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 typedef struct{
 189     WORD SequenceIndex;
 190     WORD LookupListIndex;
 191
 192 }GSUB_SubstLookupRecord;
 193
 194 typedef struct{
 195     WORD SubstFormat; /* = 1 */
 196     WORD Coverage;
 197     WORD ChainSubRuleSetCount;
 198     WORD ChainSubRuleSet[1];
 199 }GSUB_ChainContextSubstFormat1;
 200
 201 typedef struct {
 202     WORD SubstFormat; /* = 3 */
 203     WORD BacktrackGlyphCount;
 204     WORD Coverage[1];
 205 }GSUB_ChainContextSubstFormat3_1;
 206
 207 typedef struct{
 208     WORD InputGlyphCount;
 209     WORD Coverage[1];
 210 }GSUB_ChainContextSubstFormat3_2;
 211
 212 typedef struct{
 213     WORD LookaheadGlyphCount;
 214     WORD Coverage[1];
 215 }GSUB_ChainContextSubstFormat3_3;
 216
 217 typedef struct{
 218     WORD SubstCount;
 219     GSUB_SubstLookupRecord SubstLookupRecord[1];
 220 }GSUB_ChainContextSubstFormat3_4;
 221
 222 static INT GSUB_apply_lookup(const GSUB_LookupList* lookup, INT lookup_index, WORD *glyphs, INT glyph_index, INT write_dir, INT *glyph_count);
 223
 224 /* the orders of joined_forms and contextual_features need to line up */
 225 static const char* contextual_features[] =
 226 {
 227     "isol",
 228     "fina",
 229     "init",
 230     "medi"
 231 };
 232
 233 static const char* arabic_GSUB_features[] =
 234 {
 235     "rlig",
 236     "calt",
 237     "liga",
 238     "dlig",
 239     "cswh",
 240     "mset",
 241     NULL
 242 };
 243
 244 static INT GSUB_is_glyph_covered(LPCVOID table , UINT glyph)
 245 {
 246     const GSUB_CoverageFormat1* cf1;
 247
 248     cf1 = table;
 249
 250     if (GET_BE_WORD(cf1->CoverageFormat) == 1)
 251     {
 252         int count = GET_BE_WORD(cf1->GlyphCount);
 253         int i;
 254         TRACE("Coverage Format 1, %i glyphs\n",count);
 255         for (i = 0; i < count; i++)
 256             if (glyph == GET_BE_WORD(cf1->GlyphArray[i]))
 257                 return i;
 258         return -1;
 259     }
 260     else if (GET_BE_WORD(cf1->CoverageFormat) == 2)
 261     {
 262         const GSUB_CoverageFormat2* cf2;
 263         int i;
 264         int count;
 265         cf2 = (const GSUB_CoverageFormat2*)cf1;
 266
 267         count = GET_BE_WORD(cf2->RangeCount);
 268         TRACE("Coverage Format 2, %i ranges\n",count);
 269         for (i = 0; i < count; i++)
 270         {
 271             if (glyph < GET_BE_WORD(cf2->RangeRecord[i].Start))
 272                 return -1;
 273             if ((glyph >= GET_BE_WORD(cf2->RangeRecord[i].Start)) &&
 274                 (glyph <= GET_BE_WORD(cf2->RangeRecord[i].End)))
 275             {
 276                 return (GET_BE_WORD(cf2->RangeRecord[i].StartCoverageIndex) +
 277                     glyph - GET_BE_WORD(cf2->RangeRecord[i].Start));
 278             }
 279         }
 280         return -1;
 281     }
 282     else
 283         ERR("Unknown CoverageFormat %i\n",GET_BE_WORD(cf1->CoverageFormat));
 284
 285     return -1;
 286 }
 287
 288 static const GSUB_Script* GSUB_get_script_table( const GSUB_Header* header, const char* tag)
 289 {
 290     const GSUB_ScriptList *script;
 291     const GSUB_Script *deflt = NULL;
 292     int i;
 293     script = (const GSUB_ScriptList*)((const BYTE*)header + GET_BE_WORD(header->ScriptList));
 294
 295     TRACE("%i scripts in this font\n",GET_BE_WORD(script->ScriptCount));
 296     for (i = 0; i < GET_BE_WORD(script->ScriptCount); i++)
 297     {
 298         const GSUB_Script *scr;
 299         int offset;
 300
 301         offset = GET_BE_WORD(script->ScriptRecord[i].Script);
 302         scr = (const GSUB_Script*)((const BYTE*)script + offset);
 303
 304         if (strncmp(script->ScriptRecord[i].ScriptTag, tag,4)==0)
 305             return scr;
 306         if (strncmp(script->ScriptRecord[i].ScriptTag, "dflt",4)==0)
 307             deflt = scr;
 308     }
 309     return deflt;
 310 }
 311
 312 static const GSUB_LangSys* GSUB_get_lang_table( const GSUB_Script* script, const char* tag)
 313 {
 314     int i;
 315     int offset;
 316     const GSUB_LangSys *Lang;
 317
 318     TRACE("Deflang %x, LangCount %i\n",GET_BE_WORD(script->DefaultLangSys), GET_BE_WORD(script->LangSysCount));
 319
 320     for (i = 0; i < GET_BE_WORD(script->LangSysCount) ; i++)
 321     {
 322         offset = GET_BE_WORD(script->LangSysRecord[i].LangSys);
 323         Lang = (const GSUB_LangSys*)((const BYTE*)script + offset);
 324
 325         if ( strncmp(script->LangSysRecord[i].LangSysTag,tag,4)==0)
 326             return Lang;
 327     }
 328     offset = GET_BE_WORD(script->DefaultLangSys);
 329     if (offset)
 330     {
 331         Lang = (const GSUB_LangSys*)((const BYTE*)script + offset);
 332         return Lang;
 333     }
 334     return NULL;
 335 }
 336
 337 static const GSUB_Feature * GSUB_get_feature(const GSUB_Header *header, const GSUB_LangSys *lang, const char* tag)
 338 {
 339     int i;
 340     const GSUB_FeatureList *feature;
 341     feature = (const GSUB_FeatureList*)((const BYTE*)header + GET_BE_WORD(header->FeatureList));
 342
 343     TRACE("%i features\n",GET_BE_WORD(lang->FeatureCount));
 344     for (i = 0; i < GET_BE_WORD(lang->FeatureCount); i++)
 345     {
 346         int index = GET_BE_WORD(lang->FeatureIndex[i]);
 347         if (strncmp(feature->FeatureRecord[index].FeatureTag,tag,4)==0)
 348         {
 349             const GSUB_Feature *feat;
 350             feat = (const GSUB_Feature*)((const BYTE*)feature + GET_BE_WORD(feature->FeatureRecord[index].Feature));
 351             return feat;
 352         }
 353     }
 354     return NULL;
 355 }
 356
 357 static INT GSUB_apply_SingleSubst(const GSUB_LookupTable *look, WORD *glyphs, INT glyph_index, INT write_dir, INT *glyph_count)
 358 {
 359     int j;
 360     TRACE("Single Substitution Subtable\n");
 361
 362     for (j = 0; j < GET_BE_WORD(look->SubTableCount); j++)
 363     {
 364         int offset;
 365         const GSUB_SingleSubstFormat1 *ssf1;
 366         offset = GET_BE_WORD(look->SubTable[j]);
 367         ssf1 = (const GSUB_SingleSubstFormat1*)((const BYTE*)look+offset);
 368         if (GET_BE_WORD(ssf1->SubstFormat) == 1)
 369         {
 370             int offset = GET_BE_WORD(ssf1->Coverage);
 371             TRACE("  subtype 1, delta %i\n", GET_BE_WORD(ssf1->DeltaGlyphID));
 372             if (GSUB_is_glyph_covered((const BYTE*)ssf1+offset, glyphs[glyph_index]) != -1)
 373             {
 374                 TRACE("  Glyph 0x%x ->",glyphs[glyph_index]);
 375                 glyphs[glyph_index] = glyphs[glyph_index] + GET_BE_WORD(ssf1->DeltaGlyphID);
 376                 TRACE(" 0x%x\n",glyphs[glyph_index]);
 377                 return glyph_index + 1;
 378             }
 379         }
 380         else
 381         {
 382             const GSUB_SingleSubstFormat2 *ssf2;
 383             INT index;
 384             INT offset;
 385
 386             ssf2 = (const GSUB_SingleSubstFormat2 *)ssf1;
 387             offset = GET_BE_WORD(ssf1->Coverage);
 388             TRACE("  subtype 2,  glyph count %i\n", GET_BE_WORD(ssf2->GlyphCount));
 389             index = GSUB_is_glyph_covered((const BYTE*)ssf2+offset, glyphs[glyph_index]);
 390             TRACE("  Coverage index %i\n",index);
 391             if (index != -1)
 392             {
 393                 TRACE("    Glyph is 0x%x ->",glyphs[glyph_index]);
 394                 glyphs[glyph_index] = GET_BE_WORD(ssf2->Substitute[index]);
 395                 TRACE("0x%x\n",glyphs[glyph_index]);
 396                 return glyph_index + 1;
 397             }
 398         }
 399     }
 400     return GSUB_E_NOGLYPH;
 401 }
 402
 403 static INT GSUB_apply_LigatureSubst(const GSUB_LookupTable *look, WORD *glyphs, INT glyph_index, INT write_dir, INT *glyph_count)
 404 {
 405     int j;
 406
 407     TRACE("Ligature Substitution Subtable\n");
 408     for (j = 0; j < GET_BE_WORD(look->SubTableCount); j++)
 409     {
 410         const GSUB_LigatureSubstFormat1 *lsf1;
 411         int offset,index;
 412
 413         offset = GET_BE_WORD(look->SubTable[j]);
 414         lsf1 = (const GSUB_LigatureSubstFormat1*)((const BYTE*)look+offset);
 415         offset = GET_BE_WORD(lsf1->Coverage);
 416         index = GSUB_is_glyph_covered((const BYTE*)lsf1+offset, glyphs[glyph_index]);
 417         TRACE("  Coverage index %i\n",index);
 418         if (index != -1)
 419         {
 420             const GSUB_LigatureSet *ls;
 421             int k, count;
 422
 423             offset = GET_BE_WORD(lsf1->LigatureSet[index]);
 424             ls = (const GSUB_LigatureSet*)((const BYTE*)lsf1+offset);
 425             count = GET_BE_WORD(ls->LigatureCount);
 426             TRACE("  LigatureSet has %i members\n",count);
 427             for (k = 0; k < count; k++)
 428             {
 429                 const GSUB_Ligature *lig;
 430                 int CompCount,l,CompIndex;
 431
 432                 offset = GET_BE_WORD(ls->Ligature[k]);
 433                 lig = (const GSUB_Ligature*)((const BYTE*)ls+offset);
 434                 CompCount = GET_BE_WORD(lig->CompCount) - 1;
 435                 CompIndex = glyph_index+write_dir;
 436                 for (l = 0; l < CompCount && CompIndex >= 0 && CompIndex < *glyph_count; l++)
 437                 {
 438                     int CompGlyph;
 439                     CompGlyph = GET_BE_WORD(lig->Component[l]);
 440                     if (CompGlyph != glyphs[CompIndex])
 441                         break;
 442                     CompIndex += write_dir;
 443                 }
 444                 if (l == CompCount)
 445                 {
 446                     int replaceIdx = glyph_index;
 447                     if (write_dir < 0)
 448                         replaceIdx = glyph_index - CompCount;
 449
 450                     TRACE("    Glyph is 0x%x (+%i) ->",glyphs[glyph_index],CompCount);
 451                     glyphs[replaceIdx] = GET_BE_WORD(lig->LigGlyph);
 452                     TRACE("0x%x\n",glyphs[replaceIdx]);
 453                     if (CompCount > 0)
 454                     {
 455                         int j;
 456                         for (j = replaceIdx + 1; j < *glyph_count; j++)
 457                             glyphs[j] =glyphs[j+CompCount];
 458                         *glyph_count = *glyph_count - CompCount;
 459                     }
 460                     return replaceIdx + 1;
 461                 }
 462             }
 463         }
 464     }
 465     return GSUB_E_NOGLYPH;
 466 }
 467
 468 static INT GSUB_apply_ChainContextSubst(const GSUB_LookupList* lookup, const GSUB_LookupTable *look, WORD *glyphs, INT glyph_index, INT write_dir, INT *glyph_count)
 469 {
 470     int j;
 471     BOOL done = FALSE;
 472
 473     TRACE("Chaining Contextual Substitution Subtable\n");
 474     for (j = 0; j < GET_BE_WORD(look->SubTableCount) && !done; j++)
 475     {
 476         const GSUB_ChainContextSubstFormat1 *ccsf1;
 477         int offset;
 478         int dirLookahead = write_dir;
 479         int dirBacktrack = -1 * write_dir;
 480
 481         offset = GET_BE_WORD(look->SubTable[j]);
 482         ccsf1 = (const GSUB_ChainContextSubstFormat1*)((const BYTE*)look+offset);
 483         if (GET_BE_WORD(ccsf1->SubstFormat) == 1)
 484         {
 485             FIXME("  TODO: subtype 1 (Simple context glyph substitution)\n");
 486             return -1;
 487         }
 488         else if (GET_BE_WORD(ccsf1->SubstFormat) == 2)
 489         {
 490             FIXME("  TODO: subtype 2 (Class-based Chaining Context Glyph Substitution)\n");
 491             return -1;
 492         }
 493         else if (GET_BE_WORD(ccsf1->SubstFormat) == 3)
 494         {
 495             int k;
 496             int indexGlyphs;
 497             const GSUB_ChainContextSubstFormat3_1 *ccsf3_1;
 498             const GSUB_ChainContextSubstFormat3_2 *ccsf3_2;
 499             const GSUB_ChainContextSubstFormat3_3 *ccsf3_3;
 500             const GSUB_ChainContextSubstFormat3_4 *ccsf3_4;
 501             int newIndex = glyph_index;
 502
 503             ccsf3_1 = (const GSUB_ChainContextSubstFormat3_1 *)ccsf1;
 504
 505             TRACE("  subtype 3 (Coverage-based Chaining Context Glyph Substitution)\n");
 506
 507             for (k = 0; k < GET_BE_WORD(ccsf3_1->BacktrackGlyphCount); k++)
 508             {
 509                 offset = GET_BE_WORD(ccsf3_1->Coverage[k]);
 510                 if (GSUB_is_glyph_covered((const BYTE*)ccsf3_1+offset, glyphs[glyph_index + (dirBacktrack * (k+1))]) == -1)
 511                     break;
 512             }
 513             if (k != GET_BE_WORD(ccsf3_1->BacktrackGlyphCount))
 514                 return -1;
 515             TRACE("Matched Backtrack\n");
 516
 517             ccsf3_2 = (const GSUB_ChainContextSubstFormat3_2 *)(((LPBYTE)ccsf1)+sizeof(GSUB_ChainContextSubstFormat3_1) + (sizeof(WORD) * (GET_BE_WORD(ccsf3_1->BacktrackGlyphCount)-1)));
 518
 519             indexGlyphs = GET_BE_WORD(ccsf3_2->InputGlyphCount);
 520             for (k = 0; k < indexGlyphs; k++)
 521             {
 522                 offset = GET_BE_WORD(ccsf3_2->Coverage[k]);
 523                 if (GSUB_is_glyph_covered((const BYTE*)ccsf3_1+offset, glyphs[glyph_index + (write_dir * k)]) == -1)
 524                     break;
 525             }
 526             if (k != indexGlyphs)
 527                 return -1;
 528             TRACE("Matched IndexGlyphs\n");
 529
 530             ccsf3_3 = (const GSUB_ChainContextSubstFormat3_3 *)(((LPBYTE)ccsf3_2)+sizeof(GSUB_ChainContextSubstFormat3_2) + (sizeof(WORD) * (GET_BE_WORD(ccsf3_2->InputGlyphCount)-1)));
 531
 532             for (k = 0; k < GET_BE_WORD(ccsf3_3->LookaheadGlyphCount); k++)
 533             {
 534                 offset = GET_BE_WORD(ccsf3_3->Coverage[k]);
 535                 if (GSUB_is_glyph_covered((const BYTE*)ccsf3_1+offset, glyphs[glyph_index + (dirLookahead * (indexGlyphs + k+1))]) == -1)
 536                     break;
 537             }
 538             if (k != GET_BE_WORD(ccsf3_3->LookaheadGlyphCount))
 539                 return -1;
 540             TRACE("Matched LookAhead\n");
 541
 542             ccsf3_4 = (const GSUB_ChainContextSubstFormat3_4 *)(((LPBYTE)ccsf3_3)+sizeof(GSUB_ChainContextSubstFormat3_3) + (sizeof(WORD) * (GET_BE_WORD(ccsf3_3->LookaheadGlyphCount)-1)));
 543
 544             for (k = 0; k < GET_BE_WORD(ccsf3_4->SubstCount); k++)
 545             {
 546                 int lookupIndex = GET_BE_WORD(ccsf3_4->SubstLookupRecord[k].LookupListIndex);
 547                 int SequenceIndex = GET_BE_WORD(ccsf3_4->SubstLookupRecord[k].SequenceIndex) * write_dir;
 548
 549                 TRACE("SUBST: %i -> %i %i\n",k, SequenceIndex, lookupIndex);
 550                 newIndex = GSUB_apply_lookup(lookup, lookupIndex, glyphs, glyph_index + SequenceIndex, write_dir, glyph_count);
 551                 if (newIndex == -1)
 552                 {
 553                     ERR("Chain failed to generate a glyph\n");
 554                     return -1;
 555                 }
 556             }
 557             return newIndex + 1;
 558         }
 559     }
 560     return -1;
 561 }
 562
 563 static INT GSUB_apply_lookup(const GSUB_LookupList* lookup, INT lookup_index, WORD *glyphs, INT glyph_index, INT write_dir, INT *glyph_count)
 564 {
 565     int offset;
 566     const GSUB_LookupTable *look;
 567
 568     offset = GET_BE_WORD(lookup->Lookup[lookup_index]);
 569     look = (const GSUB_LookupTable*)((const BYTE*)lookup + offset);
 570     TRACE("type %i, flag %x, subtables %i\n",GET_BE_WORD(look->LookupType),GET_BE_WORD(look->LookupFlag),GET_BE_WORD(look->SubTableCount));
 571     switch(GET_BE_WORD(look->LookupType))
 572     {
 573         case 1:
 574             return GSUB_apply_SingleSubst(look, glyphs, glyph_index, write_dir, glyph_count);
 575         case 4:
 576             return GSUB_apply_LigatureSubst(look, glyphs, glyph_index, write_dir, glyph_count);
 577         case 6:
 578             return GSUB_apply_ChainContextSubst(lookup, look, glyphs, glyph_index, write_dir, glyph_count);
 579         default:
 580             FIXME("We do not handle SubType %i\n",GET_BE_WORD(look->LookupType));
 581     }
 582     return GSUB_E_NOGLYPH;
 583 }
 584
 585 static INT GSUB_apply_feature(const GSUB_Header * header, const GSUB_Feature* feature, WORD *glyphs, INT glyph_index, INT write_dir, INT *glyph_count)
 586 {
 587     int i;
 588     int out_index = GSUB_E_NOGLYPH;
 589     const GSUB_LookupList *lookup;
 590
 591     lookup = (const GSUB_LookupList*)((const BYTE*)header + GET_BE_WORD(header->LookupList));
 592
 593     TRACE("%i lookups\n", GET_BE_WORD(feature->LookupCount));
 594     for (i = 0; i < GET_BE_WORD(feature->LookupCount); i++)
 595     {
 596         out_index = GSUB_apply_lookup(lookup, GET_BE_WORD(feature->LookupListIndex[i]), glyphs, glyph_index, write_dir, glyph_count);
 597         if (out_index != GSUB_E_NOGLYPH)
 598             break;
 599     }
 600     if (out_index == GSUB_E_NOGLYPH)
 601         TRACE("lookups found no glyphs\n");
 602     return out_index;
 603 }
 604
 605 static const char* get_opentype_script(HDC hdc, SCRIPT_ANALYSIS *psa)
 606 {
 607     UINT charset;
 608
 609     switch (psa->eScript)
 610     {
 611         case Script_Arabic:
 612             return "arab";
 613         case Script_Syriac:
 614             return "syrc";
 615         case Script_Hebrew:
 616             return "hebr";
 617         case Script_Latin:
 618         case Script_Numeric:
 619         case Script_CR:
 620         case Script_LF:
 621             return "latn";
 622     }
 623
 624     /*
 625      * fall back to the font charset
 626      */
 627     charset = GetTextCharsetInfo(hdc, NULL, 0x0);
 628     switch (charset)
 629     {
 630         case ANSI_CHARSET: return "latn";
 631         case BALTIC_CHARSET: return "latn"; /* ?? */
 632         case CHINESEBIG5_CHARSET: return "hani";
 633         case EASTEUROPE_CHARSET: return "latn"; /* ?? */
 634         case GB2312_CHARSET: return "hani";
 635         case GREEK_CHARSET: return "grek";
 636         case HANGUL_CHARSET: return "hang";
 637         case RUSSIAN_CHARSET: return "cyrl";
 638         case SHIFTJIS_CHARSET: return "kana";
 639         case TURKISH_CHARSET: return "latn"; /* ?? */
 640         case VIETNAMESE_CHARSET: return "latn";
 641         case JOHAB_CHARSET: return "latn"; /* ?? */
 642         case ARABIC_CHARSET: return "arab";
 643         case HEBREW_CHARSET: return "hebr";
 644         case THAI_CHARSET: return "thai";
 645         default: return "latn";
 646     }
 647 }
 648
 649 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)
 650 {
 651     const GSUB_Header *header;
 652     const GSUB_Script *script;
 653     const GSUB_LangSys *language;
 654     const GSUB_Feature *feature;
 655
 656     if (!GSUB_Table)
 657         return GSUB_E_NOFEATURE;
 658
 659     header = GSUB_Table;
 660
 661     script = GSUB_get_script_table(header, get_opentype_script(hdc,psa));
 662     if (!script)
 663     {
 664         TRACE("Script not found\n");
 665         return GSUB_E_NOFEATURE;
 666     }
 667     language = GSUB_get_lang_table(script, "xxxx"); /* Need to get Lang tag */
 668     if (!language)
 669     {
 670         TRACE("Language not found\n");
 671         return GSUB_E_NOFEATURE;
 672     }
 673     feature  =  GSUB_get_feature(header, language, feat);
 674     if (!feature)
 675     {
 676         TRACE("%s feature not found\n",feat);
 677         return GSUB_E_NOFEATURE;
 678     }
 679     TRACE("applying feature %s\n",feat);
 680     return GSUB_apply_feature(header, feature, glyphs, index, write_dir, glyph_count);
 681 }
 682
 683 static VOID *load_gsub_table(HDC hdc)
 684 {
 685     VOID* GSUB_Table = NULL;
 686     int length = GetFontData(hdc, GSUB_TAG , 0, NULL, 0);
 687     if (length != GDI_ERROR)
 688     {
 689         GSUB_Table = HeapAlloc(GetProcessHeap(),0,length);
 690         GetFontData(hdc, GSUB_TAG , 0, GSUB_Table, length);
 691         TRACE("Loaded GSUB table of %i bytes\n",length);
 692     }
 693     return GSUB_Table;
 694 }
 695
 696 static int apply_GSUB_feature(HDC hdc, SCRIPT_ANALYSIS *psa, void* GSUB_Table, WORD *pwOutGlyphs, int write_dir, INT* pcGlyphs, const char* feat)
 697 {
 698     int i;
 699
 700     if (GSUB_Table)
 701     {
 702         const GSUB_Header *header;
 703         const GSUB_Script *script;
 704         const GSUB_LangSys *language;
 705         const GSUB_Feature *feature;
 706
 707         if (!GSUB_Table)
 708             return GSUB_E_NOFEATURE;
 709
 710         header = GSUB_Table;
 711
 712         script = GSUB_get_script_table(header, get_opentype_script(hdc,psa));
 713         if (!script)
 714         {
 715             TRACE("Script not found\n");
 716             return GSUB_E_NOFEATURE;
 717         }
 718         language = GSUB_get_lang_table(script, "xxxx");
 719         if (!language)
 720         {
 721             TRACE("Language not found\n");
 722             return GSUB_E_NOFEATURE;
 723         }
 724         feature  =  GSUB_get_feature(header, language, feat);
 725         if (!feature)
 726         {
 727             TRACE("%s feature not found\n",feat);
 728             return GSUB_E_NOFEATURE;
 729         }
 730
 731         i = 0;
 732         TRACE("applying feature %s\n",feat);
 733         while(i < *pcGlyphs)
 734         {
 735                 INT nextIndex;
 736                 nextIndex = GSUB_apply_feature(header, feature, pwOutGlyphs, i, write_dir, pcGlyphs);
 737                 if (nextIndex > GSUB_E_NOGLYPH)
 738                     i = nextIndex;
 739                 else
 740                     i++;
 741         }
 742         return *pcGlyphs;
 743     }
 744     return GSUB_E_NOFEATURE;
 745 }
 746
 747 static CHAR neighbour_joining_type(int i, int delta, const CHAR* context_type, INT cchLen, SCRIPT_ANALYSIS *psa)
 748 {
 749     if (i + delta < 0)
 750     {
 751         if (psa->fLinkBefore)
 752             return jtR;
 753         else
 754             return jtU;
 755     }
 756     if ( i+ delta >= cchLen)
 757     {
 758         if (psa->fLinkAfter)
 759             return jtL;
 760         else
 761             return jtU;
 762     }
 763
 764     i += delta;
 765
 766     if (context_type[i] == jtT)
 767         return neighbour_joining_type(i,delta,context_type,cchLen,psa);
 768     else
 769         return context_type[i];
 770 }
 771
 772 static inline BOOL right_join_causing(CHAR joining_type)
 773 {
 774     return (joining_type == jtL || joining_type == jtD || joining_type == jtC);
 775 }
 776
 777 static inline BOOL left_join_causing(CHAR joining_type)
 778 {
 779     return (joining_type == jtR || joining_type == jtD || joining_type == jtC);
 780 }
 781
 782 /* SHAPE_ShapeArabicGlyphs
 783  */
 784 void SHAPE_ShapeArabicGlyphs(HDC hdc, ScriptCache *psc, SCRIPT_ANALYSIS *psa, WCHAR* pwcChars, INT cChars, WORD* pwOutGlyphs, INT* pcGlyphs, INT cMaxGlyphs)
 785 {
 786     CHAR *context_type;
 787     INT *context_shape;
 788     INT dirR, dirL;
 789     int i;
 790
 791     if (psa->eScript != Script_Arabic)
 792         return;
 793
 794     if (*pcGlyphs != cChars)
 795     {
 796         ERR("Number of Glyphs and Chars need to match at the beginning\n");
 797         return;
 798     }
 799
 800
 801     if (!psa->fLogicalOrder && psa->fRTL)
 802     {
 803         dirR = 1;
 804         dirL = -1;
 805     }
 806     else
 807     {
 808         dirR = -1;
 809         dirL = 1;
 810     }
 811
 812     if (!psc->GSUB_Table)
 813         psc->GSUB_Table = load_gsub_table(hdc);
 814
 815     context_type = HeapAlloc(GetProcessHeap(),0,cChars);
 816     context_shape = HeapAlloc(GetProcessHeap(),0,sizeof(INT) * cChars);
 817
 818     for (i = 0; i < cChars; i++)
 819         context_type[i] = wine_shaping_table[wine_shaping_table[pwcChars[i] >> 8] + (pwcChars[i] & 0xff)];
 820
 821     for (i = 0; i < cChars; i++)
 822     {
 823         if (context_type[i] == jtR && right_join_causing(neighbour_joining_type(i,dirR,context_type,cChars,psa)))
 824             context_shape[i] = Xr;
 825         else if (context_type[i] == jtL && left_join_causing(neighbour_joining_type(i,dirL,context_type,cChars,psa)))
 826             context_shape[i] = Xl;
 827         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)))
 828             context_shape[i] = Xm;
 829         else if (context_type[i] == jtD && right_join_causing(neighbour_joining_type(i,dirR,context_type,cChars,psa)))
 830             context_shape[i] = Xr;
 831         else if (context_type[i] == jtD && left_join_causing(neighbour_joining_type(i,dirL,context_type,cChars,psa)))
 832             context_shape[i] = Xl;
 833         else
 834             context_shape[i] = Xn;
 835     }
 836
 837     /* Contextual Shaping */
 838     i = 0;
 839     while(i < *pcGlyphs)
 840     {
 841         BOOL shaped = FALSE;
 842
 843         if (psc->GSUB_Table)
 844         {
 845             INT nextIndex;
 846             nextIndex = apply_GSUB_feature_to_glyph(hdc, psa, psc->GSUB_Table, pwOutGlyphs, i, dirL, pcGlyphs, contextual_features[context_shape[i]]);
 847             if (nextIndex > GSUB_E_NOGLYPH)
 848                 i = nextIndex;
 849             shaped = (nextIndex > GSUB_E_NOGLYPH);
 850         }
 851
 852         if (!shaped)
 853         {
 854             WORD newGlyph = pwOutGlyphs[i];
 855             if (pwcChars[i] >= FIRST_ARABIC_CHAR && pwcChars[i] <= LAST_ARABIC_CHAR)
 856             {
 857                 /* fall back to presentation form B */
 858                 WCHAR context_char = wine_shaping_forms[pwcChars[i] - FIRST_ARABIC_CHAR][context_shape[i]];
 859                 if (context_char != pwcChars[i] && GetGlyphIndicesW(hdc, &context_char, 1, &newGlyph, 0) != GDI_ERROR && newGlyph != 0x0000)
 860                     pwOutGlyphs[i] = newGlyph;
 861             }
 862             i++;
 863         }
 864     }
 865
 866     i = 0;
 867     while (arabic_GSUB_features[i] != NULL)
 868     {
 869         apply_GSUB_feature(hdc, psa, psc->GSUB_Table, pwOutGlyphs, dirL, pcGlyphs, arabic_GSUB_features[i]);
 870         i++;
 871     }
 872
 873     HeapFree(GetProcessHeap(),0,context_shape);
 874     HeapFree(GetProcessHeap(),0,context_type);
 875 }