git.oblomov.eu Git - wine/blob - dlls/usp10/shape.c

   1 /*
   2  * Implementation of Shaping for the Uniscribe Script Processor (usp10.dll)
   3  *
   4  * Copyright 2010 CodeWeavers, Aric Stewart
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  */
  21 #include <stdarg.h>
  22
  23 #include "windef.h"
  24 #include "winbase.h"
  25 #include "wingdi.h"
  26 #include "winuser.h"
  27 #include "winnls.h"
  28 #include "usp10.h"
  29 #include "winternl.h"
  30
  31 #include "usp10_internal.h"
  32
  33 #include "wine/debug.h"
  34
  35 WINE_DEFAULT_DEBUG_CHANNEL(uniscribe);
  36
  37 #define FIRST_ARABIC_CHAR 0x0600
  38 #define LAST_ARABIC_CHAR  0x06ff
  39
  40 extern const unsigned short wine_shaping_table[];
  41 extern const unsigned short wine_shaping_forms[LAST_ARABIC_CHAR - FIRST_ARABIC_CHAR + 1][4];
  42
  43 enum joining_types {
  44     jtU,
  45     jtT,
  46     jtR,
  47     jtL,
  48     jtD,
  49     jtC
  50 };
  51
  52 enum joined_forms {
  53     Xn=0,
  54     Xr,
  55     Xl,
  56     Xm
  57 };
  58
  59 #ifdef WORDS_BIGENDIAN
  60 #define GET_BE_WORD(x) (x)
  61 #else
  62 #define GET_BE_WORD(x) RtlUshortByteSwap(x)
  63 #endif
  64
  65 /* These are all structures needed for the GSUB table */
  66 #define MS_MAKE_TAG( _x1, _x2, _x3, _x4 ) \
  67           ( ( (ULONG)_x4 << 24 ) |     \
  68             ( (ULONG)_x3 << 16 ) |     \
  69             ( (ULONG)_x2 <<  8 ) |     \
  70               (ULONG)_x1         )
  71
  72 #define GSUB_TAG MS_MAKE_TAG('G', 'S', 'U', 'B')
  73 #define GSUB_E_NOFEATURE -2
  74 #define GSUB_E_NOGLYPH -1
  75
  76 typedef struct {
  77     DWORD version;
  78     WORD ScriptList;
  79     WORD FeatureList;
  80     WORD LookupList;
  81 } GSUB_Header;
  82
  83 typedef struct {
  84     CHAR ScriptTag[4];
  85     WORD Script;
  86 } GSUB_ScriptRecord;
  87
  88 typedef struct {
  89     WORD ScriptCount;
  90     GSUB_ScriptRecord ScriptRecord[1];
  91 } GSUB_ScriptList;
  92
  93 typedef struct {
  94     CHAR LangSysTag[4];
  95     WORD LangSys;
  96 } GSUB_LangSysRecord;
  97
  98 typedef struct {
  99     WORD DefaultLangSys;
 100     WORD LangSysCount;
 101     GSUB_LangSysRecord LangSysRecord[1];
 102 } GSUB_Script;
 103
 104 typedef struct {
 105     WORD LookupOrder; /* Reserved */
 106     WORD ReqFeatureIndex;
 107     WORD FeatureCount;
 108     WORD FeatureIndex[1];
 109 } GSUB_LangSys;
 110
 111 typedef struct {
 112     CHAR FeatureTag[4];
 113     WORD Feature;
 114 } GSUB_FeatureRecord;
 115
 116 typedef struct {
 117     WORD FeatureCount;
 118     GSUB_FeatureRecord FeatureRecord[1];
 119 } GSUB_FeatureList;
 120
 121 typedef struct {
 122     WORD FeatureParams; /* Reserved */
 123     WORD LookupCount;
 124     WORD LookupListIndex[1];
 125 } GSUB_Feature;
 126
 127 typedef struct {
 128     WORD LookupCount;
 129     WORD Lookup[1];
 130 } GSUB_LookupList;
 131
 132 typedef struct {
 133     WORD LookupType;
 134     WORD LookupFlag;
 135     WORD SubTableCount;
 136     WORD SubTable[1];
 137 } GSUB_LookupTable;
 138
 139 typedef struct {
 140     WORD CoverageFormat;
 141     WORD GlyphCount;
 142     WORD GlyphArray[1];
 143 } GSUB_CoverageFormat1;
 144
 145 typedef struct {
 146     WORD Start;
 147     WORD End;
 148     WORD StartCoverageIndex;
 149 } GSUB_RangeRecord;
 150
 151 typedef struct {
 152     WORD CoverageFormat;
 153     WORD RangeCount;
 154     GSUB_RangeRecord RangeRecord[1];
 155 } GSUB_CoverageFormat2;
 156
 157 typedef struct {
 158     WORD SubstFormat; /* = 1 */
 159     WORD Coverage;
 160     WORD DeltaGlyphID;
 161 } GSUB_SingleSubstFormat1;
 162
 163 typedef struct {
 164     WORD SubstFormat; /* = 2 */
 165     WORD Coverage;
 166     WORD GlyphCount;
 167     WORD Substitute[1];
 168 }GSUB_SingleSubstFormat2;
 169
 170 typedef struct {
 171     WORD SubstFormat; /* = 1 */
 172     WORD Coverage;
 173     WORD LigSetCount;
 174     WORD LigatureSet[1];
 175 }GSUB_LigatureSubstFormat1;
 176
 177 typedef struct {
 178     WORD LigatureCount;
 179     WORD Ligature[1];
 180 }GSUB_LigatureSet;
 181
 182 typedef struct{
 183     WORD LigGlyph;
 184     WORD CompCount;
 185     WORD Component[1];
 186 }GSUB_Ligature;
 187
 188 /* the orders of joined_forms and contextual_features need to line up */
 189 static const char* contextual_features[] =
 190 {
 191     "isol",
 192     "fina",
 193     "init",
 194     "medi"
 195 };
 196
 197 static INT GSUB_is_glyph_covered(LPCVOID table , UINT glyph)
 198 {
 199     const GSUB_CoverageFormat1* cf1;
 200
 201     cf1 = table;
 202
 203     if (GET_BE_WORD(cf1->CoverageFormat) == 1)
 204     {
 205         int count = GET_BE_WORD(cf1->GlyphCount);
 206         int i;
 207         TRACE("Coverage Format 1, %i glyphs\n",count);
 208         for (i = 0; i < count; i++)
 209             if (glyph == GET_BE_WORD(cf1->GlyphArray[i]))
 210                 return i;
 211         return -1;
 212     }
 213     else if (GET_BE_WORD(cf1->CoverageFormat) == 2)
 214     {
 215         const GSUB_CoverageFormat2* cf2;
 216         int i;
 217         int count;
 218         cf2 = (const GSUB_CoverageFormat2*)cf1;
 219
 220         count = GET_BE_WORD(cf2->RangeCount);
 221         TRACE("Coverage Format 2, %i ranges\n",count);
 222         for (i = 0; i < count; i++)
 223         {
 224             if (glyph < GET_BE_WORD(cf2->RangeRecord[i].Start))
 225                 return -1;
 226             if ((glyph >= GET_BE_WORD(cf2->RangeRecord[i].Start)) &&
 227                 (glyph <= GET_BE_WORD(cf2->RangeRecord[i].End)))
 228             {
 229                 return (GET_BE_WORD(cf2->RangeRecord[i].StartCoverageIndex) +
 230                     glyph - GET_BE_WORD(cf2->RangeRecord[i].Start));
 231             }
 232         }
 233         return -1;
 234     }
 235     else
 236         ERR("Unknown CoverageFormat %i\n",GET_BE_WORD(cf1->CoverageFormat));
 237
 238     return -1;
 239 }
 240
 241 static const GSUB_Script* GSUB_get_script_table( const GSUB_Header* header, const char* tag)
 242 {
 243     const GSUB_ScriptList *script;
 244     const GSUB_Script *deflt = NULL;
 245     int i;
 246     script = (const GSUB_ScriptList*)((const BYTE*)header + GET_BE_WORD(header->ScriptList));
 247
 248     TRACE("%i scripts in this font\n",GET_BE_WORD(script->ScriptCount));
 249     for (i = 0; i < GET_BE_WORD(script->ScriptCount); i++)
 250     {
 251         const GSUB_Script *scr;
 252         int offset;
 253
 254         offset = GET_BE_WORD(script->ScriptRecord[i].Script);
 255         scr = (const GSUB_Script*)((const BYTE*)script + offset);
 256
 257         if (strncmp(script->ScriptRecord[i].ScriptTag, tag,4)==0)
 258             return scr;
 259         if (strncmp(script->ScriptRecord[i].ScriptTag, "dflt",4)==0)
 260             deflt = scr;
 261     }
 262     return deflt;
 263 }
 264
 265 static const GSUB_LangSys* GSUB_get_lang_table( const GSUB_Script* script, const char* tag)
 266 {
 267     int i;
 268     int offset;
 269     const GSUB_LangSys *Lang;
 270
 271     TRACE("Deflang %x, LangCount %i\n",GET_BE_WORD(script->DefaultLangSys), GET_BE_WORD(script->LangSysCount));
 272
 273     for (i = 0; i < GET_BE_WORD(script->LangSysCount) ; i++)
 274     {
 275         offset = GET_BE_WORD(script->LangSysRecord[i].LangSys);
 276         Lang = (const GSUB_LangSys*)((const BYTE*)script + offset);
 277
 278         if ( strncmp(script->LangSysRecord[i].LangSysTag,tag,4)==0)
 279             return Lang;
 280     }
 281     offset = GET_BE_WORD(script->DefaultLangSys);
 282     if (offset)
 283     {
 284         Lang = (const GSUB_LangSys*)((const BYTE*)script + offset);
 285         return Lang;
 286     }
 287     return NULL;
 288 }
 289
 290 static const GSUB_Feature * GSUB_get_feature(const GSUB_Header *header, const GSUB_LangSys *lang, const char* tag)
 291 {
 292     int i;
 293     const GSUB_FeatureList *feature;
 294     feature = (const GSUB_FeatureList*)((const BYTE*)header + GET_BE_WORD(header->FeatureList));
 295
 296     TRACE("%i features\n",GET_BE_WORD(lang->FeatureCount));
 297     for (i = 0; i < GET_BE_WORD(lang->FeatureCount); i++)
 298     {
 299         int index = GET_BE_WORD(lang->FeatureIndex[i]);
 300         if (strncmp(feature->FeatureRecord[index].FeatureTag,tag,4)==0)
 301         {
 302             const GSUB_Feature *feat;
 303             feat = (const GSUB_Feature*)((const BYTE*)feature + GET_BE_WORD(feature->FeatureRecord[index].Feature));
 304             return feat;
 305         }
 306     }
 307     return NULL;
 308 }
 309
 310 static INT GSUB_apply_SingleSubst(const GSUB_LookupTable *look, WORD *glyphs, INT glyph_index, INT write_dir, INT *glyph_count)
 311 {
 312     int j;
 313     TRACE("Single Substitution Subtable\n");
 314
 315     for (j = 0; j < GET_BE_WORD(look->SubTableCount); j++)
 316     {
 317         int offset;
 318         const GSUB_SingleSubstFormat1 *ssf1;
 319         offset = GET_BE_WORD(look->SubTable[j]);
 320         ssf1 = (const GSUB_SingleSubstFormat1*)((const BYTE*)look+offset);
 321         if (GET_BE_WORD(ssf1->SubstFormat) == 1)
 322         {
 323             int offset = GET_BE_WORD(ssf1->Coverage);
 324             TRACE("  subtype 1, delta %i\n", GET_BE_WORD(ssf1->DeltaGlyphID));
 325             if (GSUB_is_glyph_covered((const BYTE*)ssf1+offset, glyphs[glyph_index]) != -1)
 326             {
 327                 TRACE("  Glyph 0x%x ->",glyphs[glyph_index]);
 328                 glyphs[glyph_index] = glyphs[glyph_index] + GET_BE_WORD(ssf1->DeltaGlyphID);
 329                 TRACE(" 0x%x\n",glyphs[glyph_index]);
 330                 return glyph_index + 1;
 331             }
 332         }
 333         else
 334         {
 335             const GSUB_SingleSubstFormat2 *ssf2;
 336             INT index;
 337             INT offset;
 338
 339             ssf2 = (const GSUB_SingleSubstFormat2 *)ssf1;
 340             offset = GET_BE_WORD(ssf1->Coverage);
 341             TRACE("  subtype 2,  glyph count %i\n", GET_BE_WORD(ssf2->GlyphCount));
 342             index = GSUB_is_glyph_covered((const BYTE*)ssf2+offset, glyphs[glyph_index]);
 343             TRACE("  Coverage index %i\n",index);
 344             if (index != -1)
 345             {
 346                 TRACE("    Glyph is 0x%x ->",glyphs[glyph_index]);
 347                 glyphs[glyph_index] = GET_BE_WORD(ssf2->Substitute[index]);
 348                 TRACE("0x%x\n",glyphs[glyph_index]);
 349                 return glyph_index + 1;
 350             }
 351         }
 352     }
 353     return GSUB_E_NOGLYPH;
 354 }
 355
 356 static INT GSUB_apply_LigatureSubst(const GSUB_LookupTable *look, WORD *glyphs, INT glyph_index, INT write_dir, INT *glyph_count)
 357 {
 358     int j;
 359
 360     TRACE("Ligature Substitution Subtable\n");
 361     for (j = 0; j < GET_BE_WORD(look->SubTableCount); j++)
 362     {
 363         const GSUB_LigatureSubstFormat1 *lsf1;
 364         int offset,index;
 365
 366         offset = GET_BE_WORD(look->SubTable[j]);
 367         lsf1 = (const GSUB_LigatureSubstFormat1*)((const BYTE*)look+offset);
 368         offset = GET_BE_WORD(lsf1->Coverage);
 369         index = GSUB_is_glyph_covered((const BYTE*)lsf1+offset, glyphs[glyph_index]);
 370         TRACE("  Coverage index %i\n",index);
 371         if (index != -1)
 372         {
 373             const GSUB_LigatureSet *ls;
 374             int k, count;
 375
 376             offset = GET_BE_WORD(lsf1->LigatureSet[index]);
 377             ls = (const GSUB_LigatureSet*)((const BYTE*)lsf1+offset);
 378             count = GET_BE_WORD(ls->LigatureCount);
 379             TRACE("  LigatureSet has %i members\n",count);
 380             for (k = 0; k < count; k++)
 381             {
 382                 const GSUB_Ligature *lig;
 383                 int CompCount,l,CompIndex;
 384
 385                 offset = GET_BE_WORD(ls->Ligature[k]);
 386                 lig = (const GSUB_Ligature*)((const BYTE*)ls+offset);
 387                 CompCount = GET_BE_WORD(lig->CompCount) - 1;
 388                 CompIndex = glyph_index+write_dir;
 389                 for (l = 0; l < CompCount && CompIndex >= 0 && CompIndex < *glyph_count; l++)
 390                 {
 391                     int CompGlyph;
 392                     CompGlyph = GET_BE_WORD(lig->Component[l]);
 393                     if (CompGlyph != glyphs[CompIndex])
 394                         break;
 395                     CompIndex += write_dir;
 396                 }
 397                 if (l == CompCount)
 398                 {
 399                     int replaceIdx = glyph_index;
 400                     if (write_dir < 0)
 401                         replaceIdx = glyph_index - CompCount;
 402
 403                     TRACE("    Glyph is 0x%x (+%i) ->",glyphs[glyph_index],CompCount);
 404                     glyphs[replaceIdx] = GET_BE_WORD(lig->LigGlyph);
 405                     TRACE("0x%x\n",glyphs[replaceIdx]);
 406                     if (CompCount > 0)
 407                     {
 408                         int j;
 409                         for (j = replaceIdx + 1; j < *glyph_count; j++)
 410                             glyphs[j] =glyphs[j+CompCount];
 411                         *glyph_count = *glyph_count - CompCount;
 412                     }
 413                     return replaceIdx + 1;
 414                 }
 415             }
 416         }
 417     }
 418     return GSUB_E_NOGLYPH;
 419 }
 420
 421 static INT GSUB_apply_lookup(const GSUB_LookupList* lookup, INT lookup_index, WORD *glyphs, INT glyph_index, INT write_dir, INT *glyph_count)
 422 {
 423     int offset;
 424     const GSUB_LookupTable *look;
 425
 426     offset = GET_BE_WORD(lookup->Lookup[lookup_index]);
 427     look = (const GSUB_LookupTable*)((const BYTE*)lookup + offset);
 428     TRACE("type %i, flag %x, subtables %i\n",GET_BE_WORD(look->LookupType),GET_BE_WORD(look->LookupFlag),GET_BE_WORD(look->SubTableCount));
 429     switch(GET_BE_WORD(look->LookupType))
 430     {
 431         case 1:
 432             return GSUB_apply_SingleSubst(look, glyphs, glyph_index, write_dir, glyph_count);
 433         case 4:
 434             return GSUB_apply_LigatureSubst(look, glyphs, glyph_index, write_dir, glyph_count);
 435         default:
 436             FIXME("We do not handle SubType %i\n",GET_BE_WORD(look->LookupType));
 437     }
 438     return GSUB_E_NOGLYPH;
 439 }
 440
 441 static INT GSUB_apply_feature(const GSUB_Header * header, const GSUB_Feature* feature, WORD *glyphs, INT glyph_index, INT write_dir, INT *glyph_count)
 442 {
 443     int i;
 444     int out_index = GSUB_E_NOGLYPH;
 445     const GSUB_LookupList *lookup;
 446
 447     lookup = (const GSUB_LookupList*)((const BYTE*)header + GET_BE_WORD(header->LookupList));
 448
 449     TRACE("%i lookups\n", GET_BE_WORD(feature->LookupCount));
 450     for (i = 0; i < GET_BE_WORD(feature->LookupCount); i++)
 451     {
 452         out_index = GSUB_apply_lookup(lookup, GET_BE_WORD(feature->LookupListIndex[i]), glyphs, glyph_index, write_dir, glyph_count);
 453         if (out_index != GSUB_E_NOGLYPH)
 454             break;
 455     }
 456     if (out_index == GSUB_E_NOGLYPH)
 457         TRACE("lookups found no glyphs\n");
 458     return out_index;
 459 }
 460
 461 static const char* get_opentype_script(HDC hdc, SCRIPT_ANALYSIS *psa)
 462 {
 463     UINT charset;
 464
 465     switch (psa->eScript)
 466     {
 467         case Script_Arabic:
 468             return "arab";
 469         case Script_Syriac:
 470             return "syrc";
 471         case Script_Hebrew:
 472             return "hebr";
 473         case Script_Latin:
 474         case Script_Numeric:
 475         case Script_CR:
 476         case Script_LF:
 477             return "latn";
 478     }
 479
 480     /*
 481      * fall back to the font charset
 482      */
 483     charset = GetTextCharsetInfo(hdc, NULL, 0x0);
 484     switch (charset)
 485     {
 486         case ANSI_CHARSET: return "latn";
 487         case BALTIC_CHARSET: return "latn"; /* ?? */
 488         case CHINESEBIG5_CHARSET: return "hani";
 489         case EASTEUROPE_CHARSET: return "latn"; /* ?? */
 490         case GB2312_CHARSET: return "hani";
 491         case GREEK_CHARSET: return "grek";
 492         case HANGUL_CHARSET: return "hang";
 493         case RUSSIAN_CHARSET: return "cyrl";
 494         case SHIFTJIS_CHARSET: return "kana";
 495         case TURKISH_CHARSET: return "latn"; /* ?? */
 496         case VIETNAMESE_CHARSET: return "latn";
 497         case JOHAB_CHARSET: return "latn"; /* ?? */
 498         case ARABIC_CHARSET: return "arab";
 499         case HEBREW_CHARSET: return "hebr";
 500         case THAI_CHARSET: return "thai";
 501         default: return "latn";
 502     }
 503 }
 504
 505 static INT apply_GSUB_feature_to_glyph(HDC hdc, SCRIPT_ANALYSIS *psa, void* GSUB_Table, WORD *glyphs, INT index, INT write_dir, INT* glyph_count, const char* feat)
 506 {
 507     const GSUB_Header *header;
 508     const GSUB_Script *script;
 509     const GSUB_LangSys *language;
 510     const GSUB_Feature *feature;
 511
 512     if (!GSUB_Table)
 513         return GSUB_E_NOFEATURE;
 514
 515     header = GSUB_Table;
 516
 517     script = GSUB_get_script_table(header, get_opentype_script(hdc,psa));
 518     if (!script)
 519     {
 520         TRACE("Script not found\n");
 521         return GSUB_E_NOFEATURE;
 522     }
 523     language = GSUB_get_lang_table(script, "xxxx"); /* Need to get Lang tag */
 524     if (!language)
 525     {
 526         TRACE("Language not found\n");
 527         return GSUB_E_NOFEATURE;
 528     }
 529     feature  =  GSUB_get_feature(header, language, feat);
 530     if (!feature)
 531     {
 532         TRACE("%s feature not found\n",feat);
 533         return GSUB_E_NOFEATURE;
 534     }
 535     TRACE("applying feature %s\n",feat);
 536     return GSUB_apply_feature(header, feature, glyphs, index, write_dir, glyph_count);
 537 }
 538
 539 static VOID *load_gsub_table(HDC hdc)
 540 {
 541     VOID* GSUB_Table = NULL;
 542     int length = GetFontData(hdc, GSUB_TAG , 0, NULL, 0);
 543     if (length != GDI_ERROR)
 544     {
 545         GSUB_Table = HeapAlloc(GetProcessHeap(),0,length);
 546         GetFontData(hdc, GSUB_TAG , 0, GSUB_Table, length);
 547         TRACE("Loaded GSUB table of %i bytes\n",length);
 548     }
 549     return GSUB_Table;
 550 }
 551
 552 static CHAR neighbour_joining_type(int i, int delta, const CHAR* context_type, INT cchLen, SCRIPT_ANALYSIS *psa)
 553 {
 554     if (i + delta < 0)
 555     {
 556         if (psa->fLinkBefore)
 557             return jtR;
 558         else
 559             return jtU;
 560     }
 561     if ( i+ delta >= cchLen)
 562     {
 563         if (psa->fLinkAfter)
 564             return jtL;
 565         else
 566             return jtU;
 567     }
 568
 569     i += delta;
 570
 571     if (context_type[i] == jtT)
 572         return neighbour_joining_type(i,delta,context_type,cchLen,psa);
 573     else
 574         return context_type[i];
 575 }
 576
 577 static inline BOOL right_join_causing(CHAR joining_type)
 578 {
 579     return (joining_type == jtL || joining_type == jtD || joining_type == jtC);
 580 }
 581
 582 static inline BOOL left_join_causing(CHAR joining_type)
 583 {
 584     return (joining_type == jtR || joining_type == jtD || joining_type == jtC);
 585 }
 586
 587 /* SHAPE_ShapeArabicGlyphs
 588  */
 589 void SHAPE_ShapeArabicGlyphs(HDC hdc, ScriptCache *psc, SCRIPT_ANALYSIS *psa, WCHAR* pwcChars, INT cChars, WORD* pwOutGlyphs, INT* pcGlyphs, INT cMaxGlyphs)
 590 {
 591     CHAR *context_type;
 592     INT *context_shape;
 593     INT dirR, dirL;
 594     int i;
 595
 596     if (psa->eScript != Script_Arabic)
 597         return;
 598
 599     if (*pcGlyphs != cChars)
 600     {
 601         ERR("Number of Glyphs and Chars need to match at the beginning\n");
 602         return;
 603     }
 604
 605
 606     if (!psa->fLogicalOrder && psa->fRTL)
 607     {
 608         dirR = 1;
 609         dirL = -1;
 610     }
 611     else
 612     {
 613         dirR = -1;
 614         dirL = 1;
 615     }
 616
 617     if (!psc->GSUB_Table)
 618         psc->GSUB_Table = load_gsub_table(hdc);
 619
 620     context_type = HeapAlloc(GetProcessHeap(),0,cChars);
 621     context_shape = HeapAlloc(GetProcessHeap(),0,sizeof(INT) * cChars);
 622
 623     for (i = 0; i < cChars; i++)
 624         context_type[i] = wine_shaping_table[wine_shaping_table[pwcChars[i] >> 8] + (pwcChars[i] & 0xff)];
 625
 626     for (i = 0; i < cChars; i++)
 627     {
 628         if (context_type[i] == jtR && right_join_causing(neighbour_joining_type(i,dirR,context_type,cChars,psa)))
 629             context_shape[i] = Xr;
 630         else if (context_type[i] == jtL && left_join_causing(neighbour_joining_type(i,dirL,context_type,cChars,psa)))
 631             context_shape[i] = Xl;
 632         else if (context_type[i] == jtD && left_join_causing(neighbour_joining_type(i,dirL,context_type,cChars,psa)) && right_join_causing(neighbour_joining_type(i,dirR,context_type,cChars,psa)))
 633             context_shape[i] = Xm;
 634         else if (context_type[i] == jtD && right_join_causing(neighbour_joining_type(i,dirR,context_type,cChars,psa)))
 635             context_shape[i] = Xr;
 636         else if (context_type[i] == jtD && left_join_causing(neighbour_joining_type(i,dirL,context_type,cChars,psa)))
 637             context_shape[i] = Xl;
 638         else
 639             context_shape[i] = Xn;
 640     }
 641
 642     /* Contextual Shaping */
 643     i = 0;
 644     while(i < *pcGlyphs)
 645     {
 646         BOOL shaped = FALSE;
 647
 648         if (psc->GSUB_Table)
 649         {
 650             INT nextIndex;
 651             nextIndex = apply_GSUB_feature_to_glyph(hdc, psa, psc->GSUB_Table, pwOutGlyphs, i, dirL, pcGlyphs, contextual_features[context_shape[i]]);
 652             if (nextIndex > GSUB_E_NOGLYPH)
 653                 i = nextIndex;
 654             shaped = (nextIndex > GSUB_E_NOGLYPH);
 655         }
 656
 657         if (!shaped)
 658         {
 659             WORD newGlyph = pwOutGlyphs[i];
 660             if (pwcChars[i] >= FIRST_ARABIC_CHAR && pwcChars[i] <= LAST_ARABIC_CHAR)
 661             {
 662                 /* fall back to presentation form B */
 663                 WCHAR context_char = wine_shaping_forms[pwcChars[i] - FIRST_ARABIC_CHAR][context_shape[i]];
 664                 if (context_char != pwcChars[i] && GetGlyphIndicesW(hdc, &context_char, 1, &newGlyph, 0) != GDI_ERROR && newGlyph != 0x0000)
 665                     pwOutGlyphs[i] = newGlyph;
 666             }
 667             i++;
 668         }
 669     }
 670
 671     /* Required ligature substitution */
 672     if (psc->GSUB_Table)
 673     {
 674         i = 0;
 675         while(i < *pcGlyphs)
 676         {
 677                 INT nextIndex;
 678                 nextIndex = apply_GSUB_feature_to_glyph(hdc, psa, psc->GSUB_Table, pwOutGlyphs, i, dirL, pcGlyphs, "rlig");
 679                 if (nextIndex > GSUB_E_NOGLYPH)
 680                     i = nextIndex;
 681                 else if (nextIndex == GSUB_E_NOFEATURE)
 682                     break;
 683                 else
 684                     i++;
 685         }
 686     }
 687
 688     HeapFree(GetProcessHeap(),0,context_shape);
 689     HeapFree(GetProcessHeap(),0,context_type);
 690 }