CoverageTables.cpp

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 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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/*
 *
 * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved
 *
 */

#include "LETypes.h"
#include "OpenTypeTables.h"
#include "OpenTypeUtilities.h"
#include "CoverageTables.h"
#include "LESwaps.h"

U_NAMESPACE_BEGIN

le_int32 CoverageTable::getGlyphCoverage(const LETableReference &base, LEGlyphID glyphID, LEErrorCode &success) const
{
  if(LE_FAILURE(success)) return -1;

    switch(SWAPW(coverageFormat))
    {
    case 0:
        return -1;

    case 1:
    {
      LEReferenceTo<CoverageFormat1Table> f1Table(base, success);

      return f1Table->getGlyphCoverage(f1Table, glyphID, success);
    }

    case 2:
    {
      LEReferenceTo<CoverageFormat2Table> f2Table(base, success);

      return f2Table->getGlyphCoverage(f2Table, glyphID, success);
    }

    default:
        return -1;
    }
}

le_int32 CoverageFormat1Table::getGlyphCoverage(LEReferenceTo<CoverageFormat1Table> &base, LEGlyphID glyphID, LEErrorCode &success) const
{
  if(LE_FAILURE(success)) return -1;

    TTGlyphID ttGlyphID = (TTGlyphID) LE_GET_GLYPH(glyphID);
    le_uint16 count = SWAPW(glyphCount);
    le_uint8 bit = OpenTypeUtilities::highBit(count);
    le_uint16 power = 1 << bit;
    le_uint16 extra = count - power;
    le_uint16 probe = power;
    le_uint16 index = 0;

    if (count == 0) {
      return -1;
    }

    LEReferenceToArrayOf<TTGlyphID>(base, success, glyphArray, count);
    if(LE_FAILURE(success)) return -1;  // range checks array


    if (SWAPW(glyphArray[extra]) <= ttGlyphID) {
      index = extra;
    }

    while (probe > (1 << 0)) {
      probe >>= 1;

      if (SWAPW(glyphArray[index + probe]) <= ttGlyphID) {
        index += probe;
      }
    }

    if (SWAPW(glyphArray[index]) == ttGlyphID) {
      return index;
    }

    return -1;
}

le_int32 CoverageFormat2Table::getGlyphCoverage(LEReferenceTo<CoverageFormat2Table> &base, LEGlyphID glyphID, LEErrorCode &success) const
{
  if(LE_FAILURE(success)) return -1;

    TTGlyphID ttGlyphID = (TTGlyphID) LE_GET_GLYPH(glyphID);
    le_uint16 count = SWAPW(rangeCount);

    LEReferenceToArrayOf<GlyphRangeRecord> rangeRecordArrayRef(base, success, rangeRecordArray, count);
    le_int32 rangeIndex =
        OpenTypeUtilities::getGlyphRangeIndex(ttGlyphID, rangeRecordArrayRef, success);

    if (rangeIndex < 0 || LE_FAILURE(success)) { // could fail if array out of bounds
        return -1;
    }

    TTGlyphID firstInRange = SWAPW(rangeRecordArray[rangeIndex].firstGlyph);
    le_uint16  startCoverageIndex = SWAPW(rangeRecordArray[rangeIndex].rangeValue);

    return startCoverageIndex + (ttGlyphID - firstInRange);
}

U_NAMESPACE_END