1 /* 2 * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved 3 * 4 */ 5 6 #include "LETypes.h" 7 #include "LEFontInstance.h" 8 #include "OpenTypeTables.h" 9 #include "AnchorTables.h" 10 #include "MarkArrays.h" 11 #include "GlyphPositioningTables.h" 12 #include "AttachmentPosnSubtables.h" 13 #include "MarkToLigaturePosnSubtables.h" 14 #include "GlyphIterator.h" 15 #include "LESwaps.h" 16 17 U_NAMESPACE_BEGIN 18 19 LEGlyphID MarkToLigaturePositioningSubtable::findLigatureGlyph(GlyphIterator *glyphIterator) const 20 { 21 if (glyphIterator->prev()) { 22 return glyphIterator->getCurrGlyphID(); 23 } 24 25 return 0xFFFF; 26 } 27 28 le_int32 MarkToLigaturePositioningSubtable::process(GlyphIterator *glyphIterator, const LEFontInstance *fontInstance) const 29 { 30 LEGlyphID markGlyph = glyphIterator->getCurrGlyphID(); 31 le_int32 markCoverage = getGlyphCoverage((LEGlyphID) markGlyph); 32 33 if (markCoverage < 0) { 34 // markGlyph isn't a covered mark glyph 35 return 0; 36 } 37 38 LEPoint markAnchor; 39 const MarkArray *markArray = (const MarkArray *) ((char *) this + SWAPW(markArrayOffset)); 40 le_int32 markClass = markArray->getMarkClass(markGlyph, markCoverage, fontInstance, markAnchor); 41 le_uint16 mcCount = SWAPW(classCount); 42 43 if (markClass < 0 || markClass >= mcCount) { 44 // markGlyph isn't in the mark array or its 45 // mark class is too big. The table is mal-formed! 46 return 0; 47 } 48 49 // FIXME: we probably don't want to find a ligature before a previous base glyph... 50 GlyphIterator ligatureIterator(*glyphIterator, (le_uint16) (lfIgnoreMarks /*| lfIgnoreBaseGlyphs*/)); 51 LEGlyphID ligatureGlyph = findLigatureGlyph(&ligatureIterator); 52 le_int32 ligatureCoverage = getBaseCoverage((LEGlyphID) ligatureGlyph); 53 const LigatureArray *ligatureArray = (const LigatureArray *) ((char *) this + SWAPW(baseArrayOffset)); 54 le_uint16 ligatureCount = SWAPW(ligatureArray->ligatureCount); 55 56 if (ligatureCoverage < 0 || ligatureCoverage >= ligatureCount) { 57 // The ligature glyph isn't covered, or the coverage 58 // index is too big. The latter means that the 59 // table is mal-formed... 60 return 0; 61 } 62 63 le_int32 markPosition = glyphIterator->getCurrStreamPosition(); 64 Offset ligatureAttachOffset = SWAPW(ligatureArray->ligatureAttachTableOffsetArray[ligatureCoverage]); 65 const LigatureAttachTable *ligatureAttachTable = (const LigatureAttachTable *) ((char *) ligatureArray + ligatureAttachOffset); 66 le_int32 componentCount = SWAPW(ligatureAttachTable->componentCount); 67 le_int32 component = ligatureIterator.getMarkComponent(markPosition); 68 69 if (component >= componentCount) { 70 // should really just bail at this point... 71 component = componentCount - 1; 72 } 73 74 const ComponentRecord *componentRecord = &ligatureAttachTable->componentRecordArray[component * mcCount]; 75 Offset anchorTableOffset = SWAPW(componentRecord->ligatureAnchorTableOffsetArray[markClass]); 76 const AnchorTable *anchorTable = (const AnchorTable *) ((char *) ligatureAttachTable + anchorTableOffset); 77 LEPoint ligatureAnchor, markAdvance, pixels; 78 79 anchorTable->getAnchor(ligatureGlyph, fontInstance, ligatureAnchor); 80 81 fontInstance->getGlyphAdvance(markGlyph, pixels); 82 fontInstance->pixelsToUnits(pixels, markAdvance); 83 84 float anchorDiffX = ligatureAnchor.fX - markAnchor.fX; 85 float anchorDiffY = ligatureAnchor.fY - markAnchor.fY; 86 87 glyphIterator->setCurrGlyphBaseOffset(ligatureIterator.getCurrStreamPosition()); 88 89 if (glyphIterator->isRightToLeft()) { 90 glyphIterator->setCurrGlyphPositionAdjustment(anchorDiffX, anchorDiffY, -markAdvance.fX, -markAdvance.fY); 91 } else { 92 LEPoint ligatureAdvance; 93 94 fontInstance->getGlyphAdvance(ligatureGlyph, pixels); 95 fontInstance->pixelsToUnits(pixels, ligatureAdvance); 96 97 glyphIterator->setCurrGlyphPositionAdjustment(anchorDiffX - ligatureAdvance.fX, anchorDiffY - ligatureAdvance.fY, -markAdvance.fX, -markAdvance.fY); 98 } 99 100 return 1; 101 } 102 103 U_NAMESPACE_END 104
