--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/fontservices/textshaperplugin/IcuSource/layout/ContextualSubstSubtables.cpp Tue Feb 02 02:02:46 2010 +0200
@@ -0,0 +1,563 @@
+/*
+ *
+ * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved
+ *
+ */
+
+#include "LETypes.h"
+#include "LEFontInstance.h"
+#include "OpenTypeTables.h"
+#include "GlyphSubstitutionTables.h"
+#include "ContextualSubstSubtables.h"
+#include "GlyphIterator.h"
+#include "LookupProcessor.h"
+#include "CoverageTables.h"
+#include "LESwaps.h"
+
+U_NAMESPACE_BEGIN
+
+/*
+ NOTE: This could be optimized somewhat by keeping track
+ of the previous sequenceIndex in the loop and doing next()
+ or prev() of the delta between that and the current
+ sequenceIndex instead of always resetting to the front.
+*/
+void ContextualSubstitutionBase::applySubstitutionLookups(
+ const LookupProcessor *lookupProcessor,
+ const SubstitutionLookupRecord *substLookupRecordArray,
+ le_uint16 substCount,
+ GlyphIterator *glyphIterator,
+ const LEFontInstance *fontInstance,
+ le_int32 position,
+ LEErrorCode& success)
+{
+ if (LE_FAILURE(success)) {
+ return;
+ }
+
+ GlyphIterator tempIterator(*glyphIterator);
+
+ for (le_int16 subst = 0; subst < substCount && LE_SUCCESS(success); subst += 1) {
+ le_uint16 sequenceIndex = SWAPW(substLookupRecordArray[subst].sequenceIndex);
+ le_uint16 lookupListIndex = SWAPW(substLookupRecordArray[subst].lookupListIndex);
+
+ tempIterator.setCurrStreamPosition(position);
+ tempIterator.next(sequenceIndex);
+
+ lookupProcessor->applySingleLookup(lookupListIndex, &tempIterator,
+ fontInstance, success);
+ }
+}
+
+le_bool ContextualSubstitutionBase::matchGlyphIDs(const TTGlyphID *glyphArray, le_uint16 glyphCount,
+ GlyphIterator *glyphIterator, le_bool backtrack)
+{
+ le_int32 direction = 1;
+ le_int32 match = 0;
+
+ if (backtrack) {
+ match = glyphCount -1;
+ direction = -1;
+ }
+
+ while (glyphCount > 0) {
+ if (! glyphIterator->next()) {
+ return FALSE;
+ }
+
+ TTGlyphID glyph = (TTGlyphID) glyphIterator->getCurrGlyphID();
+
+ if (glyph != SWAPW(glyphArray[match])) {
+ return FALSE;
+ }
+
+ glyphCount -= 1;
+ match += direction;
+ }
+
+ return TRUE;
+}
+
+le_bool ContextualSubstitutionBase::matchGlyphClasses(const le_uint16 *classArray, le_uint16 glyphCount,
+ GlyphIterator *glyphIterator,
+ const ClassDefinitionTable *classDefinitionTable,
+ le_bool backtrack)
+{
+ le_int32 direction = 1;
+ le_int32 match = 0;
+
+ if (backtrack) {
+ match = glyphCount - 1;
+ direction = -1;
+ }
+
+ while (glyphCount > 0) {
+ if (! glyphIterator->next()) {
+ return FALSE;
+ }
+
+ LEGlyphID glyph = glyphIterator->getCurrGlyphID();
+ le_int32 glyphClass = classDefinitionTable->getGlyphClass(glyph);
+ le_int32 matchClass = SWAPW(classArray[match]);
+
+ if (glyphClass != matchClass) {
+ // Some fonts, e.g. Traditional Arabic, have classes
+ // in the class array which aren't in the class definition
+ // table. If we're looking for such a class, pretend that
+ // we found it.
+ if (classDefinitionTable->hasGlyphClass(matchClass)) {
+ return FALSE;
+ }
+ }
+
+ glyphCount -= 1;
+ match += direction;
+ }
+
+ return TRUE;
+}
+
+le_bool ContextualSubstitutionBase::matchGlyphCoverages(const Offset *coverageTableOffsetArray, le_uint16 glyphCount,
+ GlyphIterator *glyphIterator, const char *offsetBase, le_bool backtrack)
+{
+ le_int32 direction = 1;
+ le_int32 glyph = 0;
+
+ if (backtrack) {
+ glyph = glyphCount - 1;
+ direction = -1;
+ }
+
+ while (glyphCount > 0) {
+ Offset coverageTableOffset = SWAPW(coverageTableOffsetArray[glyph]);
+ const CoverageTable *coverageTable = (const CoverageTable *) (offsetBase + coverageTableOffset);
+
+ if (! glyphIterator->next()) {
+ return FALSE;
+ }
+
+ if (coverageTable->getGlyphCoverage((LEGlyphID) glyphIterator->getCurrGlyphID()) < 0) {
+ return FALSE;
+ }
+
+ glyphCount -= 1;
+ glyph += direction;
+ }
+
+ return TRUE;
+}
+
+le_uint32 ContextualSubstitutionSubtable::process(const LookupProcessor *lookupProcessor, GlyphIterator *glyphIterator,
+ const LEFontInstance *fontInstance, LEErrorCode& success) const
+{
+ if (LE_FAILURE(success)) {
+ return 0;
+ }
+
+ switch(SWAPW(subtableFormat))
+ {
+ case 0:
+ return 0;
+
+ case 1:
+ {
+ const ContextualSubstitutionFormat1Subtable *subtable = (const ContextualSubstitutionFormat1Subtable *) this;
+
+ return subtable->process(lookupProcessor, glyphIterator, fontInstance, success);
+ }
+
+ case 2:
+ {
+ const ContextualSubstitutionFormat2Subtable *subtable = (const ContextualSubstitutionFormat2Subtable *) this;
+
+ return subtable->process(lookupProcessor, glyphIterator, fontInstance, success);
+ }
+
+ case 3:
+ {
+ const ContextualSubstitutionFormat3Subtable *subtable = (const ContextualSubstitutionFormat3Subtable *) this;
+
+ return subtable->process(lookupProcessor, glyphIterator, fontInstance, success);
+ }
+
+ default:
+ return 0;
+ }
+}
+
+le_uint32 ContextualSubstitutionFormat1Subtable::process(const LookupProcessor *lookupProcessor, GlyphIterator *glyphIterator,
+ const LEFontInstance *fontInstance, LEErrorCode& success) const
+{
+ if (LE_FAILURE(success)) {
+ return 0;
+ }
+
+ LEGlyphID glyph = glyphIterator->getCurrGlyphID();
+ le_int32 coverageIndex = getGlyphCoverage(glyph);
+
+ if (coverageIndex >= 0) {
+ le_uint16 srSetCount = SWAPW(subRuleSetCount);
+
+ if (coverageIndex < srSetCount) {
+ Offset subRuleSetTableOffset = SWAPW(subRuleSetTableOffsetArray[coverageIndex]);
+ const SubRuleSetTable *subRuleSetTable =
+ (const SubRuleSetTable *) ((char *) this + subRuleSetTableOffset);
+ le_uint16 subRuleCount = SWAPW(subRuleSetTable->subRuleCount);
+ le_int32 position = glyphIterator->getCurrStreamPosition();
+
+ for (le_uint16 subRule = 0; subRule < subRuleCount; subRule += 1) {
+ Offset subRuleTableOffset =
+ SWAPW(subRuleSetTable->subRuleTableOffsetArray[subRule]);
+ const SubRuleTable *subRuleTable =
+ (const SubRuleTable *) ((char *) subRuleSetTable + subRuleTableOffset);
+ le_uint16 matchCount = SWAPW(subRuleTable->glyphCount) - 1;
+ le_uint16 substCount = SWAPW(subRuleTable->substCount);
+
+ if (matchGlyphIDs(subRuleTable->inputGlyphArray, matchCount, glyphIterator)) {
+ const SubstitutionLookupRecord *substLookupRecordArray =
+ (const SubstitutionLookupRecord *) &subRuleTable->inputGlyphArray[matchCount];
+
+ applySubstitutionLookups(lookupProcessor, substLookupRecordArray,
+ substCount, glyphIterator, fontInstance, position, success);
+
+ return matchCount + 1;
+ }
+
+ glyphIterator->setCurrStreamPosition(position);
+ }
+ }
+
+ // XXX If we get here, the table is mal-formed...
+ }
+
+ return 0;
+}
+
+le_uint32 ContextualSubstitutionFormat2Subtable::process(const LookupProcessor *lookupProcessor, GlyphIterator *glyphIterator,
+ const LEFontInstance *fontInstance, LEErrorCode& success) const
+{
+ if (LE_FAILURE(success)) {
+ return 0;
+ }
+
+ LEGlyphID glyph = glyphIterator->getCurrGlyphID();
+ le_int32 coverageIndex = getGlyphCoverage(glyph);
+
+ if (coverageIndex >= 0) {
+ const ClassDefinitionTable *classDefinitionTable =
+ (const ClassDefinitionTable *) ((char *) this + SWAPW(classDefTableOffset));
+ le_uint16 scSetCount = SWAPW(subClassSetCount);
+ le_int32 setClass = classDefinitionTable->getGlyphClass(glyphIterator->getCurrGlyphID());
+
+ if (setClass < scSetCount && subClassSetTableOffsetArray[setClass] != 0) {
+ Offset subClassSetTableOffset = SWAPW(subClassSetTableOffsetArray[setClass]);
+ const SubClassSetTable *subClassSetTable =
+ (const SubClassSetTable *) ((char *) this + subClassSetTableOffset);
+ le_uint16 subClassRuleCount = SWAPW(subClassSetTable->subClassRuleCount);
+ le_int32 position = glyphIterator->getCurrStreamPosition();
+
+ for (le_uint16 scRule = 0; scRule < subClassRuleCount; scRule += 1) {
+ Offset subClassRuleTableOffset =
+ SWAPW(subClassSetTable->subClassRuleTableOffsetArray[scRule]);
+ const SubClassRuleTable *subClassRuleTable =
+ (const SubClassRuleTable *) ((char *) subClassSetTable + subClassRuleTableOffset);
+ le_uint16 matchCount = SWAPW(subClassRuleTable->glyphCount) - 1;
+ le_uint16 substCount = SWAPW(subClassRuleTable->substCount);
+
+ if (matchGlyphClasses(subClassRuleTable->classArray, matchCount, glyphIterator, classDefinitionTable)) {
+ const SubstitutionLookupRecord *substLookupRecordArray =
+ (const SubstitutionLookupRecord *) &subClassRuleTable->classArray[matchCount];
+
+ applySubstitutionLookups(lookupProcessor, substLookupRecordArray,
+ substCount, glyphIterator, fontInstance, position, success);
+
+ return matchCount + 1;
+ }
+
+ glyphIterator->setCurrStreamPosition(position);
+ }
+ }
+
+ // XXX If we get here, the table is mal-formed...
+ }
+
+ return 0;
+}
+
+le_uint32 ContextualSubstitutionFormat3Subtable::process(const LookupProcessor *lookupProcessor, GlyphIterator *glyphIterator,
+ const LEFontInstance *fontInstance, LEErrorCode& success) const
+{
+ if (LE_FAILURE(success)) {
+ return 0;
+ }
+
+ le_uint16 gCount = SWAPW(glyphCount);
+ le_uint16 subCount = SWAPW(substCount);
+ le_int32 position = glyphIterator->getCurrStreamPosition();
+
+ // Back up the glyph iterator so that we
+ // can call next() before the check, which
+ // will leave it pointing at the last glyph
+ // that matched when we're done.
+ glyphIterator->prev();
+
+ if (ContextualSubstitutionBase::matchGlyphCoverages(coverageTableOffsetArray, gCount, glyphIterator, (const char *) this)) {
+ const SubstitutionLookupRecord *substLookupRecordArray =
+ (const SubstitutionLookupRecord *) &coverageTableOffsetArray[gCount];
+
+ ContextualSubstitutionBase::applySubstitutionLookups(lookupProcessor, substLookupRecordArray,
+ subCount, glyphIterator, fontInstance, position, success);
+
+ return gCount + 1;
+ }
+
+ glyphIterator->setCurrStreamPosition(position);
+
+ return 0;
+}
+
+le_uint32 ChainingContextualSubstitutionSubtable::process(const LookupProcessor *lookupProcessor, GlyphIterator *glyphIterator,
+ const LEFontInstance *fontInstance, LEErrorCode& success) const
+{
+ if (LE_FAILURE(success)) {
+ return 0;
+ }
+
+ switch(SWAPW(subtableFormat))
+ {
+ case 0:
+ return 0;
+
+ case 1:
+ {
+ const ChainingContextualSubstitutionFormat1Subtable *subtable = (const ChainingContextualSubstitutionFormat1Subtable *) this;
+
+ return subtable->process(lookupProcessor, glyphIterator, fontInstance, success);
+ }
+
+ case 2:
+ {
+ const ChainingContextualSubstitutionFormat2Subtable *subtable = (const ChainingContextualSubstitutionFormat2Subtable *) this;
+
+ return subtable->process(lookupProcessor, glyphIterator, fontInstance, success);
+ }
+
+ case 3:
+ {
+ const ChainingContextualSubstitutionFormat3Subtable *subtable = (const ChainingContextualSubstitutionFormat3Subtable *) this;
+
+ return subtable->process(lookupProcessor, glyphIterator, fontInstance, success);
+ }
+
+ default:
+ return 0;
+ }
+}
+
+static const LETag emptyTag = 0;
+
+le_uint32 ChainingContextualSubstitutionFormat1Subtable::process(const LookupProcessor *lookupProcessor, GlyphIterator *glyphIterator,
+ const LEFontInstance *fontInstance, LEErrorCode& success) const
+{
+ if (LE_FAILURE(success)) {
+ return 0;
+ }
+
+ LEGlyphID glyph = glyphIterator->getCurrGlyphID();
+ le_int32 coverageIndex = getGlyphCoverage(glyph);
+
+ if (coverageIndex >= 0) {
+ le_uint16 srSetCount = SWAPW(chainSubRuleSetCount);
+
+ if (coverageIndex < srSetCount) {
+ Offset chainSubRuleSetTableOffset = SWAPW(chainSubRuleSetTableOffsetArray[coverageIndex]);
+ const ChainSubRuleSetTable *chainSubRuleSetTable =
+ (const ChainSubRuleSetTable *) ((char *) this + chainSubRuleSetTableOffset);
+ le_uint16 chainSubRuleCount = SWAPW(chainSubRuleSetTable->chainSubRuleCount);
+ le_int32 position = glyphIterator->getCurrStreamPosition();
+ GlyphIterator tempIterator(*glyphIterator, emptyTag);
+
+ for (le_uint16 subRule = 0; subRule < chainSubRuleCount; subRule += 1) {
+ Offset chainSubRuleTableOffset =
+ SWAPW(chainSubRuleSetTable->chainSubRuleTableOffsetArray[subRule]);
+ const ChainSubRuleTable *chainSubRuleTable =
+ (const ChainSubRuleTable *) ((char *) chainSubRuleSetTable + chainSubRuleTableOffset);
+ le_uint16 backtrackGlyphCount = SWAPW(chainSubRuleTable->backtrackGlyphCount);
+ le_uint16 inputGlyphCount = (le_uint16) SWAPW(chainSubRuleTable->backtrackGlyphArray[backtrackGlyphCount]) - 1;
+ const TTGlyphID *inputGlyphArray = &chainSubRuleTable->backtrackGlyphArray[backtrackGlyphCount + 1];
+ le_uint16 lookaheadGlyphCount = (le_uint16) SWAPW(inputGlyphArray[inputGlyphCount]);
+ const TTGlyphID *lookaheadGlyphArray = &inputGlyphArray[inputGlyphCount + 1];
+ le_uint16 substCount = (le_uint16) SWAPW(lookaheadGlyphArray[lookaheadGlyphCount]);
+
+ tempIterator.setCurrStreamPosition(position);
+
+ if (! tempIterator.prev(backtrackGlyphCount)) {
+ continue;
+ }
+
+ tempIterator.prev();
+ if (! matchGlyphIDs(chainSubRuleTable->backtrackGlyphArray, backtrackGlyphCount, &tempIterator, TRUE)) {
+ continue;
+ }
+
+ tempIterator.setCurrStreamPosition(position);
+ tempIterator.next(inputGlyphCount);
+ if (!matchGlyphIDs(lookaheadGlyphArray, lookaheadGlyphCount, &tempIterator)) {
+ continue;
+ }
+
+ if (matchGlyphIDs(inputGlyphArray, inputGlyphCount, glyphIterator)) {
+ const SubstitutionLookupRecord *substLookupRecordArray =
+ (const SubstitutionLookupRecord *) &lookaheadGlyphArray[lookaheadGlyphCount + 1];
+
+ applySubstitutionLookups(lookupProcessor, substLookupRecordArray,
+ substCount, glyphIterator, fontInstance, position, success);
+
+ return inputGlyphCount + 1;
+ }
+
+ glyphIterator->setCurrStreamPosition(position);
+ }
+ }
+
+ // XXX If we get here, the table is mal-formed...
+ }
+
+ return 0;
+}
+
+le_uint32 ChainingContextualSubstitutionFormat2Subtable::process(const LookupProcessor *lookupProcessor, GlyphIterator *glyphIterator,
+ const LEFontInstance *fontInstance, LEErrorCode& success) const
+{
+ if (LE_FAILURE(success)) {
+ return 0;
+ }
+
+ LEGlyphID glyph = glyphIterator->getCurrGlyphID();
+ le_int32 coverageIndex = getGlyphCoverage(glyph);
+
+ if (coverageIndex >= 0) {
+ const ClassDefinitionTable *backtrackClassDefinitionTable =
+ (const ClassDefinitionTable *) ((char *) this + SWAPW(backtrackClassDefTableOffset));
+ const ClassDefinitionTable *inputClassDefinitionTable =
+ (const ClassDefinitionTable *) ((char *) this + SWAPW(inputClassDefTableOffset));
+ const ClassDefinitionTable *lookaheadClassDefinitionTable =
+ (const ClassDefinitionTable *) ((char *) this + SWAPW(lookaheadClassDefTableOffset));
+ le_uint16 scSetCount = SWAPW(chainSubClassSetCount);
+ le_int32 setClass = inputClassDefinitionTable->getGlyphClass(glyphIterator->getCurrGlyphID());
+
+ if (setClass < scSetCount && chainSubClassSetTableOffsetArray[setClass] != 0) {
+ Offset chainSubClassSetTableOffset = SWAPW(chainSubClassSetTableOffsetArray[setClass]);
+ const ChainSubClassSetTable *chainSubClassSetTable =
+ (const ChainSubClassSetTable *) ((char *) this + chainSubClassSetTableOffset);
+ le_uint16 chainSubClassRuleCount = SWAPW(chainSubClassSetTable->chainSubClassRuleCount);
+ le_int32 position = glyphIterator->getCurrStreamPosition();
+ GlyphIterator tempIterator(*glyphIterator, emptyTag);
+
+ for (le_uint16 scRule = 0; scRule < chainSubClassRuleCount; scRule += 1) {
+ Offset chainSubClassRuleTableOffset =
+ SWAPW(chainSubClassSetTable->chainSubClassRuleTableOffsetArray[scRule]);
+ const ChainSubClassRuleTable *chainSubClassRuleTable =
+ (const ChainSubClassRuleTable *) ((char *) chainSubClassSetTable + chainSubClassRuleTableOffset);
+ le_uint16 backtrackGlyphCount = SWAPW(chainSubClassRuleTable->backtrackGlyphCount);
+ le_uint16 inputGlyphCount = SWAPW(chainSubClassRuleTable->backtrackClassArray[backtrackGlyphCount]) - 1;
+ const le_uint16 *inputClassArray = &chainSubClassRuleTable->backtrackClassArray[backtrackGlyphCount + 1];
+ le_uint16 lookaheadGlyphCount = SWAPW(inputClassArray[inputGlyphCount]);
+ const le_uint16 *lookaheadClassArray = &inputClassArray[inputGlyphCount + 1];
+ le_uint16 substCount = SWAPW(lookaheadClassArray[lookaheadGlyphCount]);
+
+
+ tempIterator.setCurrStreamPosition(position);
+
+ if (! tempIterator.prev(backtrackGlyphCount)) {
+ continue;
+ }
+
+ tempIterator.prev();
+ if (! matchGlyphClasses(chainSubClassRuleTable->backtrackClassArray, backtrackGlyphCount,
+ &tempIterator, backtrackClassDefinitionTable, TRUE)) {
+ continue;
+ }
+
+ tempIterator.setCurrStreamPosition(position);
+ tempIterator.next(inputGlyphCount);
+ if (! matchGlyphClasses(lookaheadClassArray, lookaheadGlyphCount, &tempIterator, lookaheadClassDefinitionTable)) {
+ continue;
+ }
+
+ if (matchGlyphClasses(inputClassArray, inputGlyphCount, glyphIterator, inputClassDefinitionTable)) {
+ const SubstitutionLookupRecord *substLookupRecordArray =
+ (const SubstitutionLookupRecord *) &lookaheadClassArray[lookaheadGlyphCount + 1];
+
+ applySubstitutionLookups(lookupProcessor, substLookupRecordArray,
+ substCount, glyphIterator, fontInstance, position, success);
+
+ return inputGlyphCount + 1;
+ }
+
+ glyphIterator->setCurrStreamPosition(position);
+ }
+ }
+
+ // XXX If we get here, the table is mal-formed...
+ }
+
+ return 0;
+}
+
+le_uint32 ChainingContextualSubstitutionFormat3Subtable::process(const LookupProcessor *lookupProcessor, GlyphIterator *glyphIterator,
+ const LEFontInstance *fontInstance, LEErrorCode& success) const
+{
+ if (LE_FAILURE(success)) {
+ return 0;
+ }
+
+ le_uint16 backtrkGlyphCount = SWAPW(backtrackGlyphCount);
+ le_uint16 inputGlyphCount = (le_uint16) SWAPW(backtrackCoverageTableOffsetArray[backtrkGlyphCount]);
+ const Offset *inputCoverageTableOffsetArray = &backtrackCoverageTableOffsetArray[backtrkGlyphCount + 1];
+ const le_uint16 lookaheadGlyphCount = (le_uint16) SWAPW(inputCoverageTableOffsetArray[inputGlyphCount]);
+ const Offset *lookaheadCoverageTableOffsetArray = &inputCoverageTableOffsetArray[inputGlyphCount + 1];
+ le_uint16 substCount = (le_uint16) SWAPW(lookaheadCoverageTableOffsetArray[lookaheadGlyphCount]);
+ le_int32 position = glyphIterator->getCurrStreamPosition();
+ GlyphIterator tempIterator(*glyphIterator, emptyTag);
+
+ if (! tempIterator.prev(backtrkGlyphCount)) {
+ return 0;
+ }
+
+ tempIterator.prev();
+ if (! ContextualSubstitutionBase::matchGlyphCoverages(backtrackCoverageTableOffsetArray,
+ backtrkGlyphCount, &tempIterator, (const char *) this, TRUE)) {
+ return 0;
+ }
+
+ tempIterator.setCurrStreamPosition(position);
+ tempIterator.next(inputGlyphCount - 1);
+ if (! ContextualSubstitutionBase::matchGlyphCoverages(lookaheadCoverageTableOffsetArray,
+ lookaheadGlyphCount, &tempIterator, (const char *) this)) {
+ return 0;
+ }
+
+ // Back up the glyph iterator so that we
+ // can call next() before the check, which
+ // will leave it pointing at the last glyph
+ // that matched when we're done.
+ glyphIterator->prev();
+
+ if (ContextualSubstitutionBase::matchGlyphCoverages(inputCoverageTableOffsetArray,
+ inputGlyphCount, glyphIterator, (const char *) this)) {
+ const SubstitutionLookupRecord *substLookupRecordArray =
+ (const SubstitutionLookupRecord *) &lookaheadCoverageTableOffsetArray[lookaheadGlyphCount + 1];
+
+ ContextualSubstitutionBase::applySubstitutionLookups(lookupProcessor, substLookupRecordArray,
+ substCount, glyphIterator, fontInstance, position, success);
+
+ return inputGlyphCount;
+ }
+
+ glyphIterator->setCurrStreamPosition(position);
+
+ return 0;
+}
+
+U_NAMESPACE_END