icuSources/layout/PairPositioningSubtables.cpp

   1 /*
   2  *
   3  * (C) Copyright IBM Corp. 1998-2006 - 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         // back up glyphIterator so second glyph can be
  80         // first glyph in the next pair
  81         glyphIterator->prev();
  82         return 1;
  83     }
  84
  85     return 0;
  86 }
  87
  88 le_uint32 PairPositioningFormat2Subtable::process(GlyphIterator *glyphIterator, const LEFontInstance *fontInstance) const
  89 {
  90     LEGlyphID firstGlyph = glyphIterator->getCurrGlyphID();
  91     le_int32 coverageIndex = getGlyphCoverage(firstGlyph);
  92     GlyphIterator tempIterator(*glyphIterator);
  93
  94     if (coverageIndex >= 0 && glyphIterator->next()) {
  95         LEGlyphID secondGlyph = glyphIterator->getCurrGlyphID();
  96         const ClassDefinitionTable *classDef1 = (const ClassDefinitionTable *) ((char *) this + SWAPW(classDef1Offset));
  97         const ClassDefinitionTable *classDef2 = (const ClassDefinitionTable *) ((char *) this + SWAPW(classDef2Offset));
  98         le_int32 class1 = classDef1->getGlyphClass(firstGlyph);
  99         le_int32 class2 = classDef2->getGlyphClass(secondGlyph);
 100         le_int16 valueRecord1Size = ValueRecord::getSize(SWAPW(valueFormat1));
 101         le_int16 valueRecord2Size = ValueRecord::getSize(SWAPW(valueFormat2));
 102         le_int16 class2RecordSize = valueRecord1Size + valueRecord2Size;
 103         le_int16 class1RecordSize = class2RecordSize * SWAPW(class2Count);
 104         const Class1Record *class1Record = (const Class1Record *) ((char *) class1RecordArray + (class1RecordSize * class1));
 105         const Class2Record *class2Record = (const Class2Record *) ((char *) class1Record->class2RecordArray + (class2RecordSize * class2));
 106
 107
 108         if (valueFormat1 != 0) {
 109             class2Record->valueRecord1.adjustPosition(SWAPW(valueFormat1), (char *) this, tempIterator, fontInstance);
 110         }
 111
 112         if (valueFormat2 != 0) {
 113             const ValueRecord *valueRecord2 = (const ValueRecord *) ((char *) &class2Record->valueRecord1 + valueRecord1Size);
 114
 115             valueRecord2->adjustPosition(SWAPW(valueFormat2), (const char *) this, *glyphIterator, fontInstance);
 116         }
 117
 118         // back up glyphIterator so second glyph can be
 119         // first glyph in the next pair
 120         glyphIterator->prev();
 121         return 1;
 122     }
 123
 124     return 0;
 125 }
 126
 127 const PairValueRecord *PairPositioningFormat1Subtable::findPairValueRecord(TTGlyphID glyphID, const PairValueRecord *records, le_uint16 recordCount, le_uint16 recordSize) const
 128 {
 129 #if 1
 130         // The OpenType spec. says that the ValueRecord table is
 131         // sorted by secondGlyph. Unfortunately, there are fonts
 132         // around that have an unsorted ValueRecord table.
 133         const PairValueRecord *record = records;
 134
 135         for(le_int32 r = 0; r < recordCount; r += 1) {
 136                 if (SWAPW(record->secondGlyph) == glyphID) {
 137                         return record;
 138                 }
 139
 140                 record = (const PairValueRecord *) ((char *) record + recordSize);
 141         }
 142 #else
 143     le_uint8 bit = OpenTypeUtilities::highBit(recordCount);
 144     le_uint16 power = 1 << bit;
 145     le_uint16 extra = (recordCount - power) * recordSize;
 146     le_uint16 probe = power * recordSize;
 147     const PairValueRecord *record = records;
 148     const PairValueRecord *trial = (const PairValueRecord *) ((char *) record + extra);
 149
 150     if (SWAPW(trial->secondGlyph) <= glyphID) {
 151         record = trial;
 152     }
 153
 154     while (probe > recordSize) {
 155         probe >>= 1;
 156         trial = (const PairValueRecord *) ((char *) record + probe);
 157
 158         if (SWAPW(trial->secondGlyph) <= glyphID) {
 159             record = trial;
 160         }
 161     }
 162
 163     if (SWAPW(record->secondGlyph) == glyphID) {
 164         return record;
 165     }
 166 #endif
 167
 168     return NULL;
 169 }
 170
 171 U_NAMESPACE_END