/*

 * (C) Copyright IBM Corp. 1998-2004 - 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, (le_uint16) (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->setCurrGlyphPositionAdjustment(anchorDiffX, anchorDiffY, -markAdvance.fX, -markAdvance.fY);

    } else {

        LEPoint ligatureAdvance;

        fontInstance->getGlyphAdvance(ligatureGlyph, pixels);

        fontInstance->pixelsToUnits(pixels, ligatureAdvance);

        glyphIterator->setCurrGlyphPositionAdjustment(anchorDiffX - ligatureAdvance.fX, anchorDiffY - ligatureAdvance.fY, -markAdvance.fX, -markAdvance.fY);

    }

    return 1;

}

U_NAMESPACE_END