scuffed-code/icu4c/source/layout/MultipleSubstSubtables.cpp
Steven R. Loomis f2fbc8c394 ICU-10107 LayoutEngine improvements
X-SVN-Rev: 33535
2013-04-18 21:24:51 +00:00

96 lines
2.8 KiB
C++

/*
*
* (C) Copyright IBM Corp. 1998-2013 - All Rights Reserved
*
*/
#include "LETypes.h"
#include "LEGlyphFilter.h"
#include "OpenTypeTables.h"
#include "GlyphSubstitutionTables.h"
#include "MultipleSubstSubtables.h"
#include "GlyphIterator.h"
#include "LESwaps.h"
U_NAMESPACE_BEGIN
le_uint32 MultipleSubstitutionSubtable::process(const LETableReference &base, GlyphIterator *glyphIterator, LEErrorCode& success, const LEGlyphFilter *filter) const
{
if (LE_FAILURE(success)) {
return 0;
}
LEGlyphID glyph = glyphIterator->getCurrGlyphID();
// If there's a filter, we only want to do the
// substitution if the *input* glyphs doesn't
// exist.
//
// FIXME: is this always the right thing to do?
// FIXME: should this only be done for a non-zero
// glyphCount?
if (filter != NULL && filter->accept(glyph)) {
return 0;
}
le_int32 coverageIndex = getGlyphCoverage(base, glyph, success);
le_uint16 seqCount = SWAPW(sequenceCount);
if (coverageIndex >= 0 && coverageIndex < seqCount) {
Offset sequenceTableOffset = SWAPW(sequenceTableOffsetArray[coverageIndex]);
const SequenceTable *sequenceTable = (const SequenceTable *) ((char *) this + sequenceTableOffset);
le_uint16 glyphCount = SWAPW(sequenceTable->glyphCount);
if (glyphCount == 0) {
glyphIterator->setCurrGlyphID(0xFFFF);
return 1;
} else if (glyphCount == 1) {
TTGlyphID substitute = SWAPW(sequenceTable->substituteArray[0]);
if (filter != NULL && ! filter->accept(LE_SET_GLYPH(glyph, substitute))) {
return 0;
}
glyphIterator->setCurrGlyphID(substitute);
return 1;
} else {
// If there's a filter, make sure all of the output glyphs
// exist.
if (filter != NULL) {
for (le_int32 i = 0; i < glyphCount; i += 1) {
TTGlyphID substitute = SWAPW(sequenceTable->substituteArray[i]);
if (! filter->accept(substitute)) {
return 0;
}
}
}
LEGlyphID *newGlyphs = glyphIterator->insertGlyphs(glyphCount, success);
if (LE_FAILURE(success)) {
return 0;
}
le_int32 insert = 0, direction = 1;
if (glyphIterator->isRightToLeft()) {
insert = glyphCount - 1;
direction = -1;
}
for (le_int32 i = 0; i < glyphCount; i += 1) {
TTGlyphID substitute = SWAPW(sequenceTable->substituteArray[i]);
newGlyphs[insert] = LE_SET_GLYPH(glyph, substitute);
insert += direction;
}
return 1;
}
}
return 0;
}
U_NAMESPACE_END