icuSources/layout/ExtensionSubtables.cpp

   1 /*
   2  * %W% %E%
   3  *
   4  * (C) Copyright IBM Corp. 2008-2013 - 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 static inline le_uint32 READ_LONG(le_uint32 code) {
  20     le_uint16* first = ((le_uint16*)&code);
  21     le_uint16* second = (((le_uint16*)&code) + 1);
  22     return (le_uint32)((SWAPW(*first) << 16) + SWAPW(*second));
  23 }
  24
  25 // FIXME: should look at the format too... maybe have a sub-class for it?
  26 le_uint32 ExtensionSubtable::process(const LookupProcessor *lookupProcessor, le_uint16 lookupType,
  27                                       GlyphIterator *glyphIterator, const LEFontInstance *fontInstance, LEErrorCode& success) const
  28 {
  29     const LEReferenceTo<ExtensionSubtable> thisRef(lookupProcessor->getReference(), success); // create a reference to this
  30
  31     if (LE_FAILURE(success)) {
  32         return 0;
  33     }
  34
  35     le_uint16 elt = SWAPW(extensionLookupType);
  36
  37     if (elt != lookupType) {
  38         le_uint32 extOffset = READ_LONG(extensionOffset);
  39         LEReferenceTo<LookupSubtable> subtable(thisRef, success, extOffset);
  40
  41         if(LE_SUCCESS(success)) {
  42           return lookupProcessor->applySubtable(subtable, elt, glyphIterator, fontInstance, success);
  43         }
  44     }
  45
  46     return 0;
  47 }
  48
  49 U_NAMESPACE_END