1 /*

     2  * @(#)DeviceTables.cpp 1.5 00/03/15

     3  *

     4  * (C) Copyright IBM Corp. 1998 - 2005 - All Rights Reserved

     5  *

     6  */

     7 

     8 #include "LETypes.h"

     9 #include "OpenTypeTables.h"

    10 #include "DeviceTables.h"

    11 #include "LESwaps.h"

    12 

    13 U_NAMESPACE_BEGIN

    14 

    15 const le_uint16 DeviceTable::fieldMasks[]    = {0x0003, 0x000F, 0x00FF};

    16 const le_uint16 DeviceTable::fieldSignBits[] = {0x0002, 0x0008, 0x0080};

    17 const le_uint16 DeviceTable::fieldBits[]     = {     2,      4,      8};

    18 

    19 le_int16 DeviceTable::getAdjustment(le_uint16 ppem) const

    20 {

    21     le_uint16 start = SWAPW(startSize);

    22     le_uint16 format = SWAPW(deltaFormat) - 1;

    23     le_int16 result = 0;

    24     

    25     if (ppem >= start && ppem <= SWAPW(endSize)) {

    26         le_uint16 sizeIndex = ppem - start;

    27         le_uint16 bits = fieldBits[format];

    28         le_uint16 count = 16 / bits;

    29         le_uint16 word = SWAPW(deltaValues[sizeIndex / count]);

    30         le_uint16 fieldIndex = sizeIndex % count;

    31         le_uint16 shift = 16 - (bits * (fieldIndex + 1));

    32         le_uint16 field = (word >> shift) & fieldMasks[format];

    33 

    34         result = field;

    35 

    36         if ((field & fieldSignBits[format]) != 0) {

    37             result |= ~ fieldMasks[format];

    38         }

    39     }

    40 

    41     return result;

    42 }

    43 

    44 U_NAMESPACE_END