icuSources/layout/MarkToMarkPosnSubtables.cpp

   1 /*
   2  *
   3  * (C) Copyright IBM Corp. 1998-2005 - All Rights Reserved
   4  *
   5  */
   6
   7 #include "LETypes.h"
   8 #include "LEFontInstance.h"
   9 #include "OpenTypeTables.h"
  10 #include "AnchorTables.h"
  11 #include "MarkArrays.h"
  12 #include "GlyphPositioningTables.h"
  13 #include "AttachmentPosnSubtables.h"
  14 #include "MarkToMarkPosnSubtables.h"
  15 #include "GlyphIterator.h"
  16 #include "LESwaps.h"
  17
  18 U_NAMESPACE_BEGIN
  19
  20 LEGlyphID MarkToMarkPositioningSubtable::findMark2Glyph(GlyphIterator *glyphIterator) const
  21 {
  22     if (glyphIterator->findMark2Glyph()) {
  23         return glyphIterator->getCurrGlyphID();
  24     }
  25
  26     return 0xFFFF;
  27 }
  28
  29 le_int32 MarkToMarkPositioningSubtable::process(GlyphIterator *glyphIterator, const LEFontInstance *fontInstance) const
  30 {
  31     LEGlyphID markGlyph = glyphIterator->getCurrGlyphID();
  32     le_int32 markCoverage = getGlyphCoverage((LEGlyphID) markGlyph);
  33
  34     if (markCoverage < 0) {
  35         // markGlyph isn't a covered mark glyph
  36         return 0;
  37     }
  38
  39     LEPoint markAnchor;
  40     const MarkArray *markArray = (const MarkArray *) ((char *) this + SWAPW(markArrayOffset));
  41     le_int32 markClass = markArray->getMarkClass(markGlyph, markCoverage, fontInstance, markAnchor);
  42     le_uint16 mcCount = SWAPW(classCount);
  43
  44     if (markClass < 0 || markClass >= mcCount) {
  45         // markGlyph isn't in the mark array or its
  46         // mark class is too big. The table is mal-formed!
  47         return 0;
  48     }
  49
  50     GlyphIterator mark2Iterator(*glyphIterator);
  51     LEGlyphID mark2Glyph = findMark2Glyph(&mark2Iterator);
  52     le_int32 mark2Coverage = getBaseCoverage((LEGlyphID) mark2Glyph);
  53     const Mark2Array *mark2Array = (const Mark2Array *) ((char *) this + SWAPW(baseArrayOffset));
  54     le_uint16 mark2Count = SWAPW(mark2Array->mark2RecordCount);
  55
  56     if (mark2Coverage < 0 || mark2Coverage >= mark2Count) {
  57         // The mark2 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     const Mark2Record *mark2Record = &mark2Array->mark2RecordArray[mark2Coverage * mcCount];
  64     Offset anchorTableOffset = SWAPW(mark2Record->mark2AnchorTableOffsetArray[markClass]);
  65     const AnchorTable *anchorTable = (const AnchorTable *) ((char *) mark2Array + anchorTableOffset);
  66     LEPoint mark2Anchor, markAdvance, pixels;
  67
  68     if (anchorTableOffset == 0) {
  69         // this seems to mean that the marks don't attach...
  70         return 0;
  71     }
  72
  73     anchorTable->getAnchor(mark2Glyph, fontInstance, mark2Anchor);
  74
  75     fontInstance->getGlyphAdvance(markGlyph, pixels);
  76     fontInstance->pixelsToUnits(pixels, markAdvance);
  77
  78     float anchorDiffX = mark2Anchor.fX - markAnchor.fX;
  79     float anchorDiffY = mark2Anchor.fY - markAnchor.fY;
  80
  81     glyphIterator->setCurrGlyphBaseOffset(mark2Iterator.getCurrStreamPosition());
  82
  83     if (glyphIterator->isRightToLeft()) {
  84         glyphIterator->setCurrGlyphPositionAdjustment(anchorDiffX, anchorDiffY, -markAdvance.fX, -markAdvance.fY);
  85     } else {
  86         LEPoint mark2Advance;
  87
  88         fontInstance->getGlyphAdvance(mark2Glyph, pixels);
  89         fontInstance->pixelsToUnits(pixels, mark2Advance);
  90
  91         glyphIterator->setCurrGlyphPositionAdjustment(anchorDiffX - mark2Advance.fX, anchorDiffY - mark2Advance.fY, -markAdvance.fX, -markAdvance.fY);
  92     }
  93
  94     return 1;
  95 }
  96
  97 U_NAMESPACE_END