os/textandloc/fontservices/textshaperplugin/IcuSource/layout/MarkToBasePosnSubtables.cpp
author sl@SLION-WIN7.fritz.box
Fri, 15 Jun 2012 03:10:57 +0200
changeset 0 bde4ae8d615e
permissions -rw-r--r--
First public contribution.
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/*
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 *
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 * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved
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 *
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 */
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#include "LETypes.h"
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#include "LEFontInstance.h"
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#include "OpenTypeTables.h"
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#include "AnchorTables.h"
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#include "MarkArrays.h"
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#include "GlyphPositioningTables.h"
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#include "AttachmentPosnSubtables.h"
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#include "MarkToBasePosnSubtables.h"
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#include "GlyphIterator.h"
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#include "LESwaps.h"
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U_NAMESPACE_BEGIN
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LEGlyphID MarkToBasePositioningSubtable::findBaseGlyph(GlyphIterator *glyphIterator) const
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{
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    if (glyphIterator->prev()) {
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        return glyphIterator->getCurrGlyphID();
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    }
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    return 0xFFFF;
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}
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le_int32 MarkToBasePositioningSubtable::process(GlyphIterator *glyphIterator, const LEFontInstance *fontInstance) const
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{
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    LEGlyphID markGlyph = glyphIterator->getCurrGlyphID();
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    le_int32 markCoverage = getGlyphCoverage((LEGlyphID) markGlyph);
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    if (markCoverage < 0) {
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        // markGlyph isn't a covered mark glyph
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        return 0;
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    }
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    LEPoint markAnchor;
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    const MarkArray *markArray = (const MarkArray *) ((char *) this + SWAPW(markArrayOffset));
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    le_int32 markClass = markArray->getMarkClass(markGlyph, markCoverage, fontInstance, markAnchor);
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    le_uint16 mcCount = SWAPW(classCount);
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    if (markClass < 0 || markClass >= mcCount) {
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        // markGlyph isn't in the mark array or its
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        // mark class is too big. The table is mal-formed!
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        return 0;
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    }
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    // FIXME: We probably don't want to find a base glyph before a previous ligature... 
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    GlyphIterator baseIterator(*glyphIterator, (le_uint16) (lfIgnoreMarks /*| lfIgnoreLigatures*/));
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    LEGlyphID baseGlyph = findBaseGlyph(&baseIterator);
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    le_int32 baseCoverage = getBaseCoverage((LEGlyphID) baseGlyph);
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    const BaseArray *baseArray = (const BaseArray *) ((char *) this + SWAPW(baseArrayOffset));
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    le_uint16 baseCount = SWAPW(baseArray->baseRecordCount);
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    if (baseCoverage < 0 || baseCoverage >= baseCount) {
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        // The base glyph isn't covered, or the coverage
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        // index is too big. The latter means that the
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        // table is mal-formed...
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        return 0;
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    }
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    const BaseRecord *baseRecord = &baseArray->baseRecordArray[baseCoverage * mcCount];
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    Offset anchorTableOffset = SWAPW(baseRecord->baseAnchorTableOffsetArray[markClass]);
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    const AnchorTable *anchorTable = (const AnchorTable *) ((char *) baseArray + anchorTableOffset);
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    LEPoint baseAnchor, markAdvance, pixels;
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    if (anchorTableOffset == 0) {
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        // this means the table is mal-formed...
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        glyphIterator->setCurrGlyphBaseOffset(baseIterator.getCurrStreamPosition());
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        return 0;
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    }
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    anchorTable->getAnchor(baseGlyph, fontInstance, baseAnchor);
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    fontInstance->getGlyphAdvance(markGlyph, pixels);
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    fontInstance->pixelsToUnits(pixels, markAdvance);
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    float anchorDiffX = baseAnchor.fX - markAnchor.fX;
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    float anchorDiffY = baseAnchor.fY - markAnchor.fY;
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    glyphIterator->setCurrGlyphBaseOffset(baseIterator.getCurrStreamPosition());
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    if (glyphIterator->isRightToLeft()) {
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        glyphIterator->setCurrGlyphPositionAdjustment(anchorDiffX, anchorDiffY, -markAdvance.fX, -markAdvance.fY);
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    } else {
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        LEPoint baseAdvance;
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        fontInstance->getGlyphAdvance(baseGlyph, pixels);
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        fontInstance->pixelsToUnits(pixels, baseAdvance);
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        glyphIterator->setCurrGlyphPositionAdjustment(anchorDiffX - baseAdvance.fX, anchorDiffY - baseAdvance.fY, -markAdvance.fX, -markAdvance.fY);
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    }
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    return 1;
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}
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U_NAMESPACE_END