scuffed-code/icu4c/source/layout/MarkToLigaturePosnSubtables.cpp
2002-07-02 23:48:35 +00:00

106 lines
4.0 KiB
C++

/*
* %W% %E%
*
* (C) Copyright IBM Corp. 1998, 1999, 2000, 2001 - All Rights Reserved
*
*/
#include "LETypes.h"
#include "LEFontInstance.h"
#include "OpenTypeTables.h"
#include "AnchorTables.h"
#include "MarkArrays.h"
#include "GlyphPositioningTables.h"
#include "AttachmentPosnSubtables.h"
#include "MarkToLigaturePosnSubtables.h"
#include "GlyphIterator.h"
#include "LESwaps.h"
U_NAMESPACE_BEGIN
LEGlyphID MarkToLigaturePositioningSubtable::findLigatureGlyph(GlyphIterator *glyphIterator) const
{
if (glyphIterator->prev()) {
return glyphIterator->getCurrGlyphID();
}
return 0xFFFF;
}
le_int32 MarkToLigaturePositioningSubtable::process(GlyphIterator *glyphIterator, const LEFontInstance *fontInstance) const
{
LEGlyphID markGlyph = glyphIterator->getCurrGlyphID();
le_int32 markCoverage = getGlyphCoverage((LEGlyphID) markGlyph);
if (markCoverage < 0) {
// markGlyph isn't a covered mark glyph
return 0;
}
LEPoint markAnchor;
const MarkArray *markArray = (const MarkArray *) ((char *) this + SWAPW(markArrayOffset));
le_int32 markClass = markArray->getMarkClass(markGlyph, markCoverage, fontInstance, markAnchor);
le_uint16 mcCount = SWAPW(classCount);
if (markClass < 0 || markClass >= mcCount) {
// markGlyph isn't in the mark array or its
// mark class is too big. The table is mal-formed!
return 0;
}
// FIXME: we probably don't want to find a ligature before a previous base glyph...
GlyphIterator ligatureIterator(*glyphIterator, lfIgnoreMarks /*| lfIgnoreBaseGlyphs*/);
LEGlyphID ligatureGlyph = findLigatureGlyph(&ligatureIterator);
le_int32 ligatureCoverage = getBaseCoverage((LEGlyphID) ligatureGlyph);
const LigatureArray *ligatureArray = (const LigatureArray *) ((char *) this + SWAPW(baseArrayOffset));
le_uint16 ligatureCount = SWAPW(ligatureArray->ligatureCount);
if (ligatureCoverage < 0 || ligatureCoverage >= ligatureCount) {
// The ligature glyph isn't covered, or the coverage
// index is too big. The latter means that the
// table is mal-formed...
return 0;
}
le_int32 markPosition = glyphIterator->getCurrStreamPosition();
Offset ligatureAttachOffset = SWAPW(ligatureArray->ligatureAttachTableOffsetArray[ligatureCoverage]);
const LigatureAttachTable *ligatureAttachTable = (const LigatureAttachTable *) ((char *) ligatureArray + ligatureAttachOffset);
le_int32 componentCount = SWAPW(ligatureAttachTable->componentCount);
le_int32 component = ligatureIterator.getMarkComponent(markPosition);
if (component >= componentCount) {
// should really just bail at this point...
component = componentCount - 1;
}
const ComponentRecord *componentRecord = &ligatureAttachTable->componentRecordArray[component * mcCount];
Offset anchorTableOffset = SWAPW(componentRecord->ligatureAnchorTableOffsetArray[markClass]);
const AnchorTable *anchorTable = (const AnchorTable *) ((char *) ligatureAttachTable + anchorTableOffset);
LEPoint ligatureAnchor, markAdvance, pixels;
anchorTable->getAnchor(ligatureGlyph, fontInstance, ligatureAnchor);
fontInstance->getGlyphAdvance(markGlyph, pixels);
fontInstance->pixelsToUnits(pixels, markAdvance);
float anchorDiffX = ligatureAnchor.fX - markAnchor.fX;
float anchorDiffY = ligatureAnchor.fY - markAnchor.fY;
glyphIterator->setCurrGlyphBaseOffset(ligatureIterator.getCurrStreamPosition());
if (glyphIterator->isRightToLeft()) {
glyphIterator->adjustCurrGlyphPositionAdjustment(anchorDiffX, anchorDiffY, -markAdvance.fX, -markAdvance.fY);
} else {
LEPoint ligatureAdvance;
fontInstance->getGlyphAdvance(ligatureGlyph, pixels);
fontInstance->pixelsToUnits(pixels, ligatureAdvance);
glyphIterator->adjustCurrGlyphPositionAdjustment(anchorDiffX - ligatureAdvance.fX, anchorDiffY - ligatureAdvance.fY, -markAdvance.fX, -markAdvance.fY);
}
return 1;
}
U_NAMESPACE_END