scuffed-code/icu4c/source/layout/LookupProcessor.cpp
Eric Mader de674fe66c ICU-120 changes for ICULayoutEngine
X-SVN-Rev: 3312
2000-12-21 01:18:44 +00:00

171 lines
5.4 KiB
C++

/*
* %W% %E%
*
* (C) Copyright IBM Corp. 1998, 1999, 2000 - All Rights Reserved
*
*/
#include "LETypes.h"
#include "LEFontInstance.h"
#include "OpenTypeTables.h"
#include "Features.h"
#include "Lookups.h"
#include "ScriptAndLanguage.h"
#include "GlyphDefinitionTables.h"
#include "GlyphPositionAdjustments.h"
#include "LookupProcessor.h"
#include "LESwaps.h"
LETag LookupProcessor::notSelected = 0x00000000;
LETag LookupProcessor::defaultFeature = 0xFFFFFFFF;
le_uint32 LookupProcessor::applyLookupTable(LookupTable *lookupTable, GlyphIterator *glyphIterator,
const LEFontInstance *fontInstance)
{
le_uint16 lookupType = SWAPW(lookupTable->lookupType);
le_uint16 subtableCount = SWAPW(lookupTable->subTableCount);
le_int32 startPosition = glyphIterator->getCurrStreamPosition();
le_uint32 delta;
for (le_uint16 subtable = 0; subtable < subtableCount; subtable += 1) {
LookupSubtable *lookupSubtable = lookupTable->getLookupSubtable(subtable);
delta = applySubtable(lookupSubtable, lookupType, glyphIterator, fontInstance);
if (delta > 0) {
return 1;
}
glyphIterator->setCurrStreamPosition(startPosition);
}
return 1;
}
void LookupProcessor::process(LEGlyphID *glyphs, GlyphPositionAdjustment *glyphPositionAdjustments, const LETag **glyphTags, le_int32 glyphCount,
le_bool rightToLeft, GlyphDefinitionTableHeader *glyphDefinitionTableHeader,
const LEFontInstance *fontInstance)
{
if (lookupSelectArray == NULL) {
return;
}
le_uint16 lookupListCount = SWAPW(lookupListTable->lookupCount);
for (le_uint16 lookup = 0; lookup < lookupListCount; lookup += 1) {
LETag selectTag = lookupSelectArray[lookup];
if (selectTag != notSelected) {
LookupTable *lookupTable = lookupListTable->getLookupTable(lookup);
le_uint16 lookupFlags = SWAPW(lookupTable->lookupFlags);
GlyphIterator glyphIterator(glyphs, glyphPositionAdjustments, glyphCount,
rightToLeft, lookupFlags, selectTag, glyphTags,
glyphDefinitionTableHeader);
while (glyphIterator.findFeatureTag()) {
le_uint32 delta = 1;
while (glyphIterator.next(delta)) {
delta = applyLookupTable(lookupTable, &glyphIterator, fontInstance);
}
}
}
}
}
le_uint32 LookupProcessor::applySingleLookup(le_uint16 lookupTableIndex, GlyphIterator *glyphIterator,
const LEFontInstance *fontInstance)
{
LookupTable *lookupTable = lookupListTable->getLookupTable(lookupTableIndex);
le_uint16 lookupFlags = SWAPW(lookupTable->lookupFlags);
GlyphIterator tempIterator(*glyphIterator, lookupFlags);
le_uint32 delta = applyLookupTable(lookupTable, &tempIterator, fontInstance);
return delta;
}
LETag LookupProcessor::selectFeature(le_uint16 featureIndex, LETag tagOverride)
{
LETag featureTag;
FeatureTable *featureTable = featureListTable->getFeatureTable(featureIndex, &featureTag);
le_uint16 lookupCount = featureTable? SWAPW(featureTable->lookupCount) : 0;
if (tagOverride != notSelected) {
featureTag = tagOverride;
}
for (le_uint16 lookup = 0; lookup < lookupCount; lookup += 1) {
le_uint16 lookupListIndex = SWAPW(featureTable->lookupListIndexArray[lookup]);
lookupSelectArray[lookupListIndex] = featureTag;
}
return featureTag;
}
LookupProcessor::LookupProcessor(char *baseAddress,
Offset scriptListOffset, Offset featureListOffset, Offset lookupListOffset,
LETag scriptTag, LETag languageTag)
: lookupListTable(NULL), featureListTable(NULL), lookupSelectArray(NULL),
requiredFeatureTag(notSelected)
{
ScriptListTable *scriptListTable = NULL;
LangSysTable *langSysTable = NULL;
le_uint16 featureCount = 0;
le_uint16 lookupListCount = 0;
le_uint16 requiredFeatureIndex;
if (scriptListOffset != 0) {
scriptListTable = (ScriptListTable *) (baseAddress + scriptListOffset);
langSysTable = scriptListTable->findLanguage(scriptTag, languageTag);
if (langSysTable != 0) {
featureCount = SWAPW(langSysTable->featureCount);
}
}
if (featureListOffset != 0) {
featureListTable = (FeatureListTable *) (baseAddress + featureListOffset);
}
if (lookupListOffset != 0) {
lookupListTable = (LookupListTable *) (baseAddress + lookupListOffset);
lookupListCount = SWAPW(lookupListTable->lookupCount);
}
if (langSysTable == NULL || featureListTable == NULL || lookupListTable == NULL ||
featureCount == 0 || lookupListCount == 0) {
return;
}
requiredFeatureIndex = SWAPW(langSysTable->reqFeatureIndex);
lookupSelectArray = new LETag[lookupListCount];
for (int i = 0; i < lookupListCount; i += 1) {
lookupSelectArray[i] = notSelected;
}
if (requiredFeatureIndex != 0xFFFF) {
requiredFeatureTag = selectFeature(requiredFeatureIndex, defaultFeature);
}
for (le_uint16 feature = 0; feature < featureCount; feature += 1) {
le_uint16 featureIndex = SWAPW(langSysTable->featureIndexArray[feature]);
selectFeature(featureIndex);
}
}
LookupProcessor::LookupProcessor()
{
}
LookupProcessor::~LookupProcessor()
{
delete[] lookupSelectArray;
};