icuSources/layout/PairPositioningSubtables.cpp

   1 /*
   2  *
   3  * (C) Copyright IBM Corp. 1998-2005 - 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(GlyphIterator *glyphIterator, const LEFontInstance *fontInstance) const
  20 {
  21     switch(SWAPW(subtableFormat))
  22     {
  23     case 0:
  24         return 0;
  25
  26     case 1:
  27     {
  28         const PairPositioningFormat1Subtable *subtable = (const PairPositioningFormat1Subtable *) this;
  29
  30         return subtable->process(glyphIterator, fontInstance);
  31     }
  32
  33     case 2:
  34     {
  35         const PairPositioningFormat2Subtable *subtable = (const PairPositioningFormat2Subtable *) this;
  36
  37         return subtable->process(glyphIterator, fontInstance);
  38     }
  39
  40     default:
  41         return 0;
  42     }
  43 }
  44
  45 le_uint32 PairPositioningFormat1Subtable::process(GlyphIterator *glyphIterator, const LEFontInstance *fontInstance) const
  46 {
  47     LEGlyphID firstGlyph = glyphIterator->getCurrGlyphID();
  48     le_int32 coverageIndex = getGlyphCoverage(firstGlyph);
  49     GlyphIterator tempIterator(*glyphIterator);
  50
  51     if (coverageIndex >= 0 && glyphIterator->next()) {
  52         Offset pairSetTableOffset = SWAPW(pairSetTableOffsetArray[coverageIndex]);
  53         PairSetTable *pairSetTable = (PairSetTable *) ((char *) this + pairSetTableOffset);
  54         le_uint16 pairValueCount = SWAPW(pairSetTable->pairValueCount);
  55         le_int16 valueRecord1Size = ValueRecord::getSize(SWAPW(valueFormat1));
  56         le_int16 valueRecord2Size = ValueRecord::getSize(SWAPW(valueFormat2));
  57         le_int16 recordSize = sizeof(PairValueRecord) - sizeof(ValueRecord) + valueRecord1Size + valueRecord2Size;
  58         LEGlyphID secondGlyph = glyphIterator->getCurrGlyphID();
  59         const PairValueRecord *pairValueRecord = NULL;
  60
  61         if (pairValueCount != 0) {
  62             pairValueRecord = findPairValueRecord((TTGlyphID) LE_GET_GLYPH(secondGlyph), pairSetTable->pairValueRecordArray, pairValueCount, recordSize);
  63         }
  64
  65         if (pairValueRecord == NULL) {
  66             return 0;
  67         }
  68
  69         if (valueFormat1 != 0) {
  70             pairValueRecord->valueRecord1.adjustPosition(SWAPW(valueFormat1), (char *) this, tempIterator, fontInstance);
  71         }
  72
  73         if (valueFormat2 != 0) {
  74             const ValueRecord *valueRecord2 = (const ValueRecord *) ((char *) &pairValueRecord->valueRecord1 + valueRecord1Size);
  75
  76             valueRecord2->adjustPosition(SWAPW(valueFormat2), (char *) this, *glyphIterator, fontInstance);
  77         }
  78
  79         return 2;
  80     }
  81
  82     return 0;
  83 }
  84
  85 le_uint32 PairPositioningFormat2Subtable::process(GlyphIterator *glyphIterator, const LEFontInstance *fontInstance) const
  86 {
  87     LEGlyphID firstGlyph = glyphIterator->getCurrGlyphID();
  88     le_int32 coverageIndex = getGlyphCoverage(firstGlyph);
  89     GlyphIterator tempIterator(*glyphIterator);
  90
  91     if (coverageIndex >= 0 && glyphIterator->next()) {
  92         LEGlyphID secondGlyph = glyphIterator->getCurrGlyphID();
  93         const ClassDefinitionTable *classDef1 = (const ClassDefinitionTable *) ((char *) this + SWAPW(classDef1Offset));
  94         const ClassDefinitionTable *classDef2 = (const ClassDefinitionTable *) ((char *) this + SWAPW(classDef2Offset));
  95         le_int32 class1 = classDef1->getGlyphClass(firstGlyph);
  96         le_int32 class2 = classDef2->getGlyphClass(secondGlyph);
  97         le_int16 valueRecord1Size = ValueRecord::getSize(SWAPW(valueFormat1));
  98         le_int16 valueRecord2Size = ValueRecord::getSize(SWAPW(valueFormat2));
  99         le_int16 class2RecordSize = valueRecord1Size + valueRecord2Size;
 100         le_int16 class1RecordSize = class2RecordSize * SWAPW(class2Count);
 101         const Class1Record *class1Record = (const Class1Record *) ((char *) class1RecordArray + (class1RecordSize * class1));
 102         const Class2Record *class2Record = (const Class2Record *) ((char *) class1Record->class2RecordArray + (class2RecordSize * class2));
 103
 104
 105         if (valueFormat1 != 0) {
 106             class2Record->valueRecord1.adjustPosition(SWAPW(valueFormat1), (char *) this, tempIterator, fontInstance);
 107         }
 108
 109         if (valueFormat2 != 0) {
 110             const ValueRecord *valueRecord2 = (const ValueRecord *) ((char *) &class2Record->valueRecord1 + valueRecord1Size);
 111
 112             valueRecord2->adjustPosition(SWAPW(valueFormat2), (const char *) this, *glyphIterator, fontInstance);
 113         }
 114
 115         return 2;
 116     }
 117
 118     return 0;
 119 }
 120
 121 const PairValueRecord *PairPositioningFormat1Subtable::findPairValueRecord(TTGlyphID glyphID, const PairValueRecord *records, le_uint16 recordCount, le_uint16 recordSize) const
 122 {
 123     le_uint8 bit = OpenTypeUtilities::highBit(recordCount);
 124     le_uint16 power = 1 << bit;
 125     le_uint16 extra = (recordCount - power) * recordSize;
 126     le_uint16 probe = power * recordSize;
 127     const PairValueRecord *record = records;
 128     const PairValueRecord *trial = (const PairValueRecord *) ((char *) record + extra);
 129
 130     if (SWAPW(trial->secondGlyph) <= glyphID) {
 131         record = trial;
 132     }
 133
 134     while (probe > recordSize) {
 135         probe >>= 1;
 136         trial = (const PairValueRecord *) ((char *) record + probe);
 137
 138         if (SWAPW(trial->secondGlyph) <= glyphID) {
 139             record = trial;
 140         }
 141     }
 142
 143     if (SWAPW(record->secondGlyph) == glyphID) {
 144         return record;
 145     }
 146
 147     return NULL;
 148 }
 149
 150 U_NAMESPACE_END