWIDTH is an average width (1/10 pixel unit) of the
       font.  */
    FONT_AVGWIDTH_INDEX,

#if 0
    /* The following two members are to substitute for the above 6
       members (FONT_WEIGHT_INDEX to FONT_AVGWIDTH_INDEX excluding
       FONT_SIZE_INDEX) if it is found that font-entities consumes too
       much memory.  */

    /* FONT-STYLE is a 24-bit integer containing indices for
       style-related properties WEIGHT, SLANT, and WIDTH.  The lowest
128 129 130 131
       8 bits is an index to the weight table AREF (font_style_table,
       0), the next 8 bits is an index to the slant table AREF
       (font_style_table, 1), the highest 8 bits is an index to the
       slant table AREF (font_style_table, 2).  The index 0 indicates
132 133 134 135 136 137
       that the corresponding style is not specified.  This way, we
       can represent at most 255 different names for each style, which
       is surely sufficient.  */
    FONT_STYLE_INDEX,

    /* FONT-METRICS is a 27-bit integer containing metrics-related
138 139
       properties DPI, AVGWIDTH, SPACING.  The lowest 12 bits is for
       DPI, the next 12 bits is for AVGWIDTH, the highest 3 bits is for
140 141 142 143 144 145 146 147
       SPACING.  In each bit field, the highest bit indicates that the
       corresponding value is set or not.  This way, we can represent
       DPI by 11-bit (0 to 2047), AVGWIDTH by 11-bit (0 to 2047),
       SPACING by 3-bit (0 for proportional, 1 for dual, 2 for mono, 3
       for charcell), which is surely sufficient.  */
    FONT_METRICS_INDEX,
#endif

Kenichi Handa's avatar
Kenichi Handa committed
148 149
    /* In a font-spec, the value is an alist of extra information of a
       font such as name, OpenType features, and language coverage.
150
       In addition, in a font-entity, the value may contain a pair
Adrian Robert's avatar
Adrian Robert committed
151
       (font-entity . INFO) where INFO is extra information to identify
Kenichi Handa's avatar
Kenichi Handa committed
152
       a font (font-driver dependent).  */
Kenichi Handa's avatar
Kenichi Handa committed
153 154 155 156 157
    FONT_EXTRA_INDEX,		/* alist		alist */

    /* This value is the length of font-spec vector.  */
    FONT_SPEC_MAX,

158
    /* The followings are used only for a font-entity and a font-object.  */
Kenichi Handa's avatar
Kenichi Handa committed
159

160 161
    /* List of font-objects opened from the font-entity.  */
    FONT_OBJLIST_INDEX = FONT_SPEC_MAX,
Kenichi Handa's avatar
Kenichi Handa committed
162

163 164 165
    /* Font-entity from which the font-object is opened.  */
    FONT_ENTITY_INDEX = FONT_SPEC_MAX,

Kenichi Handa's avatar
Kenichi Handa committed
166
    /* This value is the length of font-entity vector.  */
167 168
    FONT_ENTITY_MAX,

169 170
    /* The followings are used only for a font-object.  */

171 172
    /* XLFD name of the font (string). */
    FONT_NAME_INDEX = FONT_ENTITY_MAX,
Juanma Barranquero's avatar
Juanma Barranquero committed
173

174
    /* Full name of the font (string).  It is the name extracted from
175
       the opened font, and may be different from the above.  It may be
176 177 178 179 180 181 182
       nil if the opened font doesn't give a name.  */
    FONT_FULLNAME_INDEX,

    /* File name of the font or nil if a file associated with the font
       is not available.  */
    FONT_FILE_INDEX,

Kenichi Handa's avatar
Kenichi Handa committed
183
    /* Format of the font (symbol) or nil if unknown.  */
184 185 186 187
    FONT_FORMAT_INDEX,

    /* This value is the length of font-object vector.  */
    FONT_OBJECT_MAX
Kenichi Handa's avatar
Kenichi Handa committed
188 189
  };

190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237
/* Return the numeric weight value of FONT.  */
#define FONT_WEIGHT_NUMERIC(font)		\
  (INTEGERP (AREF ((font), FONT_WEIGHT_INDEX))	\
   ? (XINT (AREF ((font), FONT_WEIGHT_INDEX)) >> 8) : -1)
/* Return the numeric slant value of FONT.  */
#define FONT_SLANT_NUMERIC(font)		\
  (INTEGERP (AREF ((font), FONT_SLANT_INDEX))	\
   ? (XINT (AREF ((font), FONT_SLANT_INDEX)) >> 8) : -1)
/* Return the numeric width value of FONT.  */
#define FONT_WIDTH_NUMERIC(font)		\
  (INTEGERP (AREF ((font), FONT_WIDTH_INDEX))	\
   ? (XINT (AREF ((font), FONT_WIDTH_INDEX)) >> 8) : -1)
/* Return the symbolic weight value of FONT.  */
#define FONT_WEIGHT_SYMBOLIC(font)	\
  font_style_symbolic (font, FONT_WEIGHT_INDEX, 0)
/* Return the symbolic slant value of FONT.  */
#define FONT_SLANT_SYMBOLIC(font)	\
  font_style_symbolic (font, FONT_SLANT_INDEX, 0)
/* Return the symbolic width value of FONT.  */
#define FONT_WIDTH_SYMBOLIC(font)	\
  font_style_symbolic (font, FONT_WIDTH_INDEX, 0)
/* Return the face-weight corresponding to the weight of FONT.  */
#define FONT_WEIGHT_FOR_FACE(font)	\
  font_style_symbolic (font, FONT_WEIGHT_INDEX, 1)
/* Return the face-slant corresponding to the slant of FONT.  */
#define FONT_SLANT_FOR_FACE(font)	\
  font_style_symbolic (font, FONT_SLANT_INDEX, 1)
/* Return the face-swidth corresponding to the slant of FONT.  */
#define FONT_WIDTH_FOR_FACE(font)	\
  font_style_symbolic (font, FONT_WIDTH_INDEX, 1)

/* Return the numeric weight value corresponding ot the symbol NAME.  */
#define FONT_WEIGHT_NAME_NUMERIC(name)	\
  (font_style_to_value (FONT_WEIGHT_INDEX, (name), 0) >> 8)
/* Return the numeric slant value corresponding ot the symbol NAME.  */
#define FONT_SLANT_NAME_NUMERIC(name)	\
  (font_style_to_value (FONT_SLANT_INDEX, (name), 0) >> 8)
/* Return the numeric width value corresponding ot the symbol NAME.  */
#define FONT_WIDTH_NAME_NUMERIC(name)	\
  (font_style_to_value (FONT_WIDTH_INDEX, (name), 0) >> 8)

/* Set the font property PROP of FONT to VAL.  PROP is one of
   style-related font property index (FONT_WEIGHT/SLANT/WIDTH_INDEX).
   VAL (integer or symbol) is the numeric or symbolic style value.  */
#define FONT_SET_STYLE(font, prop, val)	\
  ASET ((font), prop, make_number (font_style_to_value (prop, val, 1)))

extern Lisp_Object QCspacing, QCdpi, QCscalable, QCotf, QClang, QCscript;
238
extern Lisp_Object QCavgwidth, QCantialias, QCfont_entity;
239 240
extern Lisp_Object Qp;

Kenichi Handa's avatar
Kenichi Handa committed
241

242
/* Important character set symbols.  */
Kenichi Handa's avatar
Kenichi Handa committed
243
extern Lisp_Object Qascii_0;
Kenichi Handa's avatar
Kenichi Handa committed
244
extern Lisp_Object Qiso8859_1, Qiso10646_1, Qunicode_bmp, Qunicode_sip;
245

246 247 248
/* Special ADSTYLE properties to avoid fonts used for Latin characters.  */
extern Lisp_Object Qja, Qko;

249 250 251 252
/* Structure for a font-spec.  */

struct font_spec
{
253
  struct vectorlike_header header;
254 255 256 257 258 259 260
  Lisp_Object props[FONT_SPEC_MAX];
};

/* Structure for a font-entity.  */

struct font_entity
{
261
  struct vectorlike_header header;
262 263
  Lisp_Object props[FONT_ENTITY_MAX];
};
Kenichi Handa's avatar
Kenichi Handa committed
264

265 266 267 268 269 270
/* A value which may appear in the member `encoding' of struct font
   indicating that a font itself doesn't tell which encoding to be
   used.  */
#define FONT_ENCODING_NOT_DECIDED 255

/* Structure for a font-object.  */
Kenichi Handa's avatar
Kenichi Handa committed
271 272 273

struct font
{
274
  struct vectorlike_header header;
275 276 277

  /* All Lisp_Object components must come first.
     That ensures they are all aligned normally.  */
Kenichi Handa's avatar
Kenichi Handa committed
278

279 280 281 282
  Lisp_Object props[FONT_OBJECT_MAX];

  /* Beyond here, there should be no more Lisp_Object components.  */

283 284 285 286 287
  /* Minimum and maximum glyph widths, in pixels.  Some font backends,
     such as xft, lack the information to easily compute minimum and
     maximum widths over all characters; in that case, these values
     are approximate.  */
  int min_width;
288
  int max_width;
Kenichi Handa's avatar
Kenichi Handa committed
289 290 291 292

  /* By which pixel size the font is opened.  */
  int pixel_size;

293 294 295 296 297 298 299 300 301
  /* Height of the font.  On X window, this is the same as
     (font->ascent + font->descent).  */
  int height;

  /* Width of the space glyph of the font.  If the font doesn't have a
     SPACE glyph, the value is 0.  */
  int space_width;

  /* Average width of glyphs in the font.  If the font itself doesn't
302
     have that information but has glyphs of ASCII characters, the
303
     value is the average width of those glyphs.  Otherwise, the value
304 305 306 307 308
     is 0.  */
  int average_width;

  /* Ascent and descent of the font (in pixels).  */
  int ascent, descent;
309

310 311 312 313 314 315 316 317 318
  /* Vertical pixel width of the underline.  If is zero if that
     information is not in the font.  */
  int underline_thickness;

  /* Vertical pixel position (relative to the baseline) of the
     underline.  If it is positive, it is below the baseline.  It is
     negative if that information is not in the font.  */
  int underline_position;

319
  /* True if `vertical-centering-font-regexp' matches this font name.
320
     In this case, we render characters at vertical center positions
321
     of lines.  */
322
  bool vertical_centering;
323 324

  /* The baseline position of a font is normally `ascent' value of the
325
     font.  However, there exist many fonts which don't set `ascent' to
326 327 328 329 330
     an appropriate value to be used as baseline position.  This is
     typical in such ASCII fonts which are designed to be used with
     Chinese, Japanese, Korean characters.  When we use mixture of
     such fonts and normal fonts (having correct `ascent' value), a
     display line gets very ugly.  Since we have no way to fix it
331
     automatically, it is user's responsibility to supply well designed
332 333 334 335 336
     fonts or correct `ascent' value of fonts.  But, the latter
     requires heavy work (modifying all bitmap data in BDF files).
     So, Emacs accepts a private font property
     `_MULE_BASELINE_OFFSET'.  If a font has this property, we
     calculate the baseline position by subtracting the value from
337 338 339
     `ascent'.  In other words, the value indicates how many pixels
     higher than normal ASCII text we should draw a character of the
     font for better appearance.
340 341 342

     We also have to consider the fact that the concept of `baseline'
     differs among scripts to which each character belongs.  For
343
     instance, baseline should be at the bottom-most position of all
344
     glyphs for Chinese, Japanese, and Korean.  But, many of existing
345
     fonts for those characters don't have correct `ascent' values
346 347 348 349 350 351 352 353 354
     because they are designed to be used with ASCII fonts.  To
     display characters of different language on the same line, the
     best way will be to arrange them in the middle of the line.  So,
     in such a case, again, we utilize the font property
     `_MULE_BASELINE_OFFSET'.  If the value is larger than `ascent' we
     calculate baseline so that a character is arranged in the middle
     of a line.  */
  int baseline_offset;

355
  /* Non-zero means a character should be composed at a position
356 357 358 359 360
     relative to the height (or depth) of previous glyphs in the
     following cases:
	(1) The bottom of the character is higher than this value.  In
	this case, the character is drawn above the previous glyphs.
	(2) The top of the character is lower than 0 (i.e. baseline
361
	height).  In this case, the character is drawn below the
362 363 364 365 366 367
	previous glyphs.

     This value is taken from a private font property
     `_MULE_RELATIVE_COMPOSE' which is introduced by Emacs.  */
  int relative_compose;

368
  /* Non-zero means an ascent value to be used for a character
369 370 371 372 373 374 375 376
     registered in char-table `use-default-ascent'.  */
  int default_ascent;

  /* CCL program to calculate code points of the font.  */
  struct ccl_program *font_encoder;

  /* Font-driver for the font.  */
  struct font_driver *driver;
Kenichi Handa's avatar
Kenichi Handa committed
377

378 379 380
  /* Charset to encode a character code into a glyph code of the font.
     -1 means that the font doesn't require this information to encode
     a character.  */
Kenichi Handa's avatar
Kenichi Handa committed
381 382 383 384
  int encoding_charset;

  /* Charset to check if a character code is supported by the font.
     -1 means that the contents of the font must be looked up to
385
     determine it.  */
386
  int repertory_charset;
Kenichi Handa's avatar
Kenichi Handa committed
387

388 389
  /* There are more members in this structure, but they are private
     to the font-driver.  */
Kenichi Handa's avatar
Kenichi Handa committed
390 391
};

392 393 394 395 396 397 398 399
enum font_spacing
  {
    FONT_SPACING_PROPORTIONAL = 0,
    FONT_SPACING_DUAL = 90,
    FONT_SPACING_MONO = 100,
    FONT_SPACING_CHARCELL = 110
  };

Kenichi Handa's avatar
Kenichi Handa committed
400 401 402 403 404 405 406
struct font_metrics
{
  short lbearing, rbearing, width, ascent, descent;
};

struct font_bitmap
{
407
  int bits_per_pixel;
Kenichi Handa's avatar
Kenichi Handa committed
408 409 410 411 412 413 414 415 416 417 418 419
  int rows;
  int width;
  int pitch;
  unsigned char *buffer;
  int left;
  int top;
  int advance;
  void *extra;
};

/* Predicates to check various font-related objects.  */

420 421 422
/* 1 iff X is one of font-spec, font-entity, and font-object.  */
#define FONTP(x) PSEUDOVECTORP (x, PVEC_FONT)
/* 1 iff X is font-spec.  */
Kenichi Handa's avatar
Kenichi Handa committed
423
#define FONT_SPEC_P(x)	\
424 425
  (FONTP (x) && (ASIZE (x) & PSEUDOVECTOR_SIZE_MASK) == FONT_SPEC_MAX)
/* 1 iff X is font-entity.  */
Kenichi Handa's avatar
Kenichi Handa committed
426
#define FONT_ENTITY_P(x)	\
427 428
  (FONTP (x) && (ASIZE (x) & PSEUDOVECTOR_SIZE_MASK) == FONT_ENTITY_MAX)
/* 1 iff X is font-object.  */
Kenichi Handa's avatar
Kenichi Handa committed
429
#define FONT_OBJECT_P(x)	\
430
  (FONTP (x) && (ASIZE (x) & PSEUDOVECTOR_SIZE_MASK) == FONT_OBJECT_MAX)
Kenichi Handa's avatar
Kenichi Handa committed
431

432
/* 1 iff ENTITY can't be loaded.  */
Kenichi Handa's avatar
Kenichi Handa committed
433 434 435
#define FONT_ENTITY_NOT_LOADABLE(entity)	\
  EQ (AREF (entity, FONT_OBJLIST_INDEX), Qt)

436
/* Flag ENTITY not loadable.  */
Kenichi Handa's avatar
Kenichi Handa committed
437 438 439
#define FONT_ENTITY_SET_NOT_LOADABLE(entity)	\
  ASET (entity, FONT_OBJLIST_INDEX, Qt)

Kenichi Handa's avatar
Kenichi Handa committed
440 441 442 443

/* Check macros for various font-related objects.  */

#define CHECK_FONT(x)	\
444
  do { if (! FONTP (x)) wrong_type_argument (Qfont, x); } while (0)
Kenichi Handa's avatar
Kenichi Handa committed
445
#define CHECK_FONT_SPEC(x)	\
446
  do { if (! FONT_SPEC_P (x)) wrong_type_argument (Qfont_spec, x); } while (0)
Kenichi Handa's avatar
Kenichi Handa committed
447
#define CHECK_FONT_ENTITY(x)	\
448
  do { if (! FONT_ENTITY_P (x)) wrong_type_argument (Qfont_entity, x); } while (0)
Kenichi Handa's avatar
Kenichi Handa committed
449
#define CHECK_FONT_OBJECT(x)	\
450
  do { if (! FONT_OBJECT_P (x)) wrong_type_argument (Qfont_object, x); } while (0)
Kenichi Handa's avatar
Kenichi Handa committed
451

452 453 454 455
#define CHECK_FONT_GET_OBJECT(x, font)	\
  do {					\
    CHECK_FONT_OBJECT (x);		\
    font = XFONT_OBJECT (x);		\
Kenichi Handa's avatar
Kenichi Handa committed
456 457
  } while (0)

458
#define XFONT_SPEC(p)	\
459
  (eassert (FONT_SPEC_P (p)), (struct font_spec *) XUNTAG (p, Lisp_Vectorlike))
460
#define XFONT_ENTITY(p)	\
461 462
  (eassert (FONT_ENTITY_P (p)), \
   (struct font_entity *) XUNTAG (p, Lisp_Vectorlike))
463
#define XFONT_OBJECT(p)	\
464
  (eassert (FONT_OBJECT_P (p)), (struct font *) XUNTAG (p, Lisp_Vectorlike))
465 466 467 468 469 470 471 472 473
#define XSETFONT(a, b) (XSETPSEUDOVECTOR (a, b, PVEC_FONT))

/* Number of pt per inch (from the TeXbook).  */
#define PT_PER_INCH 72.27

/* Return a pixel size (integer) corresponding to POINT size (double)
   on resolution DPI.  */
#define POINT_TO_PIXEL(POINT, DPI) ((POINT) * (DPI) / PT_PER_INCH + 0.5)

474
/* Return a point size corresponding to POINT size (integer)
475 476
   on resolution DPI.  Note that though point size is a double, we expect
   it to be rounded to an int, so we add 0.5 here.  If the desired value
477 478
   is tenths of points (as in xfld specs), then the pixel size should
   be multiplied BEFORE the conversion to avoid magnifying the error.  */
479 480
#define PIXEL_TO_POINT(PIXEL, DPI) ((PIXEL) * PT_PER_INCH / (DPI) + 0.5)

481 482 483 484
/* Ignore the difference of font pixel sizes less than or equal to
   this value.  */
#define FONT_PIXEL_SIZE_QUANTUM 1

Kenichi Handa's avatar
Kenichi Handa committed
485 486
#define FONT_INVALID_CODE 0xFFFFFFFF

487 488
/* Font driver.  Members specified as "optional" can be NULL.  */

Kenichi Handa's avatar
Kenichi Handa committed
489 490 491 492 493
struct font_driver
{
  /* Symbol indicating the type of the font-driver.  */
  Lisp_Object type;

494
  /* True iff the font's foundry, family, and adstyle names are case
Paul Eggert's avatar
Paul Eggert committed
495
     sensitive.  */
496
  bool case_sensitive;
497

498
  /* Return a cache of font-entities on frame F.  The cache must be a
Kenichi Handa's avatar
Kenichi Handa committed
499
     cons whose cdr part is the actual cache area.  */
Dmitry Antipov's avatar
Dmitry Antipov committed
500
  Lisp_Object (*get_cache) (struct frame *f);
Kenichi Handa's avatar
Kenichi Handa committed
501

502
  /* List fonts exactly matching with FONT_SPEC on FRAME.  The value
Kenichi Handa's avatar
Kenichi Handa committed
503
     is a list of font-entities.  The font properties to be considered
504
     are: :foundry, :family, :adstyle, :registry, :script, :lang, and
Kenichi Handa's avatar
Kenichi Handa committed
505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520
     :otf.  See the function `font-spec' for their meanings.  Note
     that the last three properties are stored in FONT_EXTRA_INDEX
     slot of FONT_SPEC.

     The returned value is a list of font-entities.  Each font-entity
     has :type property whose value is the same as the above `type'.
     It also has these properties if they are available from the
     corresponding font; :foundry, :family, :adstyle, :registry,
     :weight, :slant, :width, :size, :dpi, :spacing, :avgwidth.  If
     the font is scalable, :size and :avgwidth must be 0.

     The `open' method of the same font-backend is called with one of
     the returned font-entities.  If the backend needs additional
     information to be used in `open' method, this method can add any
     Lispy value by the property :font-entity to the entities.

521 522
     This and the following `match' are the only APIs that allocate
     font-entities.  */
523
  Lisp_Object (*list) (struct frame *frame, Lisp_Object font_spec);
Kenichi Handa's avatar
Kenichi Handa committed
524

525
  /* Return a font-entity most closely matching with FONT_SPEC on
Kenichi Handa's avatar
Kenichi Handa committed
526
     FRAME.  Which font property to consider, and how to calculate the
527
     closeness is determined by the font backend, thus
Kenichi Handa's avatar
Kenichi Handa committed
528 529 530 531
     `face-font-selection-order' is ignored here.

     The properties that the font-entity has is the same as `list'
     method.  */
532
  Lisp_Object (*match) (struct frame *f, Lisp_Object spec);
533

534 535 536
  /* Optional.
     List available families.  The value is a list of family names
     (symbols).  */
537
  Lisp_Object (*list_family) (struct frame *f);
Kenichi Handa's avatar
Kenichi Handa committed
538

539 540
  /* Optional (if FONT_EXTRA_INDEX is not Lisp_Save_Value).
     Free FONT_EXTRA_INDEX field of FONT_ENTITY.  */
Jan D's avatar
Jan D committed
541
  void (*free_entity) (Lisp_Object font_entity);
Kenichi Handa's avatar
Kenichi Handa committed
542 543 544

  /* Open a font specified by FONT_ENTITY on frame F.  If the font is
     scalable, open it with PIXEL_SIZE.  */
Dmitry Antipov's avatar
Dmitry Antipov committed
545
  Lisp_Object (*open) (struct frame *f, Lisp_Object font_entity,
Jan D's avatar
Jan D committed
546
                       int pixel_size);
Kenichi Handa's avatar
Kenichi Handa committed
547 548

  /* Close FONT on frame F.  */
Dmitry Antipov's avatar
Dmitry Antipov committed
549
  void (*close) (struct frame *f, struct font *font);
Kenichi Handa's avatar
Kenichi Handa committed
550

551 552 553 554
  /* Optional (if FACE->extra is not used).
     Prepare FACE for displaying characters by FONT on frame F by
     storing some data in FACE->extra.  If successful, return 0.
     Otherwise, return -1.  */
Dmitry Antipov's avatar
Dmitry Antipov committed
555
  int (*prepare_face) (struct frame *f, struct face *face);
Kenichi Handa's avatar
Kenichi Handa committed
556

557 558
  /* Optional.
     Done FACE for displaying characters by FACE->font on frame F.  */
Dmitry Antipov's avatar
Dmitry Antipov committed
559
  void (*done_face) (struct frame *f, struct face *face);
Kenichi Handa's avatar
Kenichi Handa committed
560

561
  /* Optional.
562 563 564
     If FONT (FONT-ENTITY or FONT-OBJECT) has a glyph for character C
     (Unicode code point), return 1.  If not, return 0.  If FONT is
     FONT-ENTITY and it must be opened to check it, return -1.  */
Jan D's avatar
Jan D committed
565
  int (*has_char) (Lisp_Object font, int c);
Kenichi Handa's avatar
Kenichi Handa committed
566

567
  /* Return a glyph code of FONT for character C (Unicode code point).
568
     If FONT doesn't have such a glyph, return FONT_INVALID_CODE.  */
Jan D's avatar
Jan D committed
569
  unsigned (*encode_char) (struct font *font, int c);
Kenichi Handa's avatar
Kenichi Handa committed
570

571
  /* Compute the total metrics of the NGLYPHS glyphs specified by
572 573
     the font FONT and the sequence of glyph codes CODE, and store the
     result in METRICS.  */
Jan D's avatar
Jan D committed
574 575 576
  int (*text_extents) (struct font *font,
                       unsigned *code, int nglyphs,
                       struct font_metrics *metrics);
Kenichi Handa's avatar
Kenichi Handa committed
577

578 579
  /* Optional.
     Draw glyphs between FROM and TO of S->char2b at (X Y) pixel
580 581 582
     position of frame F with S->FACE and S->GC.  If WITH_BACKGROUND,
     fill the background in advance.  It is assured that WITH_BACKGROUND
     is false when (FROM > 0 || TO < S->nchars).  */
Jan D's avatar
Jan D committed
583
  int (*draw) (struct glyph_string *s, int from, int to,
584
               int x, int y, bool with_background);
Kenichi Handa's avatar
Kenichi Handa committed
585

586 587
  /* Optional.
     Store bitmap data for glyph-code CODE of FONT in BITMAP.  It is
Paul Eggert's avatar
Paul Eggert committed
588
     intended that this method is called from the other font-driver
589
     for actual drawing.  */
Jan D's avatar
Jan D committed
590 591 592
  int (*get_bitmap) (struct font *font, unsigned code,
                     struct font_bitmap *bitmap,
                     int bits_per_pixel);
Kenichi Handa's avatar
Kenichi Handa committed
593

594 595
  /* Optional.
     Free bitmap data in BITMAP.  */
Jan D's avatar
Jan D committed
596
  void (*free_bitmap) (struct font *font, struct font_bitmap *bitmap);
Kenichi Handa's avatar
Kenichi Handa committed
597

598 599 600
  /* Optional.
     Return an outline data for glyph-code CODE of FONT.  The format
     of the outline data depends on the font-driver.  */
Jan D's avatar
Jan D committed
601
  void *(*get_outline) (struct font *font, unsigned code);
Kenichi Handa's avatar
Kenichi Handa committed
602

603 604
  /* Optional.
     Free OUTLINE (that is obtained by the above method).  */
Jan D's avatar
Jan D committed
605
  void (*free_outline) (struct font *font, void *outline);
Kenichi Handa's avatar
Kenichi Handa committed
606

607 608
  /* Optional.
     Get coordinates of the INDEXth anchor point of the glyph whose
Kenichi Handa's avatar
Kenichi Handa committed
609
     code is CODE.  Store the coordinates in *X and *Y.  Return 0 if
Paul Eggert's avatar
Paul Eggert committed
610
     the operations was successful.  Otherwise return -1.  */
Jan D's avatar
Jan D committed
611 612
  int (*anchor_point) (struct font *font, unsigned code, int index,
                       int *x, int *y);
Kenichi Handa's avatar
Kenichi Handa committed
613

614 615
  /* Optional.
     Return a list describing which scripts/languages FONT
Kenichi Handa's avatar
Kenichi Handa committed
616
     supports by which GSUB/GPOS features of OpenType tables.  */
Jan D's avatar
Jan D committed
617
  Lisp_Object (*otf_capability) (struct font *font);
Kenichi Handa's avatar
Kenichi Handa committed
618

619
  /* Optional.
Kenichi Handa's avatar
Kenichi Handa committed
620 621 622 623
     Apply FONT's OTF-FEATURES to the glyph string.

     FEATURES specifies which OTF features to apply in this format:
	(SCRIPT LANGSYS GSUB-FEATURE GPOS-FEATURE)
624
     See the documentation of `font-drive-otf' for the details.
Kenichi Handa's avatar
Kenichi Handa committed
625 626 627 628 629 630 631 632 633

     This method applies the specified features to the codes in the
     elements of GSTRING-IN (between FROMth and TOth).  The output
     codes are stored in GSTRING-OUT at the IDXth element and the
     following elements.

     Return the number of output codes.  If none of the features are
     applicable to the input data, return 0.  If GSTRING-OUT is too
     short, return -1.  */
Jan D's avatar
Jan D committed
634 635
  int (*otf_drive) (struct font *font, Lisp_Object features,
                    Lisp_Object gstring_in, int from, int to,
636
                    Lisp_Object gstring_out, int idx, bool alternate_subst);
637 638 639

  /* Optional.
     Make the font driver ready for frame F.  Usually this function
640
     makes some data specific to F and stores it in F by calling
641
     font_put_frame_data ().  */
Dmitry Antipov's avatar
Dmitry Antipov committed
642
  int (*start_for_frame) (struct frame *f);
Juanma Barranquero's avatar
Juanma Barranquero committed
643

644 645 646
  /* Optional.
     End using the driver for frame F.  Usually this function free
     some data stored for F.  */
Dmitry Antipov's avatar
Dmitry Antipov committed
647
  int (*end_for_frame) (struct frame *f);
Kenichi Handa's avatar
Kenichi Handa committed
648 649

  /* Optional.
650

651 652 653 654 655
     Shape text in GSTRING.  See the docstring of
     `composition-get-gstring' for the format of GSTRING.  If the
     (N+1)th element of GSTRING is nil, input of shaping is from the
     1st to (N)th elements.  In each input glyph, FROM, TO, CHAR, and
     CODE are already set.
656 657 658

     This function updates all fields of the input glyphs.  If the
     output glyphs (M) are more than the input glyphs (N), (N+1)th
659 660 661 662
     through (M)th elements of GSTRING are updated possibly by making
     a new glyph object and storing it in GSTRING.  If (M) is greater
     than the length of GSTRING, nil should be return.  In that case,
     this function is called again with the larger GSTRING.  */
Jan D's avatar
Jan D committed
663
  Lisp_Object (*shape) (Lisp_Object lgstring);
664 665 666 667

  /* Optional.

     If FONT is usable on frame F, return 0.  Otherwise return -1.
668 669
     This method is used only for debugging.  If this method is NULL,
     Emacs assumes that the font is usable on any frame.  */
Dmitry Antipov's avatar
Dmitry Antipov committed
670
  int (*check) (struct frame *f, struct font *font);
671 672 673 674 675 676 677

  /* Optional.

     Return the number of variation glyphs of character C supported by
     FONT.  VARIATIONS is an array of 256 elements.  If the variation
     selector N (1..256) defines a glyph, that glyph code is stored in
     the (N-1)th element of VARIATIONS.  */
Jan D's avatar
Jan D committed
678 679
  int (*get_variation_glyphs) (struct font *font,
                               int c, unsigned variations[256]);
680

Jan D's avatar
Jan D committed
681
  void (*filter_properties) (Lisp_Object font, Lisp_Object properties);
682 683 684 685 686

  /* Optional.

     Return non-zero if FONT_OBJECT can be used as a (cached) font
     for ENTITY on frame F.  */
687 688 689
  bool (*cached_font_ok) (struct frame *f,
                          Lisp_Object font_object,
                          Lisp_Object entity);
Kenichi Handa's avatar
Kenichi Handa committed
690 691 692
};


693
/* Chain of font drivers.  There's one global font driver list
Dmitry Antipov's avatar
Dmitry Antipov committed
694 695
   (font_driver_list in font.c).  In addition, each frame has
   its own font driver list at F->font_driver_list.  */
696

Kenichi Handa's avatar
Kenichi Handa committed
697 698
struct font_driver_list
{
699
  /* True iff this driver is currently used.  It is ignored in the global
700
     font driver list.*/
701
  bool on;
702
  /* Pointer to the font driver.  */
Kenichi Handa's avatar
Kenichi Handa committed
703
  struct font_driver *driver;
704
  /* Pointer to the next element of the chain.  */
Kenichi Handa's avatar
Kenichi Handa committed
705 706 707
  struct font_driver_list *next;
};

708

Dmitry Antipov's avatar
Dmitry Antipov committed
709 710
/* Chain of arbitrary data specific to each font driver.
   Each frame has its own font data list at F->font_data_list.  */
711 712 713 714 715 716 717 718 719 720 721

struct font_data_list
{
  /* Pointer to the font driver.  */
  struct font_driver *driver;
  /* Data specific to the font driver.  */
  void *data;
  /* Pointer to the next element of the chain.  */
  struct font_data_list *next;
};

722 723
extern Lisp_Object copy_font_spec (Lisp_Object);
extern Lisp_Object merge_font_spec (Lisp_Object, Lisp_Object);
Kenichi Handa's avatar
Kenichi Handa committed
724

Jan D's avatar
Jan D committed
725 726 727 728 729 730 731
extern Lisp_Object font_make_entity (void);
extern Lisp_Object font_make_object (int, Lisp_Object, int);

extern Lisp_Object find_font_encoding (Lisp_Object);
extern int font_registry_charsets (Lisp_Object, struct charset **,
                                   struct charset **);
extern int font_style_to_value (enum font_property_index prop,
732
                                Lisp_Object name, bool noerror);
Jan D's avatar
Jan D committed
733 734
extern Lisp_Object font_style_symbolic (Lisp_Object font,
                                        enum font_property_index prop,
735
                                        bool for_face);
Jan D's avatar
Jan D committed
736

737
extern bool font_match_p (Lisp_Object spec, Lisp_Object font);
738
extern Lisp_Object font_list_entities (struct frame *, Lisp_Object);
Jan D's avatar
Jan D committed
739 740 741 742

extern Lisp_Object font_get_name (Lisp_Object font_object);
extern Lisp_Object font_spec_from_name (Lisp_Object font_name);
extern Lisp_Object font_get_frame (Lisp_Object font_object);
Dmitry Antipov's avatar
Dmitry Antipov committed
743
extern int font_has_char (struct frame *, Lisp_Object, int);
Jan D's avatar
Jan D committed
744 745 746

extern void font_clear_prop (Lisp_Object *attrs,
                             enum font_property_index prop);
Dmitry Antipov's avatar
Dmitry Antipov committed
747
extern Lisp_Object font_find_for_lface (struct frame *f, Lisp_Object *lface,
Jan D's avatar
Jan D committed
748
                                        Lisp_Object spec, int c);
Dmitry Antipov's avatar
Dmitry Antipov committed
749
extern Lisp_Object font_open_for_lface (struct frame *f, Lisp_Object entity,
Jan D's avatar
Jan D committed
750 751
                                        Lisp_Object *lface,
                                        Lisp_Object spec);
Dmitry Antipov's avatar
Dmitry Antipov committed
752
extern Lisp_Object font_load_for_lface (struct frame *f, Lisp_Object *lface,
Jan D's avatar
Jan D committed
753
                                        Lisp_Object spec);
Dmitry Antipov's avatar
Dmitry Antipov committed
754 755
extern void font_prepare_for_face (struct frame *f, struct face *face);
extern void font_done_for_face (struct frame *f, struct face *face);
756
extern void clear_font_cache (struct frame *);
Jan D's avatar
Jan D committed
757

Dmitry Antipov's avatar
Dmitry Antipov committed
758 759
extern Lisp_Object font_open_by_spec (struct frame *f, Lisp_Object spec);
extern Lisp_Object font_open_by_name (struct frame *f, Lisp_Object name);
Kenichi Handa's avatar
Kenichi Handa committed
760

761
extern Lisp_Object font_intern_prop (const char *str, ptrdiff_t len,
762
				     bool force_symbol);
Jan D's avatar
Jan D committed
763 764 765 766 767 768
extern void font_update_sort_order (int *order);

extern void font_parse_family_registry (Lisp_Object family,
                                        Lisp_Object registry,
                                        Lisp_Object spec);

769
extern int font_parse_xlfd (char *name, ptrdiff_t len, Lisp_Object font);
770 771
extern ptrdiff_t font_unparse_xlfd (Lisp_Object font, int pixel_size,
				    char *name, int bytes);
Jan D's avatar
Jan D committed
772
extern int font_unparse_fcname (Lisp_Object font, int pixel_size,
Dan Nicolaescu's avatar
Dan Nicolaescu committed
773
                                char *name, int bytes);
Dmitry Antipov's avatar
Dmitry Antipov committed
774 775 776
extern void register_font_driver (struct font_driver *driver, struct frame *f);
extern void free_font_driver_list (struct frame *f);
extern Lisp_Object font_update_drivers (struct frame *f, Lisp_Object list);
777
extern Lisp_Object font_range (ptrdiff_t, ptrdiff_t, ptrdiff_t *,
Stefan Monnier's avatar
Stefan Monnier committed
778 779
			       struct window *, struct face *,
			       Lisp_Object);
Jan D's avatar
Jan D committed
780
extern void font_fill_lglyph_metrics (Lisp_Object, Lisp_Object);
Kenichi Handa's avatar
Kenichi Handa committed
781

Jan D's avatar
Jan D committed
782 783
extern Lisp_Object font_put_extra (Lisp_Object font, Lisp_Object prop,
                                   Lisp_Object val);
Kenichi Handa's avatar
Kenichi Handa committed
784

Dmitry Antipov's avatar
Dmitry Antipov committed
785
extern int font_put_frame_data (struct frame *f,
Jan D's avatar
Jan D committed
786 787
                                struct font_driver *driver,
                                void *data);
Dmitry Antipov's avatar
Dmitry Antipov committed
788
extern void *font_get_frame_data (struct frame *f,
Jan D's avatar
Jan D committed
789
                                  struct font_driver *driver);
790

791 792
extern void font_filter_properties (Lisp_Object font,
				    Lisp_Object alist,
793 794
				    const char *const boolean_properties[],
				    const char *const non_boolean_properties[]);
795

Kenichi Handa's avatar
Kenichi Handa committed
796 797
#ifdef HAVE_FREETYPE
extern struct font_driver ftfont_driver;
798
extern void syms_of_ftfont (void);
Kenichi Handa's avatar
Kenichi Handa committed
799 800 801
#endif	/* HAVE_FREETYPE */
#ifdef HAVE_X_WINDOWS
extern struct font_driver xfont_driver;
802 803
extern void syms_of_xfont (void);
extern void syms_of_ftxfont (void);
Kenichi Handa's avatar
Kenichi Handa committed
804
#ifdef HAVE_XFT
Paul Eggert's avatar
Paul Eggert committed
805
extern Lisp_Object Qxft;
Kenichi Handa's avatar
Kenichi Handa committed
806
extern struct font_driver xftfont_driver;
807
extern void syms_of_xftfont (void);
808 809 810
#elif defined HAVE_FREETYPE
extern struct font_driver ftxfont_driver;
#endif
811 812 813
#ifdef HAVE_BDFFONT
extern void syms_of_bdffont (void);
#endif	/* HAVE_BDFFONT */
Kenichi Handa's avatar
Kenichi Handa committed
814
#endif	/* HAVE_X_WINDOWS */
Daniel Colascione's avatar
Daniel Colascione committed
815
#ifdef HAVE_NTGUI
Kenichi Handa's avatar
Kenichi Handa committed
816
extern struct font_driver w32font_driver;
817
extern struct font_driver uniscribe_font_driver;
818
extern void syms_of_w32font (void);
Daniel Colascione's avatar
Daniel Colascione committed
819
#endif	/* HAVE_NTGUI */
820
#ifdef HAVE_NS
821
extern Lisp_Object Qfontsize;
822
extern struct font_driver nsfont_driver;
823
extern void syms_of_nsfont (void);
824
#endif	/* HAVE_NS */
Kenichi Handa's avatar
Kenichi Handa committed
825

826 827 828 829
#ifndef FONT_DEBUG
#define FONT_DEBUG
#endif

Andreas Schwab's avatar
Andreas Schwab committed
830
extern Lisp_Object QCfoundry;
831

832 833
extern void font_add_log (const char *, Lisp_Object, Lisp_Object);
extern void font_deferred_log (const char *, Lisp_Object, Lisp_Object);
834

Kenichi Handa's avatar
Kenichi Handa committed
835 836 837 838 839 840 841 842 843 844 845 846
#define FONT_ADD_LOG(ACTION, ARG, RESULT)	\
  do {						\
    if (! EQ (Vfont_log, Qt))			\
      font_add_log ((ACTION), (ARG), (RESULT));	\
  } while (0)

#define FONT_DEFERRED_LOG(ACTION, ARG, RESULT)		\
  do {							\
    if (! EQ (Vfont_log, Qt))				\
      font_deferred_log ((ACTION), (ARG), (RESULT));	\
  } while (0)

Kenichi Handa's avatar
Kenichi Handa committed
847
#endif	/* not EMACS_FONT_H */