icuSources/layout/ExtensionSubtables.cpp

   1 /*
   2  * %W% %E%
   3  *
   4  * (C) Copyright IBM Corp. 2008-2010 - All Rights Reserved
   5  *
   6  */
   7
   8 #include "LETypes.h"
   9 #include "OpenTypeTables.h"
  10 #include "GlyphSubstitutionTables.h"
  11 #include "LookupProcessor.h"
  12 #include "ExtensionSubtables.h"
  13 #include "GlyphIterator.h"
  14 #include "LESwaps.h"
  15
  16 U_NAMESPACE_BEGIN
  17
  18 // read a 32-bit value that might only be 16-bit-aligned in memory
  19 #define READ_LONG(code) (le_uint32)((SWAPW(*(le_uint16*)&code) << 16) + SWAPW(*(((le_uint16*)&code) + 1)))
  20
  21 // FIXME: should look at the format too... maybe have a sub-class for it?
  22 le_uint32 ExtensionSubtable::process(const LookupProcessor *lookupProcessor, le_uint16 lookupType,
  23                                       GlyphIterator *glyphIterator, const LEFontInstance *fontInstance, LEErrorCode& success) const
  24 {
  25     if (LE_FAILURE(success)) {
  26         return 0;
  27     }
  28
  29     le_uint16 elt = SWAPW(extensionLookupType);
  30
  31     if (elt != lookupType) {
  32         le_uint32 extOffset = READ_LONG(extensionOffset);
  33         LookupSubtable *subtable = (LookupSubtable *) ((char *) this + extOffset);
  34
  35         return lookupProcessor->applySubtable(subtable, elt, glyphIterator, fontInstance, success);
  36     }
  37
  38     return 0;
  39 }
  40
  41 U_NAMESPACE_END