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1 /*
2  *
3  * (C) Copyright IBM Corp. 1998-2004 - 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 
15 U_NAMESPACE_BEGIN
16 
process(GlyphIterator * glyphIterator,const LEGlyphFilter * filter) const17 le_uint32 MultipleSubstitutionSubtable::process(GlyphIterator *glyphIterator, const LEGlyphFilter *filter) const
18 {
19     LEGlyphID glyph = glyphIterator->getCurrGlyphID();
20 
21     // If there's a filter, we only want to do the
22     // substitution if the *input* glyphs doesn't
23     // exist.
24     //
25     // FIXME: is this always the right thing to do?
26     // FIXME: should this only be done for a non-zero
27     //        glyphCount?
28     if (filter != NULL && filter->accept(glyph)) {
29         return 0;
30     }
31 
32     le_int32 coverageIndex = getGlyphCoverage(glyph);
33     le_uint16 seqCount = SWAPW(sequenceCount);
34 
35     if (coverageIndex >= 0 && coverageIndex < seqCount) {
36         Offset sequenceTableOffset = SWAPW(sequenceTableOffsetArray[coverageIndex]);
37         const SequenceTable *sequenceTable = (const SequenceTable *) ((char *) this + sequenceTableOffset);
38         le_uint16 glyphCount = SWAPW(sequenceTable->glyphCount);
39 
40         if (glyphCount == 0) {
41             glyphIterator->setCurrGlyphID(0xFFFF);
42             return 1;
43         } else if (glyphCount == 1) {
44             TTGlyphID substitute = SWAPW(sequenceTable->substituteArray[0]);
45 
46             if (filter != NULL && ! filter->accept(LE_SET_GLYPH(glyph, substitute))) {
47                 return 0;
48             }
49 
50             glyphIterator->setCurrGlyphID(substitute);
51             return 1;
52         } else {
53             // If there's a filter, make sure all of the output glyphs
54             // exist.
55             if (filter != NULL) {
56                 for (le_int32 i = 0; i < glyphCount; i += 1) {
57                     TTGlyphID substitute = SWAPW(sequenceTable->substituteArray[i]);
58 
59                     if (! filter->accept(substitute)) {
60                         return 0;
61                     }
62                 }
63             }
64 
65             LEGlyphID *newGlyphs = glyphIterator->insertGlyphs(glyphCount);
66             le_int32 insert = 0, direction = 1;
67 
68             if (glyphIterator->isRightToLeft()) {
69                 insert = glyphCount - 1;
70                 direction = -1;
71             }
72 
73             for (le_int32 i = 0; i < glyphCount; i += 1) {
74                 TTGlyphID substitute = SWAPW(sequenceTable->substituteArray[i]);
75 
76                 newGlyphs[insert] = LE_SET_GLYPH(glyph, substitute);
77                 insert += direction;
78             }
79 
80             return 1;
81         }
82     }
83 
84     return 0;
85 }
86 
87 U_NAMESPACE_END
88