icuSources/layout/LookupProcessor.cpp

   1 /*
   2  *
   3  * (C) Copyright IBM Corp. 1998-2011 - 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     le_uint16 lookupFlags = SWAPW(lookupTable->lookupFlags);
 103     GlyphIterator tempIterator(*glyphIterator, lookupFlags);
 104     le_uint32 delta = applyLookupTable(lookupTable, &tempIterator, fontInstance, success);
 105
 106     return delta;
 107 }
 108
 109 le_int32 LookupProcessor::selectLookups(const FeatureTable *featureTable, FeatureMask featureMask, le_int32 order)
 110 {
 111     le_uint16 lookupCount = featureTable? SWAPW(featureTable->lookupCount) : 0;
 112     le_int32  store = order;
 113
 114     for (le_uint16 lookup = 0; lookup < lookupCount; lookup += 1) {
 115         le_uint16 lookupListIndex = SWAPW(featureTable->lookupListIndexArray[lookup]);
 116         if (lookupListIndex >= lookupSelectCount) {
 117             continue;
 118         }
 119
 120         lookupSelectArray[lookupListIndex] |= featureMask;
 121         lookupOrderArray[store++] = lookupListIndex;
 122     }
 123
 124     return store - order;
 125 }
 126
 127 LookupProcessor::LookupProcessor(const char *baseAddress,
 128         Offset scriptListOffset, Offset featureListOffset, Offset lookupListOffset,
 129         LETag scriptTag, LETag languageTag, const FeatureMap *featureMap, le_int32 featureMapCount, le_bool orderFeatures,
 130         LEErrorCode& success)
 131     : lookupListTable(NULL), featureListTable(NULL), lookupSelectArray(NULL), lookupSelectCount(0),
 132       lookupOrderArray(NULL), lookupOrderCount(0)
 133 {
 134     const ScriptListTable *scriptListTable = NULL;
 135     const LangSysTable *langSysTable = NULL;
 136     le_uint16 featureCount = 0;
 137     le_uint16 lookupListCount = 0;
 138     le_uint16 requiredFeatureIndex;
 139
 140     if (LE_FAILURE(success)) {
 141         return;
 142     }
 143
 144     if (scriptListOffset != 0) {
 145         scriptListTable = (const ScriptListTable *) (baseAddress + scriptListOffset);
 146         langSysTable = scriptListTable->findLanguage(scriptTag, languageTag);
 147
 148         if (langSysTable != 0) {
 149             featureCount = SWAPW(langSysTable->featureCount);
 150         }
 151     }
 152
 153     if (featureListOffset != 0) {
 154         featureListTable = (const FeatureListTable *) (baseAddress + featureListOffset);
 155     }
 156
 157     if (lookupListOffset != 0) {
 158         lookupListTable = (const LookupListTable *) (baseAddress + lookupListOffset);
 159         lookupListCount = SWAPW(lookupListTable->lookupCount);
 160     }
 161
 162     if (langSysTable == NULL || featureListTable == NULL || lookupListTable == NULL ||
 163         featureCount == 0 || lookupListCount == 0) {
 164         return;
 165     }
 166
 167     requiredFeatureIndex = SWAPW(langSysTable->reqFeatureIndex);
 168
 169     lookupSelectArray = LE_NEW_ARRAY(FeatureMask, lookupListCount);
 170     if (lookupSelectArray == NULL) {
 171         success = LE_MEMORY_ALLOCATION_ERROR;
 172         return;
 173     }
 174
 175     for (int i = 0; i < lookupListCount; i += 1) {
 176         lookupSelectArray[i] = 0;
 177     }
 178     lookupSelectCount = lookupListCount;
 179
 180     le_int32 count, order = 0;
 181     le_int32 featureReferences = 0;
 182     const FeatureTable *featureTable = NULL;
 183     LETag featureTag;
 184
 185     const FeatureTable *requiredFeatureTable = NULL;
 186     LETag requiredFeatureTag = 0x00000000U;
 187
 188     // Count the total number of lookups referenced by all features. This will
 189     // be the maximum number of entries in the lookupOrderArray. We can't use
 190     // lookupListCount because some lookups might be referenced by more than
 191     // one feature.
 192     for (le_int32 feature = 0; feature < featureCount; feature += 1) {
 193         le_uint16 featureIndex = SWAPW(langSysTable->featureIndexArray[feature]);
 194
 195         featureTable = featureListTable->getFeatureTable(featureIndex, &featureTag);
 196         if (!featureTable) {
 197              continue;
 198         }
 199         featureReferences += SWAPW(featureTable->lookupCount);
 200     }
 201
 202     if (requiredFeatureIndex != 0xFFFF) {
 203         requiredFeatureTable = featureListTable->getFeatureTable(requiredFeatureIndex, &requiredFeatureTag);
 204         featureReferences += SWAPW(featureTable->lookupCount);
 205     }
 206
 207     lookupOrderArray = LE_NEW_ARRAY(le_uint16, featureReferences);
 208     if (lookupOrderArray == NULL) {
 209         success = LE_MEMORY_ALLOCATION_ERROR;
 210         return;
 211     }
 212
 213     for (le_int32 f = 0; f < featureMapCount; f += 1) {
 214         FeatureMap fm = featureMap[f];
 215         count = 0;
 216
 217         // If this is the required feature, add its lookups
 218         if (requiredFeatureTag == fm.tag) {
 219             count += selectLookups(requiredFeatureTable, fm.mask, order);
 220         }
 221
 222         if (orderFeatures) {
 223             // If we added lookups from the required feature, sort them
 224             if (count > 1) {
 225                 OpenTypeUtilities::sort(lookupOrderArray, order);
 226             }
 227
 228             for (le_uint16 feature = 0; feature < featureCount; feature += 1) {
 229                 le_uint16 featureIndex = SWAPW(langSysTable->featureIndexArray[feature]);
 230
 231                 // don't add the required feature to the list more than once...
 232                 // TODO: Do we need this check? (Spec. says required feature won't be in feature list...)
 233                 if (featureIndex == requiredFeatureIndex) {
 234                     continue;
 235                 }
 236
 237                 featureTable = featureListTable->getFeatureTable(featureIndex, &featureTag);
 238
 239                 if (featureTag == fm.tag) {
 240                     count += selectLookups(featureTable, fm.mask, order + count);
 241                 }
 242             }
 243
 244             if (count > 1) {
 245                 OpenTypeUtilities::sort(&lookupOrderArray[order], count);
 246             }
 247
 248             order += count;
 249         } else {
 250             for (le_uint16 feature = 0; feature < featureCount; feature += 1) {
 251                 le_uint16 featureIndex = SWAPW(langSysTable->featureIndexArray[feature]);
 252
 253                 // don't add the required feature to the list more than once...
 254                 // NOTE: This check is commented out because the spec. says that
 255                 // the required feature won't be in the feature list, and because
 256                 // any duplicate entries will be removed below.
 257 #if 0
 258                 if (featureIndex == requiredFeatureIndex) {
 259                     continue;
 260                 }
 261 #endif
 262
 263                 featureTable = featureListTable->getFeatureTable(featureIndex, &featureTag);
 264
 265                 if (featureTag == fm.tag) {
 266                     order += selectLookups(featureTable, fm.mask, order);
 267                 }
 268             }
 269         }
 270     }
 271
 272     if (!orderFeatures && (order > 1)) {
 273         OpenTypeUtilities::sort(lookupOrderArray, order);
 274
 275         // If there's no specified feature order,
 276         // we will apply the lookups in the order
 277         // that they're in the font. If a particular
 278         // lookup may be referenced by more than one feature,
 279         // it will apprear in the lookupOrderArray more than
 280         // once, so remove any duplicate entries in the sorted array.
 281         le_int32 out = 1;
 282
 283         for (le_int32 in = 1; in < order; in += 1) {
 284             if (lookupOrderArray[out - 1] != lookupOrderArray[in]) {
 285                 if (out != in) {
 286                     lookupOrderArray[out] = lookupOrderArray[in];
 287                 }
 288
 289                 out += 1;
 290             }
 291         }
 292
 293         order = out;
 294     }
 295
 296     lookupOrderCount = order;
 297 }
 298
 299 LookupProcessor::LookupProcessor()
 300 {
 301         lookupOrderArray = NULL;
 302         lookupSelectArray = NULL;
 303 }
 304
 305 LookupProcessor::~LookupProcessor()
 306 {
 307     LE_DELETE_ARRAY(lookupOrderArray);
 308     LE_DELETE_ARRAY(lookupSelectArray);
 309 }
 310
 311 U_NAMESPACE_END