sl@0: /*
sl@0:  *
sl@0:  * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved
sl@0:  *
sl@0:  */
sl@0: 
sl@0: #include "LETypes.h"
sl@0: #include "MorphTables.h"
sl@0: #include "StateTables.h"
sl@0: #include "MorphStateTables.h"
sl@0: #include "SubtableProcessor.h"
sl@0: #include "StateTableProcessor.h"
sl@0: #include "LigatureSubstProc.h"
sl@0: #include "LEGlyphStorage.h"
sl@0: #include "LESwaps.h"
sl@0: 
sl@0: U_NAMESPACE_BEGIN
sl@0: 
sl@0: #define ExtendedComplement(m) ((le_int32) (~((le_uint32) (m))))
sl@0: #define SignBit(m) ((ExtendedComplement(m) >> 1) & (le_int32)(m))
sl@0: #define SignExtend(v,m) (((v) & SignBit(m))? ((v) | ExtendedComplement(m)): (v))
sl@0: 
sl@0: UOBJECT_DEFINE_RTTI_IMPLEMENTATION(LigatureSubstitutionProcessor)
sl@0: 
sl@0: LigatureSubstitutionProcessor::LigatureSubstitutionProcessor(const MorphSubtableHeader *morphSubtableHeader)
sl@0:   : StateTableProcessor(morphSubtableHeader)
sl@0: {
sl@0:     ligatureSubstitutionHeader = (const LigatureSubstitutionHeader *) morphSubtableHeader;
sl@0:     ligatureActionTableOffset = SWAPW(ligatureSubstitutionHeader->ligatureActionTableOffset);
sl@0:     componentTableOffset = SWAPW(ligatureSubstitutionHeader->componentTableOffset);
sl@0:     ligatureTableOffset = SWAPW(ligatureSubstitutionHeader->ligatureTableOffset);
sl@0: 
sl@0:     entryTable = (const LigatureSubstitutionStateEntry *) ((char *) &stateTableHeader->stHeader + entryTableOffset);
sl@0: }
sl@0: 
sl@0: LigatureSubstitutionProcessor::~LigatureSubstitutionProcessor()
sl@0: {
sl@0: }
sl@0: 
sl@0: void LigatureSubstitutionProcessor::beginStateTable()
sl@0: {
sl@0:     m = -1;
sl@0: }
sl@0: 
sl@0: ByteOffset LigatureSubstitutionProcessor::processStateEntry(LEGlyphStorage &glyphStorage, le_int32 &currGlyph, EntryTableIndex index)
sl@0: {
sl@0:     const LigatureSubstitutionStateEntry *entry = &entryTable[index];
sl@0:     ByteOffset newState = SWAPW(entry->newStateOffset);
sl@0:     le_int16 flags = SWAPW(entry->flags);
sl@0: 
sl@0:     if (flags & lsfSetComponent) {
sl@0:         if (++m >= nComponents) {
sl@0:             m = 0;
sl@0:         }
sl@0: 
sl@0:         componentStack[m] = currGlyph;
sl@0:     }
sl@0: 
sl@0:     ByteOffset actionOffset = flags & lsfActionOffsetMask;
sl@0: 
sl@0:     if (actionOffset != 0) {
sl@0:         const LigatureActionEntry *ap = (const LigatureActionEntry *) ((char *) &ligatureSubstitutionHeader->stHeader + actionOffset);
sl@0:         LigatureActionEntry action;
sl@0:         le_int32 offset, i = 0;
sl@0:         le_int32 stack[nComponents];
sl@0:         le_int16 mm = -1;
sl@0: 
sl@0:         do {
sl@0:             le_uint32 componentGlyph = componentStack[m--];
sl@0: 
sl@0:             action = SWAPL(*ap++);
sl@0: 
sl@0:             if (m < 0) {
sl@0:                 m = nComponents - 1;
sl@0:             }
sl@0: 
sl@0:             offset = action & lafComponentOffsetMask;
sl@0:             if (offset != 0) {
sl@0:                 const le_int16 *offsetTable = (const le_int16 *)((char *) &ligatureSubstitutionHeader->stHeader + 2 * SignExtend(offset, lafComponentOffsetMask));
sl@0: 
sl@0:                 i += SWAPW(offsetTable[LE_GET_GLYPH(glyphStorage[componentGlyph])]);
sl@0: 
sl@0:                 if (action & (lafLast | lafStore))  {
sl@0:                     const TTGlyphID *ligatureOffset = (const TTGlyphID *) ((char *) &ligatureSubstitutionHeader->stHeader + i);
sl@0:                     TTGlyphID ligatureGlyph = SWAPW(*ligatureOffset);
sl@0: 
sl@0:                     glyphStorage[componentGlyph] = LE_SET_GLYPH(glyphStorage[componentGlyph], ligatureGlyph);
sl@0:                     stack[++mm] = componentGlyph;
sl@0:                     i = 0;
sl@0:                 } else {
sl@0:                     glyphStorage[componentGlyph] = LE_SET_GLYPH(glyphStorage[componentGlyph], 0xFFFF);
sl@0:                 }
sl@0:             }
sl@0:         } while (!(action & lafLast));
sl@0: 
sl@0:         while (mm >= 0) {
sl@0:             if (++m >= nComponents) {
sl@0:                 m = 0;
sl@0:             }
sl@0: 
sl@0:             componentStack[m] = stack[mm--];
sl@0:         }
sl@0:     }
sl@0: 
sl@0:     if (!(flags & lsfDontAdvance)) {
sl@0:         // should handle reverse too!
sl@0:         currGlyph += 1;
sl@0:     }
sl@0: 
sl@0:     return newState;
sl@0: }
sl@0: 
sl@0: void LigatureSubstitutionProcessor::endStateTable()
sl@0: {
sl@0: }
sl@0: 
sl@0: U_NAMESPACE_END