icuSources/layout/LookupProcessor.cpp

   1 /*
   2  *
   3  * (C) Copyright IBM Corp. and others 1998-2013 - All Rights Reserved
   4  *
   5  */
   6
   7 #include "LETypes.h"
   8 #include "OpenTypeUtilities.h"
   9 #include "LEFontInstance.h"
  10 #include "OpenTypeTables.h"
  11 #include "ICUFeatures.h"
  12 #include "Lookups.h"
  13 #include "ScriptAndLanguage.h"
  14 #include "GlyphDefinitionTables.h"
  15 #include "GlyphIterator.h"
  16 #include "LookupProcessor.h"
  17 #include "LEGlyphStorage.h"
  18 #include "LESwaps.h"
  19
  20 U_NAMESPACE_BEGIN
  21
  22 le_uint32 LookupProcessor::applyLookupTable(const LookupTable *lookupTable, GlyphIterator *glyphIterator,
  23                                          const LEFontInstance *fontInstance, LEErrorCode& success) const
  24 {
  25     if (LE_FAILURE(success)) {
  26         return 0;
  27     }
  28
  29     le_uint16 lookupType = SWAPW(lookupTable->lookupType);
  30     le_uint16 subtableCount = SWAPW(lookupTable->subTableCount);
  31     le_int32 startPosition = glyphIterator->getCurrStreamPosition();
  32     le_uint32 delta;
  33
  34     for (le_uint16 subtable = 0; subtable < subtableCount; subtable += 1) {
  35         const LookupSubtable *lookupSubtable = lookupTable->getLookupSubtable(subtable);
  36
  37         delta = applySubtable(lookupSubtable, lookupType, glyphIterator, fontInstance, success);
  38
  39         if (delta > 0 && LE_FAILURE(success)) {
  40             return 1;
  41         }
  42
  43         glyphIterator->setCurrStreamPosition(startPosition);
  44     }
  45
  46     return 1;
  47 }
  48
  49 le_int32 LookupProcessor::process(LEGlyphStorage &glyphStorage, GlyphPositionAdjustments *glyphPositionAdjustments,
  50                               le_bool rightToLeft, const GlyphDefinitionTableHeader *glyphDefinitionTableHeader,
  51                               const LEFontInstance *fontInstance, LEErrorCode& success) const
  52 {
  53     if (LE_FAILURE(success)) {
  54         return 0;
  55     }
  56
  57     le_int32 glyphCount = glyphStorage.getGlyphCount();
  58
  59     if (lookupSelectArray == NULL) {
  60         return glyphCount;
  61     }
  62
  63     GlyphIterator glyphIterator(glyphStorage, glyphPositionAdjustments,
  64                                 rightToLeft, 0, 0, glyphDefinitionTableHeader);
  65     le_int32 newGlyphCount = glyphCount;
  66
  67     for (le_uint16 order = 0; order < lookupOrderCount; order += 1) {
  68         le_uint16 lookup = lookupOrderArray[order];
  69         FeatureMask selectMask = lookupSelectArray[lookup];
  70
  71         if (selectMask != 0) {
  72             const LookupTable *lookupTable = lookupListTable->getLookupTable(lookup);
  73             if (!lookupTable) {
  74                 continue;
  75             }
  76             le_uint16 lookupFlags = SWAPW(lookupTable->lookupFlags);
  77
  78             glyphIterator.reset(lookupFlags, selectMask);
  79
  80             while (glyphIterator.findFeatureTag()) {
  81                 applyLookupTable(lookupTable, &glyphIterator, fontInstance, success);
  82                 if (LE_FAILURE(success)) {
  83                     return 0;
  84                 }
  85             }
  86
  87             newGlyphCount = glyphIterator.applyInsertions();
  88         }
  89     }
  90
  91     return newGlyphCount;
  92 }
  93
  94 le_uint32 LookupProcessor::applySingleLookup(le_uint16 lookupTableIndex, GlyphIterator *glyphIterator,
  95                                           const LEFontInstance *fontInstance, LEErrorCode& success) const
  96 {
  97     if (LE_FAILURE(success)) {
  98         return 0;
  99     }
 100
 101     const LookupTable *lookupTable = lookupListTable->getLookupTable(lookupTableIndex);
 102     if (lookupTable == NULL) {
 103         success = LE_INTERNAL_ERROR;
 104         return 0;
 105     }
 106     le_uint16 lookupFlags = SWAPW(lookupTable->lookupFlags);
 107     GlyphIterator tempIterator(*glyphIterator, lookupFlags);
 108     le_uint32 delta = applyLookupTable(lookupTable, &tempIterator, fontInstance, success);
 109
 110     return delta;
 111 }
 112
 113 le_int32 LookupProcessor::selectLookups(const FeatureTable *featureTable, FeatureMask featureMask, le_int32 order)
 114 {
 115     le_uint16 lookupCount = featureTable? SWAPW(featureTable->lookupCount) : 0;
 116     le_int32  store = order;
 117
 118     for (le_uint16 lookup = 0; lookup < lookupCount; lookup += 1) {
 119         le_uint16 lookupListIndex = SWAPW(featureTable->lookupListIndexArray[lookup]);
 120         if (lookupListIndex >= lookupSelectCount) {
 121             continue;
 122         }
 123
 124         lookupSelectArray[lookupListIndex] |= featureMask;
 125         lookupOrderArray[store++] = lookupListIndex;
 126     }
 127
 128     return store - order;
 129 }
 130
 131 LookupProcessor::LookupProcessor(const char *baseAddress,
 132         Offset scriptListOffset, Offset featureListOffset, Offset lookupListOffset,
 133         LETag scriptTag, LETag languageTag, const FeatureMap *featureMap, le_int32 featureMapCount, le_bool orderFeatures,
 134         LEErrorCode& success)
 135     : lookupListTable(NULL), featureListTable(NULL), lookupSelectArray(NULL), lookupSelectCount(0),
 136       lookupOrderArray(NULL), lookupOrderCount(0)
 137 {
 138     const ScriptListTable *scriptListTable = NULL;
 139     const LangSysTable *langSysTable = NULL;
 140     le_uint16 featureCount = 0;
 141     le_uint16 lookupListCount = 0;
 142     le_uint16 requiredFeatureIndex;
 143
 144     if (LE_FAILURE(success)) {
 145         return;
 146     }
 147
 148     if (scriptListOffset != 0) {
 149         scriptListTable = (const ScriptListTable *) (baseAddress + scriptListOffset);
 150         langSysTable = scriptListTable->findLanguage(scriptTag, languageTag);
 151
 152         if (langSysTable != 0) {
 153             featureCount = SWAPW(langSysTable->featureCount);
 154         }
 155     }
 156
 157     if (featureListOffset != 0) {
 158         featureListTable = (const FeatureListTable *) (baseAddress + featureListOffset);
 159     }
 160
 161     if (lookupListOffset != 0) {
 162         lookupListTable = (const LookupListTable *) (baseAddress + lookupListOffset);
 163         lookupListCount = SWAPW(lookupListTable->lookupCount);
 164     }
 165
 166     if (langSysTable == NULL || featureListTable == NULL || lookupListTable == NULL ||
 167         featureCount == 0 || lookupListCount == 0) {
 168         return;
 169     }
 170
 171     requiredFeatureIndex = SWAPW(langSysTable->reqFeatureIndex);
 172
 173     lookupSelectArray = LE_NEW_ARRAY(FeatureMask, lookupListCount);
 174     if (lookupSelectArray == NULL) {
 175         success = LE_MEMORY_ALLOCATION_ERROR;
 176         return;
 177     }
 178
 179     for (int i = 0; i < lookupListCount; i += 1) {
 180         lookupSelectArray[i] = 0;
 181     }
 182     lookupSelectCount = lookupListCount;
 183
 184     le_int32 count, order = 0;
 185     le_int32 featureReferences = 0;
 186     const FeatureTable *featureTable = NULL;
 187     LETag featureTag;
 188
 189     const FeatureTable *requiredFeatureTable = NULL;
 190     LETag requiredFeatureTag = 0x00000000U;
 191
 192     // Count the total number of lookups referenced by all features. This will
 193     // be the maximum number of entries in the lookupOrderArray. We can't use
 194     // lookupListCount because some lookups might be referenced by more than
 195     // one feature.
 196     for (le_int32 feature = 0; feature < featureCount; feature += 1) {
 197         le_uint16 featureIndex = SWAPW(langSysTable->featureIndexArray[feature]);
 198
 199         featureTable = featureListTable->getFeatureTable(featureIndex, &featureTag);
 200         if (!featureTable) {
 201              continue;
 202         }
 203         featureReferences += SWAPW(featureTable->lookupCount);
 204     }
 205
 206     if (!featureTable) {
 207         success = LE_INTERNAL_ERROR;
 208         return;
 209     }
 210
 211     if (requiredFeatureIndex != 0xFFFF) {
 212         requiredFeatureTable = featureListTable->getFeatureTable(requiredFeatureIndex, &requiredFeatureTag);
 213         featureReferences += SWAPW(featureTable->lookupCount);
 214     }
 215
 216     lookupOrderArray = LE_NEW_ARRAY(le_uint16, featureReferences);
 217     if (lookupOrderArray == NULL) {
 218         success = LE_MEMORY_ALLOCATION_ERROR;
 219         return;
 220     }
 221
 222     for (le_int32 f = 0; f < featureMapCount; f += 1) {
 223         FeatureMap fm = featureMap[f];
 224         count = 0;
 225
 226         // If this is the required feature, add its lookups
 227         if (requiredFeatureTag == fm.tag) {
 228             count += selectLookups(requiredFeatureTable, fm.mask, order);
 229         }
 230
 231         if (orderFeatures) {
 232             // If we added lookups from the required feature, sort them
 233             if (count > 1) {
 234                 OpenTypeUtilities::sort(lookupOrderArray, order);
 235             }
 236
 237             for (le_uint16 feature = 0; feature < featureCount; feature += 1) {
 238                 le_uint16 featureIndex = SWAPW(langSysTable->featureIndexArray[feature]);
 239
 240                 // don't add the required feature to the list more than once...
 241                 // TODO: Do we need this check? (Spec. says required feature won't be in feature list...)
 242                 if (featureIndex == requiredFeatureIndex) {
 243                     continue;
 244                 }
 245
 246                 featureTable = featureListTable->getFeatureTable(featureIndex, &featureTag);
 247
 248                 if (featureTag == fm.tag) {
 249                     count += selectLookups(featureTable, fm.mask, order + count);
 250                 }
 251             }
 252
 253             if (count > 1) {
 254                 OpenTypeUtilities::sort(&lookupOrderArray[order], count);
 255             }
 256
 257             order += count;
 258         } else {
 259             for (le_uint16 feature = 0; feature < featureCount; feature += 1) {
 260                 le_uint16 featureIndex = SWAPW(langSysTable->featureIndexArray[feature]);
 261
 262                 // don't add the required feature to the list more than once...
 263                 // NOTE: This check is commented out because the spec. says that
 264                 // the required feature won't be in the feature list, and because
 265                 // any duplicate entries will be removed below.
 266 #if 0
 267                 if (featureIndex == requiredFeatureIndex) {
 268                     continue;
 269                 }
 270 #endif
 271
 272                 featureTable = featureListTable->getFeatureTable(featureIndex, &featureTag);
 273
 274                 if (featureTag == fm.tag) {
 275                     order += selectLookups(featureTable, fm.mask, order);
 276                 }
 277             }
 278         }
 279     }
 280
 281     if (!orderFeatures && (order > 1)) {
 282         OpenTypeUtilities::sort(lookupOrderArray, order);
 283
 284         // If there's no specified feature order,
 285         // we will apply the lookups in the order
 286         // that they're in the font. If a particular
 287         // lookup may be referenced by more than one feature,
 288         // it will apprear in the lookupOrderArray more than
 289         // once, so remove any duplicate entries in the sorted array.
 290         le_int32 out = 1;
 291
 292         for (le_int32 in = 1; in < order; in += 1) {
 293             if (lookupOrderArray[out - 1] != lookupOrderArray[in]) {
 294                 if (out != in) {
 295                     lookupOrderArray[out] = lookupOrderArray[in];
 296                 }
 297
 298                 out += 1;
 299             }
 300         }
 301
 302         order = out;
 303     }
 304
 305     lookupOrderCount = order;
 306 }
 307
 308 LookupProcessor::LookupProcessor()
 309 {
 310         lookupOrderArray = NULL;
 311         lookupSelectArray = NULL;
 312 }
 313
 314 LookupProcessor::~LookupProcessor()
 315 {
 316     LE_DELETE_ARRAY(lookupOrderArray);
 317     LE_DELETE_ARRAY(lookupSelectArray);
 318 }
 319
 320 U_NAMESPACE_END