sl@0: /*
sl@0:  * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved
sl@0:  *
sl@0:  */
sl@0: 
sl@0: #include "LETypes.h"
sl@0: #include "LEFontInstance.h"
sl@0: #include "OpenTypeTables.h"
sl@0: #include "AnchorTables.h"
sl@0: #include "MarkArrays.h"
sl@0: #include "GlyphPositioningTables.h"
sl@0: #include "AttachmentPosnSubtables.h"
sl@0: #include "MarkToLigaturePosnSubtables.h"
sl@0: #include "GlyphIterator.h"
sl@0: #include "LESwaps.h"
sl@0: 
sl@0: U_NAMESPACE_BEGIN
sl@0: 
sl@0: LEGlyphID MarkToLigaturePositioningSubtable::findLigatureGlyph(GlyphIterator *glyphIterator) const
sl@0: {
sl@0:     if (glyphIterator->prev()) {
sl@0:         return glyphIterator->getCurrGlyphID();
sl@0:     }
sl@0: 
sl@0:     return 0xFFFF;
sl@0: }
sl@0: 
sl@0: le_int32 MarkToLigaturePositioningSubtable::process(GlyphIterator *glyphIterator, const LEFontInstance *fontInstance) const
sl@0: {
sl@0:     LEGlyphID markGlyph = glyphIterator->getCurrGlyphID();
sl@0:     le_int32 markCoverage = getGlyphCoverage((LEGlyphID) markGlyph);
sl@0: 
sl@0:     if (markCoverage < 0) {
sl@0:         // markGlyph isn't a covered mark glyph
sl@0:         return 0;
sl@0:     }
sl@0: 
sl@0:     LEPoint markAnchor;
sl@0:     const MarkArray *markArray = (const MarkArray *) ((char *) this + SWAPW(markArrayOffset));
sl@0:     le_int32 markClass = markArray->getMarkClass(markGlyph, markCoverage, fontInstance, markAnchor);
sl@0:     le_uint16 mcCount = SWAPW(classCount);
sl@0: 
sl@0:     if (markClass < 0 || markClass >= mcCount) {
sl@0:         // markGlyph isn't in the mark array or its
sl@0:         // mark class is too big. The table is mal-formed!
sl@0:         return 0;
sl@0:     }
sl@0: 
sl@0:     // FIXME: we probably don't want to find a ligature before a previous base glyph...
sl@0:     GlyphIterator ligatureIterator(*glyphIterator, (le_uint16) (lfIgnoreMarks /*| lfIgnoreBaseGlyphs*/));
sl@0:     LEGlyphID ligatureGlyph = findLigatureGlyph(&ligatureIterator);
sl@0:     le_int32 ligatureCoverage = getBaseCoverage((LEGlyphID) ligatureGlyph);
sl@0:     const LigatureArray *ligatureArray = (const LigatureArray *) ((char *) this + SWAPW(baseArrayOffset));
sl@0:     le_uint16 ligatureCount = SWAPW(ligatureArray->ligatureCount);
sl@0: 
sl@0:     if (ligatureCoverage < 0 || ligatureCoverage >= ligatureCount) {
sl@0:         // The ligature glyph isn't covered, or the coverage
sl@0:         // index is too big. The latter means that the
sl@0:         // table is mal-formed...
sl@0:         return 0;
sl@0:     }
sl@0: 
sl@0:     le_int32 markPosition = glyphIterator->getCurrStreamPosition();
sl@0:     Offset ligatureAttachOffset = SWAPW(ligatureArray->ligatureAttachTableOffsetArray[ligatureCoverage]);
sl@0:     const LigatureAttachTable *ligatureAttachTable = (const LigatureAttachTable *) ((char *) ligatureArray + ligatureAttachOffset);
sl@0:     le_int32 componentCount = SWAPW(ligatureAttachTable->componentCount);
sl@0:     le_int32 component = ligatureIterator.getMarkComponent(markPosition);
sl@0: 
sl@0:     if (component >= componentCount) {
sl@0:         // should really just bail at this point...
sl@0:         component = componentCount - 1;
sl@0:     }
sl@0: 
sl@0:     const ComponentRecord *componentRecord = &ligatureAttachTable->componentRecordArray[component * mcCount];
sl@0:     Offset anchorTableOffset = SWAPW(componentRecord->ligatureAnchorTableOffsetArray[markClass]);
sl@0:     const AnchorTable *anchorTable = (const AnchorTable *) ((char *) ligatureAttachTable + anchorTableOffset);
sl@0:     LEPoint ligatureAnchor, markAdvance, pixels;
sl@0: 
sl@0:     anchorTable->getAnchor(ligatureGlyph, fontInstance, ligatureAnchor);
sl@0: 
sl@0:     fontInstance->getGlyphAdvance(markGlyph, pixels);
sl@0:     fontInstance->pixelsToUnits(pixels, markAdvance);
sl@0: 
sl@0:     float anchorDiffX = ligatureAnchor.fX - markAnchor.fX;
sl@0:     float anchorDiffY = ligatureAnchor.fY - markAnchor.fY;
sl@0: 
sl@0:     glyphIterator->setCurrGlyphBaseOffset(ligatureIterator.getCurrStreamPosition());
sl@0: 
sl@0:     if (glyphIterator->isRightToLeft()) {
sl@0:         glyphIterator->setCurrGlyphPositionAdjustment(anchorDiffX, anchorDiffY, -markAdvance.fX, -markAdvance.fY);
sl@0:     } else {
sl@0:         LEPoint ligatureAdvance;
sl@0: 
sl@0:         fontInstance->getGlyphAdvance(ligatureGlyph, pixels);
sl@0:         fontInstance->pixelsToUnits(pixels, ligatureAdvance);
sl@0: 
sl@0:         glyphIterator->setCurrGlyphPositionAdjustment(anchorDiffX - ligatureAdvance.fX, anchorDiffY - ligatureAdvance.fY, -markAdvance.fX, -markAdvance.fY);
sl@0:     }
sl@0: 
sl@0:     return 1;
sl@0: }
sl@0: 
sl@0: U_NAMESPACE_END