source/layout/AlternateSubstSubtables.cpp

   1 /*
   2  *
   3  * (C) Copyright IBM Corp. 1998-2013 - 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(const LEReferenceTo<AlternateSubstitutionSubtable> &base,
  18                                        GlyphIterator *glyphIterator, LEErrorCode &success, const LEGlyphFilter *filter) const
  19 {
  20     // NOTE: For now, we'll just pick the first alternative...
  21     LEGlyphID glyph = glyphIterator->getCurrGlyphID();
  22     le_int32 coverageIndex = getGlyphCoverage(base, glyph, success);
  23
  24     if (coverageIndex >= 0 && LE_SUCCESS(success)) {
  25         le_uint16 altSetCount = SWAPW(alternateSetCount);
  26
  27         if (coverageIndex < altSetCount) {
  28             Offset alternateSetTableOffset = SWAPW(alternateSetTableOffsetArray[coverageIndex]);
  29             const LEReferenceTo<AlternateSetTable> alternateSetTable(base, success,
  30                                   (const AlternateSetTable *) ((char *) this + alternateSetTableOffset));
  31             TTGlyphID alternate = SWAPW(alternateSetTable->alternateArray[0]);
  32
  33             if (filter == NULL || filter->accept(LE_SET_GLYPH(glyph, alternate))) {
  34                 glyphIterator->setCurrGlyphID(SWAPW(alternateSetTable->alternateArray[0]));
  35             }
  36
  37             return 1;
  38         }
  39
  40         // XXXX If we get here, the table's mal-formed...
  41     }
  42
  43     return 0;
  44 }
  45
  46 U_NAMESPACE_END