icuSources/layout/AlternateSubstSubtables.cpp

   1 /*
   2  *
   3  * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved
   4  *
   5  */
   6
   7 #include "LETypes.h"
   8 #include "LEGlyphFilter.h"
   9 #include "OpenTypeTables.h"
  10 #include "GlyphSubstitutionTables.h"
  11 #include "AlternateSubstSubtables.h"
  12 #include "GlyphIterator.h"
  13 #include "LESwaps.h"
  14
  15 U_NAMESPACE_BEGIN
  16
  17 le_uint32 AlternateSubstitutionSubtable::process(GlyphIterator *glyphIterator, const LEGlyphFilter *filter) const
  18 {
  19     // NOTE: For now, we'll just pick the first alternative...
  20     LEGlyphID glyph = glyphIterator->getCurrGlyphID();
  21     le_int32 coverageIndex = getGlyphCoverage(glyph);
  22
  23     if (coverageIndex >= 0) {
  24         le_uint16 altSetCount = SWAPW(alternateSetCount);
  25
  26         if (coverageIndex < altSetCount) {
  27             Offset alternateSetTableOffset = SWAPW(alternateSetTableOffsetArray[coverageIndex]);
  28             const AlternateSetTable *alternateSetTable =
  29                 (const AlternateSetTable *) ((char *) this + alternateSetTableOffset);
  30             TTGlyphID alternate = SWAPW(alternateSetTable->alternateArray[0]);
  31
  32             if (filter == NULL || filter->accept(LE_SET_GLYPH(glyph, alternate))) {
  33                 glyphIterator->setCurrGlyphID(SWAPW(alternateSetTable->alternateArray[0]));
  34             }
  35
  36             return 1;
  37         }
  38
  39         // XXXX If we get here, the table's mal-formed...
  40     }
  41
  42     return 0;
  43 }
  44
  45 U_NAMESPACE_END