icuSources/layout/LookupProcessor.cpp

   1 /*
   2  *
   3  * (C) Copyright IBM Corp. 1998-2010 - 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             le_uint16 lookupFlags = SWAPW(lookupTable->lookupFlags);
  74
  75             glyphIterator.reset(lookupFlags, selectMask);
  76
  77             while (glyphIterator.findFeatureTag()) {
  78                 applyLookupTable(lookupTable, &glyphIterator, fontInstance, success);
  79                 if (LE_FAILURE(success)) {
  80                     return 0;
  81                 }
  82             }
  83
  84             newGlyphCount = glyphIterator.applyInsertions();
  85         }
  86     }
  87
  88     return newGlyphCount;
  89 }
  90
  91 le_uint32 LookupProcessor::applySingleLookup(le_uint16 lookupTableIndex, GlyphIterator *glyphIterator,
  92                                           const LEFontInstance *fontInstance, LEErrorCode& success) const
  93 {
  94     if (LE_FAILURE(success)) {
  95         return 0;
  96     }
  97
  98     const LookupTable *lookupTable = lookupListTable->getLookupTable(lookupTableIndex);
  99     le_uint16 lookupFlags = SWAPW(lookupTable->lookupFlags);
 100     GlyphIterator tempIterator(*glyphIterator, lookupFlags);
 101     le_uint32 delta = applyLookupTable(lookupTable, &tempIterator, fontInstance, success);
 102
 103     return delta;
 104 }
 105
 106 le_int32 LookupProcessor::selectLookups(const FeatureTable *featureTable, FeatureMask featureMask, le_int32 order)
 107 {
 108     le_uint16 lookupCount = featureTable? SWAPW(featureTable->lookupCount) : 0;
 109     le_int32  store = order;
 110
 111     for (le_uint16 lookup = 0; lookup < lookupCount; lookup += 1) {
 112         le_uint16 lookupListIndex = SWAPW(featureTable->lookupListIndexArray[lookup]);
 113
 114         lookupSelectArray[lookupListIndex] |= featureMask;
 115         lookupOrderArray[store++] = lookupListIndex;
 116     }
 117
 118     return store - order;
 119 }
 120
 121 LookupProcessor::LookupProcessor(const char *baseAddress,
 122         Offset scriptListOffset, Offset featureListOffset, Offset lookupListOffset,
 123         LETag scriptTag, LETag languageTag, const FeatureMap *featureMap, le_int32 featureMapCount, le_bool orderFeatures,
 124         LEErrorCode& success)
 125     : lookupListTable(NULL), featureListTable(NULL), lookupSelectArray(NULL),
 126       lookupOrderArray(NULL), lookupOrderCount(0)
 127 {
 128     const ScriptListTable *scriptListTable = NULL;
 129     const LangSysTable *langSysTable = NULL;
 130     le_uint16 featureCount = 0;
 131     le_uint16 lookupListCount = 0;
 132     le_uint16 requiredFeatureIndex;
 133
 134     if (LE_FAILURE(success)) {
 135         return;
 136     }
 137
 138     if (scriptListOffset != 0) {
 139         scriptListTable = (const ScriptListTable *) (baseAddress + scriptListOffset);
 140         langSysTable = scriptListTable->findLanguage(scriptTag, languageTag);
 141
 142         if (langSysTable != 0) {
 143             featureCount = SWAPW(langSysTable->featureCount);
 144         }
 145     }
 146
 147     if (featureListOffset != 0) {
 148         featureListTable = (const FeatureListTable *) (baseAddress + featureListOffset);
 149     }
 150
 151     if (lookupListOffset != 0) {
 152         lookupListTable = (const LookupListTable *) (baseAddress + lookupListOffset);
 153         lookupListCount = SWAPW(lookupListTable->lookupCount);
 154     }
 155
 156     if (langSysTable == NULL || featureListTable == NULL || lookupListTable == NULL ||
 157         featureCount == 0 || lookupListCount == 0) {
 158         return;
 159     }
 160
 161     requiredFeatureIndex = SWAPW(langSysTable->reqFeatureIndex);
 162
 163     lookupSelectArray = LE_NEW_ARRAY(FeatureMask, lookupListCount);
 164     if (lookupSelectArray == NULL) {
 165         success = LE_MEMORY_ALLOCATION_ERROR;
 166         return;
 167     }
 168
 169     for (int i = 0; i < lookupListCount; i += 1) {
 170         lookupSelectArray[i] = 0;
 171     }
 172
 173     le_int32 count, order = 0;
 174     le_int32 featureReferences = 0;
 175     const FeatureTable *featureTable = NULL;
 176     LETag featureTag;
 177
 178     const FeatureTable *requiredFeatureTable = NULL;
 179     LETag requiredFeatureTag = 0x00000000U;
 180
 181     // Count the total number of lookups referenced by all features. This will
 182     // be the maximum number of entries in the lookupOrderArray. We can't use
 183     // lookupListCount because some lookups might be referenced by more than
 184     // one feature.
 185     for (le_int32 feature = 0; feature < featureCount; feature += 1) {
 186         le_uint16 featureIndex = SWAPW(langSysTable->featureIndexArray[feature]);
 187
 188         featureTable = featureListTable->getFeatureTable(featureIndex, &featureTag);
 189         featureReferences += SWAPW(featureTable->lookupCount);
 190     }
 191
 192     if (requiredFeatureIndex != 0xFFFF) {
 193         requiredFeatureTable = featureListTable->getFeatureTable(requiredFeatureIndex, &requiredFeatureTag);
 194         featureReferences += SWAPW(featureTable->lookupCount);
 195     }
 196
 197     lookupOrderArray = LE_NEW_ARRAY(le_uint16, featureReferences);
 198     if (lookupOrderArray == NULL) {
 199         success = LE_MEMORY_ALLOCATION_ERROR;
 200         return;
 201     }
 202
 203     for (le_int32 f = 0; f < featureMapCount; f += 1) {
 204         FeatureMap fm = featureMap[f];
 205         count = 0;
 206
 207         // If this is the required feature, add its lookups
 208         if (requiredFeatureTag == fm.tag) {
 209             count += selectLookups(requiredFeatureTable, fm.mask, order);
 210         }
 211
 212         if (orderFeatures) {
 213             // If we added lookups from the required feature, sort them
 214             if (count > 1) {
 215                 OpenTypeUtilities::sort(lookupOrderArray, order);
 216             }
 217
 218             for (le_uint16 feature = 0; feature < featureCount; feature += 1) {
 219                 le_uint16 featureIndex = SWAPW(langSysTable->featureIndexArray[feature]);
 220
 221                 // don't add the required feature to the list more than once...
 222                 // TODO: Do we need this check? (Spec. says required feature won't be in feature list...)
 223                 if (featureIndex == requiredFeatureIndex) {
 224                     continue;
 225                 }
 226
 227                 featureTable = featureListTable->getFeatureTable(featureIndex, &featureTag);
 228
 229                 if (featureTag == fm.tag) {
 230                     count += selectLookups(featureTable, fm.mask, order + count);
 231                 }
 232             }
 233
 234             if (count > 1) {
 235                 OpenTypeUtilities::sort(&lookupOrderArray[order], count);
 236             }
 237
 238             order += count;
 239         } else {
 240             for (le_uint16 feature = 0; feature < featureCount; feature += 1) {
 241                 le_uint16 featureIndex = SWAPW(langSysTable->featureIndexArray[feature]);
 242
 243                 // don't add the required feature to the list more than once...
 244                 // NOTE: This check is commented out because the spec. says that
 245                 // the required feature won't be in the feature list, and because
 246                 // any duplicate entries will be removed below.
 247 #if 0
 248                 if (featureIndex == requiredFeatureIndex) {
 249                     continue;
 250                 }
 251 #endif
 252
 253                 featureTable = featureListTable->getFeatureTable(featureIndex, &featureTag);
 254
 255                 if (featureTag == fm.tag) {
 256                     order += selectLookups(featureTable, fm.mask, order);
 257                 }
 258             }
 259         }
 260     }
 261
 262     if (!orderFeatures && (order > 1)) {
 263         OpenTypeUtilities::sort(lookupOrderArray, order);
 264
 265         // If there's no specified feature order,
 266         // we will apply the lookups in the order
 267         // that they're in the font. If a particular
 268         // lookup may be referenced by more than one feature,
 269         // it will apprear in the lookupOrderArray more than
 270         // once, so remove any duplicate entries in the sorted array.
 271         le_int32 out = 1;
 272
 273         for (le_int32 in = 1; in < order; in += 1) {
 274             if (lookupOrderArray[out - 1] != lookupOrderArray[in]) {
 275                 if (out != in) {
 276                     lookupOrderArray[out] = lookupOrderArray[in];
 277                 }
 278
 279                 out += 1;
 280             }
 281         }
 282
 283         order = out;
 284     }
 285
 286     lookupOrderCount = order;
 287 }
 288
 289 LookupProcessor::LookupProcessor()
 290 {
 291         lookupOrderArray = NULL;
 292         lookupSelectArray = NULL;
 293 }
 294
 295 LookupProcessor::~LookupProcessor()
 296 {
 297     LE_DELETE_ARRAY(lookupOrderArray);
 298     LE_DELETE_ARRAY(lookupSelectArray);
 299 }
 300
 301 U_NAMESPACE_END