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/*
* (C) Copyright IBM Corp. 1998-2013 - All Rights Reserved
*
*/
#include "LETypes.h"
#include "OpenTypeTables.h"
#include "OpenTypeUtilities.h"
#include "ScriptAndLanguage.h"
#include "LESwaps.h"
U_NAMESPACE_BEGIN
LEReferenceTo<LangSysTable> ScriptTable::findLanguage(const LETableReference& base, LETag languageTag, LEErrorCode &success, le_bool exactMatch) const
{
le_uint16 count = SWAPW(langSysCount);
Offset langSysTableOffset = exactMatch? 0 : SWAPW(defaultLangSysTableOffset);
if (count > 0) {
LEReferenceToArrayOf<TagAndOffsetRecord> langSysRecords(base, success, langSysRecordArray, count);
Offset foundOffset =
OpenTypeUtilities::getTagOffset(languageTag, langSysRecords, success);
if (foundOffset != 0 && LE_SUCCESS(success)) {
langSysTableOffset = foundOffset;
}
}
if (langSysTableOffset != 0) {
return LEReferenceTo<LangSysTable>(base, success, langSysTableOffset);
}
return LEReferenceTo<LangSysTable>();
}
LEReferenceTo<ScriptTable> ScriptListTable::findScript(const LETableReference &base, LETag scriptTag, LEErrorCode &success) const
{
if (LE_FAILURE(success) ) {
return LEReferenceTo<ScriptTable>(); // get out
}
/*
* There are some fonts that have a large, bogus value for scriptCount. To try
* and protect against this, we use the offset in the first scriptRecord,
* which we know has to be past the end of the scriptRecordArray, to compute
* a value which is greater than or equal to the actual script count.
*
* Note: normally, the first offset will point to just after the scriptRecordArray,
* but there's no guarantee of this, only that it's *after* the scriptRecordArray.
* Because of this, a binary serach isn't safe, because the new count may include
* data that's not actually in the scriptRecordArray and hence the array will appear
* to be unsorted.
*/
le_uint16 count = SWAPW(scriptCount);
if (count == 0) {
return LEReferenceTo<ScriptTable>(); // no items, no search
}
// attempt to construct a ref with at least one element
LEReferenceToArrayOf<ScriptRecord> oneElementTable(base, success, &scriptRecordArray[0], 1);
if( LE_FAILURE(success) ) {
return LEReferenceTo<ScriptTable>(); // couldn't even read the first record - bad font.
}
le_uint16 limit = ((SWAPW(scriptRecordArray[0].offset) - sizeof(ScriptListTable)) / sizeof(scriptRecordArray)) + ANY_NUMBER;
Offset scriptTableOffset = 0;
if (count > limit) {
// the scriptCount value is bogus; do a linear search
// because limit may still be too large.
LEReferenceToArrayOf<ScriptRecord> scriptRecordArrayRef(base, success, &scriptRecordArray[0], limit);
for(le_int32 s = 0; (s < limit)&&LE_SUCCESS(success); s += 1) {
if (SWAPT(scriptRecordArrayRef(s,success).tag) == scriptTag) {
scriptTableOffset = SWAPW(scriptRecordArrayRef(s,success).offset);
break;
}
}
} else {
LEReferenceToArrayOf<ScriptRecord> scriptRecordArrayRef(base, success, &scriptRecordArray[0], count);
scriptTableOffset = OpenTypeUtilities::getTagOffset(scriptTag, scriptRecordArrayRef, success);
}
if (scriptTableOffset != 0) {
return LEReferenceTo<ScriptTable>(base, success, scriptTableOffset);
}
return LEReferenceTo<ScriptTable>();
}
LEReferenceTo<LangSysTable> ScriptListTable::findLanguage(const LETableReference &base, LETag scriptTag, LETag languageTag, LEErrorCode &success, le_bool exactMatch) const
{
const LEReferenceTo<ScriptTable> scriptTable = findScript(base, scriptTag, success);
if (scriptTable.isEmpty()) {
return LEReferenceTo<LangSysTable>();
}
return scriptTable->findLanguage(scriptTable, languageTag, success, exactMatch).reparent(base);
}
U_NAMESPACE_END
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