| | 1 | /* |
| | 2 | * (C) Copyright IBM Corp. 1998-2013 - All Rights Reserved |
| | 3 | * |
| | 4 | */ |
| | 5 | |
| | 6 | #include "LETypes.h" |
| | 7 | #include "OpenTypeTables.h" |
| | 8 | #include "OpenTypeUtilities.h" |
| | 9 | #include "ScriptAndLanguage.h" |
| | 10 | #include "LESwaps.h" |
| | 11 | |
| | 12 | U_NAMESPACE_BEGIN |
| | 13 | |
| | 14 | LEReferenceTo<LangSysTable> ScriptTable::findLanguage(const LETableReference& base, LETag languageTag, LEErrorCode &success, le_bool exactMatch) const |
| | 15 | { |
| | 16 | le_uint16 count = SWAPW(langSysCount); |
| | 17 | Offset langSysTableOffset = exactMatch? 0 : SWAPW(defaultLangSysTableOffset); |
| | 18 | |
| | 19 | if (count > 0) { |
| | 20 | LEReferenceToArrayOf<TagAndOffsetRecord> langSysRecords(base, success, langSysRecordArray, count); |
| | 21 | Offset foundOffset = |
| | 22 | OpenTypeUtilities::getTagOffset(languageTag, langSysRecords, success); |
| | 23 | |
| | 24 | if (foundOffset != 0 && LE_SUCCESS(success)) { |
| | 25 | langSysTableOffset = foundOffset; |
| | 26 | } |
| | 27 | } |
| | 28 | |
| | 29 | if (langSysTableOffset != 0) { |
| | 30 | return LEReferenceTo<LangSysTable>(base, success, langSysTableOffset); |
| | 31 | } |
| | 32 | |
| | 33 | return LEReferenceTo<LangSysTable>(); |
| | 34 | } |
| | 35 | |
| | 36 | LEReferenceTo<ScriptTable> ScriptListTable::findScript(const LETableReference &base, LETag scriptTag, LEErrorCode &success) const |
| | 37 | { |
| | 38 | if (LE_FAILURE(success) ) { |
| | 39 | return LEReferenceTo<ScriptTable>(); // get out |
| | 40 | } |
| | 41 | /* |
| | 42 | * There are some fonts that have a large, bogus value for scriptCount. To try |
| | 43 | * and protect against this, we use the offset in the first scriptRecord, |
| | 44 | * which we know has to be past the end of the scriptRecordArray, to compute |
| | 45 | * a value which is greater than or equal to the actual script count. |
| | 46 | * |
| | 47 | * Note: normally, the first offset will point to just after the scriptRecordArray, |
| | 48 | * but there's no guarantee of this, only that it's *after* the scriptRecordArray. |
| | 49 | * Because of this, a binary serach isn't safe, because the new count may include |
| | 50 | * data that's not actually in the scriptRecordArray and hence the array will appear |
| | 51 | * to be unsorted. |
| | 52 | */ |
| | 53 | le_uint16 count = SWAPW(scriptCount); |
| | 54 | |
| | 55 | if (count == 0) { |
| | 56 | return LEReferenceTo<ScriptTable>(); // no items, no search |
| | 57 | } |
| | 58 | |
| | 59 | // attempt to construct a ref with at least one element |
| | 60 | LEReferenceToArrayOf<ScriptRecord> oneElementTable(base, success, &scriptRecordArray[0], 1); |
| | 61 | |
| | 62 | if( LE_FAILURE(success) ) { |
| | 63 | return LEReferenceTo<ScriptTable>(); // couldn't even read the first record - bad font. |
| | 64 | } |
| | 65 | |
| | 66 | le_uint16 limit = ((SWAPW(scriptRecordArray[0].offset) - sizeof(ScriptListTable)) / sizeof(scriptRecordArray)) + ANY_NUMBER; |
| | 67 | Offset scriptTableOffset = 0; |
| | 68 | |
| | 69 | |
| | 70 | if (count > limit) { |
| | 71 | // the scriptCount value is bogus; do a linear search |
| | 72 | // because limit may still be too large. |
| | 73 | LEReferenceToArrayOf<ScriptRecord> scriptRecordArrayRef(base, success, &scriptRecordArray[0], limit); |
| | 74 | for(le_int32 s = 0; (s < limit)&&LE_SUCCESS(success); s += 1) { |
| | 75 | if (SWAPT(scriptRecordArrayRef(s,success).tag) == scriptTag) { |
| | 76 | scriptTableOffset = SWAPW(scriptRecordArrayRef(s,success).offset); |
| | 77 | break; |
| | 78 | } |
| | 79 | } |
| | 80 | } else { |
| | 81 | LEReferenceToArrayOf<ScriptRecord> scriptRecordArrayRef(base, success, &scriptRecordArray[0], count); |
| | 82 | |
| | 83 | scriptTableOffset = OpenTypeUtilities::getTagOffset(scriptTag, scriptRecordArrayRef, success); |
| | 84 | } |
| | 85 | |
| | 86 | if (scriptTableOffset != 0) { |
| | 87 | return LEReferenceTo<ScriptTable>(base, success, scriptTableOffset); |
| | 88 | } |
| | 89 | |
| | 90 | return LEReferenceTo<ScriptTable>(); |
| | 91 | } |
| | 92 | |
| | 93 | LEReferenceTo<LangSysTable> ScriptListTable::findLanguage(const LETableReference &base, LETag scriptTag, LETag languageTag, LEErrorCode &success, le_bool exactMatch) const |
| | 94 | { |
| | 95 | const LEReferenceTo<ScriptTable> scriptTable = findScript(base, scriptTag, success); |
| | 96 | |
| | 97 | if (scriptTable.isEmpty()) { |
| | 98 | return LEReferenceTo<LangSysTable>(); |
| | 99 | } |
| | 100 | |
| | 101 | return scriptTable->findLanguage(scriptTable, languageTag, success, exactMatch).reparent(base); |
| | 102 | } |
| | 103 | |
| | 104 | U_NAMESPACE_END |
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