text: /*
   * (C) Copyright IBM Corp. 1998-2008 - All Rights Reserved
   *
   */
  
  #include "LETypes.h"
  #include "OpenTypeTables.h"
  #include "OpenTypeUtilities.h"
  #include "ScriptAndLanguage.h"
  #include "LESwaps.h"
  
  U_NAMESPACE_BEGIN
  
  const LangSysTable *ScriptTable::findLanguage(LETag languageTag, le_bool exactMatch) const
  {
      le_uint16 count = SWAPW(langSysCount);
      Offset langSysTableOffset = exactMatch? 0 : SWAPW(defaultLangSysTableOffset);
  
      if (count > 0) {
          Offset foundOffset =
              OpenTypeUtilities::getTagOffset(languageTag, langSysRecordArray, count);
  
          if (foundOffset != 0) {
              langSysTableOffset = foundOffset;
          }
      }
  
      if (langSysTableOffset != 0) {
          return (const LangSysTable *) ((char *)this + langSysTableOffset);
      }
  
      return NULL;
  }
  
  const ScriptTable *ScriptListTable::findScript(LETag scriptTag) const
  {
      /*
       * 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);
      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.
          for(le_int32 s = 0; s < limit; s += 1) {
              if (SWAPT(scriptRecordArray[s].tag) == scriptTag) {
                  scriptTableOffset = SWAPW(scriptRecordArray[s].offset);
                  break;
              }
          }
      } else {
          scriptTableOffset = OpenTypeUtilities::getTagOffset(scriptTag, scriptRecordArray, count);
      }
  
      if (scriptTableOffset != 0) {
          return (const ScriptTable *) ((char *)this + scriptTableOffset);
      }
  
      return NULL;
  }
  
  const LangSysTable *ScriptListTable::findLanguage(LETag scriptTag, LETag languageTag, le_bool exactMatch) const
  {
      const ScriptTable *scriptTable = findScript(scriptTag);
  
      if (scriptTable == 0) {
          return NULL;
      }
  
      return scriptTable->findLanguage(languageTag, exactMatch);
  }
  
  U_NAMESPACE_END
  