/*

 *

 * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved

 *

 */

#include "LETypes.h"

#include "MorphTables.h"

#include "StateTables.h"

#include "MorphStateTables.h"

#include "SubtableProcessor.h"

#include "StateTableProcessor.h"

#include "LigatureSubstProc.h"

#include "LEGlyphStorage.h"

#include "LESwaps.h"

U_NAMESPACE_BEGIN

#define ExtendedComplement(m) ((le_int32) (~((le_uint32) (m))))

#define SignBit(m) ((ExtendedComplement(m) >> 1) & (le_int32)(m))

#define SignExtend(v,m) (((v) & SignBit(m))? ((v) | ExtendedComplement(m)): (v))

UOBJECT_DEFINE_RTTI_IMPLEMENTATION(LigatureSubstitutionProcessor)

LigatureSubstitutionProcessor::LigatureSubstitutionProcessor(const MorphSubtableHeader *morphSubtableHeader)

  : StateTableProcessor(morphSubtableHeader)

{

    ligatureSubstitutionHeader = (const LigatureSubstitutionHeader *) morphSubtableHeader;

    ligatureActionTableOffset = SWAPW(ligatureSubstitutionHeader->ligatureActionTableOffset);

    componentTableOffset = SWAPW(ligatureSubstitutionHeader->componentTableOffset);

    ligatureTableOffset = SWAPW(ligatureSubstitutionHeader->ligatureTableOffset);

    entryTable = (const LigatureSubstitutionStateEntry *) ((char *) &stateTableHeader->stHeader + entryTableOffset);

}

LigatureSubstitutionProcessor::~LigatureSubstitutionProcessor()

{

}

void LigatureSubstitutionProcessor::beginStateTable()

{

    m = -1;

}

ByteOffset LigatureSubstitutionProcessor::processStateEntry(LEGlyphStorage &glyphStorage, le_int32 &currGlyph, EntryTableIndex index)

{

    const LigatureSubstitutionStateEntry *entry = &entryTable[index];

    ByteOffset newState = SWAPW(entry->newStateOffset);

    le_int16 flags = SWAPW(entry->flags);

    if (flags & lsfSetComponent) {

        if (++m >= nComponents) {

            m = 0;

        }

        componentStack[m] = currGlyph;

    }

    ByteOffset actionOffset = flags & lsfActionOffsetMask;

    if (actionOffset != 0) {

        const LigatureActionEntry *ap = (const LigatureActionEntry *) ((char *) &ligatureSubstitutionHeader->stHeader + actionOffset);

        LigatureActionEntry action;

        le_int32 offset, i = 0;

        le_int32 stack[nComponents];

        le_int16 mm = -1;

        do {

            le_uint32 componentGlyph = componentStack[m--];

            action = SWAPL(*ap++);

            if (m < 0) {

                m = nComponents - 1;

            }

            offset = action & lafComponentOffsetMask;

            if (offset != 0) {

                const le_int16 *offsetTable = (const le_int16 *)((char *) &ligatureSubstitutionHeader->stHeader + 2 * SignExtend(offset, lafComponentOffsetMask));

                i += SWAPW(offsetTable[LE_GET_GLYPH(glyphStorage[componentGlyph])]);

                if (action & (lafLast | lafStore))  {

                    const TTGlyphID *ligatureOffset = (const TTGlyphID *) ((char *) &ligatureSubstitutionHeader->stHeader + i);

                    TTGlyphID ligatureGlyph = SWAPW(*ligatureOffset);

                    glyphStorage[componentGlyph] = LE_SET_GLYPH(glyphStorage[componentGlyph], ligatureGlyph);

                    stack[++mm] = componentGlyph;

                    i = 0;

                } else {

                    glyphStorage[componentGlyph] = LE_SET_GLYPH(glyphStorage[componentGlyph], 0xFFFF);

                }

            }

        } while (!(action & lafLast));

        while (mm >= 0) {

            if (++m >= nComponents) {

                m = 0;

            }

            componentStack[m] = stack[mm--];

        }

    }

    if (!(flags & lsfDontAdvance)) {

        // should handle reverse too!

        currGlyph += 1;

    }

    return newState;

}

void LigatureSubstitutionProcessor::endStateTable()

{

}

U_NAMESPACE_END