icuSources/layout/ContextualGlyphSubstProc.cpp

   1 /*
   2  *
   3  * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved
   4  *
   5  */
   6
   7 #include "LETypes.h"
   8 #include "MorphTables.h"
   9 #include "StateTables.h"
  10 #include "MorphStateTables.h"
  11 #include "SubtableProcessor.h"
  12 #include "StateTableProcessor.h"
  13 #include "ContextualGlyphSubstProc.h"
  14 #include "LEGlyphStorage.h"
  15 #include "LESwaps.h"
  16
  17 U_NAMESPACE_BEGIN
  18
  19 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(ContextualGlyphSubstitutionProcessor)
  20
  21 ContextualGlyphSubstitutionProcessor::ContextualGlyphSubstitutionProcessor(const MorphSubtableHeader *morphSubtableHeader)
  22   : StateTableProcessor(morphSubtableHeader)
  23 {
  24     contextualGlyphSubstitutionHeader = (const ContextualGlyphSubstitutionHeader *) morphSubtableHeader;
  25     substitutionTableOffset = SWAPW(contextualGlyphSubstitutionHeader->substitutionTableOffset);
  26
  27     entryTable = (const ContextualGlyphSubstitutionStateEntry *) ((char *) &stateTableHeader->stHeader + entryTableOffset);
  28 }
  29
  30 ContextualGlyphSubstitutionProcessor::~ContextualGlyphSubstitutionProcessor()
  31 {
  32 }
  33
  34 void ContextualGlyphSubstitutionProcessor::beginStateTable()
  35 {
  36     markGlyph = 0;
  37 }
  38
  39 ByteOffset ContextualGlyphSubstitutionProcessor::processStateEntry(LEGlyphStorage &glyphStorage, le_int32 &currGlyph, EntryTableIndex index)
  40 {
  41     const ContextualGlyphSubstitutionStateEntry *entry = &entryTable[index];
  42     ByteOffset newState = SWAPW(entry->newStateOffset);
  43     le_int16 flags = SWAPW(entry->flags);
  44     WordOffset markOffset = SWAPW(entry->markOffset);
  45     WordOffset currOffset = SWAPW(entry->currOffset);
  46
  47     if (markOffset != 0) {
  48         const le_int16 *table = (const le_int16 *) ((char *) &stateTableHeader->stHeader + markOffset * 2);
  49         LEGlyphID mGlyph = glyphStorage[markGlyph];
  50         TTGlyphID newGlyph = SWAPW(table[LE_GET_GLYPH(mGlyph)]);
  51
  52          glyphStorage[markGlyph] = LE_SET_GLYPH(mGlyph, newGlyph);
  53     }
  54
  55     if (currOffset != 0) {
  56         const le_int16 *table = (const le_int16 *) ((char *) &stateTableHeader->stHeader + currOffset * 2);
  57         LEGlyphID thisGlyph = glyphStorage[currGlyph];
  58         TTGlyphID newGlyph = SWAPW(table[LE_GET_GLYPH(thisGlyph)]);
  59
  60         glyphStorage[currGlyph] = LE_SET_GLYPH(thisGlyph, newGlyph);
  61     }
  62
  63     if (flags & cgsSetMark) {
  64         markGlyph = currGlyph;
  65     }
  66
  67     if (!(flags & cgsDontAdvance)) {
  68         // should handle reverse too!
  69         currGlyph += 1;
  70     }
  71
  72     return newState;
  73 }
  74
  75 void ContextualGlyphSubstitutionProcessor::endStateTable()
  76 {
  77 }
  78
  79 U_NAMESPACE_END