font.h 32.2 KB
Newer Older
Kenichi Handa's avatar
Kenichi Handa committed
1
/* font.h -- Interface definition for font handling.
2 3
   Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
   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 26 27 28 29 30

#ifndef EMACS_FONT_H
#define EMACS_FONT_H

#include "ccl.h"

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

   FONT-SPEC

31
	Pseudo vector (length FONT_SPEC_MAX) of font properties.  Some
Kenichi Handa's avatar
Kenichi Handa committed
32 33 34
	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
35
	preferable properties.
Kenichi Handa's avatar
Kenichi Handa committed
36 37 38

   FONT-ENTITY

39 40
	Pseudo vector (length FONT_ENTITY_MAX) of fully instanciated
	font properties that a font-driver returns upon a request of
Kenichi Handa's avatar
Kenichi Handa committed
41 42
	FONT-SPEC.

43 44
	Note: Only the method `list' and `match' of a font-driver can
	create this object, and should never be modified by Lisp.
Kenichi Handa's avatar
Kenichi Handa committed
45 46 47

   FONT-OBJECT

48
	Pseudo vector (length FONT_OBJECT_MAX) of a opend font.
Kenichi Handa's avatar
Kenichi Handa committed
49

50 51 52 53 54 55 56
	Lisp object encapsulating "struct font".  This corresponds to
	an opened font.

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

extern Lisp_Object Qfont_spec, Qfont_entity, Qfont_object;
Kenichi Handa's avatar
Kenichi Handa committed
57 58 59 60


struct font_driver;
struct font;
61
struct glyph_string;
Kenichi Handa's avatar
Kenichi Handa committed
62 63 64 65 66 67 68 69 70

/* 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',
Juanma Barranquero's avatar
Juanma Barranquero committed
71 72
       `xft', `ftx' are available on X, `uniscribe' and `gdi' on
       Windows, and `ns' under Cocoa / GNUstep.  */
Kenichi Handa's avatar
Kenichi Handa committed
73 74 75 76 77 78 79 80 81 82 83 84
    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
85
       charset-encoding name (symbol).  */
Kenichi Handa's avatar
Kenichi Handa committed
86 87 88
    FONT_REGISTRY_INDEX,

    /* FONT-WEIGHT is a numeric value of weight (e.g. medium, bold) of
89 90 91
       the font.  The lowest 8-bit is an index determining the
       symbolic name, and the higher bits is the actual numeric value
       defined in `font-weight-table'. */
Kenichi Handa's avatar
Kenichi Handa committed
92 93 94
    FONT_WEIGHT_INDEX,

    /* FONT-SLANT is a numeric value of slant (e.g. r, i, o) of the
95 96 97
       font.  The lowest 8-bit is an index determining the symbolic
       name, and the higher bits is the actual numeric value defined
       in `font-slant-table'.  */
Kenichi Handa's avatar
Kenichi Handa committed
98 99
    FONT_SLANT_INDEX,

100 101 102 103
    /* FONT-WIDTH is a numeric value of setwidth (e.g. normal) of the
       font.  The lowest 8-bit is an index determining the symbolic
       name, and the higher bits is the actual numeric value defined
       `font-width-table'.  */
Kenichi Handa's avatar
Kenichi Handa committed
104 105 106 107
    FONT_WIDTH_INDEX,

    /* FONT-SIZE is a size of the font.  If integer, it is a pixel
       size.  For a font-spec, the value can be float specifying a
108 109
       point size.  The value zero means that the font is
       scalable.  */
Kenichi Handa's avatar
Kenichi Handa committed
110 111
    FONT_SIZE_INDEX,

112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151
    /* 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
       8-bit is an indice to the weight table AREF (font_style_table,
       0), the next 8-bit is an indice to the slant table AREF
       (font_style_table, 1), the highest 8-bit is an indice to the
       slant table AREF (font_style_table, 2).  The indice 0 indicates
       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
       properties DPI, AVGWIDTH, SPACING.  The lowest 12-bit is for
       DPI, the next 12-bit is for AVGWIDTH, the highest 3-bit is for
       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
152 153
    /* In a font-spec, the value is an alist of extra information of a
       font such as name, OpenType features, and language coverage.
154
       In addition, in a font-entity, the value may contain a pair
Adrian Robert's avatar
Adrian Robert committed
155
       (font-entity . INFO) where INFO is extra information to identify
Kenichi Handa's avatar
Kenichi Handa committed
156
       a font (font-driver dependent).  */
Kenichi Handa's avatar
Kenichi Handa committed
157 158 159 160 161
    FONT_EXTRA_INDEX,		/* alist		alist */

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

162
    /* The followings are used only for a font-entity and a font-object.  */
Kenichi Handa's avatar
Kenichi Handa committed
163

164 165
    /* List of font-objects opened from the font-entity.  */
    FONT_OBJLIST_INDEX = FONT_SPEC_MAX,
Kenichi Handa's avatar
Kenichi Handa committed
166

167 168 169
    /* Font-entity from which the font-object is opened.  */
    FONT_ENTITY_INDEX = FONT_SPEC_MAX,

Kenichi Handa's avatar
Kenichi Handa committed
170
    /* This value is the length of font-entity vector.  */
171 172
    FONT_ENTITY_MAX,

173 174
    /* The followings are used only for a font-object.  */

175 176
    /* XLFD name of the font (string). */
    FONT_NAME_INDEX = FONT_ENTITY_MAX,
Juanma Barranquero's avatar
Juanma Barranquero committed
177

178 179 180 181 182 183 184 185 186
    /* Full name of the font (string).  It is the name extracted from
       the opend font, and may be different from the above.  It may be
       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
187
    /* Format of the font (symbol) or nil if unknown.  */
188 189 190 191
    FONT_FORMAT_INDEX,

    /* This value is the length of font-object vector.  */
    FONT_OBJECT_MAX
Kenichi Handa's avatar
Kenichi Handa committed
192 193
  };

194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241
/* 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;
242 243 244
extern Lisp_Object QCavgwidth, QCantialias, QCfont_entity, QCfc_unknown_spec;
extern Lisp_Object Qp;

Kenichi Handa's avatar
Kenichi Handa committed
245

246
/* Important character set symbols.  */
Kenichi Handa's avatar
Kenichi Handa committed
247
extern Lisp_Object Qascii_0;
Kenichi Handa's avatar
Kenichi Handa committed
248
extern Lisp_Object Qiso8859_1, Qiso10646_1, Qunicode_bmp, Qunicode_sip;
249

250 251 252
/* Special ADSTYLE properties to avoid fonts used for Latin characters.  */
extern Lisp_Object Qja, Qko;

253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269
/* Structure for a font-spec.  */

struct font_spec
{
  EMACS_UINT size;
  struct Lisp_Vector *next;
  Lisp_Object props[FONT_SPEC_MAX];
};

/* Structure for a font-entity.  */

struct font_entity
{
  EMACS_UINT size;
  struct Lisp_Vector *next;
  Lisp_Object props[FONT_ENTITY_MAX];
};
Kenichi Handa's avatar
Kenichi Handa committed
270

271 272 273 274 275 276
/* 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
277 278 279

struct font
{
280 281 282 283 284
  EMACS_UINT size;
  struct Lisp_Vector *next;

  /* All Lisp_Object components must come first.
     That ensures they are all aligned normally.  */
Kenichi Handa's avatar
Kenichi Handa committed
285

286 287 288 289 290 291 292
  Lisp_Object props[FONT_OBJECT_MAX];

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

  /* Maximum bound width over all existing characters of the font.  On
     X window, this is same as (font->max_bounds.width).  */
  int max_width;
Kenichi Handa's avatar
Kenichi Handa committed
293 294 295 296

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

297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312
  /* 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
     have that information but has glyphs of ASCII character, the
     value is the average with of those glyphs.  Otherwise, the value
     is 0.  */
  int average_width;

  /* Minimum glyph width (in pixels).  */
  int min_width;
Kenichi Handa's avatar
Kenichi Handa committed
313

314 315
  /* Ascent and descent of the font (in pixels).  */
  int ascent, descent;
316

317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392
  /* 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;

  /* 1 if `vertical-centering-font-regexp' matches this font name.
     In this case, we render characters at vartical center positions
     of lines.  */
  int vertical_centering;

  /* Encoding type of the font.  The value is one of
     0, 1, 2, or 3:
	0: code points 0x20..0x7F or 0x2020..0x7F7F are used
	1: code points 0xA0..0xFF or 0xA0A0..0xFFFF are used
	2: code points 0x20A0..0x7FFF are used
	3: code points 0xA020..0xFF7F are used
     If the member `font_encoder' is not NULL, this member is ignored.  */
  unsigned char encoding_type;

  /* The baseline position of a font is normally `ascent' value of the
     font.  However, there exists many fonts which don't set `ascent'
     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
     automatically, it is users responsibility to supply well designed
     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
     `ascent'.  In other words, the value indicates how many bits
     higher we should draw a character of the font than normal ASCII
     text for a better looking.

     We also have to consider the fact that the concept of `baseline'
     differs among scripts to which each character belongs.  For
     instance, baseline should be at the bottom most position of all
     glyphs for Chinese, Japanese, and Korean.  But, many of existing
     fonts for those characters doesn't have correct `ascent' values
     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;

  /* Non zero means a character should be composed at a position
     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
	height).  In this case, the character is drawn beneath the
	previous glyphs.

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

  /* Non zero means an ascent value to be used for a character
     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
393

394 395 396
  /* 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
397 398 399 400
  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
401
     determine it.  */
402
  int repertory_charset;
Kenichi Handa's avatar
Kenichi Handa committed
403 404 405 406 407

  /* There will be more to this structure, but they are private to a
     font-driver.  */
};

408 409 410 411 412 413 414 415
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
416 417 418 419 420 421 422
struct font_metrics
{
  short lbearing, rbearing, width, ascent, descent;
};

struct font_bitmap
{
423
  int bits_per_pixel;
Kenichi Handa's avatar
Kenichi Handa committed
424 425 426 427 428 429 430 431 432 433 434 435
  int rows;
  int width;
  int pitch;
  unsigned char *buffer;
  int left;
  int top;
  int advance;
  void *extra;
};

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

436 437 438
/* 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
439
#define FONT_SPEC_P(x)	\
440 441
  (FONTP (x) && (ASIZE (x) & PSEUDOVECTOR_SIZE_MASK) == FONT_SPEC_MAX)
/* 1 iff X is font-entity.  */
Kenichi Handa's avatar
Kenichi Handa committed
442
#define FONT_ENTITY_P(x)	\
443 444
  (FONTP (x) && (ASIZE (x) & PSEUDOVECTOR_SIZE_MASK) == FONT_ENTITY_MAX)
/* 1 iff X is font-object.  */
Kenichi Handa's avatar
Kenichi Handa committed
445
#define FONT_OBJECT_P(x)	\
446
  (FONTP (x) && (ASIZE (x) & PSEUDOVECTOR_SIZE_MASK) == FONT_OBJECT_MAX)
Kenichi Handa's avatar
Kenichi Handa committed
447

448
/* 1 iff ENTITY can't be loaded.  */
Kenichi Handa's avatar
Kenichi Handa committed
449 450 451
#define FONT_ENTITY_NOT_LOADABLE(entity)	\
  EQ (AREF (entity, FONT_OBJLIST_INDEX), Qt)

452
/* Flag ENTITY not loadable.  */
Kenichi Handa's avatar
Kenichi Handa committed
453 454 455
#define FONT_ENTITY_SET_NOT_LOADABLE(entity)	\
  ASET (entity, FONT_OBJLIST_INDEX, Qt)

Kenichi Handa's avatar
Kenichi Handa committed
456 457 458 459

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

#define CHECK_FONT(x)	\
460
  do { if (! FONTP (x)) wrong_type_argument (Qfont, x); } while (0)
Kenichi Handa's avatar
Kenichi Handa committed
461
#define CHECK_FONT_SPEC(x)	\
462
  do { if (! FONT_SPEC_P (x)) wrong_type_argument (Qfont_spec, x); } while (0)
Kenichi Handa's avatar
Kenichi Handa committed
463
#define CHECK_FONT_ENTITY(x)	\
464
  do { if (! FONT_ENTITY_P (x)) wrong_type_argument (Qfont_entity, x); } while (0)
Kenichi Handa's avatar
Kenichi Handa committed
465
#define CHECK_FONT_OBJECT(x)	\
466
  do { if (! FONT_OBJECT_P (x)) wrong_type_argument (Qfont_object, x); } while (0)
Kenichi Handa's avatar
Kenichi Handa committed
467

468 469 470 471
#define CHECK_FONT_GET_OBJECT(x, font)	\
  do {					\
    CHECK_FONT_OBJECT (x);		\
    font = XFONT_OBJECT (x);		\
Kenichi Handa's avatar
Kenichi Handa committed
472 473
  } while (0)

474 475 476 477 478 479 480 481 482 483 484 485 486 487 488
#define XFONT_SPEC(p)	\
  (eassert (FONT_SPEC_P(p)), (struct font_spec *) XPNTR (p))
#define XFONT_ENTITY(p)	\
  (eassert (FONT_ENTITY_P(p)), (struct font_entity *) XPNTR (p))
#define XFONT_OBJECT(p)	\
  (eassert (FONT_OBJECT_P(p)), (struct font *) XPNTR (p))
#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)

489 490 491 492 493
/* Return a point size corresponding to POINT size (integer)
   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
   is tenths of points (as in xfld specs), then the pixel size should
   be multiplied BEFORE the conversion to avoid magnifying the error.  */
494 495
#define PIXEL_TO_POINT(PIXEL, DPI) ((PIXEL) * PT_PER_INCH / (DPI) + 0.5)

496 497 498 499
/* 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
500 501 502 503
struct face;

#define FONT_INVALID_CODE 0xFFFFFFFF

504 505
/* Font driver.  Members specified as "optional" can be NULL.  */

Kenichi Handa's avatar
Kenichi Handa committed
506 507 508 509 510
struct font_driver
{
  /* Symbol indicating the type of the font-driver.  */
  Lisp_Object type;

Kenichi Handa's avatar
Kenichi Handa committed
511
  /* 1 iff the font's foundry, family, and adstyle names are case
512 513 514
     sensitve.  */
  int case_sensitive;

515
  /* Return a cache of font-entities on frame F.  The cache must be a
Kenichi Handa's avatar
Kenichi Handa committed
516
     cons whose cdr part is the actual cache area.  */
Jan D's avatar
Jan D committed
517
  Lisp_Object (*get_cache) (FRAME_PTR F);
Kenichi Handa's avatar
Kenichi Handa committed
518

519
  /* List fonts exactly matching with FONT_SPEC on FRAME.  The value
Kenichi Handa's avatar
Kenichi Handa committed
520
     is a list of font-entities.  The font properties to be considered
521
     are: :foundry, :family, :adstyle, :registry, :script, :lang, and
Kenichi Handa's avatar
Kenichi Handa committed
522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537
     :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.

538 539
     This and the following `match' are the only APIs that allocate
     font-entities.  */
Jan D's avatar
Jan D committed
540
  Lisp_Object (*list) (Lisp_Object frame, Lisp_Object font_spec);
Kenichi Handa's avatar
Kenichi Handa committed
541

542
  /* Return a font-entity most closely matching with FONT_SPEC on
Kenichi Handa's avatar
Kenichi Handa committed
543
     FRAME.  Which font property to consider, and how to calculate the
544
     closeness is determined by the font backend, thus
Kenichi Handa's avatar
Kenichi Handa committed
545 546 547 548
     `face-font-selection-order' is ignored here.

     The properties that the font-entity has is the same as `list'
     method.  */
Jan D's avatar
Jan D committed
549
  Lisp_Object (*match) (Lisp_Object frame, Lisp_Object font_spec);
550

551 552 553
  /* Optional.
     List available families.  The value is a list of family names
     (symbols).  */
Jan D's avatar
Jan D committed
554
  Lisp_Object (*list_family) (Lisp_Object frame);
Kenichi Handa's avatar
Kenichi Handa committed
555

556 557
  /* 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
558
  void (*free_entity) (Lisp_Object font_entity);
Kenichi Handa's avatar
Kenichi Handa committed
559 560 561

  /* Open a font specified by FONT_ENTITY on frame F.  If the font is
     scalable, open it with PIXEL_SIZE.  */
Jan D's avatar
Jan D committed
562 563
  Lisp_Object (*open) (FRAME_PTR f, Lisp_Object font_entity,
                       int pixel_size);
Kenichi Handa's avatar
Kenichi Handa committed
564 565

  /* Close FONT on frame F.  */
Jan D's avatar
Jan D committed
566
  void (*close) (FRAME_PTR f, struct font *font);
Kenichi Handa's avatar
Kenichi Handa committed
567

568 569 570 571
  /* 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.  */
Jan D's avatar
Jan D committed
572
  int (*prepare_face) (FRAME_PTR f, struct face *face);
Kenichi Handa's avatar
Kenichi Handa committed
573

574 575
  /* Optional.
     Done FACE for displaying characters by FACE->font on frame F.  */
Jan D's avatar
Jan D committed
576
  void (*done_face) (FRAME_PTR f, struct face *face);
Kenichi Handa's avatar
Kenichi Handa committed
577

578
  /* Optional.
579 580 581
     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
582
  int (*has_char) (Lisp_Object font, int c);
Kenichi Handa's avatar
Kenichi Handa committed
583

584
  /* Return a glyph code of FONT for character C (Unicode code point).
585
     If FONT doesn't have such a glyph, return FONT_INVALID_CODE.  */
Jan D's avatar
Jan D committed
586
  unsigned (*encode_char) (struct font *font, int c);
Kenichi Handa's avatar
Kenichi Handa committed
587

588 589 590
  /* Computate the total metrics of the NGLYPHS glyphs specified by
     the font FONT and the sequence of glyph codes CODE, and store the
     result in METRICS.  */
Jan D's avatar
Jan D committed
591 592 593
  int (*text_extents) (struct font *font,
                       unsigned *code, int nglyphs,
                       struct font_metrics *metrics);
Kenichi Handa's avatar
Kenichi Handa committed
594

595 596
  /* Optional.
     Draw glyphs between FROM and TO of S->char2b at (X Y) pixel
Kenichi Handa's avatar
Kenichi Handa committed
597 598 599
     position of frame F with S->FACE and S->GC.  If WITH_BACKGROUND
     is nonzero, fill the background in advance.  It is assured that
     WITH_BACKGROUND is zero when (FROM > 0 || TO < S->nchars).  */
Jan D's avatar
Jan D committed
600 601
  int (*draw) (struct glyph_string *s, int from, int to,
               int x, int y, int with_background);
Kenichi Handa's avatar
Kenichi Handa committed
602

603 604 605 606
  /* Optional.
     Store bitmap data for glyph-code CODE of FONT in BITMAP.  It is
     intended that this method is callled from the other font-driver
     for actual drawing.  */
Jan D's avatar
Jan D committed
607 608 609
  int (*get_bitmap) (struct font *font, unsigned code,
                     struct font_bitmap *bitmap,
                     int bits_per_pixel);
Kenichi Handa's avatar
Kenichi Handa committed
610

611 612
  /* Optional.
     Free bitmap data in BITMAP.  */
Jan D's avatar
Jan D committed
613
  void (*free_bitmap) (struct font *font, struct font_bitmap *bitmap);
Kenichi Handa's avatar
Kenichi Handa committed
614

615 616 617
  /* 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
618
  void *(*get_outline) (struct font *font, unsigned code);
Kenichi Handa's avatar
Kenichi Handa committed
619

620 621
  /* Optional.
     Free OUTLINE (that is obtained by the above method).  */
Jan D's avatar
Jan D committed
622
  void (*free_outline) (struct font *font, void *outline);
Kenichi Handa's avatar
Kenichi Handa committed
623

624 625
  /* Optional.
     Get coordinates of the INDEXth anchor point of the glyph whose
Kenichi Handa's avatar
Kenichi Handa committed
626
     code is CODE.  Store the coordinates in *X and *Y.  Return 0 if
627
     the operations was successfull.  Otherwise return -1.  */
Jan D's avatar
Jan D committed
628 629
  int (*anchor_point) (struct font *font, unsigned code, int index,
                       int *x, int *y);
Kenichi Handa's avatar
Kenichi Handa committed
630

631 632
  /* Optional.
     Return a list describing which scripts/languages FONT
Kenichi Handa's avatar
Kenichi Handa committed
633
     supports by which GSUB/GPOS features of OpenType tables.  */
Jan D's avatar
Jan D committed
634
  Lisp_Object (*otf_capability) (struct font *font);
Kenichi Handa's avatar
Kenichi Handa committed
635

636
  /* Optional.
Kenichi Handa's avatar
Kenichi Handa committed
637 638 639 640 641
     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)
     See the documentation of `font-drive-otf' for the detail.
Kenichi Handa's avatar
Kenichi Handa committed
642 643 644 645 646 647 648 649 650

     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
651 652 653
  int (*otf_drive) (struct font *font, Lisp_Object features,
                    Lisp_Object gstring_in, int from, int to,
                    Lisp_Object gstring_out, int idx, int alternate_subst);
654 655 656

  /* Optional.
     Make the font driver ready for frame F.  Usually this function
657
     makes some data specific to F and stores it in F by calling
658
     font_put_frame_data ().  */
Jan D's avatar
Jan D committed
659
  int (*start_for_frame) (FRAME_PTR f);
Juanma Barranquero's avatar
Juanma Barranquero committed
660

661 662 663
  /* Optional.
     End using the driver for frame F.  Usually this function free
     some data stored for F.  */
Jan D's avatar
Jan D committed
664
  int (*end_for_frame) (FRAME_PTR f);
Kenichi Handa's avatar
Kenichi Handa committed
665 666

  /* Optional.
667

668 669 670 671 672
     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.
673 674 675

     This function updates all fields of the input glyphs.  If the
     output glyphs (M) are more than the input glyphs (N), (N+1)th
676 677 678 679
     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
680
  Lisp_Object (*shape) (Lisp_Object lgstring);
681 682 683 684

  /* Optional.

     If FONT is usable on frame F, return 0.  Otherwise return -1.
685 686
     This method is used only for debugging.  If this method is NULL,
     Emacs assumes that the font is usable on any frame.  */
Jan D's avatar
Jan D committed
687
  int (*check) (FRAME_PTR F, struct font *font);
688 689 690 691 692 693 694

  /* 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
695 696
  int (*get_variation_glyphs) (struct font *font,
                               int c, unsigned variations[256]);
697

Jan D's avatar
Jan D committed
698
  void (*filter_properties) (Lisp_Object font, Lisp_Object properties);
699 700 701 702 703

  /* Optional.

     Return non-zero if FONT_OBJECT can be used as a (cached) font
     for ENTITY on frame F.  */
Jan D's avatar
Jan D committed
704 705 706
  int (*cached_font_ok) (struct frame *f,
                         Lisp_Object font_object,
                         Lisp_Object entity);
Kenichi Handa's avatar
Kenichi Handa committed
707 708 709
};


710 711 712 713
/* Chain of font drivers.  There's one global font driver list
   (font_driver_list in font.c).  In addition, each frame has it's own
   font driver list at FRAME_PTR->font_driver_list.  */

Kenichi Handa's avatar
Kenichi Handa committed
714 715
struct font_driver_list
{
716 717
  /* 1 iff this driver is currently used.  It is igonred in the global
     font driver list.*/
Kenichi Handa's avatar
Kenichi Handa committed
718
  int on;
719
  /* Pointer to the font driver.  */
Kenichi Handa's avatar
Kenichi Handa committed
720
  struct font_driver *driver;
721
  /* Pointer to the next element of the chain.  */
Kenichi Handa's avatar
Kenichi Handa committed
722 723 724
  struct font_driver_list *next;
};

725 726 727 728 729 730 731 732 733 734 735 736 737 738

/* Chain of arbitrary data specific to each font driver.  Each frame
   has it's own font data list at FRAME_PTR->font_data_list.  */

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;
};

Kenichi Handa's avatar
Kenichi Handa committed
739
EXFUN (Ffont_spec, MANY);
740 741
EXFUN (Fcopy_font_spec, 1);
EXFUN (Fmerge_font_spec, 2);
Kenichi Handa's avatar
Kenichi Handa committed
742
EXFUN (Ffont_get, 2);
743
EXFUN (Ffont_put, 3);
Kenichi Handa's avatar
Kenichi Handa committed
744
EXFUN (Flist_fonts, 4);
745
EXFUN (Ffont_xlfd_name, 2);
Kenichi Handa's avatar
Kenichi Handa committed
746

Jan D's avatar
Jan D committed
747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780
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,
                                Lisp_Object name, int noerror);
extern Lisp_Object font_style_symbolic (Lisp_Object font,
                                        enum font_property_index prop,
                                        int for_face);

extern int font_match_p (Lisp_Object spec, Lisp_Object font);
extern Lisp_Object font_list_entities (Lisp_Object frame,
                                       Lisp_Object spec);

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);
extern int font_has_char (FRAME_PTR, Lisp_Object, int);

extern void font_clear_prop (Lisp_Object *attrs,
                             enum font_property_index prop);
extern Lisp_Object font_find_for_lface (FRAME_PTR f, Lisp_Object *lface,
                                        Lisp_Object spec, int c);
extern Lisp_Object font_open_for_lface (FRAME_PTR f, Lisp_Object entity,
                                        Lisp_Object *lface,
                                        Lisp_Object spec);
extern Lisp_Object font_load_for_lface (FRAME_PTR f, Lisp_Object *lface,
                                        Lisp_Object spec);
extern void font_prepare_for_face (FRAME_PTR f, struct face *face);
extern void font_done_for_face (FRAME_PTR f, struct face *face);

extern Lisp_Object font_open_by_spec (FRAME_PTR f, Lisp_Object spec);
781
extern Lisp_Object font_open_by_name (FRAME_PTR f, const char *name);
782
extern void font_close_object (FRAME_PTR f, Lisp_Object font_object);
Kenichi Handa's avatar
Kenichi Handa committed
783

784
extern Lisp_Object font_intern_prop (const char *str, int len, int force_symbol);
Jan D's avatar
Jan D committed
785 786 787 788 789 790
extern void font_update_sort_order (int *order);

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

Dan Nicolaescu's avatar
Dan Nicolaescu committed
791
extern int font_parse_xlfd (char *name, Lisp_Object font);
Jan D's avatar
Jan D committed
792 793 794
extern int font_unparse_xlfd (Lisp_Object font, int pixel_size,
                              char *name, int bytes);
extern int font_unparse_fcname (Lisp_Object font, int pixel_size,
Dan Nicolaescu's avatar
Dan Nicolaescu committed
795
                                char *name, int bytes);
Jan D's avatar
Jan D committed
796 797 798
extern void register_font_driver (struct font_driver *driver, FRAME_PTR f);
extern void free_font_driver_list (FRAME_PTR f);
extern Lisp_Object font_update_drivers (FRAME_PTR f, Lisp_Object list);
Stefan Monnier's avatar
Stefan Monnier committed
799 800 801
extern Lisp_Object font_range (EMACS_INT, EMACS_INT *,
			       struct window *, struct face *,
			       Lisp_Object);
Jan D's avatar
Jan D committed
802
extern void font_fill_lglyph_metrics (Lisp_Object, Lisp_Object);
Kenichi Handa's avatar
Kenichi Handa committed
803

Jan D's avatar
Jan D committed
804 805
extern Lisp_Object font_put_extra (Lisp_Object font, Lisp_Object prop,
                                   Lisp_Object val);
Kenichi Handa's avatar
Kenichi Handa committed
806

Jan D's avatar
Jan D committed
807 808 809 810 811
extern int font_put_frame_data (FRAME_PTR f,
                                struct font_driver *driver,
                                void *data);
extern void *font_get_frame_data (FRAME_PTR f,
                                  struct font_driver *driver);
812

813 814
extern void font_filter_properties (Lisp_Object font,
				    Lisp_Object alist,
815 816
				    const char *const boolean_properties[],
				    const char *const non_boolean_properties[]);
817

Kenichi Handa's avatar
Kenichi Handa committed
818 819
#ifdef HAVE_FREETYPE
extern struct font_driver ftfont_driver;
820
extern void syms_of_ftfont (void);
Kenichi Handa's avatar
Kenichi Handa committed
821 822 823 824
#endif	/* HAVE_FREETYPE */
#ifdef HAVE_X_WINDOWS
extern struct font_driver xfont_driver;
extern struct font_driver ftxfont_driver;
825 826
extern void syms_of_xfont (void);
extern void syms_of_ftxfont (void);
Kenichi Handa's avatar
Kenichi Handa committed
827 828
#ifdef HAVE_XFT
extern struct font_driver xftfont_driver;
829
extern void syms_of_xftfont (void);
Kenichi Handa's avatar
Kenichi Handa committed
830
#endif	/* HAVE_XFT */
831 832 833
#ifdef HAVE_BDFFONT
extern void syms_of_bdffont (void);
#endif	/* HAVE_BDFFONT */
Kenichi Handa's avatar
Kenichi Handa committed
834 835 836
#endif	/* HAVE_X_WINDOWS */
#ifdef WINDOWSNT
extern struct font_driver w32font_driver;
837
extern struct font_driver uniscribe_font_driver;
838
extern void syms_of_w32font (void);
Kenichi Handa's avatar
Kenichi Handa committed
839
#endif	/* WINDOWSNT */
840
#ifdef HAVE_NS
841
extern Lisp_Object Qfontsize;
842
extern struct font_driver nsfont_driver;
843
extern void syms_of_nsfont (void);
844
#endif	/* HAVE_NS */
Kenichi Handa's avatar
Kenichi Handa committed
845

846 847 848 849
#ifndef FONT_DEBUG
#define FONT_DEBUG
#endif

Andreas Schwab's avatar
Andreas Schwab committed
850
extern Lisp_Object QCfoundry;
851

852 853
extern void font_add_log (const char *, Lisp_Object, Lisp_Object);
extern void font_deferred_log (const char *, Lisp_Object, Lisp_Object);
854

Kenichi Handa's avatar
Kenichi Handa committed
855 856 857 858 859 860 861 862 863 864 865 866
#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)

867 868 869 870 871 872
#ifdef FONT_DEBUG
#define font_assert(X)	do {if (!(X)) abort ();} while (0)
#else  /* not FONT_DEBUG */
#define font_assert(X)	(void) 0
#endif	/* not FONT_DEBUG */

Kenichi Handa's avatar
Kenichi Handa committed
873
#endif	/* not EMACS_FONT_H */
Miles Bader's avatar
Miles Bader committed
874