47 lines
1.2 KiB
C++
47 lines
1.2 KiB
C++
/*
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* @(#)DeviceTables.cpp 1.5 00/03/15
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*
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* (C) Copyright IBM Corp. 1998 - 2004 - All Rights Reserved
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*
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*/
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#include "LETypes.h"
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#include "OpenTypeTables.h"
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#include "DeviceTables.h"
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#include "GlyphIterator.h"
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#include "GlyphPositionAdjustments.h"
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#include "LESwaps.h"
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U_NAMESPACE_BEGIN
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const le_uint16 DeviceTable::fieldMasks[] = {0x0003, 0x000F, 0x00FF};
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const le_uint16 DeviceTable::fieldSignBits[] = {0x0002, 0x0008, 0x0080};
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const le_uint16 DeviceTable::fieldBits[] = { 2, 4, 8};
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le_int16 DeviceTable::getAdjustment(le_uint16 ppem) const
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{
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le_uint16 start = SWAPW(startSize);
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le_uint16 format = SWAPW(deltaFormat) - 1;
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le_int16 result = 0;
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if (ppem >= start && ppem <= SWAPW(endSize)) {
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le_uint16 sizeIndex = ppem - start;
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le_uint16 bits = fieldBits[format];
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le_uint16 count = 16 / bits;
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le_uint16 word = SWAPW(deltaValues[sizeIndex / count]);
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le_uint16 fieldIndex = sizeIndex % count;
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le_uint16 shift = 16 - (bits * (fieldIndex + 1));
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le_uint16 field = (word >> shift) & fieldMasks[format];
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result = field;
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if ((field & fieldSignBits[format]) != 0) {
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result |= ~ fieldMasks[format];
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}
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}
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return result;
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}
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U_NAMESPACE_END
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