1/*
2 *
3 * (C) Copyright IBM Corp. 1998-2008 - All Rights Reserved
4 *
5 */
6
7#include "LETypes.h"
8#include "LEGlyphFilter.h"
9#include "OpenTypeTables.h"
10#include "GlyphSubstitutionTables.h"
11#include "MultipleSubstSubtables.h"
12#include "GlyphIterator.h"
13#include "LESwaps.h"
14
15U_NAMESPACE_BEGIN
16
17le_uint32 MultipleSubstitutionSubtable::process(GlyphIterator *glyphIterator, LEErrorCode& success, const LEGlyphFilter *filter) const
18{
19    if (LE_FAILURE(success)) {
20        return 0;
21    }
22
23    LEGlyphID glyph = glyphIterator->getCurrGlyphID();
24
25    // If there's a filter, we only want to do the
26    // substitution if the *input* glyphs doesn't
27    // exist.
28    //
29    // FIXME: is this always the right thing to do?
30    // FIXME: should this only be done for a non-zero
31    //        glyphCount?
32    if (filter != NULL && filter->accept(glyph)) {
33        return 0;
34    }
35
36    le_int32 coverageIndex = getGlyphCoverage(glyph);
37    le_uint16 seqCount = SWAPW(sequenceCount);
38
39    if (coverageIndex >= 0 && coverageIndex < seqCount) {
40        Offset sequenceTableOffset = SWAPW(sequenceTableOffsetArray[coverageIndex]);
41        const SequenceTable *sequenceTable = (const SequenceTable *) ((char *) this + sequenceTableOffset);
42        le_uint16 glyphCount = SWAPW(sequenceTable->glyphCount);
43
44        if (glyphCount == 0) {
45            glyphIterator->setCurrGlyphID(0xFFFF);
46            return 1;
47        } else if (glyphCount == 1) {
48            TTGlyphID substitute = SWAPW(sequenceTable->substituteArray[0]);
49
50            if (filter != NULL && ! filter->accept(LE_SET_GLYPH(glyph, substitute))) {
51                return 0;
52            }
53
54            glyphIterator->setCurrGlyphID(substitute);
55            return 1;
56        } else {
57            // If there's a filter, make sure all of the output glyphs
58            // exist.
59            if (filter != NULL) {
60                for (le_int32 i = 0; i < glyphCount; i += 1) {
61                    TTGlyphID substitute = SWAPW(sequenceTable->substituteArray[i]);
62
63                    if (! filter->accept(substitute)) {
64                        return 0;
65                    }
66                }
67            }
68
69            LEGlyphID *newGlyphs = glyphIterator->insertGlyphs(glyphCount, success);
70            if (LE_FAILURE(success)) {
71                return 0;
72            }
73
74            le_int32 insert = 0, direction = 1;
75
76            if (glyphIterator->isRightToLeft()) {
77                insert = glyphCount - 1;
78                direction = -1;
79            }
80
81            for (le_int32 i = 0; i < glyphCount; i += 1) {
82                TTGlyphID substitute = SWAPW(sequenceTable->substituteArray[i]);
83
84                newGlyphs[insert] = LE_SET_GLYPH(glyph, substitute);
85                insert += direction;
86            }
87
88            return 1;
89        }
90    }
91
92    return 0;
93}
94
95U_NAMESPACE_END
96