icuSources/layout/PairPositioningSubtables.cpp

   1 /*
   2  *
   3  * (C) Copyright IBM Corp. 1998-2004 - 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 "GlyphPositionAdjustments.h"
  15 #include "OpenTypeUtilities.h"
  16 #include "LESwaps.h"
  17
  18 U_NAMESPACE_BEGIN
  19
  20 le_uint32 PairPositioningSubtable::process(GlyphIterator *glyphIterator, const LEFontInstance *fontInstance) const
  21 {
  22     switch(SWAPW(subtableFormat))
  23     {
  24     case 0:
  25         return 0;
  26
  27     case 1:
  28     {
  29         const PairPositioningFormat1Subtable *subtable = (const PairPositioningFormat1Subtable *) this;
  30
  31         return subtable->process(glyphIterator, fontInstance);
  32     }
  33
  34     case 2:
  35     {
  36         const PairPositioningFormat2Subtable *subtable = (const PairPositioningFormat2Subtable *) this;
  37
  38         return subtable->process(glyphIterator, fontInstance);
  39     }
  40
  41     default:
  42         return 0;
  43     }
  44 }
  45
  46 le_uint32 PairPositioningFormat1Subtable::process(GlyphIterator *glyphIterator, const LEFontInstance *fontInstance) const
  47 {
  48     LEGlyphID firstGlyph = glyphIterator->getCurrGlyphID();
  49     le_int32 coverageIndex = getGlyphCoverage(firstGlyph);
  50     GlyphIterator tempIterator(*glyphIterator);
  51
  52     if (coverageIndex >= 0 && glyphIterator->next()) {
  53         Offset pairSetTableOffset = SWAPW(pairSetTableOffsetArray[coverageIndex]);
  54         PairSetTable *pairSetTable = (PairSetTable *) ((char *) this + pairSetTableOffset);
  55         le_uint16 pairValueCount = SWAPW(pairSetTable->pairValueCount);
  56         le_int16 valueRecord1Size = ValueRecord::getSize(SWAPW(valueFormat1));
  57         le_int16 valueRecord2Size = ValueRecord::getSize(SWAPW(valueFormat2));
  58         le_int16 recordSize = sizeof(PairValueRecord) - sizeof(ValueRecord) + valueRecord1Size + valueRecord2Size;
  59         LEGlyphID secondGlyph = glyphIterator->getCurrGlyphID();
  60         const PairValueRecord *pairValueRecord = NULL;
  61
  62         if (pairValueCount != 0) {
  63             pairValueRecord = findPairValueRecord((TTGlyphID) LE_GET_GLYPH(secondGlyph), pairSetTable->pairValueRecordArray, pairValueCount, recordSize);
  64         }
  65
  66         if (pairValueRecord == NULL) {
  67             return 0;
  68         }
  69
  70         if (valueFormat1 != 0) {
  71             GlyphPositionAdjustment adjustment;
  72
  73             tempIterator.getCurrGlyphPositionAdjustment(adjustment);
  74             pairValueRecord->valueRecord1.adjustPosition(SWAPW(valueFormat1), (char *) this, adjustment, fontInstance);
  75             tempIterator.setCurrGlyphPositionAdjustment(&adjustment);
  76         }
  77
  78         if (valueFormat2 != 0) {
  79             const ValueRecord *valueRecord2 = (const ValueRecord *) ((char *) &pairValueRecord->valueRecord1 + valueRecord1Size);
  80             GlyphPositionAdjustment adjustment;
  81
  82             glyphIterator->getCurrGlyphPositionAdjustment(adjustment);
  83             valueRecord2->adjustPosition(SWAPW(valueFormat2), (char *) this, adjustment, fontInstance);
  84             glyphIterator->setCurrGlyphPositionAdjustment(&adjustment);
  85         }
  86
  87         return 2;
  88     }
  89
  90     return 0;
  91 }
  92
  93 le_uint32 PairPositioningFormat2Subtable::process(GlyphIterator *glyphIterator, const LEFontInstance *fontInstance) const
  94 {
  95     LEGlyphID firstGlyph = glyphIterator->getCurrGlyphID();
  96     le_int32 coverageIndex = getGlyphCoverage(firstGlyph);
  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             GlyphPositionAdjustment adjustment;
 115
 116             tempIterator.getCurrGlyphPositionAdjustment(adjustment);
 117             class2Record->valueRecord1.adjustPosition(SWAPW(valueFormat1), (char *) this, adjustment, fontInstance);
 118             tempIterator.setCurrGlyphPositionAdjustment(&adjustment);
 119         }
 120
 121         if (valueFormat2 != 0) {
 122             const ValueRecord *valueRecord2 = (const ValueRecord *) ((char *) &class2Record->valueRecord1 + valueRecord1Size);
 123             GlyphPositionAdjustment adjustment;
 124
 125             glyphIterator->getCurrGlyphPositionAdjustment(adjustment);
 126             valueRecord2->adjustPosition(SWAPW(valueFormat2), (const char *) this, adjustment, fontInstance);
 127             glyphIterator->setCurrGlyphPositionAdjustment(&adjustment);
 128         }
 129
 130         return 2;
 131     }
 132
 133     return 0;
 134 }
 135
 136 const PairValueRecord *PairPositioningFormat1Subtable::findPairValueRecord(TTGlyphID glyphID, const PairValueRecord *records, le_uint16 recordCount, le_uint16 recordSize) const
 137 {
 138     le_uint8 bit = OpenTypeUtilities::highBit(recordCount);
 139     le_uint16 power = 1 << bit;
 140     le_uint16 extra = (recordCount - power) * recordSize;
 141     le_uint16 probe = power * recordSize;
 142     const PairValueRecord *record = records;
 143     const PairValueRecord *trial = (const PairValueRecord *) ((char *) record + extra);
 144
 145     if (SWAPW(trial->secondGlyph) <= glyphID) {
 146         record = trial;
 147     }
 148
 149     while (probe > recordSize) {
 150         probe >>= 1;
 151         trial = (const PairValueRecord *) ((char *) record + probe);
 152
 153         if (SWAPW(trial->secondGlyph) <= glyphID) {
 154             record = trial;
 155         }
 156     }
 157
 158     if (SWAPW(record->secondGlyph) == glyphID) {
 159         return record;
 160     }
 161
 162     return NULL;
 163 }
 164
 165 U_NAMESPACE_END