1/*
2 * Copyright © 2011,2012,2013  Google, Inc.
3 *
4 *  This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Google Author(s): Behdad Esfahbod
25 */
26
27#define HB_SHAPER uniscribe
28#include "hb-shaper-impl-private.hh"
29
30#include <windows.h>
31#include <usp10.h>
32#include <rpc.h>
33
34#include "hb-uniscribe.h"
35
36#include "hb-open-file-private.hh"
37#include "hb-ot-name-table.hh"
38#include "hb-ot-tag.h"
39
40
41#ifndef HB_DEBUG_UNISCRIBE
42#define HB_DEBUG_UNISCRIBE (HB_DEBUG+0)
43#endif
44
45
46static inline uint16_t hb_uint16_swap (const uint16_t v)
47{ return (v >> 8) | (v << 8); }
48static inline uint32_t hb_uint32_swap (const uint32_t v)
49{ return (hb_uint16_swap (v) << 16) | hb_uint16_swap (v >> 16); }
50
51
52typedef HRESULT (WINAPI *SIOT) /*ScriptItemizeOpenType*/(
53  const WCHAR *pwcInChars,
54  int cInChars,
55  int cMaxItems,
56  const SCRIPT_CONTROL *psControl,
57  const SCRIPT_STATE *psState,
58  SCRIPT_ITEM *pItems,
59  OPENTYPE_TAG *pScriptTags,
60  int *pcItems
61);
62
63typedef HRESULT (WINAPI *SSOT) /*ScriptShapeOpenType*/(
64  HDC hdc,
65  SCRIPT_CACHE *psc,
66  SCRIPT_ANALYSIS *psa,
67  OPENTYPE_TAG tagScript,
68  OPENTYPE_TAG tagLangSys,
69  int *rcRangeChars,
70  TEXTRANGE_PROPERTIES **rpRangeProperties,
71  int cRanges,
72  const WCHAR *pwcChars,
73  int cChars,
74  int cMaxGlyphs,
75  WORD *pwLogClust,
76  SCRIPT_CHARPROP *pCharProps,
77  WORD *pwOutGlyphs,
78  SCRIPT_GLYPHPROP *pOutGlyphProps,
79  int *pcGlyphs
80);
81
82typedef HRESULT (WINAPI *SPOT) /*ScriptPlaceOpenType*/(
83  HDC hdc,
84  SCRIPT_CACHE *psc,
85  SCRIPT_ANALYSIS *psa,
86  OPENTYPE_TAG tagScript,
87  OPENTYPE_TAG tagLangSys,
88  int *rcRangeChars,
89  TEXTRANGE_PROPERTIES **rpRangeProperties,
90  int cRanges,
91  const WCHAR *pwcChars,
92  WORD *pwLogClust,
93  SCRIPT_CHARPROP *pCharProps,
94  int cChars,
95  const WORD *pwGlyphs,
96  const SCRIPT_GLYPHPROP *pGlyphProps,
97  int cGlyphs,
98  int *piAdvance,
99  GOFFSET *pGoffset,
100  ABC *pABC
101);
102
103
104/* Fallback implementations. */
105
106static HRESULT WINAPI
107hb_ScriptItemizeOpenType(
108  const WCHAR *pwcInChars,
109  int cInChars,
110  int cMaxItems,
111  const SCRIPT_CONTROL *psControl,
112  const SCRIPT_STATE *psState,
113  SCRIPT_ITEM *pItems,
114  OPENTYPE_TAG *pScriptTags,
115  int *pcItems
116)
117{
118{
119  return ScriptItemize (pwcInChars,
120			cInChars,
121			cMaxItems,
122			psControl,
123			psState,
124			pItems,
125			pcItems);
126}
127}
128
129static HRESULT WINAPI
130hb_ScriptShapeOpenType(
131  HDC hdc,
132  SCRIPT_CACHE *psc,
133  SCRIPT_ANALYSIS *psa,
134  OPENTYPE_TAG tagScript,
135  OPENTYPE_TAG tagLangSys,
136  int *rcRangeChars,
137  TEXTRANGE_PROPERTIES **rpRangeProperties,
138  int cRanges,
139  const WCHAR *pwcChars,
140  int cChars,
141  int cMaxGlyphs,
142  WORD *pwLogClust,
143  SCRIPT_CHARPROP *pCharProps,
144  WORD *pwOutGlyphs,
145  SCRIPT_GLYPHPROP *pOutGlyphProps,
146  int *pcGlyphs
147)
148{
149  SCRIPT_VISATTR *psva = (SCRIPT_VISATTR *) pOutGlyphProps;
150  return ScriptShape (hdc,
151		      psc,
152		      pwcChars,
153		      cChars,
154		      cMaxGlyphs,
155		      psa,
156		      pwOutGlyphs,
157		      pwLogClust,
158		      psva,
159		      pcGlyphs);
160}
161
162static HRESULT WINAPI
163hb_ScriptPlaceOpenType(
164  HDC hdc,
165  SCRIPT_CACHE *psc,
166  SCRIPT_ANALYSIS *psa,
167  OPENTYPE_TAG tagScript,
168  OPENTYPE_TAG tagLangSys,
169  int *rcRangeChars,
170  TEXTRANGE_PROPERTIES **rpRangeProperties,
171  int cRanges,
172  const WCHAR *pwcChars,
173  WORD *pwLogClust,
174  SCRIPT_CHARPROP *pCharProps,
175  int cChars,
176  const WORD *pwGlyphs,
177  const SCRIPT_GLYPHPROP *pGlyphProps,
178  int cGlyphs,
179  int *piAdvance,
180  GOFFSET *pGoffset,
181  ABC *pABC
182)
183{
184  SCRIPT_VISATTR *psva = (SCRIPT_VISATTR *) pGlyphProps;
185  return ScriptPlace (hdc,
186		      psc,
187		      pwGlyphs,
188		      cGlyphs,
189		      psva,
190		      psa,
191		      piAdvance,
192		      pGoffset,
193		      pABC);
194}
195
196
197struct hb_uniscribe_shaper_funcs_t {
198  SIOT ScriptItemizeOpenType;
199  SSOT ScriptShapeOpenType;
200  SPOT ScriptPlaceOpenType;
201
202  inline void init (void)
203  {
204    HMODULE hinstLib;
205    this->ScriptItemizeOpenType = NULL;
206    this->ScriptShapeOpenType   = NULL;
207    this->ScriptPlaceOpenType   = NULL;
208
209    hinstLib = GetModuleHandle (TEXT ("usp10.dll"));
210    if (hinstLib)
211    {
212      this->ScriptItemizeOpenType = (SIOT) GetProcAddress (hinstLib, "ScriptItemizeOpenType");
213      this->ScriptShapeOpenType   = (SSOT) GetProcAddress (hinstLib, "ScriptShapeOpenType");
214      this->ScriptPlaceOpenType   = (SPOT) GetProcAddress (hinstLib, "ScriptPlaceOpenType");
215    }
216    if (!this->ScriptItemizeOpenType ||
217	!this->ScriptShapeOpenType   ||
218	!this->ScriptPlaceOpenType)
219    {
220      DEBUG_MSG (UNISCRIBE, NULL, "OpenType versions of functions not found; falling back.");
221      this->ScriptItemizeOpenType = hb_ScriptItemizeOpenType;
222      this->ScriptShapeOpenType   = hb_ScriptShapeOpenType;
223      this->ScriptPlaceOpenType   = hb_ScriptPlaceOpenType;
224    }
225  }
226};
227static hb_uniscribe_shaper_funcs_t *uniscribe_funcs;
228
229static inline void
230free_uniscribe_funcs (void)
231{
232  free (uniscribe_funcs);
233}
234
235static hb_uniscribe_shaper_funcs_t *
236hb_uniscribe_shaper_get_funcs (void)
237{
238retry:
239  hb_uniscribe_shaper_funcs_t *funcs = (hb_uniscribe_shaper_funcs_t *) hb_atomic_ptr_get (&uniscribe_funcs);
240
241  if (unlikely (!funcs))
242  {
243    funcs = (hb_uniscribe_shaper_funcs_t *) calloc (1, sizeof (hb_uniscribe_shaper_funcs_t));
244    if (unlikely (!funcs))
245      return NULL;
246
247    funcs->init ();
248
249    if (!hb_atomic_ptr_cmpexch (&uniscribe_funcs, NULL, funcs)) {
250      free (funcs);
251      goto retry;
252    }
253
254#ifdef HB_USE_ATEXIT
255    atexit (free_uniscribe_funcs); /* First person registers atexit() callback. */
256#endif
257  }
258
259  return funcs;
260}
261
262
263struct active_feature_t {
264  OPENTYPE_FEATURE_RECORD rec;
265  unsigned int order;
266
267  static int cmp (const active_feature_t *a, const active_feature_t *b) {
268    return a->rec.tagFeature < b->rec.tagFeature ? -1 : a->rec.tagFeature > b->rec.tagFeature ? 1 :
269	   a->order < b->order ? -1 : a->order > b->order ? 1 :
270	   a->rec.lParameter < b->rec.lParameter ? -1 : a->rec.lParameter > b->rec.lParameter ? 1 :
271	   0;
272  }
273  bool operator== (const active_feature_t *f) {
274    return cmp (this, f) == 0;
275  }
276};
277
278struct feature_event_t {
279  unsigned int index;
280  bool start;
281  active_feature_t feature;
282
283  static int cmp (const feature_event_t *a, const feature_event_t *b) {
284    return a->index < b->index ? -1 : a->index > b->index ? 1 :
285	   a->start < b->start ? -1 : a->start > b->start ? 1 :
286	   active_feature_t::cmp (&a->feature, &b->feature);
287  }
288};
289
290struct range_record_t {
291  TEXTRANGE_PROPERTIES props;
292  unsigned int index_first; /* == start */
293  unsigned int index_last;  /* == end - 1 */
294};
295
296HB_SHAPER_DATA_ENSURE_DECLARE(uniscribe, face)
297HB_SHAPER_DATA_ENSURE_DECLARE(uniscribe, font)
298
299
300/*
301 * shaper face data
302 */
303
304struct hb_uniscribe_shaper_face_data_t {
305  HANDLE fh;
306  hb_uniscribe_shaper_funcs_t *funcs;
307  wchar_t face_name[LF_FACESIZE];
308};
309
310/* face_name should point to a wchar_t[LF_FACESIZE] object. */
311static void
312_hb_generate_unique_face_name (wchar_t *face_name, unsigned int *plen)
313{
314  /* We'll create a private name for the font from a UUID using a simple,
315   * somewhat base64-like encoding scheme */
316  const char *enc = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+-";
317  UUID id;
318  UuidCreate ((UUID*) &id);
319  ASSERT_STATIC (2 + 3 * (16/2) < LF_FACESIZE);
320  unsigned int name_str_len = 0;
321  face_name[name_str_len++] = 'F';
322  face_name[name_str_len++] = '_';
323  unsigned char *p = (unsigned char *) &id;
324  for (unsigned int i = 0; i < 16; i += 2)
325  {
326    /* Spread the 16 bits from two bytes of the UUID across three chars of face_name,
327     * using the bits in groups of 5,5,6 to select chars from enc.
328     * This will generate 24 characters; with the 'F_' prefix we already provided,
329     * the name will be 26 chars (plus the NUL terminator), so will always fit within
330     * face_name (LF_FACESIZE = 32). */
331    face_name[name_str_len++] = enc[p[i] >> 3];
332    face_name[name_str_len++] = enc[((p[i] << 2) | (p[i + 1] >> 6)) & 0x1f];
333    face_name[name_str_len++] = enc[p[i + 1] & 0x3f];
334  }
335  face_name[name_str_len] = 0;
336  if (plen)
337    *plen = name_str_len;
338}
339
340/* Destroys blob. */
341static hb_blob_t *
342_hb_rename_font (hb_blob_t *blob, wchar_t *new_name)
343{
344  /* Create a copy of the font data, with the 'name' table replaced by a
345   * table that names the font with our private F_* name created above.
346   * For simplicity, we just append a new 'name' table and update the
347   * sfnt directory; the original table is left in place, but unused.
348   *
349   * The new table will contain just 5 name IDs: family, style, unique,
350   * full, PS. All of them point to the same name data with our unique name.
351   */
352
353  blob = OT::Sanitizer<OT::OpenTypeFontFile>::sanitize (blob);
354
355  unsigned int length, new_length, name_str_len;
356  const char *orig_sfnt_data = hb_blob_get_data (blob, &length);
357
358  _hb_generate_unique_face_name (new_name, &name_str_len);
359
360  static const uint16_t name_IDs[] = { 1, 2, 3, 4, 6 };
361
362  unsigned int name_table_length = OT::name::min_size +
363                                   ARRAY_LENGTH (name_IDs) * OT::NameRecord::static_size +
364                                   name_str_len * 2; /* for name data in UTF16BE form */
365  unsigned int name_table_offset = (length + 3) & ~3;
366
367  new_length = name_table_offset + ((name_table_length + 3) & ~3);
368  void *new_sfnt_data = calloc (1, new_length);
369  if (!new_sfnt_data)
370  {
371    hb_blob_destroy (blob);
372    return NULL;
373  }
374
375  memcpy(new_sfnt_data, orig_sfnt_data, length);
376
377  OT::name &name = OT::StructAtOffset<OT::name> (new_sfnt_data, name_table_offset);
378  name.format.set (0);
379  name.count.set (ARRAY_LENGTH (name_IDs));
380  name.stringOffset.set (name.get_size ());
381  for (unsigned int i = 0; i < ARRAY_LENGTH (name_IDs); i++)
382  {
383    OT::NameRecord &record = name.nameRecord[i];
384    record.platformID.set (3);
385    record.encodingID.set (1);
386    record.languageID.set (0x0409u); /* English */
387    record.nameID.set (name_IDs[i]);
388    record.length.set (name_str_len * 2);
389    record.offset.set (0);
390  }
391
392  /* Copy string data from new_name, converting wchar_t to UTF16BE. */
393  unsigned char *p = &OT::StructAfter<unsigned char> (name);
394  for (unsigned int i = 0; i < name_str_len; i++)
395  {
396    *p++ = new_name[i] >> 8;
397    *p++ = new_name[i] & 0xff;
398  }
399
400  /* Adjust name table entry to point to new name table */
401  const OT::OpenTypeFontFile &file = * (OT::OpenTypeFontFile *) (new_sfnt_data);
402  unsigned int face_count = file.get_face_count ();
403  for (unsigned int face_index = 0; face_index < face_count; face_index++)
404  {
405    /* Note: doing multiple edits (ie. TTC) can be unsafe.  There may be
406     * toe-stepping.  But we don't really care. */
407    const OT::OpenTypeFontFace &face = file.get_face (face_index);
408    unsigned int index;
409    if (face.find_table_index (HB_OT_TAG_name, &index))
410    {
411      OT::TableRecord &record = const_cast<OT::TableRecord &> (face.get_table (index));
412      record.checkSum.set_for_data (&name, name_table_length);
413      record.offset.set (name_table_offset);
414      record.length.set (name_table_length);
415    }
416    else if (face_index == 0) /* Fail if first face doesn't have 'name' table. */
417    {
418      free (new_sfnt_data);
419      hb_blob_destroy (blob);
420      return NULL;
421    }
422  }
423
424  /* The checkSumAdjustment field in the 'head' table is now wrong,
425   * but that doesn't actually seem to cause any problems so we don't
426   * bother. */
427
428  hb_blob_destroy (blob);
429  return hb_blob_create ((const char *) new_sfnt_data, new_length,
430			 HB_MEMORY_MODE_WRITABLE, NULL, free);
431}
432
433hb_uniscribe_shaper_face_data_t *
434_hb_uniscribe_shaper_face_data_create (hb_face_t *face)
435{
436  hb_uniscribe_shaper_face_data_t *data = (hb_uniscribe_shaper_face_data_t *) calloc (1, sizeof (hb_uniscribe_shaper_face_data_t));
437  if (unlikely (!data))
438    return NULL;
439
440  data->funcs = hb_uniscribe_shaper_get_funcs ();
441  if (unlikely (!data->funcs))
442  {
443    free (data);
444    return NULL;
445  }
446
447  hb_blob_t *blob = hb_face_reference_blob (face);
448  if (unlikely (!hb_blob_get_length (blob)))
449    DEBUG_MSG (UNISCRIBE, face, "Face has empty blob");
450
451  blob = _hb_rename_font (blob, data->face_name);
452  if (unlikely (!blob))
453  {
454    free (data);
455    return NULL;
456  }
457
458  DWORD num_fonts_installed;
459  data->fh = AddFontMemResourceEx ((void *) hb_blob_get_data (blob, NULL),
460				   hb_blob_get_length (blob),
461				   0, &num_fonts_installed);
462  if (unlikely (!data->fh))
463  {
464    DEBUG_MSG (UNISCRIBE, face, "Face AddFontMemResourceEx() failed");
465    free (data);
466    return NULL;
467  }
468
469  return data;
470}
471
472void
473_hb_uniscribe_shaper_face_data_destroy (hb_uniscribe_shaper_face_data_t *data)
474{
475  RemoveFontMemResourceEx (data->fh);
476  free (data);
477}
478
479
480/*
481 * shaper font data
482 */
483
484struct hb_uniscribe_shaper_font_data_t {
485  HDC hdc;
486  LOGFONTW log_font;
487  HFONT hfont;
488  SCRIPT_CACHE script_cache;
489  double x_mult, y_mult; /* From LOGFONT space to HB space. */
490};
491
492static bool
493populate_log_font (LOGFONTW  *lf,
494		   hb_font_t *font,
495		   unsigned int font_size)
496{
497  memset (lf, 0, sizeof (*lf));
498  lf->lfHeight = -font_size;
499  lf->lfCharSet = DEFAULT_CHARSET;
500
501  hb_face_t *face = font->face;
502  hb_uniscribe_shaper_face_data_t *face_data = HB_SHAPER_DATA_GET (face);
503
504  memcpy (lf->lfFaceName, face_data->face_name, sizeof (lf->lfFaceName));
505
506  return true;
507}
508
509hb_uniscribe_shaper_font_data_t *
510_hb_uniscribe_shaper_font_data_create (hb_font_t *font)
511{
512  if (unlikely (!hb_uniscribe_shaper_face_data_ensure (font->face))) return NULL;
513
514  hb_uniscribe_shaper_font_data_t *data = (hb_uniscribe_shaper_font_data_t *) calloc (1, sizeof (hb_uniscribe_shaper_font_data_t));
515  if (unlikely (!data))
516    return NULL;
517
518  int font_size = font->face->get_upem (); /* Default... */
519  /* No idea if the following is even a good idea. */
520  if (font->y_ppem)
521    font_size = font->y_ppem;
522
523  if (font_size < 0)
524    font_size = -font_size;
525  data->x_mult = (double) font->x_scale / font_size;
526  data->y_mult = (double) font->y_scale / font_size;
527
528  data->hdc = GetDC (NULL);
529
530  if (unlikely (!populate_log_font (&data->log_font, font, font_size))) {
531    DEBUG_MSG (UNISCRIBE, font, "Font populate_log_font() failed");
532    _hb_uniscribe_shaper_font_data_destroy (data);
533    return NULL;
534  }
535
536  data->hfont = CreateFontIndirectW (&data->log_font);
537  if (unlikely (!data->hfont)) {
538    DEBUG_MSG (UNISCRIBE, font, "Font CreateFontIndirectW() failed");
539    _hb_uniscribe_shaper_font_data_destroy (data);
540     return NULL;
541  }
542
543  if (!SelectObject (data->hdc, data->hfont)) {
544    DEBUG_MSG (UNISCRIBE, font, "Font SelectObject() failed");
545    _hb_uniscribe_shaper_font_data_destroy (data);
546     return NULL;
547  }
548
549  return data;
550}
551
552void
553_hb_uniscribe_shaper_font_data_destroy (hb_uniscribe_shaper_font_data_t *data)
554{
555  if (data->hdc)
556    ReleaseDC (NULL, data->hdc);
557  if (data->hfont)
558    DeleteObject (data->hfont);
559  if (data->script_cache)
560    ScriptFreeCache (&data->script_cache);
561  free (data);
562}
563
564LOGFONTW *
565hb_uniscribe_font_get_logfontw (hb_font_t *font)
566{
567  if (unlikely (!hb_uniscribe_shaper_font_data_ensure (font))) return NULL;
568  hb_uniscribe_shaper_font_data_t *font_data =  HB_SHAPER_DATA_GET (font);
569  return &font_data->log_font;
570}
571
572HFONT
573hb_uniscribe_font_get_hfont (hb_font_t *font)
574{
575  if (unlikely (!hb_uniscribe_shaper_font_data_ensure (font))) return NULL;
576  hb_uniscribe_shaper_font_data_t *font_data =  HB_SHAPER_DATA_GET (font);
577  return font_data->hfont;
578}
579
580
581/*
582 * shaper shape_plan data
583 */
584
585struct hb_uniscribe_shaper_shape_plan_data_t {};
586
587hb_uniscribe_shaper_shape_plan_data_t *
588_hb_uniscribe_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan HB_UNUSED,
589					     const hb_feature_t *user_features HB_UNUSED,
590					     unsigned int        num_user_features HB_UNUSED,
591					     const int          *coords HB_UNUSED,
592					     unsigned int        num_coords HB_UNUSED)
593{
594  return (hb_uniscribe_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;
595}
596
597void
598_hb_uniscribe_shaper_shape_plan_data_destroy (hb_uniscribe_shaper_shape_plan_data_t *data HB_UNUSED)
599{
600}
601
602
603/*
604 * shaper
605 */
606
607
608hb_bool_t
609_hb_uniscribe_shape (hb_shape_plan_t    *shape_plan,
610		     hb_font_t          *font,
611		     hb_buffer_t        *buffer,
612		     const hb_feature_t *features,
613		     unsigned int        num_features)
614{
615  hb_face_t *face = font->face;
616  hb_uniscribe_shaper_face_data_t *face_data = HB_SHAPER_DATA_GET (face);
617  hb_uniscribe_shaper_font_data_t *font_data = HB_SHAPER_DATA_GET (font);
618  hb_uniscribe_shaper_funcs_t *funcs = face_data->funcs;
619
620  /*
621   * Set up features.
622   */
623  hb_auto_array_t<OPENTYPE_FEATURE_RECORD> feature_records;
624  hb_auto_array_t<range_record_t> range_records;
625  if (num_features)
626  {
627    /* Sort features by start/end events. */
628    hb_auto_array_t<feature_event_t> feature_events;
629    for (unsigned int i = 0; i < num_features; i++)
630    {
631      active_feature_t feature;
632      feature.rec.tagFeature = hb_uint32_swap (features[i].tag);
633      feature.rec.lParameter = features[i].value;
634      feature.order = i;
635
636      feature_event_t *event;
637
638      event = feature_events.push ();
639      if (unlikely (!event))
640	goto fail_features;
641      event->index = features[i].start;
642      event->start = true;
643      event->feature = feature;
644
645      event = feature_events.push ();
646      if (unlikely (!event))
647	goto fail_features;
648      event->index = features[i].end;
649      event->start = false;
650      event->feature = feature;
651    }
652    feature_events.qsort ();
653    /* Add a strategic final event. */
654    {
655      active_feature_t feature;
656      feature.rec.tagFeature = 0;
657      feature.rec.lParameter = 0;
658      feature.order = num_features + 1;
659
660      feature_event_t *event = feature_events.push ();
661      if (unlikely (!event))
662	goto fail_features;
663      event->index = 0; /* This value does magic. */
664      event->start = false;
665      event->feature = feature;
666    }
667
668    /* Scan events and save features for each range. */
669    hb_auto_array_t<active_feature_t> active_features;
670    unsigned int last_index = 0;
671    for (unsigned int i = 0; i < feature_events.len; i++)
672    {
673      feature_event_t *event = &feature_events[i];
674
675      if (event->index != last_index)
676      {
677        /* Save a snapshot of active features and the range. */
678	range_record_t *range = range_records.push ();
679	if (unlikely (!range))
680	  goto fail_features;
681
682	unsigned int offset = feature_records.len;
683
684	active_features.qsort ();
685	for (unsigned int j = 0; j < active_features.len; j++)
686	{
687	  if (!j || active_features[j].rec.tagFeature != feature_records[feature_records.len - 1].tagFeature)
688	  {
689	    OPENTYPE_FEATURE_RECORD *feature = feature_records.push ();
690	    if (unlikely (!feature))
691	      goto fail_features;
692	    *feature = active_features[j].rec;
693	  }
694	  else
695	  {
696	    /* Overrides value for existing feature. */
697	    feature_records[feature_records.len - 1].lParameter = active_features[j].rec.lParameter;
698	  }
699	}
700
701	/* Will convert to pointer after all is ready, since feature_records.array
702	 * may move as we grow it. */
703	range->props.potfRecords = reinterpret_cast<OPENTYPE_FEATURE_RECORD *> (offset);
704	range->props.cotfRecords = feature_records.len - offset;
705	range->index_first = last_index;
706	range->index_last  = event->index - 1;
707
708	last_index = event->index;
709      }
710
711      if (event->start) {
712        active_feature_t *feature = active_features.push ();
713	if (unlikely (!feature))
714	  goto fail_features;
715	*feature = event->feature;
716      } else {
717        active_feature_t *feature = active_features.find (&event->feature);
718	if (feature)
719	  active_features.remove (feature - active_features.array);
720      }
721    }
722
723    if (!range_records.len) /* No active feature found. */
724      goto fail_features;
725
726    /* Fixup the pointers. */
727    for (unsigned int i = 0; i < range_records.len; i++)
728    {
729      range_record_t *range = &range_records[i];
730      range->props.potfRecords = feature_records.array + reinterpret_cast<uintptr_t> (range->props.potfRecords);
731    }
732  }
733  else
734  {
735  fail_features:
736    num_features = 0;
737  }
738
739#define FAIL(...) \
740  HB_STMT_START { \
741    DEBUG_MSG (UNISCRIBE, NULL, __VA_ARGS__); \
742    return false; \
743  } HB_STMT_END;
744
745  HRESULT hr;
746
747retry:
748
749  unsigned int scratch_size;
750  hb_buffer_t::scratch_buffer_t *scratch = buffer->get_scratch_buffer (&scratch_size);
751
752#define ALLOCATE_ARRAY(Type, name, len) \
753  Type *name = (Type *) scratch; \
754  { \
755    unsigned int _consumed = DIV_CEIL ((len) * sizeof (Type), sizeof (*scratch)); \
756    assert (_consumed <= scratch_size); \
757    scratch += _consumed; \
758    scratch_size -= _consumed; \
759  }
760
761#define utf16_index() var1.u32
762
763  ALLOCATE_ARRAY (WCHAR, pchars, buffer->len * 2);
764
765  unsigned int chars_len = 0;
766  for (unsigned int i = 0; i < buffer->len; i++)
767  {
768    hb_codepoint_t c = buffer->info[i].codepoint;
769    buffer->info[i].utf16_index() = chars_len;
770    if (likely (c <= 0xFFFFu))
771      pchars[chars_len++] = c;
772    else if (unlikely (c > 0x10FFFFu))
773      pchars[chars_len++] = 0xFFFDu;
774    else {
775      pchars[chars_len++] = 0xD800u + ((c - 0x10000u) >> 10);
776      pchars[chars_len++] = 0xDC00u + ((c - 0x10000u) & ((1u << 10) - 1));
777    }
778  }
779
780  ALLOCATE_ARRAY (WORD, log_clusters, chars_len);
781  ALLOCATE_ARRAY (SCRIPT_CHARPROP, char_props, chars_len);
782
783  if (num_features)
784  {
785    /* Need log_clusters to assign features. */
786    chars_len = 0;
787    for (unsigned int i = 0; i < buffer->len; i++)
788    {
789      hb_codepoint_t c = buffer->info[i].codepoint;
790      unsigned int cluster = buffer->info[i].cluster;
791      log_clusters[chars_len++] = cluster;
792      if (hb_in_range (c, 0x10000u, 0x10FFFFu))
793	log_clusters[chars_len++] = cluster; /* Surrogates. */
794    }
795  }
796
797  /* The -2 in the following is to compensate for possible
798   * alignment needed after the WORD array.  sizeof(WORD) == 2. */
799  unsigned int glyphs_size = (scratch_size * sizeof (int) - 2)
800			   / (sizeof (WORD) +
801			      sizeof (SCRIPT_GLYPHPROP) +
802			      sizeof (int) +
803			      sizeof (GOFFSET) +
804			      sizeof (uint32_t));
805
806  ALLOCATE_ARRAY (WORD, glyphs, glyphs_size);
807  ALLOCATE_ARRAY (SCRIPT_GLYPHPROP, glyph_props, glyphs_size);
808  ALLOCATE_ARRAY (int, advances, glyphs_size);
809  ALLOCATE_ARRAY (GOFFSET, offsets, glyphs_size);
810  ALLOCATE_ARRAY (uint32_t, vis_clusters, glyphs_size);
811
812  /* Note:
813   * We can't touch the contents of glyph_props.  Our fallback
814   * implementations of Shape and Place functions use that buffer
815   * by casting it to a different type.  It works because they
816   * both agree about it, but if we want to access it here we
817   * need address that issue first.
818   */
819
820#undef ALLOCATE_ARRAY
821
822#define MAX_ITEMS 256
823
824  SCRIPT_ITEM items[MAX_ITEMS + 1];
825  SCRIPT_CONTROL bidi_control = {0};
826  SCRIPT_STATE bidi_state = {0};
827  ULONG script_tags[MAX_ITEMS];
828  int item_count;
829
830  /* MinGW32 doesn't define fMergeNeutralItems, so we bruteforce */
831  //bidi_control.fMergeNeutralItems = true;
832  *(uint32_t*)&bidi_control |= 1u<<24;
833
834  bidi_state.uBidiLevel = HB_DIRECTION_IS_FORWARD (buffer->props.direction) ? 0 : 1;
835  bidi_state.fOverrideDirection = 1;
836
837  hr = funcs->ScriptItemizeOpenType (pchars,
838				     chars_len,
839				     MAX_ITEMS,
840				     &bidi_control,
841				     &bidi_state,
842				     items,
843				     script_tags,
844				     &item_count);
845  if (unlikely (FAILED (hr)))
846    FAIL ("ScriptItemizeOpenType() failed: 0x%08xL", hr);
847
848#undef MAX_ITEMS
849
850  OPENTYPE_TAG language_tag = hb_uint32_swap (hb_ot_tag_from_language (buffer->props.language));
851  hb_auto_array_t<TEXTRANGE_PROPERTIES*> range_properties;
852  hb_auto_array_t<int> range_char_counts;
853
854  unsigned int glyphs_offset = 0;
855  unsigned int glyphs_len;
856  bool backward = HB_DIRECTION_IS_BACKWARD (buffer->props.direction);
857  for (unsigned int i = 0; i < item_count; i++)
858  {
859    unsigned int chars_offset = items[i].iCharPos;
860    unsigned int item_chars_len = items[i + 1].iCharPos - chars_offset;
861
862    if (num_features)
863    {
864      range_properties.shrink (0);
865      range_char_counts.shrink (0);
866
867      range_record_t *last_range = &range_records[0];
868
869      for (unsigned int k = chars_offset; k < chars_offset + item_chars_len; k++)
870      {
871	range_record_t *range = last_range;
872	while (log_clusters[k] < range->index_first)
873	  range--;
874	while (log_clusters[k] > range->index_last)
875	  range++;
876	if (!range_properties.len ||
877	    &range->props != range_properties[range_properties.len - 1])
878	{
879	  TEXTRANGE_PROPERTIES **props = range_properties.push ();
880	  int *c = range_char_counts.push ();
881	  if (unlikely (!props || !c))
882	  {
883	    range_properties.shrink (0);
884	    range_char_counts.shrink (0);
885	    break;
886	  }
887	  *props = &range->props;
888	  *c = 1;
889	}
890	else
891	{
892	  range_char_counts[range_char_counts.len - 1]++;
893	}
894
895	last_range = range;
896      }
897    }
898
899    /* Asking for glyphs in logical order circumvents at least
900     * one bug in Uniscribe. */
901    items[i].a.fLogicalOrder = true;
902
903  retry_shape:
904    hr = funcs->ScriptShapeOpenType (font_data->hdc,
905				     &font_data->script_cache,
906				     &items[i].a,
907				     script_tags[i],
908				     language_tag,
909				     range_char_counts.array,
910				     range_properties.array,
911				     range_properties.len,
912				     pchars + chars_offset,
913				     item_chars_len,
914				     glyphs_size - glyphs_offset,
915				     /* out */
916				     log_clusters + chars_offset,
917				     char_props + chars_offset,
918				     glyphs + glyphs_offset,
919				     glyph_props + glyphs_offset,
920				     (int *) &glyphs_len);
921
922    if (unlikely (items[i].a.fNoGlyphIndex))
923      FAIL ("ScriptShapeOpenType() set fNoGlyphIndex");
924    if (unlikely (hr == E_OUTOFMEMORY || hr == E_NOT_SUFFICIENT_BUFFER))
925    {
926      if (unlikely (!buffer->ensure (buffer->allocated * 2)))
927	FAIL ("Buffer resize failed");
928      goto retry;
929    }
930    if (unlikely (hr == USP_E_SCRIPT_NOT_IN_FONT))
931    {
932      if (items[i].a.eScript == SCRIPT_UNDEFINED)
933	FAIL ("ScriptShapeOpenType() failed: Font doesn't support script");
934      items[i].a.eScript = SCRIPT_UNDEFINED;
935      goto retry_shape;
936    }
937    if (unlikely (FAILED (hr)))
938    {
939      FAIL ("ScriptShapeOpenType() failed: 0x%08xL", hr);
940    }
941
942    for (unsigned int j = chars_offset; j < chars_offset + item_chars_len; j++)
943      log_clusters[j] += glyphs_offset;
944
945    hr = funcs->ScriptPlaceOpenType (font_data->hdc,
946				     &font_data->script_cache,
947				     &items[i].a,
948				     script_tags[i],
949				     language_tag,
950				     range_char_counts.array,
951				     range_properties.array,
952				     range_properties.len,
953				     pchars + chars_offset,
954				     log_clusters + chars_offset,
955				     char_props + chars_offset,
956				     item_chars_len,
957				     glyphs + glyphs_offset,
958				     glyph_props + glyphs_offset,
959				     glyphs_len,
960				     /* out */
961				     advances + glyphs_offset,
962				     offsets + glyphs_offset,
963				     NULL);
964    if (unlikely (FAILED (hr)))
965      FAIL ("ScriptPlaceOpenType() failed: 0x%08xL", hr);
966
967    if (DEBUG_ENABLED (UNISCRIBE))
968      fprintf (stderr, "Item %d RTL %d LayoutRTL %d LogicalOrder %d ScriptTag %c%c%c%c\n",
969	       i,
970	       items[i].a.fRTL,
971	       items[i].a.fLayoutRTL,
972	       items[i].a.fLogicalOrder,
973	       HB_UNTAG (hb_uint32_swap (script_tags[i])));
974
975    glyphs_offset += glyphs_len;
976  }
977  glyphs_len = glyphs_offset;
978
979  /* Ok, we've got everything we need, now compose output buffer,
980   * very, *very*, carefully! */
981
982  /* Calculate visual-clusters.  That's what we ship. */
983  for (unsigned int i = 0; i < glyphs_len; i++)
984    vis_clusters[i] = -1;
985  for (unsigned int i = 0; i < buffer->len; i++) {
986    uint32_t *p = &vis_clusters[log_clusters[buffer->info[i].utf16_index()]];
987    *p = MIN (*p, buffer->info[i].cluster);
988  }
989  for (unsigned int i = 1; i < glyphs_len; i++)
990    if (vis_clusters[i] == -1)
991      vis_clusters[i] = vis_clusters[i - 1];
992
993#undef utf16_index
994
995  if (unlikely (!buffer->ensure (glyphs_len)))
996    FAIL ("Buffer in error");
997
998#undef FAIL
999
1000  /* Set glyph infos */
1001  buffer->len = 0;
1002  for (unsigned int i = 0; i < glyphs_len; i++)
1003  {
1004    hb_glyph_info_t *info = &buffer->info[buffer->len++];
1005
1006    info->codepoint = glyphs[i];
1007    info->cluster = vis_clusters[i];
1008
1009    /* The rest is crap.  Let's store position info there for now. */
1010    info->mask = advances[i];
1011    info->var1.i32 = offsets[i].du;
1012    info->var2.i32 = offsets[i].dv;
1013  }
1014
1015  /* Set glyph positions */
1016  buffer->clear_positions ();
1017  double x_mult = font_data->x_mult, y_mult = font_data->y_mult;
1018  for (unsigned int i = 0; i < glyphs_len; i++)
1019  {
1020    hb_glyph_info_t *info = &buffer->info[i];
1021    hb_glyph_position_t *pos = &buffer->pos[i];
1022
1023    /* TODO vertical */
1024    pos->x_advance = x_mult * (int32_t) info->mask;
1025    pos->x_offset = x_mult * (backward ? -info->var1.i32 : info->var1.i32);
1026    pos->y_offset = y_mult * info->var2.i32;
1027  }
1028
1029  if (backward)
1030    hb_buffer_reverse (buffer);
1031
1032  /* Wow, done! */
1033  return true;
1034}
1035
1036
1037