icuSources/layout/PairPositioningSubtables.cpp

   1 /*
   2  *
   3  * (C) Copyright IBM Corp. 1998-2013 - All Rights Reserved
   4  *
   5  */
   6
   7 #include "LETypes.h"
   8 #include "LEFontInstance.h"
   9 #include "OpenTypeTables.h"
  10 #include "GlyphPositioningTables.h"
  11 #include "PairPositioningSubtables.h"
  12 #include "ValueRecords.h"
  13 #include "GlyphIterator.h"
  14 #include "OpenTypeUtilities.h"
  15 #include "LESwaps.h"
  16
  17 U_NAMESPACE_BEGIN
  18
  19 le_uint32 PairPositioningSubtable::process(const LEReferenceTo<PairPositioningSubtable> &base, GlyphIterator *glyphIterator, const LEFontInstance *fontInstance, LEErrorCode &success) const
  20 {
  21     switch(SWAPW(subtableFormat))
  22     {
  23     case 0:
  24         return 0;
  25
  26     case 1:
  27     {
  28       const LEReferenceTo<PairPositioningFormat1Subtable> subtable(base, success, (const PairPositioningFormat1Subtable *) this);
  29
  30       if(LE_SUCCESS(success))
  31       return subtable->process(subtable, glyphIterator, fontInstance, success);
  32       else
  33         return 0;
  34     }
  35
  36     case 2:
  37     {
  38       const LEReferenceTo<PairPositioningFormat2Subtable> subtable(base, success, (const PairPositioningFormat2Subtable *) this);
  39
  40       if(LE_SUCCESS(success))
  41       return subtable->process(subtable, glyphIterator, fontInstance, success);
  42       else
  43         return 0;
  44     }
  45     default:
  46       return 0;
  47     }
  48 }
  49
  50 le_uint32 PairPositioningFormat1Subtable::process(const LEReferenceTo<PairPositioningFormat1Subtable> &base, GlyphIterator *glyphIterator, const LEFontInstance *fontInstance, LEErrorCode &success) const
  51 {
  52     LEGlyphID firstGlyph = glyphIterator->getCurrGlyphID();
  53     le_int32 coverageIndex = getGlyphCoverage(base, firstGlyph, success);
  54     GlyphIterator tempIterator(*glyphIterator);
  55
  56     if (coverageIndex >= 0 && glyphIterator->next()) {
  57         Offset pairSetTableOffset = SWAPW(pairSetTableOffsetArray[coverageIndex]);
  58         PairSetTable *pairSetTable = (PairSetTable *) ((char *) this + pairSetTableOffset);
  59         le_uint16 pairValueCount = SWAPW(pairSetTable->pairValueCount);
  60         le_int16 valueRecord1Size = ValueRecord::getSize(SWAPW(valueFormat1));
  61         le_int16 valueRecord2Size = ValueRecord::getSize(SWAPW(valueFormat2));
  62         le_int16 recordSize = sizeof(PairValueRecord) - sizeof(ValueRecord) + valueRecord1Size + valueRecord2Size;
  63         LEGlyphID secondGlyph = glyphIterator->getCurrGlyphID();
  64         const PairValueRecord *pairValueRecord = NULL;
  65
  66         if (pairValueCount != 0) {
  67             pairValueRecord = findPairValueRecord((TTGlyphID) LE_GET_GLYPH(secondGlyph), pairSetTable->pairValueRecordArray, pairValueCount, recordSize);
  68         }
  69
  70         if (pairValueRecord == NULL) {
  71             return 0;
  72         }
  73
  74         if (valueFormat1 != 0) {
  75             pairValueRecord->valueRecord1.adjustPosition(SWAPW(valueFormat1), (char *) this, tempIterator, fontInstance);
  76         }
  77
  78         if (valueFormat2 != 0) {
  79             const ValueRecord *valueRecord2 = (const ValueRecord *) ((char *) &pairValueRecord->valueRecord1 + valueRecord1Size);
  80
  81             valueRecord2->adjustPosition(SWAPW(valueFormat2), (char *) this, *glyphIterator, fontInstance);
  82         }
  83
  84         // back up glyphIterator so second glyph can be
  85         // first glyph in the next pair
  86         glyphIterator->prev();
  87         return 1;
  88     }
  89
  90     return 0;
  91 }
  92
  93 le_uint32 PairPositioningFormat2Subtable::process(const LEReferenceTo<PairPositioningFormat2Subtable> &base, GlyphIterator *glyphIterator, const LEFontInstance *fontInstance, LEErrorCode &success) const
  94 {
  95     LEGlyphID firstGlyph = glyphIterator->getCurrGlyphID();
  96     le_int32 coverageIndex = getGlyphCoverage(base, firstGlyph, success);
  97     GlyphIterator tempIterator(*glyphIterator);
  98
  99     if (coverageIndex >= 0 && glyphIterator->next()) {
 100         LEGlyphID secondGlyph = glyphIterator->getCurrGlyphID();
 101         const ClassDefinitionTable *classDef1 = (const ClassDefinitionTable *) ((char *) this + SWAPW(classDef1Offset));
 102         const ClassDefinitionTable *classDef2 = (const ClassDefinitionTable *) ((char *) this + SWAPW(classDef2Offset));
 103         le_int32 class1 = classDef1->getGlyphClass(firstGlyph);
 104         le_int32 class2 = classDef2->getGlyphClass(secondGlyph);
 105         le_int16 valueRecord1Size = ValueRecord::getSize(SWAPW(valueFormat1));
 106         le_int16 valueRecord2Size = ValueRecord::getSize(SWAPW(valueFormat2));
 107         le_int16 class2RecordSize = valueRecord1Size + valueRecord2Size;
 108         le_int16 class1RecordSize = class2RecordSize * SWAPW(class2Count);
 109         const Class1Record *class1Record = (const Class1Record *) ((char *) class1RecordArray + (class1RecordSize * class1));
 110         const Class2Record *class2Record = (const Class2Record *) ((char *) class1Record->class2RecordArray + (class2RecordSize * class2));
 111
 112
 113         if (valueFormat1 != 0) {
 114             class2Record->valueRecord1.adjustPosition(SWAPW(valueFormat1), (char *) this, tempIterator, fontInstance);
 115         }
 116
 117         if (valueFormat2 != 0) {
 118             const ValueRecord *valueRecord2 = (const ValueRecord *) ((char *) &class2Record->valueRecord1 + valueRecord1Size);
 119
 120             valueRecord2->adjustPosition(SWAPW(valueFormat2), (const char *) this, *glyphIterator, fontInstance);
 121         }
 122
 123         // back up glyphIterator so second glyph can be
 124         // first glyph in the next pair
 125         glyphIterator->prev();
 126         return 1;
 127     }
 128
 129     return 0;
 130 }
 131
 132 const PairValueRecord *PairPositioningFormat1Subtable::findPairValueRecord(TTGlyphID glyphID, const PairValueRecord *records, le_uint16 recordCount, le_uint16 recordSize) const
 133 {
 134 #if 1
 135         // The OpenType spec. says that the ValueRecord table is
 136         // sorted by secondGlyph. Unfortunately, there are fonts
 137         // around that have an unsorted ValueRecord table.
 138         const PairValueRecord *record = records;
 139
 140         for(le_int32 r = 0; r < recordCount; r += 1) {
 141                 if (SWAPW(record->secondGlyph) == glyphID) {
 142                         return record;
 143                 }
 144
 145                 record = (const PairValueRecord *) ((char *) record + recordSize);
 146         }
 147 #else
 148     le_uint8 bit = OpenTypeUtilities::highBit(recordCount);
 149     le_uint16 power = 1 << bit;
 150     le_uint16 extra = (recordCount - power) * recordSize;
 151     le_uint16 probe = power * recordSize;
 152     const PairValueRecord *record = records;
 153     const PairValueRecord *trial = (const PairValueRecord *) ((char *) record + extra);
 154
 155     if (SWAPW(trial->secondGlyph) <= glyphID) {
 156         record = trial;
 157     }
 158
 159     while (probe > recordSize) {
 160         probe >>= 1;
 161         trial = (const PairValueRecord *) ((char *) record + probe);
 162
 163         if (SWAPW(trial->secondGlyph) <= glyphID) {
 164             record = trial;
 165         }
 166     }
 167
 168     if (SWAPW(record->secondGlyph) == glyphID) {
 169         return record;
 170     }
 171 #endif
 172
 173     return NULL;
 174 }
 175
 176 U_NAMESPACE_END