w32uniscribe.c 29 KB
Newer Older
1
/* Font backend for the Microsoft W32 Uniscribe API.
2
   Copyright (C) 2008-2011 Free Software Foundation, Inc.
3 4 5

This file is part of GNU Emacs.

6
GNU Emacs is free software: you can redistribute it and/or modify
7
it under the terms of the GNU General Public License as published by
8 9
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
10 11 12 13 14 15 16

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
17
along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
18 19 20 21 22 23 24


#include <config.h>
/* Override API version - Uniscribe is only available as standard since
   Windows 2000, though most users of older systems will have it
   since it installs with Internet Explorer 5.0 and other software.
   We only enable the feature if it is available, so there is no chance
Juanma Barranquero's avatar
Juanma Barranquero committed
25
   of calling non-existent functions.  */
26 27 28 29
#undef _WIN32_WINNT
#define _WIN32_WINNT 0x500
#include <windows.h>
#include <usp10.h>
30
#include <setjmp.h>
31 32 33 34 35 36 37

#include "lisp.h"
#include "w32term.h"
#include "frame.h"
#include "dispextern.h"
#include "character.h"
#include "charset.h"
38
#include "composite.h"
39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55
#include "fontset.h"
#include "font.h"
#include "w32font.h"

struct uniscribe_font_info
{
  struct w32font_info w32_font;
  SCRIPT_CACHE cache;
};

int uniscribe_available = 0;

/* Defined in w32font.c, since it is required there as well.  */
extern Lisp_Object Quniscribe;
extern Lisp_Object Qopentype;

/* EnumFontFamiliesEx callback.  */
56 57 58
static int CALLBACK add_opentype_font_name_to_list (ENUMLOGFONTEX *,
                                                    NEWTEXTMETRICEX *,
                                                    DWORD, LPARAM);
59 60 61 62
/* Used by uniscribe_otf_capability.  */
static Lisp_Object otf_features (HDC context, char *table);

static int
63
memq_no_quit (Lisp_Object elt, Lisp_Object list)
64 65 66 67 68 69 70 71 72
{
  while (CONSP (list) && ! EQ (XCAR (list), elt))
    list = XCDR (list);
  return (CONSP (list));
}


/* Font backend interface implementation.  */
static Lisp_Object
73
uniscribe_list (Lisp_Object frame, Lisp_Object font_spec)
74
{
75
  Lisp_Object fonts = w32font_list_internal (frame, font_spec, 1);
76
  FONT_ADD_LOG ("uniscribe-list", font_spec, fonts);
77
  return fonts;
78 79 80
}

static Lisp_Object
81
uniscribe_match (Lisp_Object frame, Lisp_Object font_spec)
82
{
83
  Lisp_Object entity = w32font_match_internal (frame, font_spec, 1);
84
  FONT_ADD_LOG ("uniscribe-match", font_spec, entity);
85
  return entity;
86 87 88
}

static Lisp_Object
89
uniscribe_list_family (Lisp_Object frame)
90 91 92 93 94 95
{
  Lisp_Object list = Qnil;
  LOGFONT font_match_pattern;
  HDC dc;
  FRAME_PTR f = XFRAME (frame);

96
  memset (&font_match_pattern, 0, sizeof (font_match_pattern));
97 98 99 100 101 102 103 104 105 106 107 108 109
  /* Limit enumerated fonts to outline fonts to save time.  */
  font_match_pattern.lfOutPrecision = OUT_OUTLINE_PRECIS;

  dc = get_frame_dc (f);

  EnumFontFamiliesEx (dc, &font_match_pattern,
                      (FONTENUMPROC) add_opentype_font_name_to_list,
                      (LPARAM) &list, 0);
  release_frame_dc (f, dc);

  return list;
}

110
static Lisp_Object
111
uniscribe_open (FRAME_PTR f, Lisp_Object font_entity, int pixel_size)
112
{
113
  Lisp_Object font_object
114 115
    = font_make_object (VECSIZE (struct uniscribe_font_info),
			font_entity, pixel_size);
116
  struct uniscribe_font_info *uniscribe_font
117
    = (struct uniscribe_font_info *) XFONT_OBJECT (font_object);
118

119 120
  ASET (font_object, FONT_TYPE_INDEX, Quniscribe);

121
  if (!w32font_open_internal (f, font_entity, pixel_size, font_object))
122
    {
123
      return Qnil;
124 125 126 127
    }

  /* Initialize the cache for this font.  */
  uniscribe_font->cache = NULL;
128

129 130 131
  /* Uniscribe backend uses glyph indices.  */
  uniscribe_font->w32_font.glyph_idx = ETO_GLYPH_INDEX;

132
  /* Mark the format as opentype  */
133
  uniscribe_font->w32_font.font.props[FONT_FORMAT_INDEX] = Qopentype;
134 135
  uniscribe_font->w32_font.font.driver = &uniscribe_font_driver;

136
  return font_object;
137 138 139
}

static void
140
uniscribe_close (FRAME_PTR f, struct font *font)
141 142 143 144 145
{
  struct uniscribe_font_info *uniscribe_font
    = (struct uniscribe_font_info *) font;

  if (uniscribe_font->cache)
146
    ScriptFreeCache (&(uniscribe_font->cache));
147 148 149 150 151 152 153

  w32font_close (f, font);
}

/* Return a list describing which scripts/languages FONT supports by
   which GSUB/GPOS features of OpenType tables.  */
static Lisp_Object
154
uniscribe_otf_capability (struct font *font)
155 156 157 158 159 160 161 162 163
{
  HDC context;
  HFONT old_font;
  struct frame *f;
  Lisp_Object capability = Fcons (Qnil, Qnil);
  Lisp_Object features;

  f = XFRAME (selected_frame);
  context = get_frame_dc (f);
164
  old_font = SelectObject (context, FONT_HANDLE (font));
165 166 167 168 169 170 171 172 173 174 175 176 177 178

  features = otf_features (context, "GSUB");
  XSETCAR (capability, features);
  features = otf_features (context, "GPOS");
  XSETCDR (capability, features);

  SelectObject (context, old_font);
  release_frame_dc (f, context);

  return capability;
}

/* Uniscribe implementation of shape for font backend.

179 180 181 182 183
   Shape text in LGSTRING.  See the docstring of
   `composition-get-gstring' for the format of LGSTRING.  If the
   (N+1)th element of LGSTRING 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.
184 185 186 187 188

   This function updates all fields of the input glyphs.  If the
   output glyphs (M) are more than the input glyphs (N), (N+1)th
   through (M)th elements of LGSTRING are updated possibly by making
   a new glyph object and storing it in LGSTRING.  If (M) is greater
189 190
   than the length of LGSTRING, nil should be returned.  In that case,
   this function is called again with a larger LGSTRING.  */
191
static Lisp_Object
192
uniscribe_shape (Lisp_Object lgstring)
193 194 195 196
{
  struct font * font;
  struct uniscribe_font_info * uniscribe_font;
  EMACS_UINT nchars;
197
  int nitems, max_items, i, max_glyphs, done_glyphs;
198 199 200 201 202 203 204 205
  wchar_t *chars;
  WORD *glyphs, *clusters;
  SCRIPT_ITEM *items;
  SCRIPT_VISATTR *attributes;
  int *advances;
  GOFFSET *offsets;
  ABC overall_metrics;
  HRESULT result;
206 207 208
  struct frame * f = NULL;
  HDC context = NULL;
  HFONT old_font = NULL;
209 210 211 212 213

  CHECK_FONT_GET_OBJECT (LGSTRING_FONT (lgstring), font);
  uniscribe_font = (struct uniscribe_font_info *) font;

  /* Get the chars from lgstring in a form we can use with uniscribe.  */
214
  max_glyphs = nchars = LGSTRING_GLYPH_LEN (lgstring);
215
  done_glyphs = 0;
216
  chars = (wchar_t *) alloca (nchars * sizeof (wchar_t));
217 218 219
  /* FIXME: This loop assumes that characters in the input LGSTRING
     are all inside the BMP.  Need to encode characters beyond the BMP
     as UTF-16.  */
220 221 222 223 224 225 226 227 228 229 230 231 232 233
  for (i = 0; i < nchars; i++)
    {
      /* lgstring can be bigger than the number of characters in it, in
	 the case where more glyphs are required to display those characters.
         If that is the case, note the real number of characters.  */
      if (NILP (LGSTRING_GLYPH (lgstring, i)))
	nchars = i;
      else
	chars[i] = LGLYPH_CHAR (LGSTRING_GLYPH (lgstring, i));
    }

  /* First we need to break up the glyph string into runs of glyphs that
     can be treated together.  First try a single run.  */
  max_items = 2;
234
  items = (SCRIPT_ITEM *) xmalloc (sizeof (SCRIPT_ITEM) * max_items + 1);
235

236
  while ((result = ScriptItemize (chars, nchars, max_items, NULL, NULL,
237 238 239 240 241
				  items, &nitems)) == E_OUTOFMEMORY)
    {
      /* If that wasn't enough, keep trying with one more run.  */
      max_items++;
      items = (SCRIPT_ITEM *) xrealloc (items,
242
					sizeof (SCRIPT_ITEM) * max_items + 1);
243 244
    }

245
  if (FAILED (result))
246 247 248 249 250 251 252 253 254 255 256 257 258
    {
      xfree (items);
      return Qnil;
    }

  glyphs = alloca (max_glyphs * sizeof (WORD));
  clusters = alloca (nchars * sizeof (WORD));
  attributes = alloca (max_glyphs * sizeof (SCRIPT_VISATTR));
  advances = alloca (max_glyphs * sizeof (int));
  offsets = alloca (max_glyphs * sizeof (GOFFSET));

  for (i = 0; i < nitems; i++)
    {
259
      int nglyphs, nchars_in_run;
260
      nchars_in_run = items[i+1].iCharPos - items[i].iCharPos;
261 262 263 264
      /* Force ScriptShape to generate glyphs in the same order as
	 they are in the input LGSTRING, which is in the logical
	 order.  */
      items[i].a.fLogicalOrder = 1;
265

266 267
      /* Context may be NULL here, in which case the cache should be
         used without needing to select the font.  */
268 269 270 271
      result = ScriptShape (context, &(uniscribe_font->cache),
			    chars + items[i].iCharPos, nchars_in_run,
			    max_glyphs - done_glyphs, &(items[i].a),
			    glyphs, clusters, attributes, &nglyphs);
272 273 274 275 276 277 278 279

      if (result == E_PENDING && !context)
	{
	  /* This assumes the selected frame is on the same display as the
	     one we are drawing.  It would be better for the frame to be
	     passed in.  */
	  f = XFRAME (selected_frame);
	  context = get_frame_dc (f);
280
	  old_font = SelectObject (context, FONT_HANDLE (font));
281 282 283 284 285 286 287

	  result = ScriptShape (context, &(uniscribe_font->cache),
				chars + items[i].iCharPos, nchars_in_run,
				max_glyphs - done_glyphs, &(items[i].a),
				glyphs, clusters, attributes, &nglyphs);
	}

288 289 290 291 292 293
      if (result == E_OUTOFMEMORY)
	{
	  /* Need a bigger lgstring.  */
	  lgstring = Qnil;
	  break;
	}
294
      else if (FAILED (result))
295 296 297 298
	{
	  /* Can't shape this run - return results so far if any.  */
	  break;
	}
299 300 301 302 303 304
      else if (items[i].a.fNoGlyphIndex)
	{
	  /* Glyph indices not supported by this font (or OS), means we
	     can't really do any meaningful shaping.  */
	  break;
	}
305 306 307 308 309
      else
	{
	  result = ScriptPlace (context, &(uniscribe_font->cache),
				glyphs, nglyphs, attributes, &(items[i].a),
				advances, offsets, &overall_metrics);
310 311 312 313 314
	  if (result == E_PENDING && !context)
	    {
	      /* Cache not complete...  */
	      f = XFRAME (selected_frame);
	      context = get_frame_dc (f);
315
	      old_font = SelectObject (context, FONT_HANDLE (font));
316 317 318 319 320 321

	      result = ScriptPlace (context, &(uniscribe_font->cache),
				    glyphs, nglyphs, attributes, &(items[i].a),
				    advances, offsets, &overall_metrics);
	    }
          if (SUCCEEDED (result))
322
	    {
323
	      int j, from, to;
324

325
	      from = 0;
326
	      to = from;
327 328 329 330 331

	      for (j = 0; j < nglyphs; j++)
		{
		  int lglyph_index = j + done_glyphs;
		  Lisp_Object lglyph = LGSTRING_GLYPH (lgstring, lglyph_index);
332
		  ABC char_metric;
333
		  unsigned gl;
334 335 336 337 338 339

		  if (NILP (lglyph))
		    {
		      lglyph = Fmake_vector (make_number (LGLYPH_SIZE), Qnil);
		      LGSTRING_SET_GLYPH (lgstring, lglyph_index, lglyph);
		    }
340 341 342 343 344
		  /* Copy to a 32-bit data type to shut up the
		     compiler warning in LGLYPH_SET_CODE about
		     comparison being always false.  */
		  gl = glyphs[j];
		  LGLYPH_SET_CODE (lglyph, gl);
345

346 347
		  /* Detect clusters, for linking codes back to
		     characters.  */
348
		  if (attributes[j].fClusterStart)
349
		    {
350 351 352
		      while (from < nchars_in_run && clusters[from] < j)
			from++;
		      if (from >= nchars_in_run)
353
			from = to = nchars_in_run - 1;
354 355 356
		      else
			{
			  int k;
357 358
			  to = nchars_in_run - 1;
			  for (k = from + 1; k < nchars_in_run; k++)
359 360 361
			    {
			      if (clusters[k] > j)
				{
362
				  to = k - 1;
363 364 365 366
				  break;
				}
			    }
			}
367 368
		    }

369 370 371 372
		  LGLYPH_SET_CHAR (lglyph, chars[items[i].iCharPos
						 + from]);
		  LGLYPH_SET_FROM (lglyph, items[i].iCharPos + from);
		  LGLYPH_SET_TO (lglyph, items[i].iCharPos + to);
373

374 375 376 377 378 379 380 381
		  /* Metrics.  */
		  LGLYPH_SET_WIDTH (lglyph, advances[j]);
		  LGLYPH_SET_ASCENT (lglyph, font->ascent);
		  LGLYPH_SET_DESCENT (lglyph, font->descent);

		  result = ScriptGetGlyphABCWidth (context,
						   &(uniscribe_font->cache),
						   glyphs[j], &char_metric);
382 383 384 385 386
		  if (result == E_PENDING && !context)
		    {
		      /* Cache incomplete... */
		      f = XFRAME (selected_frame);
		      context = get_frame_dc (f);
387
		      old_font = SelectObject (context, FONT_HANDLE (font));
388 389 390 391
		      result = ScriptGetGlyphABCWidth (context,
						       &(uniscribe_font->cache),
						       glyphs[j], &char_metric);
		    }
392

393
		  if (SUCCEEDED (result))
394 395 396 397 398 399
		    {
		      LGLYPH_SET_LBEARING (lglyph, char_metric.abcA);
		      LGLYPH_SET_RBEARING (lglyph, (char_metric.abcA
						    + char_metric.abcB));
		    }
		  else
400
		    {
401 402
		      LGLYPH_SET_LBEARING (lglyph, 0);
		      LGLYPH_SET_RBEARING (lglyph, advances[j]);
403
		    }
404 405

		  if (offsets[j].du || offsets[j].dv)
406
		    {
407 408 409 410 411 412 413
		      Lisp_Object vec;
		      vec = Fmake_vector (make_number (3), Qnil);
		      ASET (vec, 0, make_number (offsets[j].du));
		      ASET (vec, 1, make_number (offsets[j].dv));
		      /* Based on what ftfont.c does... */
		      ASET (vec, 2, make_number (advances[j]));
		      LGLYPH_SET_ADJUSTMENT (lglyph, vec);
414
		    }
415 416
		  else
		    LGLYPH_SET_ADJUSTMENT (lglyph, Qnil);
417 418
		}
	    }
419 420 421 422 423
	}
      done_glyphs += nglyphs;
    }

  xfree (items);
424 425 426 427 428 429

  if (context)
    {
      SelectObject (context, old_font);
      release_frame_dc (f, context);
    }
430 431 432 433

  if (NILP (lgstring))
    return Qnil;
  else
434
    return make_number (done_glyphs);
435 436 437
}

/* Uniscribe implementation of encode_char for font backend.
438
   Return a glyph code of FONT for character C (Unicode code point).
439 440
   If FONT doesn't have such a glyph, return FONT_INVALID_CODE.  */
static unsigned
441
uniscribe_encode_char (struct font *font, int c)
442
{
443 444 445
  HDC context = NULL;
  struct frame *f = NULL;
  HFONT old_font = NULL;
446
  unsigned code = FONT_INVALID_CODE;
447 448 449 450 451 452
  wchar_t ch[2];
  int len;
  SCRIPT_ITEM* items;
  int nitems;
  struct uniscribe_font_info *uniscribe_font
    = (struct uniscribe_font_info *)font;
453 454 455

  if (c < 0x10000)
    {
456 457
      ch[0] = (wchar_t) c;
      len = 1;
458 459
    }
  else
460 461
    {
      DWORD surrogate = c - 0x10000;
462

463
      /* High surrogate: U+D800 - U+DBFF.  */
464
      ch[0] = 0xD800 + ((surrogate >> 10) & 0x03FF);
465
      /* Low surrogate: U+DC00 - U+DFFF.  */
466
      ch[1] = 0xDC00 + (surrogate & 0x03FF);
467 468
      len = 2;
    }
469

470 471 472 473 474
  /* Non BMP characters must be handled by the uniscribe shaping
     engine as GDI functions (except blindly displaying lines of
     unicode text) and the promising looking ScriptGetCMap do not
     convert surrogate pairs to glyph indexes correctly.  */
    {
475
      items = (SCRIPT_ITEM *) alloca (sizeof (SCRIPT_ITEM) * 2 + 1);
476 477 478
      if (SUCCEEDED (ScriptItemize (ch, len, 2, NULL, NULL, items, &nitems)))
	{
	  HRESULT result;
479 480 481 482 483 484
          /* Surrogates seem to need 2 here, even though only one glyph is
	     returned.  Indic characters can also produce 2 or more glyphs for
	     a single code point, but they need to use uniscribe_shape
	     above for correct display.  */
          WORD glyphs[2], clusters[2];
          SCRIPT_VISATTR attrs[2];
485 486
          int nglyphs;

487 488 489 490
	  /* Force ScriptShape to generate glyphs in the logical
	     order.  */
	  items[0].a.fLogicalOrder = 1;

491
          result = ScriptShape (context, &(uniscribe_font->cache),
492
                                ch, len, 2, &(items[0].a),
493 494 495 496 497 498 499 500
                                glyphs, clusters, attrs, &nglyphs);

          if (result == E_PENDING)
            {
              /* Use selected frame until API is updated to pass
                 the frame.  */
              f = XFRAME (selected_frame);
              context = get_frame_dc (f);
501
              old_font = SelectObject (context, FONT_HANDLE (font));
502 503 504 505 506 507
              result = ScriptShape (context, &(uniscribe_font->cache),
                                    ch, len, 2, &(items[0].a),
                                    glyphs, clusters, attrs, &nglyphs);
            }

          if (SUCCEEDED (result) && nglyphs == 1)
508
            {
509
	      /* Some fonts return .notdef glyphs instead of failing.
Juanma Barranquero's avatar
Juanma Barranquero committed
510
	         (TrueType spec reserves glyph code 0 for .notdef)  */
511 512
	      if (glyphs[0])
		code = glyphs[0];
513
            }
514 515 516 517 518 519 520 521
          else if (SUCCEEDED (result) || result == E_OUTOFMEMORY)
            {
              /* This character produces zero or more than one glyph
                 when shaped. But we still need the return from here
                 to be valid for the shaping engine to be invoked
                 later.  */
              result = ScriptGetCMap (context, &(uniscribe_font->cache),
                                      ch, len, 0, glyphs);
522
              if (SUCCEEDED (result) && glyphs[0])
523
                code = glyphs[0];
524 525
            }
	}
526
    }
527 528 529 530 531
    if (context)
      {
	SelectObject (context, old_font);
	release_frame_dc (f, context);
      }
532

533
    return code;
534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565
}

/*
   Shared with w32font:
   Lisp_Object uniscribe_get_cache (Lisp_Object frame);
   void uniscribe_free_entity (Lisp_Object font_entity);
   int uniscribe_has_char (Lisp_Object entity, int c);
   int uniscribe_text_extents (struct font *font, unsigned *code,
                               int nglyphs, struct font_metrics *metrics);
   int uniscribe_draw (struct glyph_string *s, int from, int to,
                       int x, int y, int with_background);

   Unused:
   int uniscribe_prepare_face (FRAME_PTR f, struct face *face);
   void uniscribe_done_face (FRAME_PTR f, struct face *face);
   int uniscribe_get_bitmap (struct font *font, unsigned code,
                             struct font_bitmap *bitmap, int bits_per_pixel);
   void uniscribe_free_bitmap (struct font *font, struct font_bitmap *bitmap);
   void * uniscribe_get_outline (struct font *font, unsigned code);
   void uniscribe_free_outline (struct font *font, void *outline);
   int uniscribe_anchor_point (struct font *font, unsigned code,
                               int index, int *x, int *y);
   int uniscribe_start_for_frame (FRAME_PTR f);
   int uniscribe_end_for_frame (FRAME_PTR f);

*/


/* Callback function for EnumFontFamiliesEx.
   Adds the name of opentype fonts to a Lisp list (passed in as the
   lParam arg). */
static int CALLBACK
566 567 568
add_opentype_font_name_to_list (ENUMLOGFONTEX *logical_font,
				NEWTEXTMETRICEX *physical_font,
				DWORD font_type, LPARAM list_object)
569 570 571 572 573 574 575 576 577 578 579 580 581 582 583
{
  Lisp_Object* list = (Lisp_Object *) list_object;
  Lisp_Object family;

  /* Skip vertical fonts (intended only for printing)  */
  if (logical_font->elfLogFont.lfFaceName[0] == '@')
    return 1;

  /* Skip non opentype fonts.  Count old truetype fonts as opentype,
     as some of them do contain GPOS and GSUB data that Uniscribe
     can make use of.  */
  if (!(physical_font->ntmTm.ntmFlags & NTMFLAGS_OPENTYPE)
      && font_type != TRUETYPE_FONTTYPE)
    return 1;

584 585 586 587 588 589 590
  /* Skip fonts that have no unicode coverage.  */
  if (!physical_font->ntmFontSig.fsUsb[3]
      && !physical_font->ntmFontSig.fsUsb[2]
      && !physical_font->ntmFontSig.fsUsb[1]
      && !(physical_font->ntmFontSig.fsUsb[0] & 0x3fffffff))
    return 1;

591
  family = intern_font_name (logical_font->elfLogFont.lfFaceName);
592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631
  if (! memq_no_quit (family, *list))
    *list = Fcons (family, *list);

  return 1;
}


/* :otf property handling.
   Since the necessary Uniscribe APIs for getting font tag information
   are only available in Vista, we need to parse the font data directly
   according to the OpenType Specification.  */

/* Push into DWORD backwards to cope with endianness.  */
#define OTF_TAG(STR)                                          \
  ((STR[3] << 24) | (STR[2] << 16) | (STR[1] << 8) | STR[0])

#define OTF_INT16_VAL(TABLE, OFFSET, PTR)		     \
  do {							     \
    BYTE temp, data[2];					     \
    if (GetFontData (context, TABLE, OFFSET, data, 2) != 2)  \
      goto font_table_error;				     \
    temp = data[0], data[0] = data[1], data[1] = temp;	     \
    memcpy (PTR, data, 2);				     \
  } while (0)

/* Do not reverse the bytes, because we will compare with a OTF_TAG value
   that has them reversed already.  */
#define OTF_DWORDTAG_VAL(TABLE, OFFSET, PTR)                    \
  do {								\
    if (GetFontData (context, TABLE, OFFSET, PTR, 4) != 4)	\
      goto font_table_error;					\
  } while (0)

#define OTF_TAG_VAL(TABLE, OFFSET, STR)			     \
  do {							     \
    if (GetFontData (context, TABLE, OFFSET, STR, 4) != 4)   \
      goto font_table_error;				     \
    STR[4] = '\0';                                           \
  } while (0)

632
#define SNAME(VAL) SDATA (SYMBOL_NAME (VAL))
633 634 635 636

/* Check if font supports the otf script/language/features specified.
   OTF_SPEC is in the format
     (script lang [(gsub_feature ...)|nil] [(gpos_feature ...)]?) */
637 638
int
uniscribe_check_otf (LOGFONT *font, Lisp_Object otf_spec)
639 640 641 642 643 644 645 646 647
{
  Lisp_Object script, lang, rest;
  Lisp_Object features[2];
  DWORD feature_tables[2];
  DWORD script_tag, default_script, lang_tag = 0;
  struct frame * f;
  HDC context;
  HFONT check_font, old_font;
  int i, retval = 0;
648
  struct gcpro gcpro1;
649

650
  /* Check the spec is in the right format.  */
651
  if (!CONSP (otf_spec) || XINT (Flength (otf_spec)) < 3)
652 653
    return 0;

654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684
  /* Break otf_spec into its components.  */
  script = XCAR (otf_spec);
  rest = XCDR (otf_spec);

  lang = XCAR (rest);
  rest = XCDR (rest);

  features[0] = XCAR (rest);
  rest = XCDR (rest);
  if (NILP (rest))
    features[1] = Qnil;
  else
    features[1] = XCAR (rest);

  /* Set up tags we will use in the search.  */
  feature_tables[0] = OTF_TAG ("GSUB");
  feature_tables[1] = OTF_TAG ("GPOS");
  default_script = OTF_TAG ("DFLT");
  if (NILP (script))
    script_tag = default_script;
  else
    script_tag = OTF_TAG (SNAME (script));
  if (!NILP (lang))
    lang_tag = OTF_TAG (SNAME (lang));

  /* Set up graphics context so we can use the font.  */
  f = XFRAME (selected_frame);
  context = get_frame_dc (f);
  check_font = CreateFontIndirect (font);
  old_font = SelectObject (context, check_font);

685 686 687 688
  /* Everything else is contained within otf_spec so should get
     marked along with it.  */
  GCPRO1 (otf_spec);

689 690 691 692 693 694 695 696 697 698 699 700 701
  /* Scan GSUB and GPOS tables.  */
  for (i = 0; i < 2; i++)
    {
      int j, n_match_features;
      unsigned short scriptlist_table, feature_table, n_scripts;
      unsigned short script_table, langsys_table, n_langs;
      unsigned short feature_index, n_features;
      DWORD tbl = feature_tables[i];

      /* Skip if no features requested from this table.  */
      if (NILP (features[i]))
	continue;

702 703 704 705
      /* If features is not a cons, this font spec is messed up.  */
      if (!CONSP (features[i]))
	goto no_support;

706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721
      /* Read GPOS/GSUB header.  */
      OTF_INT16_VAL (tbl, 4, &scriptlist_table);
      OTF_INT16_VAL (tbl, 6, &feature_table);
      OTF_INT16_VAL (tbl, scriptlist_table, &n_scripts);

      /* Find the appropriate script table.  */
      script_table = 0;
      for (j = 0; j < n_scripts; j++)
	{
	  DWORD script_id;
	  OTF_DWORDTAG_VAL (tbl, scriptlist_table + 2 + j * 6, &script_id);
	  if (script_id == script_tag)
	    {
	      OTF_INT16_VAL (tbl, scriptlist_table + 6 + j * 6, &script_table);
	      break;
	    }
722
#if 0	  /* Causes false positives.  */
723 724 725 726
	  /* If there is a DFLT script defined in the font, use it
	     if the specified script is not found.  */
	  else if (script_id == default_script)
	    OTF_INT16_VAL (tbl, scriptlist_table + 6 + j * 6, &script_table);
727
#endif
728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765
	}
      /* If no specific or default script table was found, then this font
	 does not support the script.  */
      if (!script_table)
	goto no_support;

      /* Offset is from beginning of scriptlist_table.  */
      script_table += scriptlist_table;

      /* Get default langsys table.  */
      OTF_INT16_VAL (tbl, script_table, &langsys_table);

      /* If lang was specified, see if font contains a specific entry.  */
      if (!NILP (lang))
	{
	  OTF_INT16_VAL (tbl, script_table + 2, &n_langs);

	  for (j = 0; j < n_langs; j++)
	    {
	      DWORD lang_id;
	      OTF_DWORDTAG_VAL (tbl, script_table + 4 + j * 6, &lang_id);
	      if (lang_id == lang_tag)
		{
		  OTF_INT16_VAL (tbl, script_table + 8 + j * 6, &langsys_table);
		  break;
		}
	    }
	}

      if (!langsys_table)
	goto no_support;

      /* Offset is from beginning of script table.  */
      langsys_table += script_table;

      /* Check the features.  Features may contain nil according to
	 documentation in font_prop_validate_otf, so count them.  */
      n_match_features = 0;
766
      for (rest = features[i]; CONSP (rest); rest = XCDR (rest))
767
	{
768
	  Lisp_Object feature = XCAR (rest);
769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912
	  if (!NILP (feature))
	    n_match_features++;
	}

      /* If there are no features to check, skip checking.  */
      if (!n_match_features)
	continue;

      /* First check required feature (if any).  */
      OTF_INT16_VAL (tbl, langsys_table + 2, &feature_index);
      if (feature_index != 0xFFFF)
	{
	  char feature_id[5];
	  OTF_TAG_VAL (tbl, feature_table + 2 + feature_index * 6, feature_id);
	  OTF_TAG_VAL (tbl, feature_table + 2 + feature_index * 6, feature_id);
	  /* Assume no duplicates in the font table. This allows us to mark
	     the features off by simply decrementing a counter.  */
	  if (!NILP (Fmemq (intern (feature_id), features[i])))
	    n_match_features--;
	}
      /* Now check all the other features.  */
      OTF_INT16_VAL (tbl, langsys_table + 4, &n_features);
      for (j = 0; j < n_features; j++)
	{
	  char feature_id[5];
	  OTF_INT16_VAL (tbl, langsys_table + 6 + j * 2, &feature_index);
	  OTF_TAG_VAL (tbl, feature_table + 2 + feature_index * 6, feature_id);
	  /* Assume no duplicates in the font table. This allows us to mark
	     the features off by simply decrementing a counter.  */
	  if (!NILP (Fmemq (intern (feature_id), features[i])))
	    n_match_features--;
	}

      if (n_match_features > 0)
	goto no_support;
    }

  retval = 1;

 no_support:
 font_table_error:
  /* restore graphics context.  */
  SelectObject (context, old_font);
  DeleteObject (check_font);
  release_frame_dc (f, context);

  return retval;
}

static Lisp_Object
otf_features (HDC context, char *table)
{
  Lisp_Object script_list = Qnil;
  unsigned short scriptlist_table, n_scripts, feature_table;
  DWORD tbl = OTF_TAG (table);
  int i, j, k;

  /* Look for scripts in the table.  */
  OTF_INT16_VAL (tbl, 4, &scriptlist_table);
  OTF_INT16_VAL (tbl, 6, &feature_table);
  OTF_INT16_VAL (tbl, scriptlist_table, &n_scripts);

  for (i = 0; i < n_scripts; i++)
    {
      char script[5], lang[5];
      unsigned short script_table, lang_count, langsys_table, feature_count;
      Lisp_Object script_tag, langsys_list, langsys_tag, feature_list;
      unsigned short record_offset = scriptlist_table + 2 + i * 6;
      OTF_TAG_VAL (tbl, record_offset, script);
      OTF_INT16_VAL (tbl, record_offset + 4, &script_table);

      /* Offset is from beginning of script table.  */
      script_table += scriptlist_table;

      script_tag = intern (script);
      langsys_list = Qnil;

      /* Optional default lang.  */
      OTF_INT16_VAL (tbl, script_table, &langsys_table);
      if (langsys_table)
	{
	  /* Offset is from beginning of script table.  */
	  langsys_table += script_table;

	  langsys_tag = Qnil;
	  feature_list = Qnil;
	  OTF_INT16_VAL (tbl, langsys_table + 4, &feature_count);
	  for (k = 0; k < feature_count; k++)
	    {
	      char feature[5];
	      unsigned short index;
	      OTF_INT16_VAL (tbl, langsys_table + 6 + k * 2, &index);
	      OTF_TAG_VAL (tbl, feature_table + 2 + index * 6, feature);
	      feature_list = Fcons (intern (feature), feature_list);
	    }
	  langsys_list = Fcons (Fcons (langsys_tag, feature_list),
				langsys_list);
	}

      /* List of supported languages.  */
      OTF_INT16_VAL (tbl, script_table + 2, &lang_count);

      for (j = 0; j < lang_count; j++)
	{
	  record_offset = script_table + 4 + j * 6;
	  OTF_TAG_VAL (tbl, record_offset, lang);
	  OTF_INT16_VAL (tbl, record_offset + 4, &langsys_table);

	  /* Offset is from beginning of script table.  */
	  langsys_table += script_table;

	  langsys_tag = intern (lang);
	  feature_list = Qnil;
	  OTF_INT16_VAL (tbl, langsys_table + 4, &feature_count);
	  for (k = 0; k < feature_count; k++)
	    {
	      char feature[5];
	      unsigned short index;
	      OTF_INT16_VAL (tbl, langsys_table + 6 + k * 2, &index);
	      OTF_TAG_VAL (tbl, feature_table + 2 + index * 6, feature);
	      feature_list = Fcons (intern (feature), feature_list);
	    }
	  langsys_list = Fcons (Fcons (langsys_tag, feature_list),
				langsys_list);

	}

      script_list = Fcons (Fcons (script_tag, langsys_list), script_list);
    }

  return script_list;

font_table_error:
  return Qnil;
}

#undef OTF_INT16_VAL
#undef OTF_TAG_VAL
#undef OTF_TAG


struct font_driver uniscribe_font_driver =
  {
    0, /* Quniscribe */
913
    0, /* case insensitive */
914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931
    w32font_get_cache,
    uniscribe_list,
    uniscribe_match,
    uniscribe_list_family,
    NULL, /* free_entity */
    uniscribe_open,
    uniscribe_close,
    NULL, /* prepare_face */
    NULL, /* done_face */
    w32font_has_char,
    uniscribe_encode_char,
    w32font_text_extents,
    w32font_draw,
    NULL, /* get_bitmap */
    NULL, /* free_bitmap */
    NULL, /* get_outline */
    NULL, /* free_outline */
    NULL, /* anchor_point */
932
    uniscribe_otf_capability, /* Defined so (font-get FONTOBJ :otf) works.  */
933 934 935
    NULL, /* otf_drive - use shape instead.  */
    NULL, /* start_for_frame */
    NULL, /* end_for_frame */
936 937 938 939 940
    uniscribe_shape,
    NULL, /* check */
    NULL, /* get_variation_glyphs */
    NULL, /* filter_properties */
    NULL, /* cached_font_ok */
941 942 943 944 945
  };

/* Note that this should be called at every startup, not just when dumping,
   as it needs to test for the existence of the Uniscribe library.  */
void
946
syms_of_w32uniscribe (void)
947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963
{
  HMODULE uniscribe;

  /* Don't init uniscribe when dumping */
  if (!initialized)
    return;

  /* Don't register if uniscribe is not available.  */
  uniscribe = GetModuleHandle ("usp10");
  if (!uniscribe)
    return;

  uniscribe_font_driver.type = Quniscribe;
  uniscribe_available = 1;

  register_font_driver (&uniscribe_font_driver, NULL);
}