ContextualGlyphSubstProc.cpp revision 51cfa1a9a96cad34675a6415fe86dfdf3f525bb6 
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
17U_NAMESPACE_BEGIN
18
19UOBJECT_DEFINE_RTTI_IMPLEMENTATION(ContextualGlyphSubstitutionProcessor)
20
21ContextualGlyphSubstitutionProcessor::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
30ContextualGlyphSubstitutionProcessor::~ContextualGlyphSubstitutionProcessor()
31{
32}
33
34void ContextualGlyphSubstitutionProcessor::beginStateTable()
35{
36    markGlyph = 0;
37}
38
39ByteOffset 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
75void ContextualGlyphSubstitutionProcessor::endStateTable()
76{
77}
78
79U_NAMESPACE_END
80