organicmaps/icu
13
Fork 0
mirror of https://github.com/unicode-org/icu.git synced 2025-04-15 01:42:37 +00:00
Code Issues 1 Projects Releases Wiki Activity Actions 1

ICU-1944 backtrack contexts are stored with the first entry corresponding to the glyph closest to the input context.

Browse source 
X-SVN-Rev: 9447
This commit is contained in:
Eric Mader 2002-07-30 22:58:29 +00:00
parent d4c289ed12
commit 2dd958480e
2 changed files with 64 additions and 15 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

72
icu4c/source/layout/ContextualSubstSubtables.cpp
View file

@ -45,9 +45,17 @@ void ContextualSubstitutionBase::applySubstitutionLookups(
}
le_bool ContextualSubstitutionBase::matchGlyphIDs(const LEGlyphID *glyphArray, le_uint16 glyphCount,
GlyphIterator *glyphIterator)
GlyphIterator *glyphIterator, le_bool backtrack)
{
for (le_uint16 match = 0; match < glyphCount; match += 1) {
le_int32 direction = 1;
le_int32 match = 0;
if (backtrack) {
match = glyphCount -1;
direction = -1;
}
while (glyphCount > 0) {
if (! glyphIterator->next()) {
return false;
}
@ -57,6 +65,9 @@ le_bool ContextualSubstitutionBase::matchGlyphIDs(const LEGlyphID *glyphArray, l
if (glyph != SWAPW(glyphArray[match])) {
return false;
}
glyphCount -= 1;
match += direction;
}
return true;
@ -64,9 +75,18 @@ le_bool ContextualSubstitutionBase::matchGlyphIDs(const LEGlyphID *glyphArray, l
le_bool ContextualSubstitutionBase::matchGlyphClasses(const le_uint16 *classArray, le_uint16 glyphCount,
GlyphIterator *glyphIterator,
const ClassDefinitionTable *classDefinitionTable)
const ClassDefinitionTable *classDefinitionTable,
le_bool backtrack)
{
for (le_uint16 match = 0; match < glyphCount; match += 1) {
le_int32 direction = 1;
le_int32 match = 0;
if (backtrack) {
match = glyphCount - 1;
direction = -1;
}
while (glyphCount > 0) {
if (! glyphIterator->next()) {
return false;
}
@ -84,15 +104,26 @@ le_bool ContextualSubstitutionBase::matchGlyphClasses(const le_uint16 *classArra
return false;
}
}
glyphCount -= 1;
match += direction;
}
return true;
}
le_bool ContextualSubstitutionBase::matchGlyphCoverages(const Offset *coverageTableOffsetArray, le_uint16 glyphCount,
GlyphIterator *glyphIterator, const char *offsetBase)
GlyphIterator *glyphIterator, const char *offsetBase, le_bool backtrack)
{
for (le_uint16 glyph = 0; glyph < glyphCount; glyph += 1) {
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);
@ -103,6 +134,9 @@ le_bool ContextualSubstitutionBase::matchGlyphCoverages(const Offset *coverageTa
if (coverageTable->getGlyphCoverage((LEGlyphID) glyphIterator->getCurrGlyphID()) < 0) {
return false;
}
glyphCount -= 1;
glyph += direction;
}
return true;
@ -322,8 +356,13 @@ le_uint32 ChainingContextualSubstitutionFormat1Subtable::process(const LookupPro
le_uint16 substCount = (le_uint16) SWAPW(lookaheadGlyphArray[lookaheadGlyphCount]);
tempIterator.setCurrStreamPosition(position);
tempIterator.prev(backtrackGlyphCount + 1);
if (! matchGlyphIDs(chainSubRuleTable->backtrackGlyphArray, backtrackGlyphCount, &tempIterator)) {
if (! tempIterator.prev(backtrackGlyphCount)) {
continue;
}
tempIterator.prev();
if (! matchGlyphIDs(chainSubRuleTable->backtrackGlyphArray, backtrackGlyphCount, &tempIterator, true)) {
continue;
}
@ -390,9 +429,14 @@ le_uint32 ChainingContextualSubstitutionFormat2Subtable::process(const LookupPro
tempIterator.setCurrStreamPosition(position);
tempIterator.prev(backtrackGlyphCount + 1);
if (! tempIterator.prev(backtrackGlyphCount)) {
continue;
}
tempIterator.prev();
if (! matchGlyphClasses(chainSubClassRuleTable->backtrackClassArray, backtrackGlyphCount,
&tempIterator, backtrackClassDefinitionTable)) {
&tempIterator, backtrackClassDefinitionTable, true)) {
continue;
}
@ -433,9 +477,13 @@ le_uint32 ChainingContextualSubstitutionFormat3Subtable::process(const LookupPro
le_int32 position = glyphIterator->getCurrStreamPosition();
GlyphIterator tempIterator(*glyphIterator);
tempIterator.prev(backtrkGlyphCount + 1);
if (! tempIterator.prev(backtrkGlyphCount)) {
return 0;
}
tempIterator.prev();
if (! ContextualSubstitutionBase::matchGlyphCoverages(backtrackCoverageTableOffsetArray,
backtrkGlyphCount, &tempIterator, (const char *) this)) {
backtrkGlyphCount, &tempIterator, (const char *) this, true)) {
return 0;
}

7
icu4c/source/layout/ContextualSubstSubtables.h
View file

@ -26,15 +26,16 @@ struct SubstitutionLookupRecord
struct ContextualSubstitutionBase : GlyphSubstitutionSubtable
{
static le_bool matchGlyphIDs(
const LEGlyphID *glyphArray, le_uint16 glyphCount, GlyphIterator *glyphIterator);
const LEGlyphID *glyphArray, le_uint16 glyphCount, GlyphIterator *glyphIterator,
le_bool backtrack = false);
static le_bool matchGlyphClasses(
const le_uint16 *classArray, le_uint16 glyphCount, GlyphIterator *glyphIterator,
const ClassDefinitionTable *classDefinitionTable);
const ClassDefinitionTable *classDefinitionTable, le_bool backtrack = false);
static le_bool matchGlyphCoverages(
const Offset *coverageTableOffsetArray, le_uint16 glyphCount,
GlyphIterator *glyphIterator, const char *offsetBase);
GlyphIterator *glyphIterator, const char *offsetBase, le_bool backtrack = false);
static void applySubstitutionLookups(
const LookupProcessor *lookupProcessor,